HomeMy WebLinkAboutSupporting Documentation - Stormwater - 01/07/2025
STORMWATER MANAGEMENT PLAN
300 E. MOUNTAIN AVENUE
FORT COLLINS, COLORADO
January 7, 2025
EPSGROUPINC.COM
970.221.4158
FORT COLLINS
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH COVER LETTER
January 7, 2025
City of Fort Collins
Stormwater Development Review
700 Wood Street
Fort Collins, CO 80522
RE: STORMWATER MANAGEMENT PLAN
300 E. Mountain Avenue
EPS PROJECT #2102-001
To Whom It May Concern:
EPS Group Inc. is pleased to submit this Stormwater Management Plan for 300 E. Mountain Avenue. This report
outlines Best Management Practices (BMPs) to be implemented with the proposed construction to minimize
potential pollutants in stormwater discharges.
We have prepared this report to accompany the Colorado Department of Public Health and Environment
General Permit for Stormwater Discharge Associated with Construction Activities (aka, Stormwater Discharge
Permit or SDP). The General Permit No. for this SDP is (to be filled in by permittee) and the Certification No. for
this SDP is (to be filled in by permittee). The Permit Certification is Effective beginning (to be filled in by
permittee), and initial certification expires (to be filled in by permittee). A copy of the issuance cover letter can
be found in the Appendix D of this document (to be provided by permittee).
Please note: this Stormwater Management plan (including the Site Maps) is not a static document. It is a
dynamic device that should be kept current and logged as construction takes place. As such, this version was
prepared to facilitate initial plan approvals and permitting, but does not necessarily reflect the final version, or
the transitions throughout the construction process. As the site develops and changes, the contractor is
expected and encouraged to make changes to what is contained herein so that the SWMP works as effectively
and efficiently as possible. It shall be the responsibility of the SWMP Administrator and/or the permit holder (or
applicant thereof) to ensure the plan is properly maintained and followed.
If you should have any questions or comments as you review this report, please feel free to contact us at your
convenience.
Sincerely,
EPS GROUP INC.
Amber Ortiz Cragg, PE
Project Engineer
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FORT COLLINS | GREELEY | MESA | TUSCON | GOODYEAR | PHEONIX | FORT WORTH TABLE OF CONTENTS
1.0 GENERAL REQUIREMENTS ............................................................................................1
1.1 OBJECTIVES ............................................................................................................................................. 1
1.2 SMWP AVAILABILITY................................................................................................................................. 1
1.3 DEFINITIONS ............................................................................................................................................ 1
1.4 ADDITIONAL PERMITTING ....................................................................................................................... 1
2.0 NARRATIVE SITE DESCRIPTION .....................................................................................1
2.1 EXISTING SITE DESCRIPTION .................................................................................................................. 1
2.2 NATURE OF CONSTRUCTION ACTIVITY ................................................................................................... 1
2.3 SEQUENCE OF MAJOR ACTIVITIES .......................................................................................................... 2
2.4 SITE DISTURBANCE ................................................................................................................................. 2
2.5 EXISTING DATA ........................................................................................................................................ 2
2.6 EXISTING VEGETATION ............................................................................................................................ 2
2.7 POTENTIAL POLLUTION SOURCES ......................................................................................................... 2
2.8 NON-STORMWATER DISCHARGES .......................................................................................................... 3
2.9 RECEIVING WATERS ................................................................................................................................. 3
3.0 STORMWATER MANAGEMENT CONTROLS .......................................................................3
3.1 SWMP ADMINISTRATOR........................................................................................................................... 3
3.2 BEST MANAGEMENT PRACTICES (BMPS) FOR STORMWATER POLLUTION PREVENTION ..................... 3
3.3 STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL ..................................................... 4
3.4 NON-STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL ............................................ 5
3.5 PHASED BMP INSTALLATION .................................................................................................................. 8
3.6 MATERIAL HANDLING AND SPILL PREVENTION ...................................................................................... 8
3.7 DEDICATED CONCRETE OR ASPHALT BATCH PLANT ............................................................................. 9
3.8 VEHICLE TRACKING CONTROL ................................................................................................................ 9
3.9 WASTE MANAGEMENT AND DISPOSAL .................................................................................................... 9
3.10 GROUNDWATER AND STORMWATER DEWATERING ............................................................................... 9
4.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT ............................. 10
4.1 FINAL STABILIZATION ............................................................................................................................ 10
4.2 LONG-TERM STORMWATER MANAGEMENT .......................................................................................... 10
4.3 BMP INSPECTION ................................................................................................................................... 10
4.4 BMP MAINTENANCE ............................................................................................................................... 10
4.5 RECORD KEEPING .................................................................................................................................. 11
5.0 ADDITIONAL SWMP AND BMP RESOURCES .................................................................... 12
6.0 REFERENCES ............................................................................................................ 12
LIST OF TABLES
TABLE 1 – PRELIMINARY PERMIT AND CONSTRUCTION SCHEDULE ........................................................................... 8
TABLE 2 - NATIVE GRASS SEED MIX............................................................................................................................. 10
APPENDICES
APPENDIX A – SITE MAPS
APPENDIX B – EROSION CONTROL DETAILS
APPENDIX C – COPIES OF PERMITS/APPLICATIONS
APPENDIX D – INSPECTION LOGS
APPENDIX E – CONTRACTOR INSERTS (AS NEEDED)
APPENDIX F – REFERENCE MATERIAL
APPENDIX G – NATURAL RESOURCES CONSERVATION RESOURCES
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1.0 GENERAL REQUIREMENTS
1.1 OBJECTIVES
The objective of a Stormwater Management Plan (SWMP) is to identify all potential sources of pollution
likely to occur as a result of construction activity associated with the site construction and describe the
practices that will be used to reduce the pollutants in stormwater discharges from the site. The SWMP
must be completed and implemented when the project breaks ground and revised as necessary as
construction proceeds to reflect the conditions and practices at the site accurately.
This report summarizes the Stormwater Management Plan for the construction activity that will occur
with 300 E. Mountain Avenue. This plan has been prepared according to regulations of the Colorado
Department of Public Health and Environment (CDPHE), Water Quality Control Division.
1.2 SMWP AVAILABILITY
This report is intended to remain on the construction site mentioned above site to allow for maintenance
and inspection updates and review during inspection.
1.3 DEFINITIONS
BMP – Best Management Practice encompassing a wide range of erosion and sediment control practices,
both structural and non-structural in nature, intended to reduce or eliminate any possible water quality
impacts from stormwater leaving a construction site.
Erosion Control BMPs – Practices that PREVENT the erosion of soil, such as minimizing the amount of
disturbed area through phasing, temporary stabilization, and preserving existing vegetation.
Sediment Control BMPs – Practices to REMOVE sediment from runoff, such as sediment basins, silt fence,
or inlet protection.
Non-structural BMPs – The implementation of methods, practices, and procedures to minimize water
quality impacts, such as the preservation of natural vegetation, preventive maintenance, and spill
response procedures.
Structural BMPs – Physical devices that prevent or minimize water quality impacts, such as sediment
basins, inlet protection, or silt fence.
1.4 ADDITIONAL PERMITTING
As mentioned above, this Stormwater Management Plan is associated with the Colorado Department of
Public Health and Environment Stormwater Permit issued by the Water Quality Control Division of the
CDPHE. Additional Environmental permitting not described in this report may be required as a part of this
project. An example is the Construction Dewatering Permit for groundwater. Another example is the Air
Pollution Emission Notice (APEN). The CDPHE website contains links to both permits and many other
potential permits. The contractor is responsible for ensuring the proper permits are acquired.
2.0 NARRATIVE SITE DESCRIPTION
2.1 EXISTING SITE DESCRIPTION
The subject site of 300 East Mountain Avenue is located in the southwest quarter of Section 12, Township
7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of
Colorado. The project site is the northeast corner lot at the intersection of Chestnut Street and Mountain
Avenue.
2.2 NATURE OF CONSTRUCTION ACTIVITY
The proposed project site plan is composed of 1 commercial building that will be part of an expansion
project with The Armory. Reconstruction of the sidewalk to the north and south of the building and
reconstruction of the parking area to the north of the building is included with the improvements.
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2.3 SEQUENCE OF MAJOR ACTIVITIES
To complete the project, many basic construction activities will take place. The project will begin by
stripping the site of topsoil, followed by overlot grading. The reconfiguration of existing utility services
will occur next, including water, sewer, and gas. Once overlot grading is complete, and utilities have been
installed, it is anticipated that construction of the building foundations will begin. While building
foundations are being constructed, curb and gutter will be installed, followed by asphalt paving of the
parking area. Vertical construction of the buildings is expected to commence once the public
infrastructure has been inspected by the City. Fine grading of the landscape areas north of the building,
and the installation of landscaping materials and tree. The final stage of construction will be the
construction of the buildings. The aforementioned sequencing is an initial best guess and is subject to
change at the contractor’s discretion.
2.4 SITE DISTURBANCE
The site disturbance will occur across approximately 0.2 acres. It is recommended existing site condition
photos be taken before the demolition.
2.5 EXISTING DATA
A topographical survey of the site was conducted to complete the associated construction plans. This
survey consisted of field measurements made by EPS Group Inc. in March and June of 2024.
2.6 EXISTING VEGETATION
The existing site vegetation consists only of trees along the sidewalk located in tree wells. The existing
ground cover consists primarily of pavement. It is highly recommended that pre-construction photos be
taken to clearly document vegetative conditions before any disturbance activities.
2.7 POTENTIAL POLLUTION SOURCES
As is typical with most construction sites, there are a number of potential pollution sources which could
affect water quality. This report can't identify all materials used or stored on the construction site. It is the
sole responsibility of the contractor to identify and properly handle all materials that are potential
pollution sources. The following are some common examples of potential pollution sources:
· Exposed and stored soils
· Management of contaminated soils
· Off-site tracking of soils and sediment
· Loading and unloading operations
· Outdoor storage of building materials, fertilizers, chemicals, etc.
· Vehicle and equipment maintenance and fueling
· Significant dust or particulate generating processes
· Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.
· On-site waste disposal practices (waste piles, dumpsters, etc.)
· Concrete truck/equipment washing
· Non-industrial waste sources that may be significant, such as worker trash and portable toilets
· Uncovered trash bins
· Other areas or procedures where potential spills can occur
· Stockpiling of materials that can be transported to receiving waterway(s)
Management of Contaminated Soils: We are not aware of on-site contaminated soils.
Loading and Unloading Operations: The contractor will be responsible for the proper handling and
management of pollution sources during loading and unloading operations.
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Dedicated Asphalt and Concrete Batch Plants: A dedicated asphalt or concrete batch plant will not be
constructed on-site.
2.8 NON-STORMWATER DISCHARGES
The Stormwater Construction Permit only covers discharges composed entirely of stormwater.
Emergency firefighting water is the only authorized exception. Concrete Washout water can NOT be
discharged to surface waters or storm drain systems without separate permit coverage. The discharge of
Concrete Washout water to the ground, under specific conditions, may be allowed by the Stormwater
Construction Permit when appropriate BMPs are implemented.
The discharge of pumped stormwater, ONLY, from excavations, ponds, depressions, etc. to surface waters
or to a municipal storm drainage system is allowed by the Stormwater Construction Permit, as long as the
dewatering activity and associated BMPs are identified in the Stormwater Management Plan (SWMP) and
are implemented in accordance with the SWMP.
Aside from the exceptions noted above, non-stormwater discharges must be addressed in a separate
permit issued for that discharge. If groundwater is encountered and dewatering is required, a
Construction Dewatering Permit must be acquired from the Colorado Department of Public Health and
Environment.
2.9 RECEIVING WATERS
The outfall for the overall site is the existing storm line system within Chestnut Street, which runs along
the northeast side of the site. This existing City outfall drains north, conveying water ultimately to the
Cache La Poudre River. The proposed post-development drainage pattern mimics the historic drainage
course.
3.0 STORMWATER MANAGEMENT CONTROLS
3.1 SWMP ADMINISTRATOR
A SWMP Administrator must be designated in conjunction with the Stormwater Permit. This person shall
be responsible for developing, implementing, maintaining, and revising the SWMP. The SWMP
Administrator will also be the contact for all SWMP-related issues and will be the person responsible for
the accuracy, completeness, and implementation of the SWMP. The Administrator should be a person
with the authority to adequately manage and direct day-to-day stormwater quality management
activities at the site.
The SWMP Administrator for this site is:
Name: (to be filled in by permittee)
Company: (to be filled in by permittee)
Phone: (to be filled in by permittee)
E-mail: (to be filled in by permittee)
3.2 BEST MANAGEMENT PRACTICES (BMPS) FOR STORMWATER POLLUTION PREVENTION
Beginning from mobilization and throughout the entire construction of the project, erosion control
devices shall be installed to ensure minimal pollutant migration. These erosion control devices may be
installed in phases or not at all, depending on actual conditions encountered at the site. It is the
contractor's responsibility to determine what practices should be employed and when. If a review agency
deems BMPs to be insufficient, it shall be the contractor's responsibility to implement modifications as
directed.
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Best Management Practices (BMPs) are loosely defined as a method, activity, maintenance procedure, or
other management practice for reducing the amount of pollution entering a water body. The term
originated from rules and regulations in Section 208 of the Clean Water Act.
Details for Structural and Non-Structural BMPs have been included in Appendix B. These details should be
used for additional information on the installation and maintenance of BMPs specified in this report. It is
also intended to serve as a resource for additional BMPs that may be appropriate for the site that have not
specifically been mentioned in the report.
3.3 STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL
Structural BMPs are physical devices implemented to prevent erosion or limit erosion once it occurs.
These devices can be temporary or permanent, and the installation of individual components will vary
depending on the stage of construction.
A table depicting construction sequence and BMP application/removal has been placed on the “Dynamic
Site Plan” to help document the implementation of these BMPs. Refer to the Stormwater Management
Plan Static Site Plan in the Appendix for the assumed location of all BMPs. Construction Details for
Temporary BMPs are in the Appendix for reference.
Again, the contractor shall make the final determination for which BMPs will be installed, where they will
be located, and when they will be installed, along with all documentation throughout the construction
process.
Construction Fencing with Rock Sock Erosion Control (Phase I)
Construction fencing with wattle erosion control shall be provided to prevent migration of sediment off-
site or into adjacent properties. All fencing shall be installed prior to any land disturbing activity
(stockpiling, stripping, grading, etc.). Fencing is to be installed prior to site excavation or earthwork
activities.
Inspections of the fencing should identify breaches in the rock socks, and should check for slumping fence
or undercut areas that allow flows to bypass the fencing. Damaged sections of fencing should be repaired
or replaced to ensure proper functioning. Sediment accumulated behind the rock socks should be
removed to maintain BMP effectiveness, typically before it reaches a depth of 6 inches.
Vehicle Tracking Control Pads (Phase I)
Vehicle tracking control pads shall be provided to minimize tracking of mud and sediment onto paved
surfaces and neighboring roadways. All vehicle tracking control pads shall be installed before any land
disturbing activity (demolition, stockpiling, stripping, grading, etc.). Location of vehicle tracking control
pads will be located at all existing and future vehicle accesses being used during any of the construction
phases. These locations will primarily be dictated by gates or openings in the temporary construction
fencing that is expected to be installed. Vehicle tracking control pads are to be installed before demolition
(as appropriate), site excavation, or earthwork activities.
Vehicle tracking pads should be inspected for degradation, and aggregate material should be replaced as
needed. If the area becomes clogged with water, excess sediment should be removed. Aggregate material
should remain rough, and at no point should aggregate be allowed to compact in a manner that causes
the tracking pad to stop working as intended.
Inlet Protection (Phase I & II)
Inlet protection shall be provided for existing inlets to prevent sediment transport from adjacent
earthwork disturbance. Installation of these filters shall occur before adjacent earth disturbing activities
(Phase I implementation). Wattle-type filters are to be implemented for new and existing inlets where
asphalt does not exist. For these inlets, if the pavement is constructed adjacent to the structure or if the
area adjacent to the inlet is changed such that the wattle type filter is no longer effective, it shall be the
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contractor's responsibility to ensure that an appropriate method is used instead. For example, the wattle
filter could be reused, or a gravel-block inlet filter may be installed. It will be left to the contractor's
discretion as to whether replacement of any inlet filter is necessary.
Inlet protection should be inspected regularly for tears resulting in sediment entering an inlet. Inlet
protection should also be inspected for sediment accumulation upstream of the inlet, and sediment
should be removed when less than half of the capacity is available or per manufacturer specifications.
Rock Sock (Phase I & II)
Rock sock inlet protection shall be provided to prevent sediment transport from adjacent earthwork
disturbance. Installation of rock socks shall occur before adjacent earthmoving activities (Phase I
implementation). If the area adjacent to the inlet is changed such that the rock sock filter is no longer
effective, it shall be the responsibility of the Contractor to ensure that an appropriate method is used
instead. For example, a gravel-block inlet filter may be installed. It will be left to the discretion of the
Contractor, or direction by the City or governing agency, as to whether replacement of any inlet filter is
necessary.
Rock sock inlet protection should be inspected regularly for tears that can result in sediment or rock
material entering an inlet. Rock socks should also be inspected for sediment accumulation, and have
sediment removed when the less than half of the capacity is available, or per manufacturer specifications.
Concrete Washout Area (Phase II)
A concrete washout should be provided on the site. The washout can be lined or unlined excavated pits in
the ground, commercially manufactured prefabricated containers, or aboveground holding areas. The
concrete washout must be located at least 400 feet from any natural drainage way or body of water and at
least 1,000 feet from any wells or drinking water sources. Washout areas should not be in an area where
shallow groundwater may be present. The contractor shall clearly show the desired location and access
to the Concrete Washout Area on the Stormwater Management Plan - Dynamic Site Plan. The contractor
shall place a Vehicle Tracking Pad if the selected location for the Concrete Washout Area is detached from
the pavement. Clear signage identifying the concrete washout should also be provided.
The Concrete Washout Area should be inspected regularly. Particular attention should be paid to signage
to ensure the area is clearly marked. Confirmation that the washout is being used should also be noted to
ensure that other undesignated areas of the site are not being used incorrectly as a concrete washout.
Permanent/Established Vegetation (Phase IV)
Permanent or established vegetation and landscaping is considered a permanent form of sediment and
erosion control for common open spaces, steep slopes and areas not exposed to prolonged scour
velocities, or acute incipient motion bed shear stresses that will create soil erosion, rill formation and
subsequent sediment transport. Areas where the previous conditions apply will contain sufficient
permanent BMPs, such as riprap and Erosion Control Blankets. Permanent/Established vegetation
defines Phase IV of development.
3.4 NON-STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL
Non-Structural BMPs are practices or activities that are implemented to prevent erosion from happening
or to limit erosion once it occurs. These BMPs can be a practice resulting in a physical change to the site,
such as mulching or slope stabilization. They can also result in behavioral changes on the site, such as
changes to construction phasing to minimize exposure to weather elements or increased employee
awareness gained through training.
Protection of Existing Vegetation (Phases I-IV)
Protection of existing vegetation on a construction site can be accomplished by installing a construction
fence around the area requiring protection. In cases where up-gradient areas are disturbed, installing
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perimeter controls to minimize sediment loading to sensitive areas such as wetlands may also be
necessary.
Trees that are to remain after construction is complete must be protected. Most tree roots grow within
the top 12”-18” of soil, and soil compaction is a significant threat to tree health. As such, particular care
should be taken to avoid activities within the dripline of the tree. Direct equipment damage should also
be prevented. The most effective way to ensure the health of trees is to establish a protection zone at the
dripline of the tree to prevent unintended activity in the area directly surrounding the tree.
Fencing should be inspected and repaired when needed. If damage occurs to a tree, an arborist should be
consulted on caring for the tree. The City Forester should be consulted on remediation measures if a tree
is damaged beyond repair.
Stockpile Management (Phases I-III)
Stockpile management should be utilized to minimize erosion and sediment transport from soil
stockpiles. In general, soil stockpiles should be located at least 100 feet from any drainage way and 50
feet from any storm drain inlets. Where practical, choose a stockpile location that will remain undisturbed
for the longest period of time as the phases of construction progress. Sediment control BMPs should be
placed around the perimeter of the stockpile, and a designated access point on the upstream side of the
stockpile should be identified. BMPs such as surface roughening, temporary seeding, mulching, erosion
control blankets, or soil binders should be used to stabilize the stockpile surface.
As a part of stockpile management, regular inspections of the perimeter controls should be completed. If
BMPs have been utilized to stabilize the surface of the stockpile, they should be inspected and repaired as
needed.
While soil stockpiles are not expected with this project, foundation excavation or landscaping material
may generate temporary stockpiles. The location of any such stockpiles shall be the responsibility of the
SWMP Administrator.
Mulching (Phase I-III)
Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration, and
reducing runoff. Although often applied in conjunction with temporary or permanent seeding, it can also
be used to temporarily stabilize areas that cannot be reseeded due to seasonal constraints. The most
common type of mulch used is hay or grass crimped into the soil to keep it secure. However, crimping
may not be practical on slopes steeper than three to one (3H:1V).
The contractor shall mulch all planted areas within twenty-four (24) hours after planting. Only weed-free
and seed-free straw mulch may be used. Straw mulch should be applied at two (2) tons per acre and shall
be adequately secured by crimping, tackifier, netting, or blankets. Hydraulic mulching may also be used
on steep slopes or where access is limited. If hydraulic mulching is utilized, the contractor shall use wood
cellulose fibers mixed with water at two thousand to two thousand five hundred (2,000-2,500) pounds per
acre and organic tackifier at one hundred to four hundred (100-400) pounds per acre.
Wind Erosion/Dust Control (Phase I-IV)
Wind Erosion and Dust Control BMPs help keep soil particles from entering the air due to land disturbing
construction activities. Examples include using a water truck or irrigation/sprinkler system to wet the top
layer of disturbed soil, seeding and mulching, soil binders, or wind fences. If a water truck or
irrigation/sprinkler system is utilized, monitoring that sufficient water is applied is crucial to ensuring soil
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particles don’t become airborne. Equally important is monitoring for overwatering, as too much water
can lead to increased erosion.
Street Sweeping (Phases I -IV)
Street sweeping should be used to remove sediment that has been tracked onto adjacent roadways.
Roadways should be inspected at least once a day, and sediment should be removed as needed. A check
of the area inlet protection should be completed after sweeping to ensure nothing was displaced during
sweeping operations. Street sweeping can reduce the sediment washed into the existing storm drain
system. Street sweeping may be necessary on existing hardscape areas which receive runoff from the
disturbed areas.
Saw Cutting Pollution Prevention (Phase I)
The following protocol is recommended to prevent dust and slurry from asphalt and concrete saw cutting
activities from migrating into the existing storm drain system.
· Slurry and cuttings shall be vacuumed during cutting and surfacing operations
· Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight
· Slurry and cuttings shall not drain to any natural or constructed drainage conveyance
· Collected slurry and cuttings shall be disposed of in a manner that does not violate groundwater or
surface water standards
Good Housekeeping Practices (All phases)
Good housekeeping practices that will prevent pollution associated with solid, liquid, and hazardous
construction-related materials and wastes should be implemented throughout the project. Examples of
good housekeeping include providing an appropriate location for waste management containers,
establishing proper building material staging areas, designating paint and concrete washout areas, and
establishing proper equipment/vehicle fueling and maintenance practices. The development of a spill
prevention and response plan is another example of Good Housekeeping practices that should be used on
the project. The following items are detailed examples of some of the good housekeeping practices that
should be utilized throughout the project. It should be noted that a complete list of practices and detailed
discussion regarding good housekeeping has been included with Appendix B.
Street Sweeping and Vacuuming – Street sweeping and vacuuming should be used to remove sediment
that has been tracked onto adjacent roadways. Roadways should be inspected at least once a day, and
sediment should be removed as needed. A check of inlet protection should be completed after sweeping
to ensure nothing was displaced during sweeping operations.
Waste Management – Designate trash and bulk waste collection areas on-site. When possible, materials
should be recycled. Hazardous material waste should be segregated from other solid waste. Waste
collection areas should be located away from streets, gutters, watercourses, and storm drains. Dumpsters
should be located near site entrances to minimize traffic on disturbed soils, and they should be placed on
a level soil surface.
Establish Proper Building Material Handling and Staging Areas – Clearly designate site areas for
staging and storage of building materials. Provide appropriate BMPs to ensure that spills or leaks are
contained.
Establish Proper Equipment/Vehicle Fueling and Maintenance Practices – If needed, create a clearly
designated on-site fueling and maintenance area that is clean and dry. Provide appropriate BMPs to
ensure that spills or leaks are contained.
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3.5 PHASED BMP INSTALLATION
It is important to recognize the four (4) major Development Phases defined by the State of Colorado’s
Stormwater Discharge Permit (SDP). These four development phases have been distinguished to aid in
the appropriate timing of installation/implementation of BMPs at different stages of the construction
process. These phases are described as follows:
Phase I – Grading Stage; BMPs for initial installation of perimeter controls
Phase II – Infrastructure Stage; BMPs for utility, paving, and curb installation
Phase III – Vertical Construction Stage; BMPs for individual building construction.
Phase IV – Permanent BMPs and final site stabilization.
The following is a rough estimate of the anticipated construction sequence for site improvements. The
schedule outlined below is subject to change as the project progresses and as determined by the General
Contractor.
TABLE 1 – PRELIMINARY PERMIT AND CONSTRUCTION SCHEDULE
Task Beginning
Date
Ending Date “BMP Phase of
Development”
Development Construction Permit
Issued by City of Fort Collins
April 2025 I
Overlot Grading (Demolition) May 2025 May 2025 I
Utility Installation June 2025 June 2025 II
Building Construction June 2025 January 2026 III
Final Stabilization January 2026 TBD IV
The back map pockets include an Erosion Control Plan. The plan displays the overall management plan all at
once. Proper implementation of BMPs does not occur at once, and certain BMPs may move location in the
construction process; therefore, the “Dynamic” Erosion Control Plan is intended for the contractor to write in
the BMP symbols to document the location and time the BMPs are installed and maintained throughout the
entire construction process.
3.6 MATERIAL HANDLING AND SPILL PREVENTION
As discussed in earlier sections, potential pollution sources are to be identified by the contractor. Spill
prevention procedures are to be determined and put in place before construction by the contractor. A
spill and flooding response procedure must also be determined and put in place before construction by
the contractor. Additionally, steps should be taken to reduce the potential for leaks and spills to come in
contact with stormwater runoff, such as storing and handling toxic materials in covered areas or storing
chemicals within berms or other secondary containment devices.
A notification procedure must be put in place by the contractor, by which workers would first notify
the site construction superintendent, who would then notify the SWMP Administrator. Depending
on the severity of the spill, the site construction superintendent and SWMP Administrator would
possibly notify the Colorado Department of Public Health and Environment - Water Quality Control
Division, downstream water users, or other appropriate agencies. The release of any chemical, oil,
petroleum product, sewage, etc., which enter the waters of the State of Colorado (which include
surface water, groundwater, and dry gullies or storm drains leading to surface water) must be
reported immediately to the Division’s emergency spill reporting line at (877) 518-5608. All spills
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requiring cleanup, even if the spill is minor and does not need to be reported to the state, should
still be reported to the Town of Fort Collins.
While not expected with this project, it will be the contractor's responsibility to designate a fueling area
and take the necessary precautions to ensure that no stormwater pollution occurs if a fueling area is
needed. Fueling areas shall be located a minimum of 100 feet from all drainage courses. A 12-inch-high
compacted earthen ridge capable of retaining potential spills shall enclose fueling areas. Other secondary
containment devices can be used instead of the earthen ridge. The area shall be covered with a non-
porous lining to prevent soil contamination. Printed instructions for cleanup procedures shall be posted
in the fueling area, and appropriate fuel absorbents shall be available along with containers for used
absorbents within the fueling area.
3.7 DEDICATED CONCRETE OR ASPHALT BATCH PLANT
There are no dedicated concrete or asphalt batch plants anticipated with this project. If a plant is needed,
the contractor should be aware additional permitting will be required. In particular, an Air Pollutant
Emission Notice (APEN) will need to be obtained from the CDPHE.
3.8 VEHICLE TRACKING CONTROL
In addition to the vehicle tracking pads discussed previously, additional measures can be taken to
minimize and control sediment discharges from the site due to vehicle tracking. These measures can
include fencing around the site to control access points. Regular street sweeping can also minimize the
transmission of sediment from the site due to vehicles leaving the site. Gravel parking areas and wash
racks can also be implemented to ensure minimal vehicle tracking from the site.
3.9 WASTE MANAGEMENT AND DISPOSAL
It will be the contractor's responsibility to designate a concrete truck chute washout area and clearly
identify that area. Detailed information about the design and maintenance of the Concrete Washout can
be found under the Structural Practices section of this report. At no time should untreated wash water be
allowed to discharge from the site or enter a storm drain system or stream. Upon completion of
construction activities, the concrete washout material shall be removed and properly disposed of before
the area being restored.
Any waste material that currently exists on the site or that is generated by construction will be disposed of
in such a manner not to cause pollutants in stormwater discharges. If waste is to be stored on-site, it shall
be in an area located a minimum of 100 feet from all drainage courses. Whenever waste is not stored in a
non-porous container, it shall be in an area enclosed by a 12-inch-high compacted earthen ridge or some
other approved secondary containment device. The area shall be covered with a non-porous lining to
prevent soil contamination. Whenever precipitation is predicted, the waste shall be covered with a non-
porous cover, anchored on all sides to prevent its removal by wind, to prevent precipitation from leaching
out potential pollutants from the waste. On-site waste disposal practices, such as dumpsters, should be
covered or otherwise contained to prevent the dispersion of waste materials from the wind. It shall also
be the contractor's responsibility to maintain a clean jobsite to prevent the dispersion of waste material
and potential pollutants into adjacent properties or waterways.
The location of and protective measures for temporary restroom facilities shall be the responsibility of the
SWMP Administrator.
3.10 GROUNDWATER AND STORMWATER DEWATERING
The BMPs selected for construction dewatering vary depending on the site-specific features, such as soils,
topography, discharge quantities, and discharge location. Typically, dewatering involves pumping water
from an inundated area to a BMP before the water is released downstream into a receiving waterway,
sediment basin, or well-vegetated area. Acceptable BMPs included discharging water into a sediment trap
or basin using a dewatering filter bag or using a series of sediment logs. A settlement tank or an active
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treatment system can also be utilized. Another commonly used method to handle the pumped water is
the “sprinkler method,” which involves applying the water to vegetated areas through a perforated
discharge hose. Dispersal from a water truck for dust control can also be used to disperse the pumped
water.
4.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT
4.1 FINAL STABILIZATION
All disturbed areas will be seeded, crimped, and mulched. Soil amendments such as compost, peat, aged
manure, or other similar materials shall also be utilized. Soil amendments shall be tilled into the soil to a
minimum depth of 6” and should comply with the requirements found City Municipal Code Sections 12-
130, 12-131, and 12-132 (refer also to Land Use Code 3.8.21. As defined by the Colorado Department of
Public Health and Environment (CDPHE) in the General Permit Application for Stormwater Discharges,
“Final stabilization is reached when all soil disturbing activities at the site have been completed, and
uniform vegetative cover has been established with a density of at least 70 percent of pre-disturbance
levels or equivalent permanent, physical erosion reduction methods have been employed.”
TABLE 2 - NATIVE GRASS SEED MIX
Preferred Varieties
Seeded Rate
(lbs. Per Acre,
Drilled)
PLS
Seeded/Acre
Leymus Cinereus Great Basin Wilrye Mangar 3 285,000
Nassella Viridula Green Needlegrass Lodorm 2 362,000
Chnatherum Hymenoides Indian Ricegrass Paloma, Nezpar 1 188,000
Elymus Trachycaulus Slender Wheatgrass Primar, Revenue 2 320,000
Elymus Lanceolatus Thickspike Wheatgrass Critana 3 580,500
Pascopyrum Smithii Western Wheatgrass Arriba, Barton 4 504,000
Totals 15 2,239,500
Species
4.2 LONG-TERM STORMWATER MANAGEMENT
The primary method of long-term stormwater management will be the regrading of curb and gutter. The
owner shall also regularly maintain drainage inlets as per the O&M Manual provided. Existing street flow
and storm drain infrastructure will not be obstructed.
4.3 BMP INSPECTION
All temporary erosion control facilities shall be inspected at a minimum of once every two (2) weeks and
after each significant storm event or snowmelt. Repairs or reconstruction of BMPs, as necessary, shall
occur as soon as possible to ensure the continued performance of their intended function. It is the
responsibility of the SWMP Administrator to conduct bi-weekly inspections, maintain BMPs if needed,
keep records of site conditions and inspections, and update the SWMP as necessary.
The construction site perimeter, disturbed areas, all applicable/installed erosion and sediment control
measures, and areas used for material storage exposed to precipitation shall be inspected for evidence of,
or the potential for, pollutants entering the drainage system. Erosion and sediment control measures
identified in the SWMP shall be observed to ensure they are operating correctly. Attention should be paid
to areas with significant potential for stormwater pollution, such as demolition areas, concrete washout
locations, and vehicle entries to the site. The inspection must be documented to ensure compliance with
the permit requirements.
4.4 BMP MAINTENANCE
Any BMP’s not operating in accordance with the SWMP must be addressed as soon as possible,
immediately in most cases, to prevent the discharge of pollutants. If modifications are necessary,
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such modifications shall be documented so that the SWMP accurately reflects on-site conditions.
The SWMP needs to accurately represent field conditions at all times.
Uncontrolled releases of mud, muddy water, or measurable amounts of sediment found off-site will be
recorded with a brief explanation of the measures taken to clean up the sediment that has left the site, as
well as the measures taken to prevent future releases. This record shall be made available to the
appropriate public agencies (Colorado Department of Public Health and Environment, Water Quality
Control Division; Environmental Protection Agency; City of Greeley; etc.) upon request.
Preventative maintenance of all temporary and permanent erosion control BMPs shall be provided to
ensure the continued performance of their intended function. Temporary erosion control measures are to
be removed after the site has been sufficiently stabilized, as determined by the City of Fort Collins.
Maintenance activities and actions to correct problems shall be noted and recorded during inspections.
Inspection and maintenance procedures specific to each BMP identified with this SWMP are discussed in
Section 3. Details have also been included in Appendix B.
4.5 RECORD KEEPING
Documentation of site inspections must be maintained. The following items are to be recorded and kept
with the SWMP:
· Date of Inspection
· Name(s) and title(s) of personnel making the inspection
· Location(s) of sediment discharges or other pollutants from the site
· Location(s) of BMPs that need to be maintained
· Location(s) of BMPs that failed to operate as designed or proved inadequate
· Locations(s) where additional BMPs are needed that were not in place at the time of inspection
· Deviations from the minimum inspection schedule
· Descriptions of corrective action taken to remedy deficiencies that have been identified
· The report shall contain a signed statement indicating the site complies with the permit to the best of
the signer’s knowledge and belief after corrective actions have been taken.
Provided within Appendix D of this SWMP is an Example Inspection Log to aid in BMP inspections and
maintenance record keeping. Photographs, field notebooks, drawings, and maps should be included by
the SWMP Administrator when appropriate.
In addition to the Inspection Log, records should be kept documenting:
· BMP maintenance and operation
· Stormwater contamination
· Contacts with suppliers
· Notes on the need for and performance of preventive maintenance and other repairs
· Implementation of specific items in the SWMP
· Training events (given or attended)
· Events involving materials handling and storage
· Contacts with regulatory agencies and personnel
· Notes of employee activities, contact, notifications, etc.
Records of spills, leaks, or overflows that result in the discharge of pollutants must be documented and
maintained. Even if they do not result in a discharge of pollutants, a record of other spills responded to
should be made. Information that should be recorded for all occurrences includes the time and date,
weather conditions, reasons for the spill, etc. Some spills may need to be reported to authorities
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immediately. Specifically, a release of any chemical, oil, petroleum product, sewage, etc., which may
enter the waters of the State of Colorado (which include surface water, groundwater, and dry gullies or
storm drains leading to surface water) must be reported to the CDPHE.
Additionally, the “Dynamic Site Plan” is intended to be a “living” document where the SWMP
Administrator can handwrite the location of BMPs as they are installed to reflect the current site
conditions appropriately. Also, on the “Dynamic Site Plan” is a “Table of Construction Sequence and BMP
Application/Removal” that the SWMP Administrator can use to document when BMPs were installed or
removed in conjunction with construction activities. These items have been included as an aid to the
SWMP Administrator, and other methods of record keeping are at his or her discretion.
This Stormwater Management Plan (both the text and map) is not a static document. It is a dynamic
device intended to be kept current and logged as construction occurs. It shall be the responsibility
of the SWMP Administrator and/or the permit holder (or applicant thereof) to ensure the plan is
properly maintained and followed. Diligent administration is critical, including processing the
Notice to Proceed and noting on the Stormwater Management Plan the dates that various
construction activities occur and respective BMPs are installed and/or removed.
5.0 ADDITIONAL SWMP AND BMP RESOURCES
Urban Drainage and Flood Control District
Urban Storm Drainage Criteria Manual - Volume 3 “Best Management Practices”
Colorado Department of Transportation
Erosion Control and Stormwater Quality Guide
BMP Field Academy
EPA Menu of BMPs
Construction Site Storm Water Runoff Control
International Stormwater Best Management (BMP) Database
Rocky Mountain Education Center
Rocky Mountain Education Center
Red Rocks Community College, Lakewood
Keep It Clean Partnership
Boulder
6.0 REFERENCES
1. Final Drainage Memorandum, 300 E. Mountain Avenue, EPS Group (unapproved-currently under City
review).
2. Soil Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service,
United States Department of Agriculture.
3. Urban Storm Drainage Criteria Manual, Volumes 1 & 2, Urban Drainage and Flood Control District,
Wright-McLaughlin Engineers, Denver, Colorado, January 2016 and Partially Updated March 2024.
4. Urban Storm Drainage Criteria Manual, Volumes 3, Urban Drainage and Flood Control District,
Wright-McLaughlin Engineers, Denver, Colorado, November 2010 and Partially Updated March
2024.
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX A
SITE MAPS
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(10
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MOUNTAIN AVENUE
ELIZABETH
DOWNTOWN HOTEL
111 CHESTNUT STREET
HO
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314 E MOUNTAIN
AVENUE
CHESTNUT STREET ALLEY
GARAGE
9
ER
O
S
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O
L
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L
A
N
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE, OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
before you dig.Call
R
NORTH
( IN FEET )
1 inch = ft.
Feet02020
20
40 60
NOTES:
TABLE OF CONSTRUCTION
SEQUENCE AND BMP APPLICATION
Project: 300 E. MOUNTAIN AVE
CONSTRUCTION PHASE MOBILIZATION DEMOLITION GRADING
BEST MANAGEMENT PRACTICES (BMPS)
STRUCTURAL "INSTALLATION"
Construction & Silt Fence Barriers *
Flow Barriers (Wattles) *
Inlet Protection *
Rip Rap
Vegetative
Temporary Seeding Planting
Mulching / Sealant
Permanent Seeding Planting
Sod Installation
Rolled Products : Netting / Blankets / Mats
Contour Furrows (Ripping / Disking)
Sediment Trap
Rock Socks *
UTILITIES
INSTALLATION
FLAT WORK
INSTALLATION LANDSCAPE DEMOBILIZATION
Vehicle Tracking Pad *
* All Temporary BMPs to be Removed once Construction is Complete
Other:
Any prior inlets that could use protecting
Any prior inlets that could use protecting
Anytime the site will sit dormant longer than 30 Days
Under slope stabilization rolled products. Reseeding
may be required.
IP
PROPOSED CONTOUR
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
BENCHMARK/BASIS OF BEARING:
SILT FENCE
ROCK SOCK
RIPRAP
1.CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED
AREAS BY SEED & CRIMP MULCHING OR SIMILAR METHODS.
2.SWMP ADMINISTRATOR:
Contact ________________________________
Company ________________________________
Address ________________________________
Phone ________________________________
3.CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR
CONCRETE WASHOUT AREA IF ACCESS IS OFF PAVEMENT.
4.REFER TO THE 300 E MOUNTAIN AVENUE DRAINAGE
MEMORANDUM BY EPS GROUP INC. FOR ADDITIONAL
INFORMATION.
5.THE CONTRACTOR SHALL INSTALL LANDSCAPE AS SHOWN ON
THE APPROVED LANDSCAPE PLANS AS WELL AS RE-ESTABLISH
UNIFORM VEGETATIVE COVER IN ALL OTHER DISTURBED AREAS
PER THE REQUIREMENTS OF THE PERMIT AND TO AT LEAST 70%
OF PRE-DISTURBANCE LEVEL UTILIZING STANDARD NATIVE
SEEDING MIXTURE OF THE JURISDICTION HAVING AUTHORITY.
GENERAL NOTES:
WATTLE DIKE
CONCRETE WASH AREA
SEDIMENT TRAP
BALE INLET PROTECTION
SLOPE DRAIN
EROSION CONTROL FABRIC
LEGEND:
BALE OUTLET PROTECTION
INLET PROTECTION
VEHICLE TRACKING CONTROL PAD
SF
IP
RS
RS
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PROJECT DATUM: NAVD88
BENCHMARK #1:
City of Fort Collins Benchmark 3-13
Approximately 40 feet south of the Linden Street bridge over the Poudre
River, on the west side of Linden Street on a storm inlet.
Elevation= 4962.27
PLEASE NOTE: This plan set is using NAVD88 for a vertical datum.
Surrounding developments have used NGVD29 Unadjusted for their
vertical datums.
If NGVD29 Unadjusted Datum is required for any purpose, the following
equation should be used: NGVD29 Unadjusted = NAVD88 - 3.18'
Basis of Bearings
The Basis of Bearings is the Northeasterly line of Lot 1
Walnut-Chestnut Subdivision as bearing South 48°32'51" East
(assumed bearing) as monumented on the Walnut-Chestnut
Subdivision Plat.
Sheet
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX B
EROSION CONTROL DETAILS
GRADATION TABLE
SIEVE SIZE
MASS PERCENT
PASSING SQUARE
MESH SIEVES
NO. 4
2"100
1-1/2"90-100
1"20-55
3/4"0-15
3/8"0-5
MATCHES SPECIFICATIONS FOR NO. 4 COARSE AGGREGATE FOR
CONCRETE PER AASHTO M43. ALL ROCK SHALL BE FRACTURED FACE,
ALL SIDES
RS
VTC
CWA
VEHICLE TRACKING CONTROL PADCONCRETE WASHOUT AREAROCK SOCK DETAIL102 103 104
ROCK SOCK SECTION ROCK SOCK PLAN
ROCK SOCK JOINTING
CURB INLET PROTECTION100
TEMPORARY CONSTRUCTION
FENCE WITH ROCK SOCK101
TEMPORARY
CHAIN-LINK FENCE
ROCK SOCK
TEMPORARY
CHAIN-LINK FENCE
ROCK SOCK
SIDE VIEW
CF
10
ER
O
S
I
O
N
C
O
N
T
R
O
L
D
E
T
A
I
L
S
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE, OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
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Chapter 7 Construction BMPs
November 2010 Urban Drainage and Flood Control District 7-13
Urban Storm Drainage Criteria Manual Volume 3
Final Stabilization
▪Revegetate Site
▪Activate Post Construction BMPs
(e.g., convert sediment basin to extended
detention basin)
▪Remove Temporary BMPs
▪Closeout State and Local Stormwater Permits
Construction Phase
Representative Phases:
▪Clearing and Grubbing
▪Rough Grading
▪Road Construction
▪Utility and Infrastructure Installation
▪Vertical Construction (Buildings)
▪Final Grading
Management Practices:
▪Phase Construction Activities to Minimize
Disturbed Area at a Given Time
▪Sequence Contruction within Phases to Avoid
Idle Disturbed Areas
▪Install, Inspect and Proactively Maintain BMPs
Appropriate for Each Phase of Construction
▪Maintain and Update SWMP as Construction
Progresses
Pre-Construction
▪Develop Site Plan
▪Obtain Site Survey, Hydrology and Soils
Information
▪Prepare SWMP
▪Obtain Stormwater Construction Permits
(State and Local)
▪Obtain Other Relevant Permits
(e.g., 404 , Floodplain, Dewatering)
Figure 7-2. Construction Stormwater Management
Construction BMPs Construction BMPs
7-14 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Functions Erosion
Control
Sediment
Control
Site/Material
Management
Surface Roughening Yes No No
Temporary/Permanent Seeding Yes No No
Soil Binders Yes No Moderate
Mulching Yes Moderate No
Compost Blankets and Filter Berms Yes Moderate No
Rolled Erosion Control Products Yes No No
Temporary Slope Drains Yes No No
Temporary Outlet Protection Yes Moderate No
Rough Cut Street Control Yes Moderate No
Earth Dikes / Drainage Swales Yes Moderate No
Terracing Yes Moderate No
Check Dams Yes Moderate No
Streambank Stabilization Yes No No
Wind Erosion / Dust Control Yes No Moderate
Silt Fence No Yes No
Sediment Control Log Moderate Yes No
Straw Bale Barrier No Moderate No
Brush Barrier Moderate Moderate No
Rock Sock (perimeter control)No Yes No
Inlet Protection (various forms)No Yes No
Sediment Basins No Yes No
Sediment Traps No Yes No
Vegetative Buffers Moderate Yes Yes
Chemical Treatment Moderate Yes No
Concrete Washout Area No No Yes
Stockpile Management Yes Yes Yes
Good Houskeeping (multiple practices)No No Yes
Construction Phasing Moderate Moderate Yes
Protection of Existing Vegetation Yes Moderate Yes
Construction Fence No No Yes
Vehicle Tracking Control Moderate Yes Yes
Stabilized Construction Roadway Yes Moderate Yes
Stabilized Staging Area Yes Moderate Yes
Street Sweeping / Vacuuming No Yes Yes
Temporary Diversion Channel Yes No No
Dewatering Operations Moderate Yes Yes
Temporary Stream Crossing Yes Yes No
Temporary Batch Plants No No Yes
Paving and Grinding Operations No No Yes
Site Management and Other Specific Practices
Sediment Control BMPs
Erosion Control BMPs
Materials Management
Table 7-2. Overview of Construction BMPs
Surface Roughening (SR) EC-1
November 2010 Urban Drainage and Flood Control District SR-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SR-1. Surface roughening via imprinting for temporary
stabilization.
Description
Surface roughening is an erosion control
practice that involves tracking,
scarifying, imprinting, or tilling a
disturbed area to provide temporary
stabilization of disturbed areas. Surface
roughening creates variations in the soil
surface that help to minimize wind and
water erosion. Depending on the
technique used, surface roughening may
also help establish conditions favorable
to establishment of vegetation.
Appropriate Uses
Surface roughening can be used to
provide temporary stabilization of
disturbed areas, such as when
revegetation cannot be immediately established due to seasonal planting limitations. Surface roughening
is not a stand-alone BMP, and should be used in conjunction with other erosion and sediment controls.
Surface roughening is often implemented in conjunction with grading and is typically performed using
heavy construction equipment to track the surface. Be aware that tracking with heavy equipment will also
compact soils, which is not desirable in areas that will be revegetated. Scarifying, tilling, or ripping are
better surface roughening techniques in locations where revegetation is planned. Roughening is not
effective in very sandy soils and cannot be effectively performed in rocky soil.
Design and Installation
Typical design details for surfacing roughening on steep and mild slopes are provided in Details SR-1 and
SR-2, respectively.
Surface roughening should be performed either after final grading or to temporarily stabilize an area
during active construction that may be inactive for a short time period. Surface roughening should create
depressions 2 to 6 inches deep and approximately 6 inches apart. The surface of exposed soil can be
roughened by a number of techniques and equipment. Horizontal grooves (running parallel to the
contours of the land) can be made using tracks from equipment treads, stair-step grading, ripping, or
tilling.
Fill slopes can be constructed with a roughened surface. Cut slopes that have been smooth graded can be
roughened as a subsequent operation. Roughening should follow along the contours of the slope. The
tracks left by truck mounted equipment working perpendicular
to the contour can leave acceptable horizontal depressions;
however, the equipment will also compact the soil.
Surface Roughening
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-1 Surface Roughening (SR)
SR-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Care should be taken not to drive vehicles or equipment over areas that have been surface roughened.
Tire tracks will smooth the roughened surface and may cause runoff to collect into rills and gullies.
Because surface roughening is only a temporary control, additional treatments may be necessary to
maintain the soil surface in a roughened condition.
Areas should be inspected for signs of erosion. Surface roughening is a temporary measure, and will not
provide long-term erosion control.
Surface Roughening (SR) EC-1
November 2010 Urban Drainage and Flood Control District SR-3
Urban Storm Drainage Criteria Manual Volume 3
EC-1 Surface Roughening (SR)
SR-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary and Permanent Seeding (TS/PS) EC-2
November 2010 Urban Drainage and Flood Control District TS/PS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TS/PS -1. Equipment used to drill seed. Photo courtesy of
Douglas County.
Description
Temporary seeding can be used to
stabilize disturbed areas that will be
inactive for an extended period.
Permanent seeding should be used to
stabilize areas at final grade that will not
be otherwise stabilized. Effective seeding
includes preparation of a seedbed,
selection of an appropriate seed mixture,
proper planting techniques, and protection
of the seeded area with mulch, geotextiles,
or other appropriate measures.
Appropriate Uses
When the soil surface is disturbed and
will remain inactive for an extended
period (typically 30 days or longer),
proactive stabilization measures should be implemented. If the inactive period is short-lived (on the order
of two weeks), techniques such as surface roughening may be appropriate. For longer periods of
inactivity, temporary seeding and mulching can provide effective erosion control. Permanent seeding
should be used on finished areas that have not been otherwise stabilized.
Typically, local governments have their own seed mixes and timelines for seeding. Check jurisdictional
requirements for seeding and temporary stabilization.
Design and Installation
Effective seeding requires proper seedbed preparation, selection of an appropriate seed mixture, use of
appropriate seeding equipment to ensure proper coverage and density, and protection with mulch or fabric
until plants are established.
The USDCM Volume 2 Revegetation Chapter contains detailed seed mix, soil preparations, and seeding
and mulching recommendations that may be referenced to supplement this Fact Sheet.
Drill seeding is the preferred seeding method. Hydroseeding is not recommended except in areas where
steep slopes prevent use of drill seeding equipment, and even in these instances it is preferable to hand
seed and mulch. Some jurisdictions do not allow hydroseeding or hydromulching.
Seedbed Preparation
Prior to seeding, ensure that areas to be revegetated have
soil conditions capable of supporting vegetation. Overlot
grading can result in loss of topsoil, resulting in poor quality
subsoils at the ground surface that have low nutrient value,
little organic matter content, few soil microorganisms,
rooting restrictions, and conditions less conducive to
infiltration of precipitation. As a result, it is typically
necessary to provide stockpiled topsoil, compost, or other
Temporary and Permanent Seeding
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
soil amendments and rototill them into the soil to a depth of 6 inches or more.
Topsoil should be salvaged during grading operations for use and spread on areas to be revegetated later.
Topsoil should be viewed as an important resource to be utilized for vegetation establishment, due to its
water-holding capacity, structure, texture, organic matter content, biological activity, and nutrient content.
The rooting depth of most native grasses in the semi-arid Denver metropolitan area is 6 to 18 inches. At a
minimum, the upper 6 inches of topsoil should be stripped, stockpiled, and ultimately respread across
areas that will be revegetated.
Where topsoil is not available, subsoils should be amended to provide an appropriate plant-growth
medium. Organic matter, such as well digested compost, can be added to improve soil characteristics
conducive to plant growth. Other treatments can be used to adjust soil pH conditions when needed. Soil
testing, which is typically inexpensive, should be completed to determine and optimize the types and
amounts of amendments that are required.
If the disturbed ground surface is compacted, rip or rototill the surface prior to placing topsoil. If adding
compost to the existing soil surface, rototilling is necessary. Surface roughening will assist in placement
of a stable topsoil layer on steeper slopes, and allow infiltration and root penetration to greater depth.
Prior to seeding, the soil surface should be rough and the seedbed should be firm, but neither too loose
nor compacted. The upper layer of soil should be in a condition suitable for seeding at the proper depth
and conducive to plant growth. Seed-to-soil contact is the key to good germination.
Seed Mix for Temporary Vegetation
To provide temporary vegetative cover on disturbed areas which will not be paved, built upon, or fully
landscaped or worked for an extended period (typically 30 days or more), plant an annual grass
appropriate for the time of planting and mulch the planted areas. Annual grasses suitable for the Denver
metropolitan area are listed in Table TS/PS-1. These are to be considered only as general
recommendations when specific design guidance for a particular site is not available. Local governments
typically specify seed mixes appropriate for their jurisdiction.
Seed Mix for Permanent Revegetation
To provide vegetative cover on disturbed areas that have reached final grade, a perennial grass mix should
be established. Permanent seeding should be performed promptly (typically within 14 days) after
reaching final grade. Each site will have different characteristics and a landscape professional or the local
jurisdiction should be contacted to determine the most suitable seed mix for a specific site. In lieu of a
specific recommendation, one of the perennial grass mixes appropriate for site conditions and growth
season listed in Table TS/PS-2 can be used. The pure live seed (PLS) rates of application recommended
in these tables are considered to be absolute minimum rates for seed applied using proper drill-seeding
equipment.
If desired for wildlife habitat or landscape diversity, shrubs such as rubber rabbitbrush (Chrysothamnus
nauseosus), fourwing saltbush (Atriplex canescens) and skunkbrush sumac (Rhus trilobata) could be
added to the upland seedmixes at 0.25, 0.5 and 1 pound PLS/acre, respectively. In riparian zones,
planting root stock of such species as American plum (Prunus americana), woods rose (Rosa woodsii),
plains cottonwood (Populus sargentii), and willow (Populus spp.) may be considered. On non-topsoiled
upland sites, a legume such as Ladak alfalfa at 1 pound PLS/acre can be included as a source of nitrogen
for perennial grasses.
Temporary and Permanent Seeding (TS/PS) EC-2
November 2010 Urban Drainage and Flood Control District TS/PS-3
Urban Storm Drainage Criteria Manual Volume 3
Seeding dates for the highest success probability of perennial species along the Front Range are generally
in the spring from April through early May and in the fall after the first of September until the ground
freezes. If the area is irrigated, seeding may occur in summer months, as well. See Table TS/PS-3 for
appropriate seeding dates.
Table TS/PS-1. Minimum Drill Seeding Rates for Various Temporary Annual Grasses
Speciesa
(Common name)
Growth
Seasonb
Pounds of
Pure Live Seed
(PLS)/acrec
Planting
Depth
(inches)
1. Oats Cool 35 - 50 1 - 2
2. Spring wheat Cool 25 - 35 1 - 2
3. Spring barley Cool 25 - 35 1 - 2
4. Annual ryegrass Cool 10 - 15 ½
5. Millet Warm 3 - 15 ½ - ¾
6. Sudangrass Warm 5–10 ½ - ¾
7. Sorghum Warm 5–10 ½ - ¾
8. Winter wheat Cool 20–35 1 - 2
9. Winter barley Cool 20–35 1 - 2
10. Winter rye Cool 20–35 1 - 2
11. Triticale Cool 25–40 1 - 2
a Successful seeding of annual grass resulting in adequate plant growth will
usually produce enough dead-plant residue to provide protection from
wind and water erosion for an additional year. This assumes that the cover
is not disturbed or mowed closer than 8 inches.
Hydraulic seeding may be substituted for drilling only where slopes are
steeper than 3:1 or where access limitations exist. When hydraulic
seeding is used, hydraulic mulching should be applied as a separate
operation, when practical, to prevent the seeds from being encapsulated in
the mulch.
b See Table TS/PS-3 for seeding dates. Irrigation, if consistently applied,
may extend the use of cool season species during the summer months.
c Seeding rates should be doubled if seed is broadcast, or increased by 50
percent if done using a Brillion Drill or by hydraulic seeding.
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses
Commona
Name
Botanical
Name
Growth
Seasonb
Growth
Form
Seeds/
Pound
Pounds of
PLS/acre
Alakali Soil Seed Mix
Alkali sacaton Sporobolus airoides Cool Bunch 1,750,000 0.25
Basin wildrye Elymus cinereus Cool Bunch 165,000 2.5
Sodar streambank wheatgrass Agropyron riparium 'Sodar' Cool Sod 170,000 2.5
Jose tall wheatgrass Agropyron elongatum 'Jose' Cool Bunch 79,000 7.0
Arriba western wheatgrass Agropyron smithii 'Arriba' Cool Sod 110,000 5.5
Total 17.75
Fertile Loamy Soil Seed Mix
Ephriam crested wheatgrass Agropyron cristatum
'Ephriam' Cool Sod 175,000 2.0
Dural hard fescue Festuca ovina 'duriuscula' Cool Bunch 565,000 1.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln' Cool Sod 130,000 3.0
Sodar streambank wheatgrass Agropyron riparium 'Sodar' Cool Sod 170,000 2.5
Arriba western wheatgrass Agropyron smithii 'Arriba' Cool Sod 110,000 7.0
Total 15.5
High Water Table Soil Seed Mix
Meadow foxtail Alopecurus pratensis Cool Sod 900,000 0.5
Redtop Agrostis alba Warm Open sod 5,000,000 0.25
Reed canarygrass Phalaris arundinacea Cool Sod 68,000 0.5
Lincoln smooth brome Bromus inermis leyss
'Lincoln' Cool Sod 130,000 3.0
Pathfinder switchgrass Panicum virgatum
'Pathfinder' Warm Sod 389,000 1.0
Alkar tall wheatgrass Agropyron elongatum
'Alkar' Cool Bunch 79,000 5.5
Total 10.75
Transition Turf Seed Mixc
Ruebens Canadian bluegrass Poa compressa 'Ruebens' Cool Sod 2,500,000 0.5
Dural hard fescue Festuca ovina 'duriuscula' Cool Bunch 565,000 1.0
Citation perennial ryegrass Lolium perenne 'Citation' Cool Sod 247,000 3.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln' Cool Sod 130,000 3.0
Total 7.5
Temporary and Permanent Seeding (TS/PS) EC-2
November 2010 Urban Drainage and Flood Control District TS/PS-5
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses (cont.)
Common
Name
Botanical
Name
Growth
Seasonb
Growth
Form
Seeds/
Pound
Pounds of
PLS/acre
Sandy Soil Seed Mix
Blue grama Bouteloua gracilis Warm Sod-forming
bunchgrass 825,000 0.5
Camper little bluestem Schizachyrium scoparium
'Camper' Warm Bunch 240,000 1.0
Prairie sandreed Calamovilfa longifolia Warm Open sod 274,000 1.0
Sand dropseed Sporobolus cryptandrus Cool Bunch 5,298,000 0.25
Vaughn sideoats grama Bouteloua curtipendula
'Vaughn' Warm Sod 191,000 2.0
Arriba western wheatgrass Agropyron smithii 'Arriba' Cool Sod 110,000 5.5
Total 10.25
Heavy Clay, Rocky Foothill Seed Mix
Ephriam crested wheatgrassd Agropyron cristatum
'Ephriam' Cool Sod 175,000 1.5
Oahe Intermediate wheatgrass Agropyron intermedium
'Oahe' Cool Sod 115,000 5.5
Vaughn sideoats gramae Bouteloua curtipendula
'Vaughn' Warm Sod 191,000 2.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln' Cool Sod 130,000 3.0
Arriba western wheatgrass Agropyron smithii 'Arriba' Cool Sod 110,000 5.5
Total 17.5
a All of the above seeding mixes and rates are based on drill seeding followed by crimped hay or straw mulch. These rates
should be doubled if seed is broadcast and should be increased by 50 percent if the seeding is done using a Brillion Drill or is
applied through hydraulic seeding. Hydraulic seeding may be substituted for drilling only where slopes are steeper than 3:1.
If hydraulic seeding is used, hydraulic mulching should be done as a separate operation.
b See Table TS/PS-3 for seeding dates.
c If site is to be irrigated, the transition turf seed rates should be doubled.
d Crested wheatgrass should not be used on slopes steeper than 6H to 1V.
e Can substitute 0.5 lbs PLS of blue grama for the 2.0 lbs PLS of Vaughn sideoats grama.
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-3. Seeding Dates for Annual and Perennial Grasses
Annual Grasses
(Numbers in table reference
species in Table TS/PS-1)
Perennial Grasses
Seeding Dates Warm Cool Warm Cool
January 1–March 15
March 16–April 30 4 1,2,3
May 1–May 15 4
May 16–June 30 4,5,6,7
July 1–July 15 5,6,7
July 16–August 31
September 1–September 30 8,9,10,11
October 1–December 31
Mulch
Cover seeded areas with mulch or an appropriate rolled erosion control product to promote establishment
of vegetation. Anchor mulch by crimping, netting or use of a non-toxic tackifier. See the Mulching BMP
Fact Sheet for additional guidance.
Maintenance and Removal
Monitor and observe seeded areas to identify areas of poor growth or areas that fail to germinate. Reseed
and mulch these areas, as needed.
An area that has been permanently seeded should have a good stand of vegetation within one growing
season if irrigated and within three growing seasons without irrigation in Colorado. Reseed portions of
the site that fail to germinate or remain bare after the first growing season.
Seeded areas may require irrigation, particularly during extended dry periods. Targeted weed control may
also be necessary.
Protect seeded areas from construction equipment and vehicle access.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-1
Urban Storm Drainage Criteria Manual Volume 3
Description
Soil binders include a broad range of
treatments that can be applied to exposed
soils for temporary stabilization to reduce
wind and water erosion. Soil binders may
be applied alone or as tackifiers in
conjunction with mulching and seeding
applications.
Acknowledgement: This BMP Fact Sheet
has been adapted from the 2003
California Stormwater Quality
Association (CASQA) Stormwater BMP
Handbook: Construction
(www.cabmphandbooks.com).
Appropriate Uses
Soil binders can be used for short-term, temporary stabilization of soils on both mild and steep slopes.
Soil binders are often used in areas where work has temporarily stopped, but is expected to resume before
revegetation can become established. Binders are also useful on stockpiled soils or where temporary or
permanent seeding has occurred.
Prior to selecting a soil binder, check with the state and local jurisdiction to ensure that the chemicals
used in the soil binders are allowed. The water quality impacts of some types of soil binders are relatively
unknown and may not be allowed due to concerns about potential environmental impacts. Soil binders
must be environmentally benign (non-toxic to plant and animal life), easy to apply, easy to maintain,
economical, and should not stain paved or painted surfaces.
Soil binders should not be used in vehicle or pedestrian high traffic areas, due to loss in effectiveness
under these conditions.
Site soil type will dictate appropriate soil binders to be used. Be aware that soil binders may not function
effectively on silt or clay soils or highly compacted areas. Check manufacturer's recommendations for
appropriateness with regard to soil conditions. Some binders may not be suitable for areas with existing
vegetation.
Design and Installation
Properties of common soil binders used for erosion control
are provided in Table SB-1. Design and installation
guidance below are provided for general reference. Follow
the manufacturer's instructions for application rates and
procedures.
Soil Binders
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management Moderate
Photograph SB-1. Tackifier being applied to provide temporary soil
stabilization. Photo courtesy of Douglas County.
EC-3 Soil Binders (SB)
SB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table SB-1. Properties of Soil Binders for Erosion Control (Source: CASQA 2003)
Evaluation Criteria
Binder Type
Plant Material
Based
(short lived)
Plant Material
Based
(long lived)
Polymeric
Emulsion Blends
Cementitious-
Based Binders
Resistance to Leaching High High Low to Moderate Moderate
Resistance to Abrasion Moderate Low Moderate to High Moderate to High
Longevity Short to Medium Medium Medium to Long Medium
Minimum Curing Time
before Rain 9 to 18 hours 19 to 24 hours 0 to 24 hours 4 to 8 hours
Compatibility with
Existing Vegetation Good Poor Poor Poor
Mode of Degradation Biodegradable Biodegradable Photodegradable/
Chemically
Degradable
Photodegradable/
Chemically
Degradable
Specialized Application
Equipment
Water Truck or
Hydraulic
Mulcher
Water Truck or
Hydraulic
Mulcher
Water Truck or
Hydraulic Mulcher
Water Truck or
Hydraulic Mulcher
Liquid/Powder Powder Liquid Liquid/Powder Powder
Surface Crusting Yes, but
dissolves on
rewetting
Yes Yes, but dissolves on
rewetting Yes
Clean Up Water Water Water Water
Erosion Control
Application Rate Varies Varies Varies 4,000 to 12,000
lbs/acre Typ.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-3
Urban Storm Drainage Criteria Manual Volume 3
Factors to consider when selecting a soil binder generally include:
Suitability to situation: Consider where the soil binder will be applied, if it needs a high resistance
to leaching or abrasion, and whether it needs to be compatible with existing vegetation. Determine
the length of time soil stabilization will be needed, and if the soil binder will be placed in an area
where it will degrade rapidly. In general, slope steepness is not a discriminating factor.
Soil types and surface materials: Fines and moisture content are key properties of surface
materials. Consider a soil binder's ability to penetrate, likelihood of leaching, and ability to form a
surface crust on the surface materials.
Frequency of application: The frequency of application can be affected by subgrade conditions,
surface type, climate, and maintenance schedule. Frequent applications could lead to high costs.
Application frequency may be minimized if the soil binder has good penetration, low evaporation,
and good longevity. Consider also that frequent application will require frequent equipment clean up.
An overview of major categories of soil binders, corresponding to the types included in Table SB-1
follows.
Plant-Material Based (Short Lived) Binders
Guar: A non-toxic, biodegradable, natural galactomannan-based hydrocolloid treated with dispersant
agents for easy field mixing. It should be mixed with water at the rate of 11 to 15 lbs per 1,000
gallons. Recommended minimum application rates are provided in Table SB-2.
Table SB-2. Application Rates for Guar Soil Stabilizer
Slope (H:V)
Flat 4:1 3:1 2:1 1:1
Application Rate (lb/acre) 40 45 50 60 70
Psyllium: Composed of the finely ground muciloid coating of plantago seeds that is applied as a wet
slurry to the surface of the soil. It dries to form a firm but rewettable membrane that binds soil
particles together but permits germination and growth of seed. Psyllium requires 12 to 18 hours
drying time. Application rates should be from 80 to 200 lbs/acre, with enough water in solution to
allow for a uniform slurry flow.
Starch: Non-ionic, cold-water soluble (pre-gelatinized) granular cornstarch. The material is mixed
with water and applied at the rate of 150 lb/acre. Approximate drying time is 9 to 12 hours.
Plant-Material Based (Long Lived) Binders
Pitch and Rosin Emulsion: Generally, a non-ionic pitch and rosin emulsion has a minimum solids
content of 48 percent. The rosin should be a minimum of 26 percent of the total solids content. The
soil stabilizer should be a non-corrosive, water dilutable emulsion that upon application cures to a
water insoluble binding and cementing agent. For soil erosion control applications, the emulsion is
diluted and should be applied as follows:
o For clayey soil: 5 parts water to 1 part emulsion
EC-3 Soil Binders (SB)
SB-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
o For sandy soil: 10 parts water to 1 part emulsion
Application can be by water truck or hydraulic seeder with the emulsion and product mixture applied
at the rate specified by the manufacturer.
Polymeric Emulsion Blend Binders
Acrylic Copolymers and Polymers: Polymeric soil stabilizers should consist of a liquid or solid
polymer or copolymer with an acrylic base that contains a minimum of 55 percent solids. The
polymeric compound should be handled and mixed in a manner that will not cause foaming or should
contain an anti-foaming agent. The polymeric emulsion should not exceed its shelf life or expiration
date; manufacturers should provide the expiration date. Polymeric soil stabilizer should be readily
miscible in water, non-injurious to seed or animal life, non-flammable, should provide surface soil
stabilization for various soil types without inhibiting water infiltration, and should not re-emulsify
when cured. The applied compound should air cure within a maximum of 36 to 48 hours. Liquid
copolymer should be diluted at a rate of 10 parts water to 1 part polymer and the mixture applied to
soil at a rate of 1,175 gallons/acre.
Liquid Polymers of Methacrylates and Acrylates: This material consists of a tackifier/sealer that is
a liquid polymer of methacrylates and acrylates. It is an aqueous 100 percent acrylic emulsion blend
of 40 percent solids by volume that is free from styrene, acetate, vinyl, ethoxylated surfactants or
silicates. For soil stabilization applications, it is diluted with water in accordance with manufacturer's
recommendations, and applied with a hydraulic seeder at the rate of 20 gallons/acre. Drying time is
12 to 18 hours after application.
Copolymers of Sodium Acrylates and Acrylamides: These materials are non-toxic, dry powders
that are copolymers of sodium acrylate and acrylamide. They are mixed with water and applied to the
soil surface for erosion control at rates that are determined by slope gradient, as summarized in Table
SB-3.
Table SB-3. Application Rates for Copolymers of Sodium Acrylates and Acrylamides
Slope (H:V)
Flat to 5:1 5:1 to 3:1 2:2 to 1:1
Application Rate (lb/acre) 3.0-5.0 5.0-10.0 10.0-20.0
Polyacrylamide and Copolymer of Acrylamide: Linear copolymer polyacrylamide is packaged as
a dry flowable solid. When used as a stand-alone stabilizer, it is diluted at a rate of 11 lb/1,000 gal. of
water and applied at the rate of 5.0 lb/acre.
Hydrocolloid Polymers: Hydrocolloid Polymers are various combinations of dry flowable
polyacrylamides, copolymers, and hydrocolloid polymers that are mixed with water and applied to the
soil surface at rates of 55 to 60 lb/acre. Drying times are 0 to 4 hours.
Cementitious-Based Binders
Gypsum: This formulated gypsum based product readily mixes with water and mulch to form a thin
protective crust on the soil surface. It is composed of high purity gypsum that is ground, calcined and
processed into calcium sulfate hemihydrate with a minimum purity of 86 percent. It is mixed in a
hydraulic seeder and applied at rates 4,000 to 12,000 lb/acre. Drying time is 4 to 8 hours.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-5
Urban Storm Drainage Criteria Manual Volume 3
Installation
After selecting an appropriate soil binder, the untreated soil surface must be prepared before applying the
soil binder. The untreated soil surface must contain sufficient moisture to assist the agent in achieving
uniform distribution. In general, the following steps should be followed:
Follow manufacturer's written recommendations for application rates, pre-wetting of application area,
and cleaning of equipment after use.
Prior to application, roughen embankment and fill areas.
Consider the drying time for the selected soil binder and apply with sufficient time before anticipated
rainfall. Soil binders should not be applied during or immediately before rainfall.
Avoid over spray onto roads, sidewalks, drainage channels, sound walls, existing vegetation, etc.
Soil binders should not be applied to frozen soil, areas with standing water, under freezing or rainy
conditions, or when the temperature is below 40°F during the curing period.
More than one treatment is often necessary, although the second treatment may be diluted or have a
lower application rate.
Generally, soil binders require a minimum curing time of 24 hours before they are fully effective.
Refer to manufacturer's instructions for specific cure time.
For liquid agents:
o Crown or slope ground to avoid ponding.
o Uniformly pre-wet ground at 0.03 to 0.3 gal/yd2 or according to manufacturer's recommendations.
o Apply solution under pressure. Overlap solution 6 to 12 in.
o Allow treated area to cure for the time recommended by the manufacturer, typically at least 24
hours.
o Apply second treatment before first treatment becomes ineffective, using 50 percent application
rate.
o In low humidity, reactivate chemicals by re-wetting with water at 0.1 to 0.2 gal/yd2.
Maintenance and Removal
Soil binders tend to break down due to natural weathering. Weathering rates depend on a variety of site-
specific and product characteristics. Consult the manufacturer for recommended reapplication rates and
reapply the selected soil binder as needed to maintain effectiveness.
Soil binders can fail after heavy rainfall events and may require reapplication. In particular, soil binders
will generally experience spot failures during heavy rainfall events. If runoff penetrates the soil at the top
of a slope treated with a soil binder, it is likely that the runoff will undercut the stabilized soil layer and
discharge at a point further down slope.
EC-3 Soil Binders (SB)
SB-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Areas where erosion is evident should be repaired and soil binder or other stabilization reapplied, as
needed. Care should be exercised to minimize the damage to protected areas while making repairs.
Most binders biodegrade after exposure to sun, oxidation, heat and biological organisms; therefore,
removal of the soil binder is not typically required.
Mulching (MU) EC-4
November 2010 Urban Drainage and Flood Control District MU-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph MU-1. An area that was recently seeded, mulched,
and crimped.
Description
Mulching consists of evenly applying
straw, hay, shredded wood mulch, bark or
compost to disturbed soils and securing
the mulch by crimping, tackifiers, netting
or other measures. Mulching helps reduce
erosion by protecting bare soil from
rainfall impact, increasing infiltration, and
reducing runoff. Although often applied
in conjunction with temporary or
permanent seeding, it can also be used for
temporary stabilization of areas that
cannot be reseeded due to seasonal
constraints.
Mulch can be applied either using
standard mechanical dry application
methods or using hydromulching equipment
that hydraulically applies a slurry of water,
wood fiber mulch, and often a tackifier.
Appropriate Uses
Use mulch in conjunction with seeding to help protect the seedbed and stabilize the soil. Mulch can also
be used as a temporary cover on low to mild slopes to help temporarily stabilize disturbed areas where
growing season constraints prevent effective reseeding. Disturbed areas should be properly mulched and
tacked, or seeded, mulched and tacked promptly after final grade is reached (typically within no longer
than 14 days) on portions of the site not otherwise permanently stabilized.
Standard dry mulching is encouraged in most jurisdictions; however, hydromulching may not be allowed
in certain jurisdictions or may not be allowed near waterways.
Do not apply mulch during windy conditions.
Design and Installation
Prior to mulching, surface-roughen areas by rolling with a crimping or punching type roller or by track
walking. Track walking should only be used where other methods are impractical because track walking
with heavy equipment typically compacts the soil.
A variety of mulches can be used effectively at construction
sites, including the following types:
Mulch
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-4 Mulching (MU)
MU-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Clean, weed- and seed-free, long-stemmed grass hay (preferred) or cereal grain straw. Hay is preferred
because it is less susceptible to removal by wind. Mulch should be applied evenly at a rate of 2 tons per
acre and must be tacked or fastened by an approved method suitable for the type of mulch used. At least
50 percent of the grass hay mulch, by weight, should be 10 inches or more in length.
Grass hay mulch must be anchored and not merely placed on the surface. This can be accomplished
mechanically by crimping or with the aid of tackifiers or nets. Anchoring with a crimping implement is
preferred, and is the recommended method for areas flatter than 3:1. Mechanical crimpers must be
capable of tucking the long mulch fibers into the soil to a depth of 3 inches without cutting them. An
agricultural disk, while not an ideal substitute, may work if the disk blades are dull or blunted and set
vertically; however, the frame may have to be weighted to afford proper soil penetration.
On small areas sheltered from the wind and heavy runoff, spraying a tackifier on the mulch is satisfactory
for holding it in place. For steep slopes and special situations where greater control is needed, erosion
control blankets anchored with stakes should be used instead of mulch.
Hydraulic mulching consists of wood cellulose fibers mixed with water and a tackifying agent and should
be applied at a rate of no less than 1,500 pounds per acre (1,425 lbs of fibers mixed with at least 75 lbs of
tackifier) with a hydraulic mulcher. For steeper slopes, up to 2000 pounds per acre may be required for
effective hydroseeding. Hydromulch typically requires up to 24 hours to dry; therefore, it should not be
applied immediately prior to inclement weather. Application to roads, waterways and existing vegetation
should be avoided.
Erosion control mats, blankets, or nets are recommended to help stabilize steep slopes (generally 3:1 and
steeper) and waterways. Depending on the product, these may be used alone or in conjunction with grass
or straw mulch. Normally, use of these products will be restricted to relatively small areas.
Biodegradable mats made of straw and jute, straw-coconut, coconut fiber, or excelsior can be used instead
of mulch. (See the ECM/TRM BMP for more information.)
Some tackifiers or binders may be used to anchor mulch. Check with the local jurisdiction for allowed
tackifiers. Manufacturer's recommendations should be followed at all times. (See the Soil Binder BMP
for more information on general types of tackifiers.)
Rock can also be used as mulch. It provides protection of exposed soils to wind and water erosion and
allows infiltration of precipitation. An aggregate base course can be spread on disturbed areas for
temporary or permanent stabilization. The rock mulch layer should be thick enough to provide full
coverage of exposed soil on the area it is applied.
Maintenance and Removal
After mulching, the bare ground surface should not be more than 10 percent exposed. Reapply mulch, as
needed, to cover bare areas.
Compost Blanket and Filter Berm (CB) EC-5
November 2010 Urban Drainage and Flood Control District CB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CB-1. Application of a compost
blanket to a disturbed area. Photo courtesy of
Caltrans.
Description
A compost blanket is a layer of compost uniformly applied
to the soil in disturbed areas to control erosion, facilitate
revegetation, and retain sediment resulting from sheet-flow
runoff.
A compost filter berm is a dike of compost or a compost
product that is placed perpendicular to runoff to control
erosion in disturbed areas and retain sediment. Compost
berms can be placed at regular intervals to help reduce the
formation of rill and gully erosion when a compost blanket
is stabilizing a slope.
Appropriate Uses
Compost blankets can be used as an alternative to erosion
control blankets and mulching to help stabilize disturbed
areas where sheet flow conditions are present. Compost
blankets should not be used in areas of concentrated flows.
Compost provides an excellent source of nutrients for plant
growth, and should be considered for use in areas that will be
permanently vegetated.
Design and Installation
See Detail CB-1 for design details and notes.
Do not place compost in areas where it can easily be transported into drainage pathways or waterways.
When using a compost blanket on a slope, berms should be installed periodically to reduce the potential
for concentrated flow and rilling. Seeding should be completed before an area is composted or
incorporated into the compost.
Compost quality is an important consideration when selecting compost blankets or berms. Representative
compost quality factors include pH, salinity, moisture content, organic matter content, stability (maturity),
and physical contaminants. The compost should meet all local, state, and federal quality requirements.
Biosolids compost must meet the Standards for Class A biosolids outlined in 40 CFR Part 503. The U.S.
Composting Council (USCC) certifies compost products under its Seal of Testing Assurance (STA)
Program. Compost producers whose products have been certified through the STA Program provide
customers with a standard product label that allows comparison between compost products. Only STA
certified, Class I compost should be used.
Compost Blankets and Berms
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-5 Compost Blanket and Filter Berm (CB)
CB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
When rills or gullies develop in an area that has been composted, fill and cover the area with additional
compost and install berms as necessary to help reduce erosion.
Weed control can be a maintenance challenge in areas using compost blankets. A weed control strategy
may be necessary, including measures such as mechanical removal and spot application of targeted
herbicides by licensed applicators.
For compost berms, accumulated sediments should be removed from behind the berm when the sediments
reach approximately one third the height of the berm. Areas that have been washed away should be
replaced. If the berm has experienced significant or repeated washouts, a compost berm may not be the
appropriate BMP for this area.
Compost blankets and berms biodegrade and do not typically require removal following site stabilization.
Compost Blanket and Filter Berm (CB) EC-5
November 2010 Urban Drainage and Flood Control District CB-3
Urban Storm Drainage Criteria Manual Volume 3
EC-5 Compost Blanket and Filter Berm (CB)
CB-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rolled Erosion Control Products (RECP) EC-6
November 2010 Urban Drainage and Flood Control District RECP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph RECP-1. Erosion control blanket protecting the slope from
erosion and providing favorable conditions for revegetation.
Description
Rolled Erosion Control Products
(RECPs) include a variety of
temporary or permanently installed
manufactured products designed to
control erosion and enhance vegetation
establishment and survivability,
particularly on slopes and in channels.
For applications where natural
vegetation alone will provide sufficient
permanent erosion protection,
temporary products such as netting,
open weave textiles and a variety of
erosion control blankets (ECBs) made
of biodegradable natural materials
(e.g., straw, coconut fiber) can be used.
For applications where natural
vegetation alone will not be sustainable under expected flow conditions, permanent rolled erosion control
products such as turf reinforcement mats (TRMs) can be used. In particular, turf reinforcement mats are
designed for discharges that exert velocities and sheer stresses that exceed the typical limits of mature
natural vegetation.
Appropriate Uses
RECPs can be used to control erosion in conjunction with revegetation efforts, providing seedbed
protection from wind and water erosion. These products are often used on disturbed areas on steep
slopes, in areas with highly erosive soils, or as part of drainageway stabilization. In order to select the
appropriate RECP for site conditions, it is important to have a general understanding of the general types
of these products, their expected longevity, and general characteristics.
The Erosion Control Technology Council (ECTC 2005) characterizes rolled erosion control products
according to these categories:
Mulch control netting: A planar woven natural fiber or extruded geosynthetic mesh used as a
temporary degradable rolled erosion control product to anchor loose fiber mulches.
Open weave textile: A temporary degradable rolled erosion control product composed of processed
natural or polymer yarns woven into a matrix, used to provide erosion control and facilitate
vegetation establishment.
Erosion control blanket (ECB): A temporary
degradable rolled erosion control product composed of
processed natural or polymer fibers which are
mechanically, structurally or chemically bound together
to form a continuous matrix to provide erosion control
and facilitate vegetation establishment. ECBs can be
further differentiated into rapidly degrading single-net
and double-net types or slowly degrading types.
Rolled Erosion Control Products
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-6 Rolled Erosion Control Products (RECP)
RECP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Turf Reinforcement Mat (TRM): A rolled erosion control product composed of non-degradable
synthetic fibers, filaments, nets, wire mesh, and/or other elements, processed into a permanent, three-
dimensional matrix of sufficient thickness. TRMs, which may be supplemented with degradable
components, are designed to impart immediate erosion protection, enhance vegetation establishment
and provide long-term functionality by permanently reinforcing vegetation during and after
maturation. Note: TRMs are typically used in hydraulic applications, such as high flow ditches and
channels, steep slopes, stream banks, and shorelines, where erosive forces may exceed the limits of
natural, unreinforced vegetation or in areas where limited vegetation establishment is anticipated.
Tables RECP-1 and RECP-2 provide guidelines for selecting rolled erosion control products appropriate
to site conditions and desired longevity. Table RECP-1 is for conditions where natural vegetation alone
will provide permanent erosion control, whereas Table RECP-2 is for conditions where vegetation alone
will not be adequately stable to provide long-term erosion protection due to flow or other conditions.
Rolled Erosion Control Products (RECP) EC-6
November 2010 Urban Drainage and Flood Control District RECP-3
Urban Storm Drainage Criteria Manual Volume 3
Table RECP-1. ECTC Standard Specification for Temporary Rolled Erosion Control Products
(Adapted from Erosion Control Technology Council 2005)
Product Description Slope
Applications*
Channel
Applications*
Minimum
Tensile
Strength1
Expected
Longevity
Maximum
Gradient C Factor2,5 Max. Shear
Stress3,4,6
Mulch Control Nets 5:1 (H:V) ≤0.10 @
5:1
0.25 lbs/ft2
(12 Pa)
5 lbs/ft
(0.073 kN/m)
Up to 12
months
Netless Rolled
Erosion Control
Blankets
4:1 (H:V) ≤0.10 @
4:1
0.5 lbs/ft2
(24 Pa)
5 lbs/ft
(0.073 kN/m)
Single-net Erosion
Control Blankets &
Open Weave Textiles
3:1 (H:V) ≤0.15 @
3:1
1.5 lbs/ft2
(72 Pa)
50 lbs/ft
(0.73 kN/m)
Double-net Erosion
Control Blankets 2:1 (H:V) ≤0.20 @
2:1
1.75 lbs/ft2
(84 Pa)
75 lbs/ft
(1.09 kN/m)
Mulch Control Nets 5:1 (H:V) ≤0.10 @
5:1
0.25 lbs/ft2
(12 Pa)
25 lbs/ft
(0.36 kN/m) 24 months
Erosion Control
Blankets & Open
Weave Textiles
(slowly degrading)
1.5:1 (H:V) ≤0.25 @
1.5:1
2.00 lbs/ft2
(96 Pa)
100 lbs/ft
(1.45 kN/m) 24 months
Erosion Control
Blankets & Open
Weave Textiles
1:1 (H:V) ≤0.25 @
1:1
2.25 lbs/ft2
(108 Pa)
125 lbs/ft
(1.82 kN/m) 36 months
* C Factor and shear stress for mulch control nettings must be obtained with netting used in conjunction
with pre-applied mulch material. (See Section 5.3 of Chapter 7 Construction BMPs for more information
on the C Factor.)
1 Minimum Average Roll Values, Machine direction using ECTC Mod. ASTM D 5035.
2 C Factor calculated as ratio of soil loss from RECP protected slope (tested at specified or greater
gradient, H:V) to ratio of soil loss from unprotected (control) plot in large-scale testing.
3 Required minimum shear stress RECP (unvegetated) can sustain without physical damage or excess
erosion (> 12.7 mm (0.5 in) soil loss) during a 30-minute flow event in large-scale testing.
4 The permissible shear stress levels established for each performance category are based on historical
experience with products characterized by Manning's roughness coefficients in the range of 0.01 - 0.05.
5 Acceptable large-scale test methods may include ASTM D 6459, or other independent testing deemed
acceptable by the engineer.
6 Per the engineer’s discretion. Recommended acceptable large-scale testing protocol may include ASTM
D 6460, or other independent testing deemed acceptable by the engineer.
EC-6 Rolled Erosion Control Products (RECP)
RECP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table RECP-2. ECTC Standard Specification for Permanent1 Rolled Erosion Control Products
(Adapted from: Erosion Control Technology Council 2005)
Product Type Slope
Applications Channel Applications
TRMs with a minimum thickness of
0.25 inches (6.35 mm) per ASTM D
6525 and UV stability of 80% per
ASTM D 4355 (500 hours
exposure).
Maximum
Gradient
Maximum
Shear Stress4,5
Minimum
Tensile
Strength2,3
0.5:1 (H:V) 6.0 lbs/ft2 (288 Pa) 125 lbs/ft (1.82
kN/m)
0.5:1 (H:V) 8.0 lbs/ft2 (384 Pa) 150 lbs/ft (2.19
kN/m)
0.5:1 (H:V) 10.0 lbs/ft2 (480 Pa) 175 lbs/ft (2.55
kN/m)
1 For TRMs containing degradable components, all property values must be obtained on the non-
degradable portion of the matting alone.
2 Minimum Average Roll Values, machine direction only for tensile strength determination using ASTM
D 6818 (Supersedes Mod. ASTM D 5035 for RECPs)
3 Field conditions with high loading and/or high survivability requirements may warrant the use of a TRM
with a tensile strength of 44 kN/m (3,000 lb/ft) or greater.
4 Required minimum shear stress TRM (fully vegetated) can sustain without physical damage or excess
erosion (> 12.7 mm (0.5 in.) soil loss) during a 30-minute flow event in large scale testing.
5 Acceptable large-scale testing protocols may include ASTM D 6460, or other independent testing
deemed acceptable by the engineer.
Design and Installation
RECPs should be installed according to manufacturer’s specifications and guidelines. Regardless of the
type of product used, it is important to ensure no gaps or voids exist under the material and that all
corners of the material are secured using stakes and trenching. Continuous contact between the product
and the soil is necessary to avoid failure. Never use metal stakes to secure temporary erosion control
products. Often wooden stakes are used to anchor RECPs; however, wood stakes may present installation
and maintenance challenges and generally take a long time to biodegrade. Some local jurisdictions have
had favorable experiences using biodegradable stakes.
This BMP Fact Sheet provides design details for several commonly used ECB applications, including:
ECB-1 Pipe Outlet to Drainageway
ECB-2 Small Ditch or Drainageway
ECB-3 Outside of Drainageway
Rolled Erosion Control Products (RECP) EC-6
November 2010 Urban Drainage and Flood Control District RECP-5
Urban Storm Drainage Criteria Manual Volume 3
Staking patterns are also provided in the design details according to these factors:
ECB type
Slope or channel type
For other types of RECPs including TRMs, these design details are intended to serve as general
guidelines for design and installation; however, engineers should adhere to manufacturer’s installation
recommendations.
Maintenance and Removal
Inspection of erosion control blankets and other RECPs includes:
Check for general signs of erosion, including voids beneath the mat. If voids are apparent, fill the
void with suitable soil and replace the erosion control blanket, following the appropriate staking
pattern.
Check for damaged or loose stakes and secure loose portions of the blanket.
Erosion control blankets and other RECPs that are biodegradable typically do not need to be removed
after construction. If they must be removed, then an alternate soil stabilization method should be installed
promptly following removal.
Turf reinforcement mats, although generally resistant to biodegradation, are typically left in place as a
dense vegetated cover grows in through the mat matrix. The turf reinforcement mat provides long-term
stability and helps the established vegetation resist erosive forces.
EC-6 Rolled Erosion Control Products (RECP)
RECP-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rolled Erosion Control Products (RECP) EC-6
November 2010 Urban Drainage and Flood Control District RECP-7
Urban Storm Drainage Criteria Manual Volume 3
EC-6 Rolled Erosion Control Products (RECP)
RECP-8 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rolled Erosion Control Products (RECP) EC-6
November 2010 Urban Drainage and Flood Control District RECP-9
Urban Storm Drainage Criteria Manual Volume 3
Temporary Slope Drains (TSD) EC-7
November 2010 Urban Drainage and Flood Control District SD-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TSD-1. A temporary slope drain installed to convey runoff down a slope during construction. Photo
courtesy of the City of Aurora.
Description
A temporary slope drain is a pipe or culvert used to convey water down a slope where there is a high
potential for erosion. A drainage channel or swale at the top of the slope typically directs upgradient
runoff to the pipe entrance for conveyance down the slope. The pipe outlet must be equipped with outlet
protection.
Appropriate Uses
Use on long, steep slopes when there is a high potential of flow concentration or rill development.
Design and Installation
Effective use of temporary slope drains involves design of an effective collection system to direct flows to
the pipe, proper sizing and anchoring of the pipe, and outlet protection. Upgradient of the temporary
slope drain, a temporary drainage ditch or swale should be constructed to collect surface runoff from the
drainage area and convey it to the drain entrance. The temporary slope drain must be sized to safely
convey the desired flow volume. At a minimum, it should be sized to convey the 2-year, 24-hour storm.
Temporary slope drains may be constructed of flexible or rigid pipe, riprap, or heavy (30 mil) plastic
lining. When piping is used, it must be properly anchored by burying it with adequate cover or by using
an anchor system to secure it to the ground.
The discharge from the slope drain must be directed to a stabilized outlet, temporary or permanent
channel, and/or sedimentation basin.
See Detail TSD-1 for additional sizing and design
information.
Temporary Slope Drains
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-7 Temporary Slope Drains (TSD)
SD-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Inspect the entrance for sediment accumulation and remove, as needed. Clogging as a result of sediment
deposition at the entrance can lead to ponding upstream causing flooding or overtopping of the slope
drain. Inspect the downstream outlet for signs of erosion and stabilize, as needed. It may also be
necessary to remove accumulated sediment at the outfall. Inspect pipe anchors to ensure that they are
secure. If the pipe is secured by ground cover, ensure erosion has not compromised the depth of cover.
Slope drains should be removed when no longer needed or just prior to installation of permanent slope
stabilization measures that cannot be installed with the slope drain in place. When slope drains are
removed, the disturbed areas should be covered with topsoil, seeded, mulched or otherwise stabilized as
required by the local jurisdiction.
Temporary Slope Drains (TSD) EC-7
November 2010 Urban Drainage and Flood Control District SD-3
Urban Storm Drainage Criteria Manual Volume 3
EC-7 Temporary Slope Drains (TSD)
SD-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary Outlet Protection (TOP) EC-8
November 2010 Urban Drainage and Flood Control District TOP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TOP-1. Riprap outlet protection.
Description
Outlet protection helps to reduce erosion
immediately downstream of a pipe,
culvert, slope drain, rundown or other
conveyance with concentrated, high-
velocity flows. Typical outlet protection
consists of riprap or rock aprons at the
conveyance outlet.
Appropriate Uses
Outlet protection should be used when a
conveyance discharges onto a disturbed
area where there is potential for accelerated
erosion due to concentrated flow. Outlet
protection should be provided where the velocity at the culvert outlet exceeds the maximum permissible
velocity of the material in the receiving channel.
Note: This Fact Sheet and detail are for temporary outlet protection, outlets that are intended to be used
for less than 2 years. For permanent, long-term outlet protection, see the Major Drainage chapter of
Volume 1.
Design and Installation
Design outlet protection to handle runoff from the largest drainage area that may be contributing runoff
during construction (the drainage area may change as a result of grading). Key in rock, around the entire
perimeter of the apron, to a minimum depth of 6 inches for stability. Extend riprap to the height of the
culvert or the normal flow depth of the downstream channel, whichever is less. Additional erosion
control measures such as vegetative lining, turf reinforcement mat and/or other channel lining methods
may be required downstream of the outlet protection if the channel is susceptible to erosion. See Design
Detail OP-1 for additional information.
Maintenance and Removal
Inspect apron for damage and displaced rocks. If rocks are missing or significantly displaced, repair or
replace as necessary. If rocks are continuously missing or displaced, consider increasing the size of the
riprap or deeper keying of the perimeter.
Remove sediment accumulated at the outlet before the outlet protection becomes buried and ineffective.
When sediment accumulation is noted, check that upgradient BMPs, including inlet protection, are in
effective operating condition.
Outlet protection may be removed once the pipe is no longer
draining an upstream area, or once the downstream area has
been sufficiently stabilized. If the drainage pipe is
permanent, outlet protection can be left in place; however,
permanent outlet protection should be designed and
constructed in accordance with the requirements of the
Major Drainage chapter of Volume 2.
Outlet Protection
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-8 Temporary Outlet Protection (TOP)
TOP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary Outlet Protection (TOP) EC-8
November 2010 Urban Drainage and Flood Control District TOP-3
Urban Storm Drainage Criteria Manual Volume 3
Rough Cut Street Control (RCS) EC-9
November 2010 Urban Drainage and Flood Control District RCS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph RCS-1. Rough cut street controls.
Description
Rough cut street controls are rock or
earthen berms placed along dirt roadways
that are under construction or used for
construction access. These temporary
berms intercept sheet flow and divert
runoff from the roadway, and control
erosion by minimizing concentration of
flow and reducing runoff velocity.
Appropriate Uses
Appropriate uses include:
Temporary dirt construction roadways
that have not received roadbase.
Roadways under construction that will not be paved within 14 days of final grading, and that have not
yet received roadbase.
Design and Installation
Rough cut street controls are designed to redirect sheet flow off the dirt roadway to prevent water from
concentrating and eroding the soil. These controls consist of runoff barriers that are constructed at
intervals along the road. These barriers are installed perpendicular to the longitudinal slope from the
outer edge of the roadside swale to the crown of the road. The barriers are positioned alternately from the
right and left side of the road to allow construction traffic to pass in the lane not barred. If construction
traffic is expected to be congested and a vehicle tracking control has been constructed, rough-cut street
controls may be omitted for 400 feet from the entrance. Runoff from the controls should be directed to
another stormwater BMP such as a roadside swale with check dams once removed from the roadway. See
Detail RCS-1 for additional information.
Maintenance and Removal
Inspect street controls for erosion and stability. If rills are forming in the roadway or cutting through the
control berms, place the street controls at shorter intervals. If earthen berms are used, periodic
recompaction may be necessary. When rock berms are used,
repair and/or replace as necessary when damaged. Street
controls may be removed 14 days prior to road surfacing and
paving.
Rough Cut Street Control
Functions Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-9 Rough Cut Street Control (RCS)
RCS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rough Cut Street Control (RCS) EC-9
November 2010 Urban Drainage and Flood Control District RCS-3
Urban Storm Drainage Criteria Manual Volume 3
Earth Dikes and Drainage Swales (ED/DS) EC-10
November 2010 Urban Drainage and Flood Control District ED/DS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph ED/DS-1. Example of an earth dike used to divert
flows at a construction site. Photo courtesy of CDOT.
Description
Earth dikes and drainage swales are
temporary storm conveyance channels
constructed either to divert runoff around
slopes or to convey runoff to additional
sediment control BMPs prior to discharge
of runoff from a site. Drainage swales
may be lined or unlined, but if an unlined
swale is used, it must be well compacted
and capable of resisting erosive velocities.
Appropriate Uses
Earth dikes and drainage swales are
typically used to control the flow path of
runoff at a construction site by diverting
runoff around areas prone to erosion, such
as steep slopes. Earth dikes and drainage
swales may also be constructed as
temporary conveyance features. This will
direct runoff to additional sediment control
treatment BMPs, such as sediment traps or
basins.
Design and Installation
When earth dikes are used to divert water for slope protection, the earth dike typically consists of a
horizontal ridge of soil placed perpendicular to the slope and angled slightly to provide drainage along the
contour. The dike is used in conjunction with a swale or a small channel upslope of the berm to convey
the diverted water. Temporary diversion dikes can be constructed by excavation of a V-shaped trench or
ditch and placement of the fill on the downslope side of the cut. There are two types of placement for
temporary slope diversion dikes:
A dike located at the top of a slope to divert upland runoff away from the disturbed area and convey it
in a temporary or permanent channel.
A diversion dike located at the base or mid-slope of a disturbed area to intercept runoff and reduce the
effective slope length.
Depending on the project, either an earth dike or drainage swale may be more appropriate. If there is a
need for cut on the project, then an excavated drainage
swale may be better suited. When the project is primarily
fill, then a conveyance constructed using a berm may be the
better option.
All dikes or swales receiving runoff from a disturbed
area should direct stormwater to a sediment control
BMP such as a sediment trap or basin.
Earth Dikes and Drainage Swales
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-10 Earth Dikes and Drainage Swales (ED/DS)
ED/DS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Unlined dikes or swales should only be used for intercepting sheet flow runoff and are not intended
for diversion of concentrated flows.
Details with notes are provided for several design variations, including:
ED-1. Unlined Earth Dike formed by Berm
DS-1. Unlined Excavated Swale
DS-2. Unlined Swale Formed by Cut and Fill
DS-3. ECB-lined Swale
DS-4. Synthetic-lined Swale
DS-5. Riprap-lined Swale
The details also include guidance on permissible velocities for cohesive channels if unlined approaches
will be used.
Maintenance and Removal
Inspect earth dikes for stability, compaction, and signs of erosion and repair. Inspect side slopes for
erosion and damage to erosion control fabric. Stabilize slopes and repair fabric as necessary. If there is
reoccurring extensive damage, consider installing rock check dams or lining the channel with riprap.
If drainage swales are not permanent, remove dikes and fill channels when the upstream area is stabilized.
Stabilize the fill or disturbed area immediately following removal by revegetation or other permanent
stabilization method approved by the local jurisdiction.
Earth Dikes and Drainage Swales (ED/DS) EC-10
November 2010 Urban Drainage and Flood Control District ED/DS-3
Urban Storm Drainage Criteria Manual Volume 3
EC-10 Earth Dikes and Drainage Swales (ED/DS)
ED/DS-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Earth Dikes and Drainage Swales (ED/DS) EC-10
November 2010 Urban Drainage and Flood Control District ED/DS-5
Urban Storm Drainage Criteria Manual Volume 3
Terracing (TER) EC-11
November 2010 Urban Drainage and Flood Control District TER-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TER-1. Use of a terrace to reduce erosion by controlling
slope length on a long, steep slope. Photo courtesy of Douglas
County.
Description
Terracing involves grading steep slopes
into a series of relatively flat sections, or
terraces, separated at intervals by steep
slope segments. Terraces shorten the
uninterrupted flow lengths on steep
slopes, helping to reduce the
development of rills and gullies.
Retaining walls, gabions, cribbing,
deadman anchors, rock-filled slope
mattresses, and other types of soil
retention systems can be used in
terracing.
Appropriate Uses
Terracing techniques are most typically used to control erosion on slopes that are steeper than 4:1.
Design and Installation
Design details with notes are provided in Detail TER-1.
The type, number, and spacing of terraces will depend on the slope, slope length, and other factors. The
Revised Universal Soil Loss Equation (RUSLE) may be helpful in determining spacing of terraces on
slopes. Terracing should be used in combination with other stabilization measures that provide cover for
exposed soils such as mulching, seeding, surface roughening, or other measures.
Maintenance and Removal
Repair rill erosion on slopes and remove accumulated sediment, as needed. Terracing may be temporary
or permanent. If terracing is temporary, the slope should be topsoiled, seeded, and mulched when the
slope is graded to its final configuration and terraces are removed. Due to the steepness of the slope, once
terraces are graded, erosion control blankets or other stabilization measures are typically required. If
terraces are permanent, vegetation should be established on slopes and terraces as soon as practical.
Terracing
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-11 Terracing (TER)
TER-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Check Dams (CD) EC-12
November 2010 Urban Drainage and Flood Control District CD-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CD-1. Rock check dams in a roadside ditch. Photo
courtesy of WWE.
Description
Check dams are temporary grade control
structures placed in drainage channels to
limit the erosivity of stormwater by
reducing flow velocity. Check dams are
typically constructed from rock, gravel
bags, sand bags, or sometimes,
proprietary devices. Reinforced check
dams are typically constructed from rock
and wire gabion. Although the primary
function of check dams is to reduce the
velocity of concentrated flows, a
secondary benefit is sediment trapping
upstream of the structure.
Appropriate Uses
Use as a grade control for temporary drainage ditches or swales until final soil stabilization measures are
established upstream and downstream. Check dams can be used on mild or moderately steep slopes.
Check dams may be used under the following conditions:
As temporary grade control facilities along waterways until final stabilization is established.
Along permanent swales that need protection prior to installation of a non-erodible lining.
Along temporary channels, ditches or swales that need protection where construction of a non-
erodible lining is not practicable.
Reinforced check dams should be used in areas subject to high flow velocities.
Design and Installation
Place check dams at regularly spaced intervals along the drainage swale or ditch. Check dams heights
should allow for pools to develop upstream of each check dam, extending to the downstream toe of the
check dam immediately upstream.
When rock is used for the check dam, place rock mechanically or by hand. Do not dump rocks into the
drainage channel. Where multiple check dams are used, the top of the lower dam should be at the same
elevation as the toe of the upper dam.
When reinforced check dams are used, install erosion control fabric under and around the check dam to
prevent erosion on the upstream and downstream sides. Each
section of the dam should be keyed in to reduce the potential
for washout or undermining. A rock apron upstream and
downstream of the dam may be necessary to further control
erosion.
Check Dams
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management No
EC-12 Check Dams (CD)
CD-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Design details with notes are provided for the following types of check dams:
Rock Check Dams (CD-1)
Reinforced Check Dams (CD-2)
Sediment control logs may also be used as check dams; however, silt fence is not appropriate for use as a
check dam. Many jurisdictions also prohibit or discourage use of straw bales for this purpose.
Maintenance and Removal
Replace missing rocks causing voids in the check dam. If gravel bags or sandbags are used, replace or
repair torn or displaced bags.
Remove accumulated sediment, as needed to maintain BMP effectiveness, typically before the sediment
depth upstream of the check dam is within ½ of the crest height. Remove accumulated sediment prior to
mulching, seeding, or chemical soil stabilization. Removed sediment can be incorporated into the
earthwork with approval from the Project Engineer, or disposed of at an alternate location in accordance
with the standard specifications.
Check dams constructed in permanent swales should be removed when perennial grasses have become
established, or immediately prior to installation of a non-erodible lining. All of the rock and accumulated
sediment should be removed, and the area seeded and mulched, or otherwise stabilized.
Check Dams (CD) EC-12
November 2010 Urban Drainage and Flood Control District CD-3
Urban Storm Drainage Criteria Manual Volume 3
EC-12 Check Dams (CD)
CD-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Check Dams (CD) EC-12
November 2010 Urban Drainage and Flood Control District CD-5
Urban Storm Drainage Criteria Manual Volume 3
EC-12 Check Dams (CD)
CD-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Streambank Stabilization (SS) EC-13
November 2010 Urban Drainage and Flood Control District SS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SS-1. Streambank stabilization using geotextiles
following installation of a permanent in-stream grade control structure.
Description
Streambank stabilization involves a
combination of erosion and sediment
control practices to protect streams,
banks, and in-stream habitat from
accelerated erosion. BMPs associated
with streambank stabilization may
include protection of existing
vegetation, check dams/grade control,
temporary and permanent seeding,
outlet protection, rolled erosion control
products, temporary diversions,
dewatering operations and
bioengineering practices such as brush
layering, live staking and fascines.
Appropriate Uses
Streambank stabilization may be a construction activity in and of itself, or it may be in conjunction with a
broader construction project that discharges to a waterway that is susceptible to accelerated erosion due to
increases in the rate and volume of stormwater runoff. Depending on the health of the stream, water
quality sampling and testing may be advisable prior to and/or during construction to evaluate health and
stability of the stream and potential effects from adjacent construction activities.
Design and Installation
Streambank stabilization consists of protecting the stream in a variety of ways to minimize negative
effects to the stream environment. The following lists the minimum requirements necessary for
construction streambank stabilization:
Protect existing vegetation along the stream bank in accordance with the Vegetated Buffers and
Protection of Existing Vegetation Fact Sheets. Preserving a riparian buffer along the streambank will
help to remove sediment and decrease runoff rates from the disturbed area.
Outside the riparian buffer, provide sediment control in the form of a silt fence or equivalent sediment
control practice along the entire length of the stream that will receive runoff from the area of
disturbance. In some cases, a double-layered perimeter control may be justified adjacent to sensitive
receiving waters and wetlands to provide additional protection.
Stabilize all areas that will be draining to the stream. Use rolled erosion control products, temporary
or permanent seeding, or other appropriate measures.
Ensure all point discharges entering the stream are
adequately armored with a velocity dissipation device and
appropriate outlet protection.
See individual design details and notes for the various BMPs
referenced in this practice. Additional information on
bioengineering techniques for stream stabilization can be
Streambank Stabilization
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-13 Streambank Stabilization (SS)
SS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
found in the Major Drainage chapter of Volume 1 and additional guidance on BMPs for working in
waterways can be found in UDFCD’s Best Management Practices for Construction in Waterways
Training Manual.
Maintenance and Removal
Inspect BMPs protecting the stream for damage on a daily basis. Maintain, repair, or replace damaged
BMPs following the guidance provided in individual BMP Fact Sheets for practices that are implemented.
Some streambank stabilization BMPs are intended to remain in place as vegetation matures (e.g. erosion
control blankets protecting seeded stream banks and turf reinforcement mats).
For BMPs that are not to remain in place as a part of final stabilization such as silt fence and other
temporary measures, BMPs should be removed when all land disturbing activities have ceased and areas
have been permanently stabilized.
Wind Erosion/Dust Control (DC) EC-14
November 2010 Urban Drainage and Flood Control District DC-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph DC-1. Water truck used for dust suppression. Photo
courtesy of Douglas County.
Description
Wind erosion and dust control BMPs
help to keep soil particles from entering
the air as a result of land disturbing
construction activities. These BMPs
include a variety of practices generally
focused on either graded disturbed areas
or construction roadways. For graded
areas, practices such as seeding and
mulching, use of soil binders, site
watering, or other practices that provide
prompt surface cover should be used.
For construction roadways, road
watering and stabilized surfaces should
be considered.
Appropriate Uses
Dust control measures should be used on any site where dust poses a problem to air quality. Dust control
is important to control for the health of construction workers and surrounding waterbodies.
Design and Installation
The following construction BMPs can be used for dust control:
An irrigation/sprinkler system can be used to wet the top layer of disturbed soil to help keep dry soil
particles from becoming airborne.
Seeding and mulching can be used to stabilize disturbed surfaces and reduce dust emissions.
Protecting existing vegetation can help to slow wind velocities across the ground surface, thereby
limiting the likelihood of soil particles to become airborne.
Spray-on soil binders form a bond between soil particles keeping them grounded. Chemical
treatments may require additional permitting requirements. Potential impacts to surrounding
waterways and habitat must be considered prior to use.
Placing rock on construction roadways and entrances will help keep dust to a minimum across the
construction site.
Wind fences can be installed on site to reduce wind
speeds. Install fences perpendicular to the prevailing
wind direction for maximum effectiveness.
Maintenance and Removal
When using an irrigation/sprinkler control system to aid in
dust control, be careful not to overwater. Overwatering will
cause construction vehicles to track mud off-site.
Wind Erosion Control/
Dust Control
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management Moderate
Concrete Washout Area (CWA) MM-1
November 2010 Urban Drainage and Flood Control District CWA-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CWA-1. Example of concrete washout area. Note gravel
tracking pad for access and sign.
Description
Concrete waste management involves
designating and properly managing a
specific area of the construction site as a
concrete washout area. A concrete
washout area can be created using one of
several approaches designed to receive
wash water from washing of tools and
concrete mixer chutes, liquid concrete
waste from dump trucks, mobile batch
mixers, or pump trucks. Three basic
approaches are available: excavation of a
pit in the ground, use of an above ground
storage area, or use of prefabricated haul-
away concrete washout containers.
Surface discharges of concrete washout
water from construction sites are prohibited.
Appropriate Uses
Concrete washout areas must be designated on all sites that will generate concrete wash water or liquid
concrete waste from onsite concrete mixing or concrete delivery.
Because pH is a pollutant of concern for washout activities, when unlined pits are used for concrete
washout, the soil must have adequate buffering capacity to result in protection of state groundwater
standards; otherwise, a liner/containment must be used. The following management practices are
recommended to prevent an impact from unlined pits to groundwater:
The use of the washout site should be temporary (less than 1 year), and
The washout site should be not be located in an area where shallow groundwater may be present, such
as near natural drainages, springs, or wetlands.
Design and Installation
Concrete washout activities must be conducted in a manner that does not contribute pollutants to surface
waters or stormwater runoff. Concrete washout areas may be lined or unlined excavated pits in the
ground, commercially manufactured prefabricated washout containers, or aboveground holding areas
constructed of berms, sandbags or straw bales with a plastic liner.
Although unlined washout areas may be used, lined pits may be required to protect groundwater under
certain conditions.
Do not locate an unlined washout area within 400 feet
of any natural drainage pathway or waterbody or
within 1,000 feet of any wells or drinking water
sources. Even for lined concrete washouts, it is
advisable to locate the facility away from waterbodies
and drainage paths. If site constraints make these
Concrete Washout Area
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
MM-1 Concrete Washout Area (CWA)
CWA-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
setbacks infeasible or if highly permeable soils exist in the area, then the pit must be installed with an
impermeable liner (16 mil minimum thickness) or surface storage alternatives using prefabricated
concrete washout devices or a lined aboveground storage area should be used.
Design details with notes are provided in Detail CWA-1 for pits and CWA-2 for aboveground storage
areas. Pre-fabricated concrete washout container information can be obtained from vendors.
Maintenance and Removal
A key consideration for concrete washout areas is to ensure that adequate signage is in place identifying
the location of the washout area. Part of inspecting and maintaining washout areas is ensuring that
adequate signage is provided and in good repair and that the washout area is being used, as opposed to
washout in non-designated areas of the site.
Remove concrete waste in the washout area, as needed to maintain BMP function (typically when filled to
about two-thirds of its capacity). Collect concrete waste and deliver offsite to a designated disposal
location.
Upon termination of use of the washout site, accumulated solid waste, including concrete waste and any
contaminated soils, must be removed from the site to prevent on-site disposal of solid waste. If the wash
water is allowed to evaporate and the concrete hardens, it may be recycled.
Photograph CWA-3. Earthen concrete washout. Photo
courtesy of CDOT.
Photograph CWA-2. Prefabricated concrete washout. Photo
courtesy of CDOT.
Concrete Washout Area (CWA) MM-1
November 2010 Urban Drainage and Flood Control District CWA-3
Urban Storm Drainage Criteria Manual Volume 3
MM-1 Concrete Washout Area (CWA)
CWA-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SP-1. A topsoil stockpile that has been partially
revegetated and is protected by silt fence perimeter control.
Description
Stockpile management includes
measures to minimize erosion and
sediment transport from soil stockpiles.
Appropriate Uses
Stockpile management should be used
when soils or other erodible materials
are stored at the construction site.
Special attention should be given to
stockpiles in close proximity to natural
or manmade storm systems.
Design and Installation
Locate stockpiles away from all drainage system components including storm sewer inlets. Where
practical, choose stockpile locations that that will remain undisturbed for the longest period of time as the
phases of construction progress. Place sediment control BMPs around the perimeter of the stockpile, such
as sediment control logs, rock socks, silt fence, straw bales and sand bags. See Detail SP-1 for guidance
on proper establishment of perimeter controls around a stockpile. For stockpiles in active use, provide a
stabilized designated access point on the upgradient side of the stockpile.
Stabilize the stockpile surface with surface roughening, temporary seeding and mulching, erosion control
blankets, or soil binders. Soils stockpiled for an extended period (typically for more than 60 days) should
be seeded and mulched with a temporary grass cover once the stockpile is placed (typically within 14
days). Use of mulch only or a soil binder is acceptable if the stockpile will be in place for a more limited
time period (typically 30-60 days). Timeframes for stabilization of stockpiles noted in this fact sheet are
"typical" guidelines. Check permit requirements for specific federal, state, and/or local requirements that
may be more prescriptive.
Stockpiles should not be placed in streets or paved areas unless no other practical alternative exists. See
the Stabilized Staging Area Fact Sheet for guidance when staging in roadways is unavoidable due to
space or right-of-way constraints. For paved areas, rock socks must be used for perimeter control and all
inlets with the potential to receive sediment from the stockpile (even from vehicle tracking) must be
protected.
Maintenance and Removal
Inspect perimeter controls and inlet protection in accordance with their respective BMP Fact Sheets.
Where seeding, mulch and/or soil binders are used, reseeding or reapplication of soil binder may be
necessary.
When temporary removal of a perimeter BMP is necessary
to access a stockpile, ensure BMPs are reinstalled in
accordance with their respective design detail section.
Stockpile Management
Functions
Erosion Control Yes
Sediment Control Yes
Site/Material Management Yes
MM-2 Stockpile Management (SM)
SP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
When the stockpile is no longer needed, properly dispose of excess materials and revegetate or otherwise
stabilize the ground surface where the stockpile was located.
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-3
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-5
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs GH-1 and GH-2. Proper materials
storage and secondary containment for fuel tanks
are important good housekeeping practices. Photos
courtesy of CDOT and City of Aurora.
Description
Implement construction site good housekeeping practices to
prevent pollution associated with solid, liquid and hazardous
construction-related materials and wastes. Stormwater
Management Plans (SWMPs) should clearly specify BMPs
including these good housekeeping practices:
Provide for waste management.
Establish proper building material staging areas.
Designate paint and concrete washout areas.
Establish proper equipment/vehicle fueling and
maintenance practices.
Control equipment/vehicle washing and allowable non-
stormwater discharges.
Develop a spill prevention and response plan.
Acknowledgement: This Fact Sheet is based directly on
EPA guidance provided in Developing Your Stormwater
Pollution Prevent Plan (EPA 2007).
Appropriate Uses
Good housekeeping practices are necessary at all construction sites.
Design and Installation
The following principles and actions should be addressed in SWMPs:
Provide for Waste Management. Implement management procedures and practices to prevent or
reduce the exposure and transport of pollutants in stormwater from solid, liquid and sanitary wastes
that will be generated at the site. Practices such as trash disposal, recycling, proper material handling,
and cleanup measures can reduce the potential for stormwater runoff to pick up construction site
wastes and discharge them to surface waters. Implement a comprehensive set of waste-management
practices for hazardous or toxic materials, such as paints, solvents, petroleum products, pesticides,
wood preservatives, acids, roofing tar, and other materials. Practices should include storage,
handling, inventory, and cleanup procedures, in case of spills. Specific practices that should be
considered include:
Solid or Construction Waste
o Designate trash and bulk waste-collection areas on-
site.
Good Housekeeping
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
MM-3 Good Housekeeping Practices (GH)
GH-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph GH-3. Locate portable toilet facilities on level
surfaces away from waterways and storm drains. Photo
courtesy of WWE.
o Recycle materials whenever possible (e.g., paper, wood, concrete, oil).
o Segregate and provide proper disposal options for hazardous material wastes.
o Clean up litter and debris from the construction site daily.
o Locate waste-collection areas away from streets, gutters, watercourses, and storm drains. Waste-
collection areas (dumpsters, and such) are often best located near construction site entrances to
minimize traffic on disturbed soils. Consider secondary containment around waste collection
areas to minimize the likelihood of contaminated discharges.
o Empty waste containers before they are full and overflowing.
Sanitary and Septic Waste
o Provide convenient, well-maintained, and properly located toilet facilities on-site.
o Locate toilet facilities away from storm drain inlets and waterways to prevent accidental spills
and contamination of stormwater.
o Maintain clean restroom facilities and empty portable toilets regularly.
o Where possible, provide secondary containment pans under portable toilets.
o Provide tie-downs or stake-downs for portable toilets.
o Educate employees, subcontractors, and suppliers on locations of facilities.
o Treat or dispose of sanitary and septic waste in accordance with state or local regulations. Do not
discharge or bury wastewater at the construction site.
o Inspect facilities for leaks. If found, repair or replace immediately.
o Special care is necessary during maintenance (pump out) to ensure that waste and/or biocide are
not spilled on the ground.
Hazardous Materials and Wastes
o Develop and implement employee and
subcontractor education, as needed, on
hazardous and toxic waste handling,
storage, disposal, and cleanup.
o Designate hazardous waste-collection
areas on-site.
o Place all hazardous and toxic material
wastes in secondary containment.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-3
Urban Storm Drainage Criteria Manual Volume 3
o Hazardous waste containers should be inspected to ensure that all containers are labeled properly
and that no leaks are present.
Establish Proper Building Material Handling and Staging Areas. The SWMP should include
comprehensive handling and management procedures for building materials, especially those that are
hazardous or toxic. Paints, solvents, pesticides, fuels and oils, other hazardous materials or building
materials that have the potential to contaminate stormwater should be stored indoors or under cover
whenever possible or in areas with secondary containment. Secondary containment measures prevent
a spill from spreading across the site and may include dikes, berms, curbing, or other containment
methods. Secondary containment techniques should also ensure the protection of groundwater.
Designate staging areas for activities such as fueling vehicles, mixing paints, plaster, mortar, and
other potential pollutants. Designated staging areas enable easier monitoring of the use of materials
and clean up of spills. Training employees and subcontractors is essential to the success of this
pollution prevention principle. Consider the following specific materials handling and staging
practices:
o Train employees and subcontractors in proper handling and storage practices.
o Clearly designate site areas for staging and storage with signs and on construction drawings.
Staging areas should be located in areas central to the construction site. Segment the staging area
into sub-areas designated for vehicles, equipment, or stockpiles. Construction entrances and exits
should be clearly marked so that delivery vehicles enter/exit through stabilized areas with vehicle
tracking controls (See Vehicle Tracking Control Fact Sheet).
o Provide storage in accordance with Spill Protection, Control and Countermeasures (SPCC)
requirements and plans and provide cover and impermeable perimeter control, as necessary, for
hazardous materials and contaminated soils that must be stored on site.
o Ensure that storage containers are regularly inspected for leaks, corrosion, support or foundation
failure, or other signs of deterioration and tested for soundness.
o Reuse and recycle construction materials when possible.
Designate Concrete Washout Areas. Concrete contractors should be encouraged to use the washout
facilities at their own plants or dispatch facilities when feasible; however, concrete washout
commonly occurs on construction sites. If it is necessary to provide for concrete washout areas on-
site, designate specific washout areas and design facilities to handle anticipated washout water.
Washout areas should also be provided for paint and stucco operations. Because washout areas can
be a source of pollutants from leaks or spills, care must be taken with regard to their placement and
proper use. See the Concrete Washout Area Fact Sheet for detailed guidance.
Both self-constructed and prefabricated washout containers can fill up quickly when concrete, paint,
and stucco work are occurring on large portions of the site. Be sure to check for evidence that
contractors are using the washout areas and not dumping materials onto the ground or into drainage
facilities. If the washout areas are not being used regularly, consider posting additional signage,
relocating the facilities to more convenient locations, or providing training to workers and
contractors.
When concrete, paint, or stucco is part of the construction process, consider these practices which will
help prevent contamination of stormwater. Include the locations of these areas and the maintenance
and inspection procedures in the SWMP.
MM-3 Good Housekeeping Practices (GH)
GH-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
o Do not washout concrete trucks or equipment into storm drains, streets, gutters, uncontained
areas, or streams. Only use designated washout areas.
o Establish washout areas and advertise their locations with signs. Ensure that signage remains in
good repair.
o Provide adequate containment for the amount of wash water that will be used.
o Inspect washout structures daily to detect leaks or tears and to identify when materials need to be
removed.
o Dispose of materials properly. The preferred method is to allow the water to evaporate and to
recycle the hardened concrete. Full service companies may provide dewatering services and
should dispose of wastewater properly. Concrete wash water can be highly polluted. It should
not be discharged to any surface water, storm sewer system, or allowed to infiltrate into the
ground in the vicinity of waterbodies. Washwater should not be discharged to a sanitary sewer
system without first receiving written permission from the system operator.
Establish Proper Equipment/Vehicle Fueling and Maintenance Practices. Create a clearly
designated on-site fueling and maintenance area that is clean and dry. The on-site fueling area should
have a spill kit, and staff should know how to use it. If possible, conduct vehicle fueling and
maintenance activities in a covered area. Consider the following practices to help prevent the
discharge of pollutants to stormwater from equipment/vehicle fueling and maintenance. Include the
locations of designated fueling and maintenance areas and inspection and maintenance procedures in
the SWMP.
o Train employees and subcontractors in proper fueling procedures (stay with vehicles during
fueling, proper use of pumps, emergency shutoff valves, etc.).
o Inspect on-site vehicles and equipment regularly for leaks, equipment damage, and other service
problems.
o Clearly designate vehicle/equipment service areas away from drainage facilities and watercourses
to prevent stormwater run-on and runoff.
o Use drip pans, drip cloths, or absorbent pads when replacing spent fluids.
o Collect all spent fluids, store in appropriate labeled containers in the proper storage areas, and
recycle fluids whenever possible.
Control Equipment/Vehicle Washing and Allowable Non-Stormwater Discharges. Implement
practices to prevent contamination of surface and groundwater from equipment and vehicle wash
water. Representative practices include:
o Educate employees and subcontractors on proper washing procedures.
o Use off-site washing facilities, when available.
o Clearly mark the washing areas and inform workers that all washing must occur in this area.
o Contain wash water and treat it using BMPs. Infiltrate washwater when possible, but maintain
separation from drainage paths and waterbodies.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-5
Urban Storm Drainage Criteria Manual Volume 3
o Use high-pressure water spray at vehicle washing facilities without detergents. Water alone can
remove most dirt adequately.
o Do not conduct other activities, such as vehicle repairs, in the wash area.
o Include the location of the washing facilities and the inspection and maintenance procedures in
the SWMP.
Develop a Spill Prevention and Response Plan. Spill prevention and response procedures must be
identified in the SWMP. Representative procedures include identifying ways to reduce the chance of
spills, stop the source of spills, contain and clean up spills, dispose of materials contaminated by
spills, and train personnel responsible for spill prevention and response. The plan should also specify
material handling procedures and storage requirements and ensure that clear and concise spill cleanup
procedures are provided and posted for areas in which spills may potentially occur. When developing
a spill prevention plan, include the following:
o Note the locations of chemical storage areas, storm drains, tributary drainage areas, surface
waterbodies on or near the site, and measures to stop spills from leaving the site.
o Provide proper handling and safety procedures for each type of waste. Keep Material Safety Data
Sheets (MSDSs) for chemical used on site with the SWMP.
o Establish an education program for employees and subcontractors on the potential hazards to
humans and the environment from spills and leaks.
o Specify how to notify appropriate authorities, such as police and fire departments, hospitals, or
municipal sewage treatment facilities to request assistance. Emergency procedures and contact
numbers should be provided in the SWMP and posted at storage locations.
o Describe the procedures, equipment and materials for immediate cleanup of spills and proper
disposal.
o Identify personnel responsible for implementing the plan in the event of a spill. Update the spill
prevention plan and clean up materials as changes occur to the types of chemicals stored and used
at the facility.
MM-3 Good Housekeeping Practices (GH)
GH-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Spill Prevention, Control, and Countermeasure (SPCC) Plan
Construction sites may be subject to 40 CFR Part 112 regulations that require the preparation and
implementation of a SPCC Plan to prevent oil spills from aboveground and underground storage tanks.
The facility is subject to this rule if it is a non-transportation-related facility that:
Has a total storage capacity greater than 1,320 gallons or a completely buried storage capacity
greater than 42,000 gallons.
Could reasonably be expected to discharge oil in quantities that may be harmful to navigable waters
of the United States and adjoining shorelines.
Furthermore, if the facility is subject to 40 CFR Part 112, the SWMP should reference the SPCC Plan.
To find out more about SPCC Plans, see EPA's website on SPPC at www.epa.gov/oilspill/spcc.htm.
Reporting Oil Spills
In the event of an oil spill, contact the National Response Center toll free at 1-800-424- 8802 for
assistance, or for more details, visit their website: www.nrc.uscg.mil.
Maintenance and Removal
Effective implementation of good housekeeping practices is dependent on clear designation of personnel
responsible for supervising and implementing good housekeeping programs, such as site cleanup and
disposal of trash and debris, hazardous material management and disposal, vehicle and equipment
maintenance, and other practices. Emergency response "drills" may aid in emergency preparedness.
Checklists may be helpful in good housekeeping efforts.
Staging and storage areas require permanent stabilization when the areas are no longer being used for
construction-related activities.
Construction-related materials, debris and waste must be removed from the construction site once
construction is complete.
Design Details
See the following Fact Sheets for related Design Details:
MM-1 Concrete Washout Area
MM-2 Stockpile Management
SM-4 Vehicle Tracking Control
Design details are not necessary for other good housekeeping practices; however, be sure to designate
where specific practices will occur on the appropriate construction drawings.
Silt Fence (SF) SC-1
November 2010 Urban Drainage and Flood Control District SF-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-1. Silt fence creates a sediment barrier, forcing
sheet flow runoff to evaporate or infiltrate.
Description
A silt fence is a woven geotextile fabric
attached to wooden posts and trenched
into the ground. It is designed as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
A silt fence can be used where runoff is
conveyed from a disturbed area as sheet
flow. Silt fence is not designed to
receive concentrated flow or to be used
as a filter fabric. Typical uses include:
Down slope of a disturbed area to
accept sheet flow.
Along the perimeter of a receiving
water such as a stream, pond or
wetland.
At the perimeter of a construction site.
Design and Installation
Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum
recommended tributary drainage area per 100 lineal feet of silt fence, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to silt fence installed along the contour. Silt fence installed for other uses, such as perimeter
control, should be installed in a way that will not produce concentrated flows. For example, a "J-hook"
installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather
than concentrate and cause erosive conditions parallel to the silt fence.
See Detail SF-1 for proper silt fence installation, which involves proper trenching, staking, securing the
fabric to the stakes, and backfilling the silt fence. Properly installed silt fence should not be easily pulled
out by hand and there should be no gaps between the ground and the fabric.
Silt fence must meet the minimum allowable strength requirements, depth of installation requirement, and
other specifications in the design details. Improper installation
of silt fence is a common reason for silt fence failure; however,
when properly installed and used for the appropriate purposes, it
can be highly effective.
Silt Fence
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-1 Silt Fence (SF)
SF-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-2. When silt fence is not installed along
the contour, a "J-hook" installation may be appropriate
to ensure that the BMP does not create concentrated
flow parallel to the silt fence. Photo courtesy of Tom
Gore.
Maintenance and Removal
Inspection of silt fence includes observing the
material for tears or holes and checking for slumping
fence and undercut areas bypassing flows. Repair of
silt fence typically involves replacing the damaged
section with a new section. Sediment accumulated
behind silt fence should be removed, as needed to
maintain BMP effectiveness, typically before it
reaches a depth of 6 inches.
Silt fence may be removed when the upstream area
has reached final stabilization.
Silt Fence (SF) SC-1
November 2010 Urban Drainage and Flood Control District SF-3
Urban Storm Drainage Criteria Manual Volume 3
SC-1 Silt Fence (SF)
SF-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs SCL-1 and SCL-2. Sediment control logs used as 1) a
perimeter control around a soil stockpile; and, 2) as a "J-hook"
perimeter control at the corner of a construction site.
Description
A sediment control log is a linear roll
made of natural materials such as
straw, coconut fiber, or other fibrous
material trenched into the ground and
held with a wooden stake. Sediment
control logs are also often referred to
as "straw wattles." They are used as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
Sediment control logs can be used in
the following applications to trap
sediment:
As perimeter control for stockpiles
and the site.
As part of inlet protection designs.
As check dams in small drainage
ditches. (Sediment control logs
are not intended for use in
channels with high flow
velocities.)
On disturbed slopes to shorten flow
lengths (as an erosion control).
As part of multi-layered perimeter control along a receiving water such as a stream, pond or wetland.
Sediment control logs work well in combination with other layers of erosion and sediment controls.
Design and Installation
Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum
allowable tributary drainage area per 100 lineal feet of sediment control log, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to sediment control logs installed along the contour. When installed for other uses, such as
perimeter control, it should be installed in a way that will not
produce concentrated flows. For example, a "J-hook"
installation may be appropriate to force runoff to pond and
evaporate or infiltrate in multiple areas rather than concentrate
and cause erosive conditions parallel to the BMP.
Sediment Control Log
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management No
SC-2 Sediment Control Log (SCL)
SCL-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Although sediment control logs initially allow runoff to flow through the BMP, they can quickly become
a barrier and should be installed is if they are impermeable.
Design details and notes for sediment control logs are provided in Detail SCL-1. Sediment logs must be
properly trenched and staked into the ground to prevent undercutting, bypassing and displacement. When
installed on slopes, sediment control logs should be installed along the contours (i.e., perpendicular to
flow).
Improper installation can lead to poor performance. Be sure that sediment control logs are properly
trenched, anchored and tightly jointed.
Maintenance and Removal
Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the
depth is one-half the height of the sediment log and repair damage to the sediment log, typically by
replacing the damaged section.
Once the upstream area is stabilized, remove and properly dispose of the logs. Areas disturbed beneath
the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may
occasionally be left in place (e.g., when logs are used in conjunction with erosion control blankets as
permanent slope breaks). However, removal of sediment control logs after final stabilization is typically
recommended when used in perimeter control, inlet protection and check dam applications.
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-3
Urban Storm Drainage Criteria Manual Volume 3
SC-2 Sediment Control Log (SCL)
SCL-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-5
Urban Storm Drainage Criteria Manual Volume 3
Brush Barrier (BB) SC-4
November 2010 Urban Drainage and Flood Control District BB-1
Urban Storm Drainage Criteria Manual Volume 3
Description
A brush barrier is a perimeter sediment
control constructed with stacked shrubs,
tree limbs, and bushy vegetation that has
been cleared from a construction area.
Brush barriers reduce sediment loads by
intercepting and slowing sheet flow
from disturbed areas.
Appropriate Uses
A brush barrier is an appropriate BMP at
sites where there is adequate brush from
the clearing and grubbing of the
construction site to construct an
effective brush barrier. Brush barriers
are typically used at the toe of slopes and
should be implemented in combination
with other BMPs such as surface
roughening and reseeding. Brush barriers should be considered short-term, supplemental BMPs because
they are constructed of materials that naturally decompose. Brush barriers are not acceptable as a sole
means of perimeter control, but they may be used internally within a site to reduce slope length or at the
site perimeter in combination with other perimeter control BMPs for multi-layered protection.
Brush barriers are not appropriate for high-velocity flow areas. A large amount of material is needed to
construct a useful brush barrier; therefore, alternative perimeter controls such as a fabric silt fence may be
more appropriate for sites with little material from clearing.
Design and Installation
The drainage area for brush barriers should be no greater than 0.25 acre per 100 feet of barrier length.
Additionally, the drainage slope leading down to a brush barrier must be no greater than 3:1 and no longer
than 150 feet.
To construct an effective brush barrier, use only small shrubs and limbs with diameters of 6 inches or less.
Larger materials (such as a tree stump) can create void spaces in the barrier, making it ineffective. The
brush barrier mound should be at least 3 feet high and 5 feet wide at its base.
In order to avoid significant movement of the brush and improve effectiveness, a filter fabric can be
placed over the top of the brush pile, keyed in on the upstream side, and anchored on the downstream
side. On the upgradient side, the filter fabric cover should be
buried in a trench 4 inches deep and 6 inches wide.
Brush Barrier
Functions
Erosion Control Moderate
Sediment Control Moderate
Site/Material
No
Photograph BB-1. Brush barrier constructed with chipped wood.
Photo courtesy of EPA.
SC-4 Brush Barrier (BB)
BB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Inspect the brush barrier for voids where concentrated flow or erosion is occurring. Voids in the brush
barrier should be filled with additional brush. Accumulated sediment should be removed from the uphill
side of the barrier when sediment height reaches one-third of the height of the barrier.
If filter fabric is used, inspect the filter fabric for damage; replace and properly secure it, as needed.
Once the upstream area has been vegetated or stabilized, the brush barrier should be removed and the
underlying area revegetated.
Rock Sock (RS) SC-5
November 2010 Urban Drainage and Flood Control District RS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph RS-1. Rock socks placed at regular intervals in a curb
line can help reduce sediment loading to storm sewer inlets. Rock
socks can also be used as perimeter controls.
Description
A rock sock is constructed of gravel
that has been wrapped by wire mesh or
a geotextile to form an elongated
cylindrical filter. Rock socks are
typically used either as a perimeter
control or as part of inlet protection.
When placed at angles in the curb line,
rock socks are typically referred to as
curb socks. Rock socks are intended to
trap sediment from stormwater runoff
that flows onto roadways as a result of
construction activities.
Appropriate Uses
Rock socks can be used at the perimeter
of a disturbed area to control localized
sediment loading. A benefit of rock
socks as opposed to other perimeter controls is that they do not have to be trenched or staked into the
ground; therefore, they are often used on roadway construction projects where paved surfaces are present.
Use rock socks in inlet protection applications when the construction of a roadway is substantially
complete and the roadway has been directly connected to a receiving storm system.
Design and Installation
When rock socks are used as perimeter controls, the maximum recommended tributary drainage area per
100 lineal feet of rock socks is approximately 0.25 acres with disturbed slope length of up to 150 feet and
a tributary slope gradient no steeper than 3:1. A rock sock design detail and notes are provided in Detail
RS-1. Also see the Inlet Protection Fact Sheet for design and installation guidance when rock socks are
used for inlet protection and in the curb line.
When placed in the gutter adjacent to a curb, rock socks should protrude no more than two feet from the
curb in order for traffic to pass safely. If located in a high traffic area, place construction markers to alert
drivers and street maintenance workers of their presence.
Maintenance and Removal
Rock socks are susceptible to displacement and breaking due to vehicle traffic. Inspect rock socks for
damage and repair or replace as necessary. Remove sediment by sweeping or vacuuming as needed to
maintain the functionality of the BMP, typically when sediment
has accumulated behind the rock sock to one-half of the sock's
height.
Once upstream stabilization is complete, rock socks and
accumulated sediment should be removed and properly disposed.
Rock Sock
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-5 Rock Sock (RS)
RS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Rock Sock (RS) SC-5
November 2010 Urban Drainage and Flood Control District RS-3
Urban Storm Drainage Criteria Manual Volume 3
Inlet Protection (IP) SC-6
November 2010 Urban Drainage and Flood Control District IP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph IP-1. Inlet protection for a curb opening inlet.
Description
Inlet protection consists of permeable
barriers installed around an inlet to
filter runoff and remove sediment prior
to entering a storm drain inlet. Inlet
protection can be constructed from rock
socks, sediment control logs, silt fence,
block and rock socks, or other materials
approved by the local jurisdiction.
Area inlets can also be protected by
over-excavating around the inlet to
form a sediment trap.
Appropriate Uses
Install protection at storm sewer inlets
that are operable during construction.
Consider the potential for tracked-out
sediment or temporary stockpile areas to contribute sediment to inlets when determining which inlets
must be protected. This may include inlets in the general proximity of the construction area, not limited
to downgradient inlets. Inlet protection is not
Design and Installation
a stand-alone BMP and should be used in conjunction with
other upgradient BMPs.
To function effectively, inlet protection measures must be installed to ensure that flows do not bypass the
inlet protection and enter the storm drain without treatment. However, designs must also enable the inlet
to function without completely blocking flows into the inlet in a manner that causes localized flooding.
When selecting the type of inlet protection, consider factors such as type of inlet (e.g., curb or area, sump
or on-grade conditions), traffic, anticipated flows, ability to secure the BMP properly, safety and other
site-specific conditions. For example, block and rock socks will be better suited to a curb and gutter
along a roadway, as opposed to silt fence or sediment control logs, which cannot be properly secured in a
curb and gutter setting, but are effective area inlet protection measures.
Several inlet protection designs are provided in the Design Details. Additionally, a variety of proprietary
products are available for inlet protection that may be approved for use by local governments. If
proprietary products are used, design details and installation procedures from the manufacturer must be
followed. Regardless of the type of inlet protection selected, inlet protection is most effective when
combined with other BMPs such as curb socks and check dams. Inlet protection is often the last barrier
before runoff enters the storm sewer or receiving water.
Design details with notes are provided for these forms of inlet
protection:
IP-1. Block and Rock Sock Inlet Protection for Sump or On-grade
Inlets
IP-2. Curb (Rock) Socks Upstream of Inlet Protection, On-grade
Inlets
Inlet Protection
(various forms)
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-6 Inlet Protection (IP)
IP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
IP-3. Rock Sock Inlet Protection for Sump/Area Inlet
IP-4. Silt Fence Inlet Protection for Sump/Area Inlet
IP-5. Over-excavation Inlet Protection
IP-6. Straw Bale Inlet Protection for Sump/Area Inlet
CIP-1. Culvert Inlet Protection
Propriety inlet protection devices should be installed in accordance with manufacturer specifications.
More information is provided below on selecting inlet protection for sump and on-grade locations.
Inlets Located in a Sump
When applying inlet protection in sump conditions, it is important that the inlet continue to function
during larger runoff events. For curb inlets, the maximum height of the protective barrier should be lower
than the top of the curb opening to allow overflow into the inlet during larger storms without excessive
localized flooding. If the inlet protection height is greater than the curb elevation, particularly if the filter
becomes clogged with sediment, runoff will not enter the inlet and may bypass it, possibly causing
localized flooding, public safety issues, and downstream erosion and damage from bypassed flows.
Area inlets located in a sump setting can be protected through the use of silt fence, concrete block and
rock socks (on paved surfaces), sediment control logs/straw wattles embedded in the adjacent soil and
stacked around the area inlet (on pervious surfaces), over-excavation around the inlet, and proprietary
products providing equivalent functions.
Inlets Located on a Slope
For curb and gutter inlets on paved sloping streets, block and rock sock inlet protection is recommended
in conjunction with curb socks in the gutter leading to the inlet. For inlets located along unpaved roads,
also see the Check Dam Fact Sheet.
Maintenance and Removal
Inspect inlet protection frequently. Inspection and maintenance guidance includes:
Inspect for tears that can result in sediment directly entering the inlet, as well as result in the contents
of the BMP (e.g., gravel) washing into the inlet.
Check for improper installation resulting in untreated flows bypassing the BMP and directly entering
the inlet or bypassing to an unprotected downstream inlet. For example, silt fence that has not been
properly trenched around the inlet can result in flows under the silt fence and directly into the inlet.
Look for displaced BMPs that are no longer protecting the inlet. Displacement may occur following
larger storm events that wash away or reposition the inlet protection. Traffic or equipment may also
crush or displace the BMP.
Monitor sediment accumulation upgradient of the inlet protection.
Inlet Protection (IP) SC-6
November 2010 Urban Drainage and Flood Control District IP-3
Urban Storm Drainage Criteria Manual Volume 3
Remove sediment accumulation from the area upstream of the inlet protection, as needed to maintain
BMP effectiveness, typically when it reaches no more than half the storage capacity of the inlet
protection. For silt fence, remove sediment when it accumulates to a depth of no more than 6 inches.
Remove sediment accumulation from the area upstream of the inlet protection as needed to maintain
the functionality of the BMP.
Propriety inlet protection devices should be inspected and maintained in accordance with
manufacturer specifications. If proprietary inlet insert devices are used, sediment should be removed
in a timely manner to prevent devices from breaking and spilling sediment into the storm drain.
Inlet protection must be removed and properly disposed of when the drainage area for the inlet has
reached final stabilization.
SC-6 Inlet Protection (IP)
IP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Inlet Protection (IP) SC-6
November 2010 Urban Drainage and Flood Control District IP-5
Urban Storm Drainage Criteria Manual Volume 3
SC-6 Inlet Protection (IP)
IP-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Inlet Protection (IP) SC-6
November 2010 Urban Drainage and Flood Control District IP-7
Urban Storm Drainage Criteria Manual Volume 3
Sediment Basin (SB) SC-7
November 2010 Urban Drainage and Flood Control District SB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SB-1. Sediment basin at the toe of a slope. Photo
courtesy of WWE.
Description
A sediment basin is a temporary pond
built on a construction site to capture
eroded or disturbed soil transported in
storm runoff prior to discharge from the
site. Sediment basins are designed to
capture site runoff and slowly release it to
allow time for settling of sediment prior
to discharge. Sediment basins are often
constructed in locations that will later be
modified to serve as post-construction
stormwater basins.
Appropriate Uses
Most large construction sites (typically
greater than 2 acres) will require one or
more sediment basins for effective
management of construction site runoff. On linear construction projects, sediment basins may be
impractical; instead, sediment traps or other combinations of BMPs may be more appropriate.
Sediment basins should not be used as stand-alone sediment controls. Erosion and other sediment
controls should also be implemented upstream.
When feasible, the sediment basin should be installed in the same location where a permanent post-
construction detention pond will be located.
Design and Installation
The design procedure for a sediment basin includes these steps:
Basin Storage Volume: Provide a storage volume of at least 3,600 cubic feet per acre of drainage
area. To the extent practical, undisturbed and/or off-site areas should be diverted around sediment
basins to prevent “clean” runoff from mixing with runoff from disturbed areas. For undisturbed areas
(both on-site and off-site) that cannot be diverted around the sediment basin, provide a minimum of
500 ft3/acre of storage for undeveloped (but stable) off-site areas in addition to the 3,600 ft3/acre for
disturbed areas. For stable, developed areas that cannot be diverted around the sediment basin,
storage volume requirements are summarized in Table SB-1.
Basin Geometry: Design basin with a minimum length-to-width ratio of 2:1 (L:W). If this cannot be
achieved because of site space constraints, baffling may
be required to extend the effective distance between the
inflow point(s) and the outlet to minimize short-circuiting.
Dam Embankment: It is recommended that
embankment slopes be 4:1 (H:V) or flatter and no steeper
than 3:1 (H:V) in any location.
Sediment Basins
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-7 Sediment Basin (SB)
SB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Inflow Structure: For concentrated flow entering the basin, provide energy dissipation at the point
of inflow.
Table SB-1. Additional Volume Requirements for Undisturbed and Developed TributaryAreas
Draining through Sediment Basins
Imperviousness (%)
Additional Storage Volume (ft3)
Per Acre of Tributary Area
Undeveloped 500
10 800
20 1230
30 1600
40 2030
50 2470
60 2980
70 3560
80 4360
90 5300
100 6460
Outlet Works: The outlet pipe shall extend through the embankment at a minimum slope of 0.5
percent. Outlet works can be designed using one of the following approaches:
o Perforated Riser/Plate: Follow the design criteria for Full Spectrum Detention outlets in the
EDB BMP Fact Sheet provided in Chapter 4 of this manual for sizing of outlet perforations with
an emptying time of approximately 72 hours. In lieu of the well-screen trash rack, pack
uniformly sized 1½ - to 2-inch gravel in front of the plate. This gravel will need to be cleaned out
frequently during the construction period as sediment accumulates within it. The gravel pack will
need to be removed and disposed of following construction to reclaim the basin for use as a
permanent detention facility. If the basin will be used as a permanent extended detention basin
for the site, a well-screen trash rack will need to be installed once contributing drainage areas
have been stabilized and the gravel pack and accumulated sediment have been removed.
o Floating Skimmer: If a floating skimmer is used, install it using manufacturer’s
recommendations. Illustration SB-1 provides an illustration of a Faircloth Skimmer Floating
Outlet™, one of the more commonly used floating skimmer outlets. A skimmer should be
designed to release the design volume in no less than 48 hours. The use of a floating skimmer
outlet can increase the sediment capture efficiency of a basin significantly. A floating outlet
continually decants cleanest water off the surface of the pond and releases cleaner water than
would discharge from a perforated riser pipe or plate.
Sediment Basin (SB) SC-7
November 2010 Urban Drainage and Flood Control District SB-3
Urban Storm Drainage Criteria Manual Volume 3
Illustration SB-1. Outlet structure for a temporary sediment basin - Faircloth Skimmer Floating Outlet. Illustration courtesy
of J. W. Faircloth & Sons, Inc., FairclothSkimmer.com.
o Outlet Protection: Outlet protection should be provided where the velocity of flow will exceed
the maximum permissible velocity of the material of the waterway into which discharge occurs.
This may require the use of a riprap apron at the outlet location and/or other measures to keep the
waterway from eroding.
o Emergency Spillway: Provide a stabilized emergency overflow spillway for rainstorms that
exceed the capacity of the sediment basin volume and its outlet. Protect basin embankments from
erosion and overtopping. If the sediment basin will be converted to a permanent detention basin,
design and construct the emergency spillway(s) as required for the permanent facility. If the
sediment basin will not become a permanent detention basin, it may be possible to substitute a
heavy polyvinyl membrane or properly bedded rock cover to line the spillway and downstream
embankment, depending on the height, slope, and width of the embankments.
Maintenance and Removal
Maintenance activities include the following:
• Dredge sediment from the basin, as needed to maintain BMP effectiveness, typically when the design
storage volume is no more than one-third filled with sediment.
• Inspect the sediment basin embankments for stability and seepage.
• Inspect the inlet and outlet of the basin, repair damage, and remove debris. Remove, clean and
replace the gravel around the outlet on a regular basis to remove the accumulated sediment within it
and keep the outlet functioning.
• Be aware that removal of a sediment basin may require dewatering and associated permit
requirements.
• Do not remove a sediment basin until the upstream area has been stabilized with vegetation.
SC-7 Sediment Basin (SB)
SB-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Final disposition of the sediment basin depends on whether the basin will be converted to a permanent
post-construction stormwater basin or whether the basin area will be returned to grade. For basins being
converted to permanent detention basins, remove accumulated sediment and reconfigure the basin and
outlet to meet the requirements of the final design for the detention facility. If the sediment basin is not to
be used as a permanent detention facility, fill the excavated area with soil and stabilize with vegetation.
Sediment Basin (SB) SC-7
November 2010 Urban Drainage and Flood Control District SB-5
Urban Storm Drainage Criteria Manual Volume 3
SC-7 Sediment Basin (SB)
SB-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Basin (SB) SC-7
November 2010 Urban Drainage and Flood Control District SB-7
Urban Storm Drainage Criteria Manual Volume 3
Sediment Trap (ST) SC-8
November 2010 Urban Drainage and Flood Control District ST-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph ST-1. Sediment traps are used to collect sediment-laden
runoff from disturbed area. Photo courtesy of EPA Menu of BMPs.
Description
Sediment traps are formed by excavating
an area or by placing an earthen
embankment across a low area or
drainage swale. Sediment traps are
designed to capture drainage from
disturbed areas less than one acre and
allow settling of sediment.
Appropriate Uses
Sediment traps can be used in
combination with other layers of erosion
and sediment controls to trap sediment
from small drainage areas (less than one
acre) or areas with localized high sediment loading. For example, sediment traps are often provided in
conjunction with vehicle tracking controls and wheel wash facilities.
Design and Installation
A sediment trap consists of a small excavated basin with an earthen berm and a riprap outlet. The berm
of the sediment trap may be constructed from the excavated material and must be compacted to
95 percent of the maximum density in accordance with ASTM D698. An overflow outlet must be
provided at an elevation at least 6 inches below the top of the berm. See Detail ST-1 for additional design
and installation information.
Maintenance and Removal
Inspect the sediment trap embankments for stability and seepage.
Remove accumulated sediment as needed to maintain the effectiveness of the sediment trap, typically
when the sediment depth is approximately one-half the height of the outflow embankment.
Inspect the outlet for debris and damage. Repair damage to the outlet, and remove all obstructions.
A sediment trap should not be removed until the upstream area is sufficiently stabilized. Upon removal of
the trap, the disturbed area should be covered with topsoil and stabilized.
Sediment Trap
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-8 Sediment Trap (ST)
ST-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Trap (ST) SC-8
November 2010 Urban Drainage and Flood Control District ST-3
Urban Storm Drainage Criteria Manual Volume 3
Vegetated Buffers (VB) SC-9
November 2010 Urban Drainage and Flood Control District VB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph VB-1. A vegetated buffer is maintained between the
area of active construction and the drainage swale. Photo courtesy
of WWE.
Description
Buffer strips of preserved natural
vegetation or grass help protect
waterways and wetlands from land
disturbing activities. Vegetated buffers
improve stormwater runoff quality by
straining sediment, promoting
infiltration, and slowing runoff
velocities.
Appropriate Uses
Vegetated buffers can be used to
separate land disturbing activities and
natural surface waters or conveyances.
In many jurisdictions, local governments
require some type of setback from natural waterways. Concentrated flow should not be directed through
a buffer; instead, runoff should be in the form of sheet flow. Vegetated buffers are typically used in
combination with other perimeter control BMPs such as sediment control logs or silt fence for multi-
layered protection.
Design and Installation
Minimum buffer widths may vary based on local regulations. Clearly delineate the boundary of the
natural buffer area using construction fencing, silt fence, or a comparable technique. In areas that have
been cleared and graded, vegetated buffers such as sod can also be installed to create or restore a
vegetated buffer around the perimeter of the site.
Maintenance and Removal
Inspect buffer areas for signs of erosion such as gullies or rills. Stabilize eroding areas, as needed. If
erosion is due to concentrated flow conditions, it may be necessary to install a level spreader or other
technique to restore sheet flow conditions. Inspect perimeter controls delineating the vegetative buffer
and repair or replace as needed.
Vegetated Buffers
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management Yes
Chemical Treatment (CT) SC-10
November 2010 Urban Drainage and Flood Control District CT-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CT-1. Proprietary chemical treatment system being
used on a construction site with sensitive receiving waters. Photo
courtesy of WWE.
Description
Chemical treatment for erosion and
sediment control can take several forms:
1. Applying chemicals to disturbed
surfaces to reduce erosion (these uses
are discussed in the Soil Binders Fact
Sheet).
2. Adding flocculants to sedimentation
ponds or tanks to enhance sediment
removal prior.
3. Using proprietary barriers or flow-
through devices containing flocculants
(e.g., "floc logs").
The use of flocculants as described in No. 2 and No. 3 above will likely require special permitting.
Check with the state permitting agency. See the Soil Binder BMP Fact Sheet for information on
surface application of chemical treatments, as described in No. 1.
Appropriate Uses
At sites with fine-grained materials such as clays, chemical addition to sedimentation ponds or tanks can
enhance settling of suspended materials through flocculation.
Prior to selecting and using chemical treatments, it is important to check state and local permit
requirements related to their use.
Design and Installation
Due to variations among proprietary chemical treatment methods, design details are not provided for this
BMP. Chemical feed systems for sedimentation ponds, settling tanks and dewatering bags should be
installed and operated in accordance with manufacturer's recommendations and applicable regulations.
Alum and chitosan are two common chemicals used as flocculants. Because the potential long-term
impact of these chemicals to natural drainageways is not yet fully understood, the state does not currently
allow chemical addition under the CDPS General Stormwater Construction Discharge Permit. Additional
permitting may be necessary, which may include sampling requirements and numeric discharge limits.
Any devices or barriers containing chemicals should be installed following manufacturer's guidelines.
Check for state and local jurisdiction usage restrictions and requirements before including these practices
in the SWMP and implementing them onsite.
Chemical Treatment
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management No
SC-10 Chemical Treatment (CT)
CT-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Chemical feed systems for sedimentation ponds or tanks should be maintained in accordance with
manufacturer's recommendations and removed when the systems are no longer being used. Accumulated
sediment should be dried and disposed of either at a landfill or in accordance with applicable regulations.
Barriers and devices containing chemicals should be removed and replaced when tears or other damage to
the devices are observed. These barriers should be removed and properly disposed of when the site has
been stabilized.
Construction Phasing/Sequencing (CP) SM-1
November 2010 Urban Drainage and Flood Control District CP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CP-1. Construction phasing to avoid disturbing the
entire area at one time. Photo courtesy of WWE.
Description
Effective construction site management
to minimize erosion and sediment
transport includes attention to
construction phasing, scheduling, and
sequencing of land disturbing activities.
On most construction projects, erosion
and sediment controls will need to be
adjusted as the project progresses and
should be documented in the SWMP.
Construction phasing refers to
disturbing only part of a site at a time to
limit the potential for erosion from
dormant parts of a site. Grading
activities and construction are completed
and soils are effectively stabilized on one
part of a site before grading and
construction begins on another portion of the site.
Construction sequencing or scheduling refers to a specified work schedule that coordinates the timing of
land disturbing activities and the installation of erosion and sediment control practices.
Appropriate Uses
All construction projects can benefit from upfront planning to phase and sequence construction activities
to minimize the extent and duration of disturbance. Larger projects and linear construction projects may
benefit most from construction sequencing or phasing, but even small projects can benefit from
construction sequencing that minimizes the duration of disturbance.
Typically, erosion and sediment controls needed at a site will change as a site progresses through the
major phases of construction. Erosion and sediment control practices corresponding to each phase of
construction must be documented in the SWMP.
Design and Installation
BMPs appropriate to the major phases of development should be identified on construction drawings. In
some cases, it will be necessary to provide several drawings showing construction-phase BMPs placed
according to stages of development (e.g., clearing and grading, utility installation, active construction,
final stabilization). Some municipalities in the Denver area set maximum sizes for disturbed area
associated with phases of a construction project. Additionally, requirements for phased construction
drawings vary among local governments within the UDFCD boundary. Some local governments require
separate erosion and sediment control drawings for initial
BMPs, interim conditions (in active construction), and final
stabilization.
Construction Scheduling
Functions
Erosion Control Moderate
Sediment Control Moderate
Site/Material Management Yes
SM-1 Construction Phasing/Sequencing (CP)
CP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Typical construction phasing BMPs include:
Limit the amount of disturbed area at any given time on a site to the extent practical. For example, a
100-acre subdivision might be constructed in five phases of 20 acres each.
If there is carryover of stockpiled material from one phase to the next, position carryover material in a
location easily accessible for the pending phase that will not require disturbance of stabilized areas to
access the stockpile. Particularly with regard to efforts to balance cut and fill at a site, careful
planning for location of stockpiles is important.
Typical construction sequencing BMPs include:
Sequence construction activities to minimize duration of soil disturbance and exposure. For example,
when multiple utilities will occupy the same trench, schedule installation so that the trench does not
have to be closed and opened multiple times.
Schedule site stabilization activities (e.g., landscaping, seeding and mulching, installation of erosion
control blankets) as soon as feasible following grading.
Install initial erosion and sediment control practices before construction begins. Promptly install
additional BMPs for inlet protection, stabilization, etc., as construction activities are completed.
Table CP-1 provides typical sequencing of construction activities and associated BMPs.
Maintenance and Removal
When the construction schedule is altered, erosion and sediment control measures in the SWMP and
construction drawings should be appropriately adjusted to reflect actual "on the ground" conditions at the
construction site. Be aware that changes in construction schedules can have significant implications for
site stabilization, particularly with regard to establishment of vegetative cover.
Construction Phasing/Sequencing (CP) SM-1
November 2010 Urban Drainage and Flood Control District CP-3
Urban Storm Drainage Criteria Manual Volume 3
Table CP-1. Typical Phased BMP Installation for Construction Projects
Project
Phase BMPs
Pre-
disturbance,
Site Access
Install sediment controls downgradient of access point (on paved streets this may consist
of inlet protection).
Establish vehicle tracking control at entrances to paved streets. Fence as needed.
Use construction fencing to define the boundaries of the project and limit access to areas of
the site that are not to be disturbed.
Note: it may be necessary to protect inlets in the general vicinity of the site, even if not
downgradient, if there is a possibility that sediment tracked from the site could contribute
to the inlets.
Site Clearing
and Grubbing
Install perimeter controls as needed on downgradient perimeter of site (silt fence, wattles,
etc).
Limit disturbance to those areas planned for disturbance and protect undisturbed areas
within the site (construction fence, flagging, etc).
Preserve vegetative buffer at site perimeter.
Create stabilized staging area.
Locate portable toilets on flat surfaces away from drainage paths. Stake in areas
susceptible to high winds.
Construct concrete washout area and provide signage.
Establish waste disposal areas.
Install sediment basins.
Create dirt perimeter berms and/or brush barriers during grubbing and clearing.
Separate and stockpile topsoil, leave roughened and/or cover.
Protect stockpiles with perimeter control BMPs. Stockpiles should be located away from
drainage paths and should be accessed from the upgradient side so that perimeter controls
can remain in place on the downgradient side. Use erosion control blankets, temporary
seeding, and/or mulch for stockpiles that will be inactive for an extended period.
Leave disturbed area of site in a roughened condition to limit erosion. Consider temporary
revegetation for areas of the site that have been disturbed but that will be inactive for an
extended period.
Water to minimize dust but not to the point that watering creates runoff.
SM-1 Construction Phasing/Sequencing (CP)
CP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Project
Phase BMPs
Utility And
Infrastructure
Installation
In Addition to the Above BMPs:
Close trench as soon as possible (generally at the end of the day).
Use rough-cut street control or apply road base for streets that will not be promptly paved.
Provide inlet protection as streets are paved and inlets are constructed.
Protect and repair BMPs, as necessary.
Perform street sweeping as needed.
Building
Construction
In Addition to the Above BMPs:
Implement materials management and good housekeeping practices for home building
activities.
Use perimeter controls for temporary stockpiles from foundation excavations.
For lots adjacent to streets, lot-line perimeter controls may be necessary at the back of
curb.
Final Grading
In Addition to the Above BMPs:
Remove excess or waste materials.
Remove stored materials.
Final
Stabilization
In Addition to the Above BMPs:
Seed and mulch/tackify.
Seed and install blankets on steep slopes.
Remove all temporary BMPs when site has reached final stabilization.
Protection of Existing Vegetation (PV) SM-2
November 2010 Urban Drainage and Flood Control District PV-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph PV-1. Protection of existing vegetation and a sensitive
area. Photo courtesy of CDOT.
Description
Protection of existing vegetation on a
construction site can be accomplished
through installation of a construction
fence around the area requiring protection.
In cases where upgradient areas are
disturbed, it may also be necessary to
install perimeter controls to minimize
sediment loading to sensitive areas such as
wetlands. Existing vegetation may be
designated for protection to maintain a
stable surface cover as part of construction
phasing, or vegetation may be protected in
areas designated to remain in natural
condition under post-development
conditions (e.g., wetlands, mature trees,
riparian areas, open space).
Appropriate Uses
Existing vegetation should be preserved for the maximum practical duration on a construction site
through the use of effective construction phasing. Preserving vegetation helps to minimize erosion and
can reduce revegetation costs following construction.
Protection of wetland areas is required under the Clean Water Act, unless a permit has been obtained from
the U.S. Army Corps of Engineers (USACE) allowing impacts in limited areas.
If trees are to be protected as part of post-development landscaping, care must be taken to avoid several
types of damage, some of which may not be apparent at the time of injury. Potential sources of injury
include soil compaction during grading or due to construction traffic, direct equipment-related injury such
as bark removal, branch breakage, surface grading and trenching, and soil cut and fill. In order to
minimize injuries that may lead to immediate or later death of the tree, tree protection zones should be
developed during site design, implemented at the beginning of a construction project, as well as continued
during active construction.
Design and Installation
General
Once an area has been designated as a preservation area, there should be no construction activity allowed
within a set distance of the area. Clearly mark the area with construction fencing. Do not allow
stockpiles, equipment, trailers or parking within the
protected area. Guidelines to protect various types of
existing vegetation follow.
Protection of Existing Vegetation
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management Yes
SM-2 Protection of Existing Vegetation (PV)
PV-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Surface Cover During Phased Construction
Install construction fencing or other perimeter controls around areas to be protected from clearing and
grading as part of construction phasing.
Maintaining surface cover on steep slopes for the maximum practical duration during construction is
recommended.
Open Space Preservation
Where natural open space areas will be preserved as part of a development, it is important to install
construction fencing around these areas to protect them from compaction. This is particularly important
when areas with soils with high infiltration rates are preserved as part of LID designs. Preserved open
space areas should not be used for staging and equipment storage.
Wetlands and Riparian Areas
Install a construction fence around the perimeter of the wetland or riparian (streamside vegetation) area to
prevent access by equipment. In areas downgradient of disturbed areas, install a perimeter control such as
silt fence, sediment control logs, or similar measure to minimize sediment loading to the wetland.
Tree Protection 1
Before beginning construction operations, establish a tree protection zone around trees to be
preserved by installing construction fences. Allow enough space from the trunk to protect the root
zone from soil compaction and mechanical damage, and the branches from mechanical damage (see
Table PV-1). If low branches will be kept, place the fence outside of the drip line. Where this is not
possible, place fencing as far away from the trunk as possible. In order to maintain a healthy tree, be
aware that about 60 percent of the tree's root zone extends beyond the drip line.
Table PV-1
Guidelines for Determining the Tree Protection Zone
(Source: Matheny and Clark, 1998; as cited in GreenCO and WWE 2008)
Distance from Trunk (ft) per inch of DBH
Species Tolerance to Damage Young Mature Over mature
Good 0.5' 0.75' 1.0'
Moderate 0.75' 1.0' 1.25'
Poor 1.0' 1.25' 1.5'
Notes: DBH = diameter at breast height (4.5 ft above grade); Young = <20% of
life expectancy; Mature = 20%-80% of life expectancy; Over mature =>80% of
life expectancy
Most tree roots grow within the top 12 to 18 inches of soil. Grade changes within the tree protection
zone should be avoided where possible because seemingly minor grade changes can either smother
1 Tree Protection guidelines adapted from GreenCO and WWE (2008). Green Industry Best Management Practices (BMPs) for
the Conservation and Protection of Water Resources in Colorado: Moving Toward Sustainability, Third Release. See
www.greenco.org for more detailed guidance on tree preservation.
Protection of Existing Vegetation (PV) SM-2
November 2010 Urban Drainage and Flood Control District PV-3
Urban Storm Drainage Criteria Manual Volume 3
roots (in fill situations) or damage roots (in cut situations). Consider small walls where needed to
avoid grade changes in the tree protection zone.
Place and maintain a layer of mulch 4 to 6-inch thick from the tree trunk to the fencing, keeping a
6-inch space between the mulch and the trunk. Mulch helps to preserve moisture and decrease soil
compaction if construction traffic is unavoidable. When planting operations are completed, the mulch
may be reused throughout planting areas.
Limit access, if needed at all, and appoint one route as the main entrance and exit to the tree
protection zone. Within the tree protection zone, do not allow any equipment to be stored, chemicals
to be dumped, or construction activities to take place except fine grading, irrigation system
installation, and planting operations. These activities should be conducted in consultation with a
landscaping professional, following Green Industry BMPs.
Be aware that soil compaction can cause extreme damage to tree health that may appear gradually
over a period of years. Soil compaction is easier to prevent than repair.
Maintenance and Removal
Repair or replace damaged or displaced fencing or other protective barriers around the vegetated area.
If damage occurs to a tree, consult an arborist for guidance on how to care for the tree. If a tree in a
designated preservation area is damaged beyond repair, remove and replace with a 2-inch diameter tree of
the same or similar species.
Construction equipment must not enter a wetland area, except as permitted by the U.S. Army Corps of
Engineers (USACE). Inadvertent placement of fill in a wetland is a 404 permit violation and will require
notification of the USACE.
If damage to vegetation occurs in a protected area, reseed the area with the same or similar species,
following the recommendations in the USDCM Revegetation chapter.
Construction Fence (CF) SM-3
November 2010 Urban Drainage and Flood Control District CF-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph CF-1. A construction fence helps delineate areas where
existing vegetation is being protected. Photo courtesy of Douglas
County.
Description
A construction fence restricts site access
to designated entrances and exits,
delineates construction site boundaries,
and keeps construction out of sensitive
areas such as natural areas to be
preserved as open space, wetlands and
riparian areas.
Appropriate Uses
A construction fence can be used to
delineate the site perimeter and locations
within the site where access is restricted
to protect natural resources such as
wetlands, waterbodies, trees, and other
natural areas of the site that should not be
disturbed.
If natural resource protection is an objective, then the construction fencing should be used in combination
with other perimeter control BMPs such as silt fence, sediment control logs or similar measures.
Design and Installation
Construction fencing may be chain link or plastic mesh and should be installed following manufacturer’s
recommendations. See Detail CF-1 for typical installations.
Do not place construction fencing in areas within work limits of machinery.
Maintenance and Removal
Inspect fences for damage; repair or replace as necessary.
Fencing should be tight and any areas with slumping or fallen posts should be reinstalled.
Fencing should be removed once construction is complete.
Construction Fence
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
SM-3 Construction Fence (CF)
CF-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Construction Fence (CF) SM-3
November 2010 Urban Drainage and Flood Control District CF-3
Urban Storm Drainage Criteria Manual Volume 3
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph VTC-1. A vehicle tracking control pad constructed with
properly sized rock reduces off-site sediment tracking.
Description
Vehicle tracking controls provide
stabilized construction site access where
vehicles exit the site onto paved public
roads. An effective vehicle tracking
control helps remove sediment (mud or
dirt) from vehicles, reducing tracking onto
the paved surface.
Appropriate Uses
Implement a stabilized construction
entrance or vehicle tracking control where
frequent heavy vehicle traffic exits the
construction site onto a paved roadway. An
effective vehicle tracking control is
particularly important during the following conditions:
Wet weather periods when mud is easily tracked off site.
During dry weather periods where dust is a concern.
When poorly drained, clayey soils are present on site.
Although wheel washes are not required in designs of vehicle tracking controls, they may be needed at
particularly muddy sites.
Design and Installation
Construct the vehicle tracking control on a level surface. Where feasible, grade the tracking control
towards the construction site to reduce off-site runoff. Place signage, as needed, to direct construction
vehicles to the designated exit through the vehicle tracking control. There are several different types of
stabilized construction entrances including:
VTC-1. Aggregate Vehicle Tracking Control. This is a coarse-aggregate surfaced pad underlain by a
geotextile. This is the most common vehicle tracking control, and when properly maintained can be
effective at removing sediment from vehicle tires.
VTC-2. Vehicle Tracking Control with Construction Mat or Turf Reinforcement Mat. This type of
control may be appropriate for site access at very small construction sites with low traffic volume over
vegetated areas. Although this application does not typically remove sediment from vehicles, it helps
protect existing vegetation and provides a stabilized entrance.
Vehicle Tracking Control
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management Yes
SM-4 Vehicle Tracking Control (VTC)
VTC-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph VTC-2. A vehicle tracking control pad with wheel wash
facility. Photo courtesy of Tom Gore.
VTC-3. Stabilized Construction Entrance/Exit with Wheel Wash. This is an aggregate pad, similar
to VTC-1, but includes equipment for tire washing. The wheel wash equipment may be as simple as
hand-held power washing equipment to more advance proprietary systems. When a wheel wash is
provided, it is important to direct wash water to a sediment trap prior to discharge from the site.
Vehicle tracking controls are sometimes installed in combination with a sediment trap to treat runoff.
Maintenance and Removal
Inspect the area for degradation and
replace aggregate or material used for a
stabilized entrance/exit as needed. If the
area becomes clogged and ponds water,
remove and dispose of excess sediment
or replace material with a fresh layer of
aggregate as necessary.
With aggregate vehicle tracking controls,
ensure rock and debris from this area do
not enter the public right-of-way.
Remove sediment that is tracked onto the
public right of way daily or more
frequently as needed. Excess sediment
in the roadway indicates that the
stabilized construction entrance needs
maintenance.
Ensure that drainage ditches at the
entrance/exit area remain clear.
A stabilized entrance should be removed only when there is no longer the potential for vehicle tracking to
occur. This is typically after the site has been stabilized.
When wheel wash equipment is used, be sure that the wash water is discharged to a sediment trap prior to
discharge. Also inspect channels conveying the water from the wash area to the sediment trap and
stabilize areas that may be eroding.
When a construction entrance/exit is removed, excess sediment from the aggregate should be removed
and disposed of appropriately. The entrance should be promptly stabilized with a permanent surface
following removal, typically by paving.
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-3
Urban Storm Drainage Criteria Manual Volume 3
SM-4 Vehicle Tracking Control (VTC)
VTC-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-5
Urban Storm Drainage Criteria Manual Volume 3
SM-4 Vehicle Tracking Control (VTC)
VTC-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Stabilized Construction Roadway (SCR) SM-5
November 2010 Urban Drainage and Flood Control District SCR-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SCR-1. Stabilized construction roadway.
Description
A stabilized construction roadway is a
temporary method to control sediment
runoff, vehicle tracking, and dust from
roads during construction activities.
Appropriate Uses
Use on high traffic construction roads to
minimize dust and erosion.
Stabilized construction roadways are
used instead of rough-cut street controls
on roadways with frequent construction
traffic.
Design and Installation
Stabilized construction roadways typically involve two key components: 1) stabilizing the road surface
with an aggregate base course of 3-inch-diameter granular material and 2) stabilizing roadside ditches, if
applicable. Early application of road base is generally suitable where a layer of coarse aggregate is
specified for final road construction.
Maintenance and Removal
Apply additional gravel as necessary to ensure roadway integrity.
Inspect drainage ditches along the roadway for erosion and stabilize, as needed, through the use of check
dams or rolled erosion control products.
Gravel may be removed once the road is ready to be paved. Prior to paving, the road should be inspected
for grade changes and damage. Regrade and repair as necessary.
Stabilized Construction Roadway
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material Management Yes
Stabilized Staging Area (SSA) SM-6
November 2010 Urban Drainage and Flood Control District SSA-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SSA-1. Example of a staging area with a gravel surface to
prevent mud tracking and reduce runoff. Photo courtesy of Douglas
County.
Description
A stabilized staging area is a clearly
designated area where construction
equipment and vehicles, stockpiles, waste
bins, and other construction-related
materials are stored. The contractor
office trailer may also be located in this
area. Depending on the size of the
construction site, more than one staging
area may be necessary.
Appropriate Uses
Most construction sites will require a
staging area, which should be clearly
designated in SWMP drawings. The layout
of the staging area may vary depending on
the type of construction activity. Staging areas located in roadways due to space constraints require
special measures to avoid materials being washed into storm inlets.
Design and Installation
Stabilized staging areas should be completed prior to other construction activities beginning on the site.
Major components of a stabilized staging area include:
Appropriate space to contain storage and provide for loading/unloading operations, as well as parking
if necessary.
A stabilized surface, either paved or covered, with 3-inch diameter aggregate or larger.
Perimeter controls such as silt fence, sediment control logs, or other measures.
Construction fencing to prevent unauthorized access to construction materials.
Provisions for Good Housekeeping practices related to materials storage and disposal, as described in
the Good Housekeeping BMP Fact Sheet.
A stabilized construction entrance/exit, as described in the Vehicle Tracking Control BMP Fact Sheet,
to accommodate traffic associated with material delivery and waste disposal vehicles.
Over-sizing the stabilized staging area may result in disturbance of existing vegetation in excess of that
required for the project. This increases costs, as well as
requirements for long-term stabilization following the
construction period. When designing the stabilized staging area,
minimize the area of disturbance to the extent practical.
Stabilized Staging Area
Functions
Erosion Control Yes
Sediment Control Moderate
Site/Material
Yes
SM-6 Stabilized Staging Area (SSA)
SSA-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
See Detail SSA-1 for a typical stabilized staging area and SSA-2 for a stabilized staging area when
materials staging in roadways is required.
Maintenance and Removal
Maintenance of stabilized staging areas includes maintaining a stable surface cover of gravel, repairing
perimeter controls, and following good housekeeping practices.
When construction is complete, debris, unused stockpiles and materials should be recycled or properly
disposed. In some cases, this will require disposal of contaminated soil from equipment leaks in an
appropriate landfill. Staging areas should then be permanently stabilized with vegetation or other surface
cover planned for the development.
Minimizing Long-Term Stabilization Requirements
Utilize off-site parking and restrict vehicle access to the site.
Use construction mats in lieu of rock when staging is provided in an area that will not be disturbed
otherwise.
Consider use of a bermed contained area for materials and equipment that do not require a
stabilized surface.
Consider phasing of staging areas to avoid disturbance in an area that will not be otherwise
disturbed.
Stabilized Staging Area (SSA) SM-6
November 2010 Urban Drainage and Flood Control District SSA-3
Urban Storm Drainage Criteria Manual Volume 3
SM-6 Stabilized Staging Area (SSA)
SSA-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Street Sweeping and Vacuuming (SS) SM-7
November 2010 Urban Drainage and Flood Control District SS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SS-1. A street sweeper removes sediment and potential
pollutants along the curb line at a construction site. Photo courtesy of
Tom Gore.
Description
Street sweeping and vacuuming remove
sediment that has been tracked onto
roadways to reduce sediment transport
into storm drain systems or a surface
waterway.
Appropriate Uses
Use this practice at construction sites
where vehicles may track sediment
offsite onto paved roadways.
Design and Installation
Street sweeping or vacuuming should be
conducted when there is noticeable
sediment accumulation on roadways adjacent to the construction site. Typically, this will be concentrated
at the entrance/exit to the construction site. Well-maintained stabilized construction entrances, vehicle
tracking controls and tire wash facilities can help reduce the necessary frequency of street sweeping and
vacuuming.
On smaller construction sites, street sweeping can be conducted manually using a shovel and broom.
Never wash accumulated sediment on roadways into storm drains.
Maintenance and Removal
Inspect paved roads around the perimeter of the construction site on a daily basis and more
frequently, as needed. Remove accumulated sediment, as needed.
Following street sweeping, check inlet protection that may have been displaced during street
sweeping.
Inspect area to be swept for materials that may be hazardous prior to beginning sweeping operations.
Street Sweeping/ Vacuuming
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management Yes
Temporary Diversion Channel (TDC) SM-8
August 2011 Urban Drainage and Flood Control District TDC-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TDC-1. Use of a temporary diversion channel (right side)
to enable installation of a grade control structure (left side). Photo
courtesy of WWE.
Description
A temporary diversion channel diverts
water from a stream to allow for
construction activities to take place
underneath or in the stream. Diversion
channels are often required during the
construction of detention ponds, dams,
in-stream grade control structures,
utility installation and other activities
that require working in waterways.
Appropriate Uses
Temporary diversion channels vary
with the size of the waterway that is
being diverted. For large streams, a
temporary diversion may consist of
berms or coffer dams constructed in the
stream to confine flow to one side of the stream while work progresses on the dry side of the berm. For
smaller streams and often for construction of dams and detention basins, a temporary diversion channel
may divert the entire waterway, as illustrated in Figure TDC-1. For very short duration projects (typically
less than 4 weeks) during dry periods with low base flows, a pump and bypass pipe may serve as a
temporary diversion. Whenever a temporary diversion is used, construction should be scheduled during
drier times of the year if possible (October 1 through April 1), and construction in the waterway should
progress as quickly as possible to reduce the risk of exceeding the temporary diversion channel capacity.
Some construction activities within a waterway are very short lived, namely a few hours or days in
duration, and are minor in nature. These are typically associated with maintenance of utilities and stream
crossings and minor repairs to outfalls and eroded banks. In these cases, construction of temporary
diversion channels can often cause more soil disturbance and sediment movement than the maintenance
activity itself. If it can be reasonably determined based on area and duration of disturbance that channel
work will result in less disturbance and movement of sediment than would be done through installation of
a temporary diversion channel, it is reasonable to exempt these activities from the requirement to
construct a temporary diversion.
Design and Installation
Temporary Diversion Channel sizing procedures typically include the following steps:
Using the tributary area, A (in acres), determine the design peak flow rate according to Figure TDC-2.
Note: For long duration projects, or where the consequences of diversion failure warrant, a larger
design flow may be necessary.
Determine depth of flow, 1-foot maximum for flows
less than 20 cfs and 3 feet maximum for flows less
than 100 cfs. (Flows in excess of 100 cfs should be
designed in accordance with the Major Drainage
chapter in Volume 1).
Temporary Diversion Channel
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
SM-8 Temporary Diversion Channel (TDC)
TDC-2 Urban Drainage and Flood Control District August 2011
Urban Storm Drainage Criteria Manual Volume 3
Determine channel slope based on existing and proposed site conditions.
Perform initial channel sizing calculations using Manning's Equation. Determine maximum
permissible velocities based on lining material.
Determine the channel geometry and check the capacity using Manning's Equation and the "n" value
given in Table TDC-1. The steepest side slope allowable for a temporary channel is two horizontal to
one vertical (2:1), unless vertical walls are installed using sheet piling, concrete or stacked stone.
Temporary diversion channels should have a minimum freeboard of 0.5 feet above the design water
surface elevation.
Figure TDC-2 may be used to estimate the design discharge for the sizing of temporary diversion
channels and pipes. The curves in this figure were developed using annual peak flow data collected from
17 watersheds within the UDFCD boundary. These data were collected over extended periods of time (up
to eleven years) and, as a result, provide a sound statistical basis for the figure. The data supporting
Figure TDC-2 were taken during the high flood potential period of April through September. The values
from Figure TDC-2 represent approximately the 95th percentile event that can occur, on the average, any
given year, which means that it is likely that about 95 percent of runoff peaks during an average year will
be less than values from this chart. This may not be the case in wetter-than-average seasons. Figure
TDC-2 provides estimated 2-year peak flow rates based on watershed imperviousness for small
waterways (< 12 square miles). Because Figure TDC-2 was developed using data from small watersheds,
it is not appropriate to extrapolate from this figure for larger, more complex watersheds. For larger
waterways (e.g., South Platte River, Sand Creek, Bear Creek, etc.), including ones controlled by flood
control reservoirs (e.g. Chatfield Dam, Cherry Creek Dam, etc.), site specific risk assessment may be
necessary to evaluate the appropriate level of protection to be provided by the temporary diversion. It is
also important to recognize that larger floods can and do occur. It is the responsibility of the designer and
the contractor to assess their risk of having the temporary diversion being exceeded and to evaluate the
damages such an event may cause to the project, adjacent properties and others. Consider larger capacity
diversions to protect a project if it will require a temporary diversion for more than one year.
Because temporary diversion channels typically are not in service long enough to establish adequate
vegetative lining, they must be designed to be stable for the design flow with the channel shear stress less
than the critical tractive shear stress for the channel lining material. This stability criterion applies not
only to diversion channels, but also to the stream-side of berms when berms are used to isolate a work
area within a stream. Unlined channels should not be used. Table TDC-1 gives Manning's "n" values for
lining materials. Design procedures for temporary channels are described in detail in the Hydraulic
Engineering Circular No. 15 published by the Federal Highway Administration. The methods presented
in this Fact Sheet are greatly simplified and are based on information developed using the most
commonly used erosion control materials.
Temporary Diversion Channel (TDC) SM-8
August 2011 Urban Drainage and Flood Control District TDC-3
Urban Storm Drainage Criteria Manual Volume 3
Figure TDC-1. Typical Temporary Diversion Channel
Former Location of
Stream Bank
Former Location of
Stream Bank
SM-8 Temporary Diversion Channel (TDC)
TDC-4 Urban Drainage and Flood Control District August 2011
Urban Storm Drainage Criteria Manual Volume 3
52.4%
40.2%
46.5%43.3%
33.3%
15.5%
18.0%
55.4%
24.3%
46.1%
39.1%
10.1%
60.9%
26.8%
29.8%
0
100
200
300
400
500
600
700
800
900
1000
0 2 4 6 8 10 12
TRIBUTARY AREA (SQUARE MILES)
FL
O
W
(
C
F
S
)
Imp. = 40%
Imp. = 30%
Imp. = 20%
Imp. = 60%
Figure TDC-2. Temporary Diversion Facility Sizing Nomograph Based on 2-year Peak Flows -
Denver Metropolitan and Adjacent Areas
Temporary Diversion Channel (TDC) SM-8
August 2011 Urban Drainage and Flood Control District TDC-5
Urban Storm Drainage Criteria Manual Volume 3
Table TDC-1. Temporary Diversion Channel Design Criteria
Lining Material
Manning's n for
Flow Depth
0 ft to 1.0 ft
Manning's n for
Flow Depth
1.0 ft to 3.0 ft
Manning's n for
Flow Depth
3.0 ft to 5.0 ft
Plastic Membrane 0.011 0.010 0.009
Straw or Curled Wood
Mats
0.035 0.025 0.020
Riprap, Type VL 0.070 0.045 0.035
Riprap, Type L 0.100 0.070 0.040
Riprap, Type M 0.125 0.075 0.045
Notes: Use manufacturer's Manning's n when available.
See the Major Drainage chapter of Volume 1 for riprap gradation.
Erosion protection should extend a minimum of 0.5 feet above the design water depth.
Maintenance and Removal
Because temporary diversion channels are one of the most critical BMPs for work in waterways, they
must be inspected and maintained frequently to remain in effective operating condition. Flow barriers
should be inspected at the start and end of each workday and at any time that excess water is noted in dry
work areas. The diversion channel itself should be inspected for signs of erosion, and the lining should be
repaired or replaced if there are signs of failure. Check armoring at the diversion return point to the
waterway, and add additional armoring if erosion is noted.
Water should not be allowed to flow back through the natural stream until all construction is completed.
After redirecting the flow through the natural channel, lining materials should be removed from the
temporary diversion channel. The diversion channel should then be backfilled and stabilized. Points of
tie-in to the natural channel should be protected with riprap sized in accordance with the Major Drainage
chapter in Volume 1.
SM-8 Temporary Diversion Channel (TDC)
TDC-6 Urban Drainage and Flood Control District August 2011
Urban Storm Drainage Criteria Manual Volume 3
Temporary Diversion Channel (TDC) SM-8
August 2011 Urban Drainage and Flood Control District TDC-7
Urban Storm Drainage Criteria Manual Volume 3
Dewatering Operations (DW) SM-9
November 2010 Urban Drainage and Flood Control District DW-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph DW-1. A relatively small dewatering operation using straw
bales and a dewatering bag.
Photograph DW-2. Dewatering bags used for a relatively large
dewatering operation.
Description
The BMPs selected for construction
dewatering vary depending on site-
specific features such as soils,
topography, anticipated discharge
quantities, and discharge location.
Dewatering typically involves pumping
water from an inundated area to a BMP,
and then downstream to a receiving
waterway, sediment basin, or well-
vegetated area. Dewatering typically
involves use of several BMPs in
sequence.
Appropriate Uses
Dewatering operations are used when an
area of the construction site needs to be
dewatered as the result of a large storm
event, groundwater, or existing ponding
conditions. This can occur during deep
excavation, utility trenching, and wetland
or pond excavation.
Design and Installation
Dewatering techniques will vary
depending on site conditions. However,
all dewatering discharges must be treated
to remove sediment before discharging
from the construction site. Discharging
water into a sediment trap or basin is an
acceptable treatment option. Water may
also be treated using a dewatering filter bag,
and a series of straw bales or sediment logs. If these previous options are not feasible due to space or the
ability to passively treat the discharge to remove sediment, then a settling tank or an active treatment
system may need to be utilized. Settling tanks are manufactured tanks with a series of baffles to promote
settling. Flocculants can also be added to the tank to induce more rapid settling. This is an approach
sometimes used on highly urbanized construction sites. Contact the state agency for special requirements
prior to using flocculents and land application techniques.
Some commonly used methods to handle the pumped
water without surface discharge include land application
to vegetated areas through a perforated discharge hose
(i.e., the "sprinkler method") or dispersal from a water
truck for dust control.
Dewatering Operations
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management Yes
SM-9 Dewatering Operations (DW)
DW-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Dewatering discharges to non-paved areas must minimize the potential for scour at the discharge point
either using a velocity dissipation device or dewatering filter bag.
Design Details are provided for these types of dewatering situations:
DW-1. Dewatering for Pond Already Filled with Water
DW-2 Dewatering Sump for Submersed Pump
DW-3 Sump Discharge Settling Basin
DW-4 Dewatering Filter Bag
Maintenance and Removal
When a sediment basin or trap is used to enable settling of sediment from construction dewatering
discharges, inspect the basin for sediment accumulation. Remove sediment prior to the basin or trap
reaching half full. Inspect treatment facilities prior to any dewatering activity. If using a sediment
control practice such as a sediment trap or basin, complete all maintenance requirements as described in
the fact sheets prior to dewatering.
Properly dispose of used dewatering bags, as well as sediment removed from the dewatering BMPs.
Depending on the size of the dewatering operation, it may also be necessary to revegetate or otherwise
stabilize the area where the dewatering operation was occurring.
Dewatering Operations (DW) SM-9
November 2010 Urban Drainage and Flood Control District DW-3
Urban Storm Drainage Criteria Manual Volume 3
SM-9 Dewatering Operations (DW)
DW-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Dewatering Operations (DW) SM-9
November 2010 Urban Drainage and Flood Control District DW-5
Urban Storm Drainage Criteria Manual Volume 3
Temporary Stream Crossing (TSC) SM-10
November 2010 Urban Drainage and Flood Control District TSC-1
Urban Storm Drainage Criteria Manual Volume 3
Description
Where an actively flowing watercourse
must be crossed regularly by
construction vehicles, a temporary
crossing should be provided. Three
primary methods are available:
Culvert crossing
Stream ford
Temporary bridge
Culvert crossings and fords are the most
commonly used methods. Due to the
expense associated with a temporary
bridge, these are used primarily on long-
term projects.
Appropriate Uses
Construction vehicles shall be kept out of waterways to the maximum extent practicable. Use a
temporary stream crossing when it is absolutely necessary to cross a stream on a construction site.
Construct a temporary crossing even if the stream or drainageway is typically dry. Multiple stream
crossings should be avoided to minimize environmental impacts.
A permit is required for placement of fill in a waterway under Section 404 of the Clean Water Act. The
local office of the U.S. Army Corps of Engineers (USACE) should be contacted concerning the
requirements for obtaining a 404 permit. In addition, a permit from the U.S. Fish and Wildlife Service
(USFWS) may be needed if endangered species are of concern in the work area. Typically, the USFWS
issues are addressed by a 404 permit, if one is required. The municipality of jurisdiction should also be
consulted, and can provide assistance. Other permits to be obtained may include a floodplain
development permit from the local jurisdiction.
Design and Installation
Design details are provided for these types of stream crossings:
TSC-1. Culvert Crossing
TSC-2. Ford Crossing
TSC-3. Flume Crossing
Temporary Stream Crossing
Functions
Erosion Control Yes
Sediment Control Yes
Site/Material Management No
Photograph TSC-1. A temporary stream crossing using culverts.
Photo courtesy of Tom Gore.
SM-10 Temporary Stream Crossing (TSC)
TSC-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
A culvert crossing should be designed to pass at least the 2-year design flow. Use Figure DC-2 from the
Temporary Channel Diversion Fact Sheet to determine the 2-year peak flow rate. Culvert sizing must
account for the headwater and tailwater controls to properly size the culvert. For additional discussion on
design of box culverts and pipes, see the Major Drainage chapter in Volume 1. The designer also needs
to confirm that the riprap selected is appropriate for the conditions in the channel being crossed.
When a ford must be used, namely when a culvert is not practical or the best solution, the ford should be
lined with at least a 12-inch thick layer of Type VL (D50 = 6 inches) or Type L (D50 = 9 inches) riprap
with void spaces filed with 1-1/2 inch diameter rock. Ford crossings are recommended primarily for
crossings of ephemeral (i.e. intermittently, briefly flowing) streams.
For a temporary bridge crossing, consult with a structural and/or geotechnical engineer for temporary
bridge design or consider pre-fabricated alternatives.
Maintenance and Removal
Inspect stream for bank erosion and in-stream degradation. If bank erosion is occurring, stabilize banks
using erosion control practices such as erosion control blankets. If in-stream degradation is occurring,
armor the culvert outlet(s) with riprap to dissipate energy (see Outlet Protection Fact Sheet). If sediment
is accumulating upstream of the crossing, remove excess sediment as needed to maintain the functionality
of the crossing.
Remove the temporary crossing when it is no longer needed for construction. Take care to minimize the
amount of sediment lost into the stream upon removal. Once the crossing has been removed, stabilize the
stream banks with seed and erosion control blankets.
Temporary Stream Crossing (TSC) SM-10
November 2010 Urban Drainage and Flood Control District TSC-3
Urban Storm Drainage Criteria Manual Volume 3
SM-10 Temporary Stream Crossing (TSC)
TSC-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary Stream Crossing (TSC) SM-10
November 2010 Urban Drainage and Flood Control District TSC-5
Urban Storm Drainage Criteria Manual Volume 3
SM-10 Temporary Stream Crossing (TSC)
TSC-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary Batch Plant (TBP) SM-11
November 2010 Urban Drainage and Flood Control District TBP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TBP-1. Effective stormwater management at temporary
batch plants requires implementation of multiple BMPs. Photo
courtesy of California Stormwater BMP Handbook.
Description
Temporary batch plant management
includes implementing multiple BMPs
such as perimeter controls, concrete
washout area, stabilized construction
access, good housekeeping, and other
practices designed to reduce polluted
runoff from the batch plant area.
Appropriate Uses
Implement this BMP at temporary batch
plants and identify the location of the
batch plant in the SWMP.
Additional permitting may be required for
the operation of batch plants depending on their duration and location.
Design and Installation
The following lists temporary management strategies to mitigate runoff from batch plant operations:
When stockpiling materials, follow the Stockpile Management BMP.
Locate batch plants away from storm drains and natural surface waters.
A perimeter control should be installed around the temporary batch plant.
Install run-on controls where feasible.
A designated concrete washout should be located within the perimeter of the site following the
procedures in the Concrete Washout Area BMP.
Follow the Good Housekeeping BMP, including proper spill containment measures, materials
storage, and waste storage practices.
A stabilized construction entrance or vehicle tracking control pad should be installed at the plant
entrance, in accordance with the Vehicle Tracking Control BMP.
Maintenance and Removal
Inspect the batch plant for proper functioning of the BMPs, with
attention to material and waste storage areas, integrity of
perimeter BMPs, and an effective stabilized construction
entrance.
Temporary Batch Plants
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
SM-11 Temporary Batch Plant (TBP)
TBP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
After the temporary batch plant is no longer needed, remove stockpiled materials and equipment, regrade
the site as needed, and revegetate or otherwise stabilize the area.
Paving and Grinding Operations (PGO) SM-12
November 2010 Urban Drainage and Flood Control District PGO-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph PGO-1. Paving operations on a Colorado highway. Photo
courtesy of CDOT.
Description
Manage runoff from paving and grinding
operations to reduce pollutants entering
storm drainage systems and natural
drainageways.
Appropriate Uses
Use runoff management practices during
all paving and grinding operations such
as surfacing, resurfacing, and saw
cutting.
Design and Installation
There are a variety of management
strategies that can be used to manage runoff from paving and grinding operations:
Establish inlet protection for all inlets that could potentially receive runoff.
Schedule paving operations when dry weather is forecasted.
Keep spill kits onsite for equipment spills and keep drip pans onsite for stored equipment.
Install perimeter controls when asphalt material is used on embankments or shoulders near
waterways, drainages, or inlets.
Do not wash any paved surface into receiving storm drain inlets or natural drainageways. Instead,
loose material should be swept or vacuumed following paving and grinding operations.
Store materials away from drainages or waterways.
Recycle asphalt and pavement material when feasible. Material that cannot be recycled must be
disposed of in accordance with applicable regulations.
See BMP Fact Sheets for Inlet Protection, Silt Fence and other perimeter controls selected for use during
paving and grinding operations.
Maintenance and Removal
Perform maintenance and removal of inlet protection and perimeter controls in accordance with their
respective fact sheets.
Promptly respond to spills in accordance with the spill
prevention and control plan.
Paving and Grinding Operations
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
Grass Buffer T-1
November 2010 Urban Drainage and Flood Control District GB-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph GB-1. A flush curb allows roadway runoff to sheet flow
through the grass buffer. Flows are then further treated by the grass
swale. Photo courtesy of Muller Engineering.
Description
Grass buffers are densely vegetated
strips of grass designed to accept sheet
flow from upgradient development.
Properly designed grass buffers play a
key role in LID, enabling infiltration and
slowing runoff. Grass buffers provide
filtration (straining) of sediment.
Buffers differ from swales in that they
are designed to accommodate overland
sheet flow rather than concentrated or
channelized flow.
Site Selection
Grass buffers can be incorporated into a
wide range of development settings.
Runoff can be directly accepted from a
parking lot, roadway, or the roof of a
structure, provided the flow is distributed in a uniform manner over the width of the buffer. This can be
achieved through the use of flush curbs, slotted curbs, or level spreaders where needed. Grass buffers are
often used in conjunction with grass swales. They are well suited for use in riparian zones to assist in
stabilizing channel banks adjacent to major drainageways and receiving waters. These areas can also
sometimes serve multiple functions such as recreation.
Hydrologic Soil Groups A and B provide the best infiltration
capacity for grass buffers. For Type C and D soils, buffers still
serve to provide filtration (straining) although infiltration rates are
lower.
Designing for Maintenance
Recommended ongoing maintenance practices for all BMPs are
provided in Chapter 6 of this manual. During design the
following should be considered to ensure ease of maintenance
over the long-term:
Where appropriate (where vehicle safety would not be
impacted), install the top of the buffer 1 to 3 inches below the
adjacent pavement so that growth of vegetation and
accumulation of sediment at the edge of the strip does not
prevent runoff from entering the buffer. Alternatively, a
sloped edge can be used adjacent to vehicular traffic areas.
Amend soils to encourage deep roots and reduce irrigation
requirements, as well as promote infiltration.
Grass Buffer
Functions
LID/Volume Red. Yes
WQCV Capture No
WQCV+Flood Control No
Fact Sheet Includes
EURV Guidance No
Typical Effectiveness for Targeted
Pollutants3
Sediment/Solids Good
Nutrients Moderate
Total Metals Good
Bacteria Poor
Other Considerations
Life-cycle Costs Low
3 Based primarily on data from the
International Stormwater BMP Database
(www.bmpdatabase.org).
T-1 Grass Buffer
GB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Benefits
Filters (strains) sediment and
trash.
Reduces directly connected
impervious area. (See Chapter 3
for quantifying benefits.)
Can easily be incorporated into a
treatment train approach.
Provides green space available
for multiple uses including
recreation and snow storage.
Straightforward maintenance
requirements when the buffer is
protected from vehicular traffic.
Limitations
Frequently damaged by vehicles
when adjacent to roadways and
unprotected.
A thick vegetative cover is
needed for grass buffers to be
effective.
Nutrient removal in grass buffers
is typically low.
High loadings of coarse solids,
trash, and debris require
pretreatment.
Space for grass buffers may not
be available in ultra urban areas
(lot-line-to-lot-line).
Design and adjust the irrigation system (temporary or
permanent) to provide water in amounts appropriate for
the selected vegetation. Irrigation needs will change from
month to month and year to year.
Protect the grass buffer from vehicular traffic when using
this BMP adjacent to roadways. This can be done with a
slotted curb (or other type of barrier) or by constructing a
reinforced grass shoulder (see Fact Sheet T-10.5).
Design Procedure and Criteria
The following steps outline the grass buffer design procedure
and criteria. Figure GB-1 is a schematic of the facility and its
components:
1. Design Discharge: Use the hydrologic procedures
described in the Runoff chapter of Volume 1 to determine
the 2-year peak flow rate (Q2) of the area draining to the
grass buffer.
2. Minimum Width: The width (W), normal to flow of the
buffer, is typically the same as the contributing basin (see
Figure GB-1). An exception to this is where flows become
concentrated. Concentrated flows require a level spreader
to distribute flows evenly across the width of the buffer.
The minimum width should be: 𝑊𝑊=𝑄𝑄20.05 Equation GB-1
Where:
W = width of buffer (ft)
Q2 = 2-year peak runoff (cfs)
3. Length: The recommended length (L), the distance along
the sheet flow direction, should be a minimum of 14 feet.
This value is based on the findings of Barrett et al. 2004 in
Stormwater Pollutant Removal in Roadside Vegetated
Strips and is appropriate for buffers with greater than 80%
vegetative cover and slopes up to 10%. The study found
that pollutant removal continues throughout a length of 14 feet. Beyond this length, a point of
diminishing returns in pollutant reduction was found. It is important to note that shorter lengths or
slightly steeper slopes will also provide some level of removal where site constraints dictate the
geometry of the buffer.
Grass Buffer T-1
November 2010 Urban Drainage and Flood Control District GB-3
Urban Storm Drainage Criteria Manual Volume 3
Photograph GB-2. This level spreader carries concentrated flows into a
slotted pipe encased in concrete to distribute flows evenly to the grass buffer
shown left in the photo. Photo courtesy of Bill Wenk.
Use of Grass Buffers
Sheet flow of stormwater through a
grassed area provides some benefit in
pollutant removal and volume
reduction even when the geometry of
the BMP does not meet the criteria
provided in this Fact Sheet. These
criteria provide a design procedure
that should be used when possible;
however, when site constraints are
limiting, this treatment concept is
still encouraged.
4. Buffer Slope: The design slope of a grass buffer in the
direction of flow should not exceed 10%. Generally, a
minimum slope of 2% or more in turf is adequate to
facilitate positive drainage. For slopes less than 2%,
consider including an underdrain system to mitigate
nuisance drainage.
5. Flow Characteristics (sheet or concentrated):
Concentrated flows can occur when the width of the
watershed differs from that of the grass buffer.
Additionally, when the product of the watershed flow
length and the interface slope (the slope of the watershed
normal to flow at the grass buffer) exceeds approximately
one, flows may become concentrated. Use the following
equations to determine flow characteristics: Sheet Flow: FL(SI) ≤ 1 Equation GB-2 Concentrated Flow: FL(SI) > 1 Equation GB-3
Where:
FL = watershed flow length (ft)
SI = interface slope (normal to flow) (ft/ft)
6. Flow Distribution: Flows delivered to a grass buffer must be sheet flows. Slotted or flush curbing,
permeable pavements, or other devices can be used to spread flows. The grass buffer should have
relatively consistent slopes to avoid concentrating flows within the buffer.
A level spreader should be used when flows are concentrated. A level spreader can be a slotted drain
designed to discharge flow through the slot as shown in Photo GB-2. It could be an exfiltration
trench filled with gravel, which allows water to infiltrate prior to discharging over a level concrete or
rock curb. There are many ways to design and construct a level spreader. They can also be used in
series when the length of the
buffer allows flows to re-
concentrate. See Figure GB-2 for
various level spreader sections.
T-1 Grass Buffer
GB-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph GB-3. This level spreader includes the added benefit of a
sedimentation basin prior to even distribution of concentrated flows
from the roadway into the grass buffer. Photo courtesy of Bill Wenk.
Photograph GB-4. Maintenance access is provided via the ramp
located at the end of the basin. Photo courtesy of Bill Wenk.
Photos GB-3 and GB-4 show a level
spreader that includes a basin for
sedimentation. Concentrated flows
enter the basin via stormsewer. The
basin is designed to drain slowly
while overflow is spread evenly to
the downstream vegetation. A small
notch, orifice, or pipe can be used to
drain the level spreader completely.
The opening should be small to
encourage frequent flows to overtop
the level spreader but not so small
that it is frequently clogged.
7. Soil Preparation: In order to
encourage establishment and long-
term health of the selected vegetation,
it is essential that soil conditions be
properly prepared prior to
installation. Following site grading,
poor soil conditions often exist.
When possible, remove, strip,
stockpile, and reuse on-site topsoil.
If the site does not contain topsoil,
the soils should be amended prior to
vegetation. Typically 3 to 5 cubic
yards of soil amendment (compost)
per 1,000 square feet, tilled 6 inches
into the soil is required in order for
vegetation to thrive, as well as to
enable infiltration of runoff.
Additionally, inexpensive soil tests
can be conducted to determine
required soil amendments. (Some
local governments may also require
proof of soil amendment in
landscaped areas for water
conservation reasons.)
8. Vegetation: This is the most critical
component for treatment within a grass buffer. Select durable, dense, and drought tolerant grasses to
vegetate the buffer. Also consider the size of the watershed as larger watersheds will experience
more frequent flows. The goal is to provide a dense mat of vegetative cover. Grass buffer
performance falls off rapidly as the vegetation coverage declines below 80% (Barrett et al.2004).
Grass Buffer T-1
November 2010 Urban Drainage and Flood Control District GB-5
Urban Storm Drainage Criteria Manual Volume 3
Turf grasses such as Kentucky bluegrass are often selected due to these qualities1
9. Irrigation: Grass buffers should be equipped with irrigation systems to promote establishment and
survival in Colorado's semi-arid environment. Systems may be temporary or permanent, depending
on the type of vegetation selected. Irrigation application rates and schedules should be developed and
adjusted throughout the establishment and growing season to meet the needs of the selected plant
species. Initially, native grasses require the same irrigation requirements as bluegrass. After the
grass is established, irrigation requirements for native grasses can be reduced. Irrigation practices
have a significant effect on the function of the grass buffer. Overwatering decreases the permeability
of the soil, reducing the infiltration capacity and contributing to nuisance baseflows. Conversely,
under watering may result in delays in establishment of the vegetation in the short term and unhealthy
vegetation that provides less filtering and increased susceptibility to erosion and rilling over the long
term.
. Dense native turf
grasses may also be selected where a more natural look is desirable. Once established, these provide
the benefit of lower irrigation requirements. See the Revegetation chapter in Volume 2 of this manual
with regard to seed mix selection, planting and ground preparation. Depending on soils and
anticipated flows, consider erosion control measures until vegetation has been established.
10. Outflow Collection: Provide a means for downstream conveyance. A grass swale can be used for
this purpose, providing additional LID benefits.
Construction Considerations
Success of grass buffers depends not only on a good design and long-term maintenance, but also on
installing the facility in a manner that enables the BMP to function as designed. Construction
considerations include:
The final grade of the buffer is critical. Oftentimes, following soil amendment and placement of sod,
the final grade is too high to accept sheet flow. The buffer should be inspected prior to placement of
seed or sod to ensure appropriate grading.
Perform soil amending, fine grading, and seeding only after tributary areas have been stabilized and
utility work crossing the buffer has been completed.
When using sod tiles stagger the ends of the tiles to prevent the formation of channels along the
joints. Use a roller on the sod to ensure there are no air pockets between the sod and soil.
Avoid over compaction of soils in the buffer area during construction to preserve infiltration
capacities.
Erosion and sediment control measures on upgradient disturbed areas must be maintained to prevent
excessive sediment loading to grass buffer.
1 Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush, green aesthetic, it also withstands
drought conditions by going dormant. Over-irrigation of Kentucky bluegrass is a common problem along the Colorado Front
Range, and it can be healthy, although less lush, with much less irrigation than is typically applied.
T-1 Grass Buffer
GB-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
PLAN
PROFILE
Figure GB-1. Typical Grass Buffer Graphic by Adia Davis.
Grass Buffer T-1
November 2010 Urban Drainage and Flood Control District GB-7
Urban Storm Drainage Criteria Manual Volume 3
Figure GB-2. Typical Level Spreader Details
Grass Swale T-2
November 2010 Urban Drainage and Flood Control District GS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph GS-1. This grass swale provides treatment of roadway
runoff in a residential area. Photo courtesy of Bill Ruzzo.
Description
Grass swales are densely vegetated
trapezoidal or triangular channels with
low-pitched side slopes designed to
convey runoff slowly. Grass swales
have low longitudinal slopes and broad
cross-sections that convey flow in a slow
and shallow manner, thereby facilitating
sedimentation and filtering (straining)
while limiting erosion. Berms or check
dams may be incorporated into grass
swales to reduce velocities and
encourage settling and infiltration.
When using berms, an underdrain
system should be provided. Grass
swales are an integral part of the Low
Impact Development (LID) concept and
may be used as an alternative to a curb and
gutter system.
Site Selection
Grass swales are well suited for sites with low to moderate slopes.
Drop structures or other features designed to provide the same
function as a drop structures (e.g., a driveway with a stabilized
grade differential at the downstream end) can be integrated into
the design to enable use of this BMP at a broader range of site
conditions. Grass swales provide conveyance so they can also be
used to replace curb and gutter systems making them well suited
for roadway projects.
Designing for Maintenance
Recommended ongoing maintenance practices for all BMPs are
provided in Chapter 6 of this manual. During design, the
following should be considered to ensure ease of maintenance
over the long-term:
Consider the use and function of other site features so that the
swale fits into the landscape in a natural way. This can
encourage upkeep of the area, which is particularly important
in residential areas where a loss of aesthetics and/or function
can lead to homeowners filling in and/or piping reaches of
this BMP.
Grass Swale
Functions
LID/Volume Red. Yes
WQCV Capture No
WQCV+Flood Control No
Fact Sheet Includes
EURV Guidance No
Typical Effectiveness for Targeted
Pollutants3
Sediment/Solids Good
Nutrients Moderate
Total Metals Good
Bacteria Poor
Other Considerations
Life-cycle Costs Low
3 Based primarily on data from the
International Stormwater BMP Database
(www.bmpdatabase.org).
T-2 Grass Swale
GS-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Provide access to the swale for mowing equipment and
design sideslopes flat enough for the safe operation of
equipment.
Design and adjust the irrigation system (temporary or
permanent) to provide appropriate water for the selected
vegetation.
An underdrain system will reduce excessively wet areas,
which can cause rutting and damage to the vegetation
during mowing operations.
When using an underdrain, do not put a filter sock on the
pipe. This is unnecessary and can cause the slots or
perforations in the pipe to clog.
Design Procedure and Criteria
The following steps outline the design procedure and criteria
for stormwater treatment in a grass swale. Figure GS-1
shows trapezoidal and triangular swale configurations.
1. Design Discharge: Determine the 2-year flow rate to be
conveyed in the grass swale under fully developed
conditions. Use the hydrologic procedures described in
the Runoff Chapter in Volume 1.
2. Hydraulic Residence Time: Increased hydraulic
residence time in a grass swale improves water quality
treatment. Maximize the length of the swale when
possible. If the length of the swale is limited due to site
constraints, the slope can also be decreased or the cross-sectional area increased to increase hydraulic
residence time.
3. Longitudinal Slope: Establish a longitudinal slope that will meet Froude number, velocity, and
depth criteria while ensuring that the grass swale maintains positive drainage. Positive drainage can
be achieved with a minimum 2% longitudinal slope or by including an underdrain system (see step 8).
Use drop structures as needed to accommodate site constraints. Provide for energy dissipation
downstream of each drop when using drop structures.
4. Swale Geometry: Select geometry for the grass swale. The cross section should be either
trapezoidal or triangular with side slopes not exceeding 4:1 (horizontal: vertical), preferably flatter.
Increase the wetted area of the swale to reduce velocity. Lower velocities result in improved
pollutant removal efficiency and greater volume reduction. If one or both sides of the grass swale are
also to be used as a grass buffer, follow grass buffer criteria.
Benefits
Removal of sediment and
associated constituents through
filtering (straining)
Reduces length of storm sewer
systems in the upper portions of a
watershed
Provides a less expensive and
more attractive conveyance
element
Reduces directly connected
impervious area and can help
reduce runoff volumes.
Limitations
Requires more area than
traditional storm sewers.
Underdrains are recommended for
slopes under 2%.
Erosion problems may occur if not
designed and constructed
properly.
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November 2010 Urban Drainage and Flood Control District GS-3
Urban Storm Drainage Criteria Manual Volume 3
Native grasses provide
a more natural aesthetic
and require less water
once established.
Use of Grass Swales
Vegetated conveyance elements provide some benefit in pollutant removal and volume reduction
even when the geometry of the BMP does not meet the criteria provided in this Fact Sheet. These
criteria provide a design procedure that should be used when possible; however, when site
constraints are limiting, vegetated conveyance elements designed for stability are still encouraged.
5. Vegetation: Select durable, dense, and drought tolerant grasses. Turf grasses, such as Kentucky
bluegrass, are often selected due to these qualities1
once established. Turf grass is a general term for any
grasses that will form a turf or mat as opposed to bunch
grass, which will grow in clumplike fashion. Grass
selection should consider both short-term (for
establishment) and long-term maintenance requirements,
given that some varieties have higher maintenance
requirements than others. Follow criteria in the
Revegetation Chapter of Volume 2, with regard to seed
mix selection, planting, and ground preparation.
. Native turf grasses may also be selected where a
more natural look is desirable. This will also provide the benefit of lower irrigation requirements,
6. Design Velocity: Maximum flow velocity in the swale
should not exceed one foot per second. Use the Soil
Conservation Service (now the NRCS) vegetal retardance
curves for the Manning coefficient (Chow 1959).
Determining the retardance coefficient is an iterative
process that the UD-BMP workbook automates. When
starting the swale vegetation from sod, curve "D" (low retardance) should be used. When starting
vegetation from seed, use the "E" curve (very low vegetal retardance).
7. Design Flow Depth: Maximum flow depth should not exceed one foot at the 2-year peak flow rate.
Check the conditions for the 100-year flow to ensure that drainage is being handled without flooding
critical areas, structures, or adjacent streets.
Table GS-1. Grass Swale Design Summary for Water Quality
1 Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush, green aesthetic, it also withstands
drought conditions by going dormant. Over-irrigation of Kentucky bluegrass is a common problem along the Colorado Front
Range. It can be healthy, although less lush, with much less irrigation than is typically applied.
Design Flow Maximum
Froude Number
Maximum
Velocity
Maximum
Flow Depth
2-year event 0.5 1 ft/s 1 ft
T-2 Grass Swale
GS-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
8. Underdrain: An underdrain is necessary for swales with longitudinal slopes less than 2.0%. The
underdrain can drain directly into an inlet box at the downstream end of the swale, daylight through
the face of a grade control structure or continue below grade through several grade control structures
as shown in Figure GS-1.
The underdrain system should be placed within an aggregate layer. If no underdrain is required, this
layer is not required. The aggregate layer should consist of an 8-inch thick layer of CDOT Class C
filter material meeting the gradation in Table GS-2. Use of CDOT Class C Filter material with a
slotted pipe that meets the slot dimensions provided in Table GS-3 will eliminate the need for
geotextile fabrics. Previous versions of this manual detailed an underdrain system that consisted of a
3- to 4-inch perforated HDPE pipe in a one-foot trench section of AASHTO #67 coarse aggregate
surrounded by geotextile fabric. If desired, this system continues to provide an acceptable alternative
for use in grass swales. Selection of the pipe size may be a function of capacity or of maintenance
equipment. Provide cleanouts at approximately 150 feet on center.
Table GS-2. Gradation Specifications for Class C Filter Material
(Source: CDOT Table 703-7)
Sieve Size Mass Percent Passing Square Mesh Sieves
19.0 mm (3/4") 100
4.75 mm (No. 4) 60 – 100
300 µm (No. 50) 10 – 30
150 µm (No. 100) 0 – 10
75 µm (No. 200) 0 - 3
Table GS-3. Dimensions for Slotted Pipe
Pipe Diameter Slot
Length1
Maximum Slot
Width
Slot
Centers1 Open Area1
(per foot)
4” 1-1/16” 0.032” 0.413” 1.90 in2
6” 1-3/8” 0.032” 0.516” 1.98 in2
1 Some variation in these values is acceptable and is expected from various pipe
manufacturers. Be aware that both increased slot length and decreased slot centers
will be beneficial to hydraulics but detrimental to the structure of the pipe.
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November 2010 Urban Drainage and Flood Control District GS-5
Urban Storm Drainage Criteria Manual Volume 3
Photograph GS-2. This community used
signage to mitigate compaction of soils post-
construction. Photo courtesy of Nancy Styles.
9. Soil preparation: Poor soil conditions often exist following site grading. When the section includes
an underdrain, provide 4 inches of sandy loam at the invert of the swale extending up to the 2-year
water surface elevation. This will improve infiltration and reduce ponding. For all sections,
encourage establishment and long-term health of the bottom and side slope vegetation by properly
preparing the soil. If the existing site provides a good layer of topsoil, this should be striped,
stockpiled, and then replaced just prior to seeding or placing sod. If not available at the site, topsoil
can be imported or the existing soil may be amended. Inexpensive soil tests can be performed
following rough grading, to determine required soil amendments. Typically, 3 to 5 cubic yards of soil
amendment per 1,000 square feet, tilled 4 to 6 inches into the soil is required in order for vegetation to
thrive, as well as to enable infiltration of runoff.
10. Irrigation: Grass swales should be equipped with irrigation systems to promote establishment and
survival in Colorado's semi-arid environment. Systems may be temporary or permanent, depending
on the type of grass selected. Irrigation practices have a significant effect on the function of the grass
swale. Overwatering decreases the permeability of the soil, reducing the infiltration capacity of the
soil and contributing to nuisance baseflows. Conversely, under watering may result in delays in
establishment of the vegetation in the short term and unhealthy vegetation that provides less filtering
(straining) and increased susceptibility to erosion and riling over the long term.
Construction Considerations
Success of grass swales depends not only on a good
design and maintenance, but also on construction
practices that enable the BMP to function as designed.
Construction considerations include:
Perform fine grading, soil amendment, and seeding
only after upgradient surfaces have been stabilized
and utility work crossing the swale has been
completed.
Avoid compaction of soils to preserve infiltration
capacities.
Provide irrigation appropriate to the grass type.
Weed the area during the establishment of vegetation
by hand or mowing. Mechanical weed control is
preferred over chemical weed killer.
Protect the swale from other construction activities.
When using an underdrain, ensure no filter sock is placed on the pipe. This is unnecessary and can
cause the slots or perforations in the pipe to clog.
T-2 Grass Swale
GS-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Figure GS-1. Grass Swale Profile and Sections
Design Example
The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at
www.udfcd.org. This section provides a completed design form from this workbook as an example.
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-1
Urban Storm Drainage Criteria Manual Volume 3
Terminology
The term bioretention refers to the
treatment process although it is also
frequently used to describe a BMP
that provides biological uptake and
retention of the pollutants found in
stormwater runoff. This BMP is
frequently referred to as a porous
landscape detention (PLD) area or
rain garden.
Photograph B-1. This recently constructed rain garden provides
bioretention of pollutants, as well as an attractive amenity for a
residential building. Treatment should improve as vegetation matures.
Description
A BMP that utilizes bioretention is an
engineered, depressed landscape area
designed to capture and filter or infiltrate
the water quality capture volume
(WQCV). BMPs that utilize bioretention
are frequently referred to as rain gardens
or porous landscape detention areas
(PLDs). The term PLD is common in the
Denver metropolitan area as this manual
first published the BMP by this name in
1999. In an effort to be consistent with
terms most prevalent in the stormwater
industry, this document generally refers to
the treatment process as bioretention and
to the BMP as a rain garden.
The design of a rain garden may provide
detention for events exceeding that of the WQCV. There are
generally two ways to achieve this. The design can provide the
flood control volume above the WQCV water surface elevation,
with flows bypassing the filter usually by overtopping into an
inlet designed to restrict the peak flow for a larger event (or
events). Alternatively, the design can provide and slowly release
the flood control volume in an area downstream of one or more
rain gardens.
This infiltrating BMP requires consultation with a
geotechnical engineer when proposed near a structure. A
geotechnical engineer can assist with evaluating the suitability of
soils, identifying potential impacts, and establishing minimum
distances between the BMP and structures.
Bioretention
(Rain Garden)
Functions
LID/Volume Red. Yes
WQCV Capture Yes
WQCV+Flood Control Yes
Fact Sheet Includes
EURV Guidance No
Typical Effectiveness for Targeted
Pollutants3
Sediment/Solids Very Good1
Nutrients Moderate
Total Metals Good
Bacteria Moderate
Other Considerations
Life-cycle Costs4 Moderate
1 Not recommended for watersheds with
high sediment yields (unless pretreatment is
provided).
3 Based primarily on data from the
International Stormwater BMP Database
(www.bmpdatabase.org).
4 Based primarily on BMP-REALCOST
available at www.udfcd.org. Analysis
based on a single installation (not based on
the maximum recommended watershed
tributary to each BMP).
T-3 Bioretention
B-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Site Selection
Bioretention can be provided in a variety of areas within new
developments, or as a retrofit within an existing site. This
BMP allows the WQCV to be treated within areas
designated for landscape (see design step 7 for appropriate
vegetation). In this way, it is an excellent alternative to
extended detention basins for small sites. A typical rain
garden serves a tributary area of one impervious acre or less,
although they can be designed for larger tributary areas.
Multiple installations can be used within larger sites. Rain
gardens should not be used when a baseflow is anticipated.
They are typically small and installed in locations such as:
Parking lot islands
Street medians
Landscape areas between the road and a detached walk
Planter boxes that collect roof drains
Bioretention requires a stable watershed. Retrofit
applications are typically successful for this reason. When
the watershed includes phased construction, sparsely
vegetated areas, or steep slopes in sandy soils, consider
another BMP or provide pretreatment before runoff from
these areas reaches the rain garden. The surface of the rain
garden should be flat. For this reason, rain gardens can be
more difficult to incorporate into steeply sloping terrain;
however, terraced applications of these facilities have been
successful in other parts of the country.
When bioretention (and other BMPs used for infiltration) are
located adjacent to buildings or pavement areas, protective measures should be implemented to avoid
adverse impacts to these structures. Oversaturated subgrade soil underlying a structure can cause the
structure to settle or result in moisture-related problems. Wetting of expansive soils or bedrock can cause
swelling, resulting in structural movements. A geotechnical engineer should evaluate the potential impact
of the BMP on adjacent structures based on an evaluation of the subgrade soil, groundwater, and bedrock
conditions at the site. Additional minimum requirements include:
In locations where subgrade soils do not allow infiltration, the growing medium should be underlain
by an underdrain system.
Where infiltration can adversely impact adjacent structures, the filter layer should be underlain by an
underdrain system designed to divert water away from the structure.
In locations where potentially expansive soils or bedrock exist, placement of a rain garden adjacent to
structures and pavement should only be considered if the BMP includes an underdrain designed to
divert water away from the structure and is lined with an essentially impermeable geomembrane liner
designed to restrict seepage.
Benefits
Bioretention uses multiple
treatment processes to remove
pollutants, including
sedimentation, filtering,
adsorption, evapotranspiration,
and biological uptake of
constituents.
Volumetric stormwater treatment
is provided within portions of a
site that are already reserved for
landscaping.
There is a potential reduction of
irrigation requirements by taking
advantage of site runoff.
Limitations
Additional design and
construction steps are required for
placement of any ponding or
infiltration area near or upgradient
from a building foundation and/or
when expansive (low to high
swell) soils exist. This is
discussed in the design procedure
section.
In developing or otherwise erosive
watersheds, high sediment loads
can clog the facility.
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November 2010 Urban Drainage and Flood Control District B-3
Urban Storm Drainage Criteria Manual Volume 3
Designing for Maintenance
Recommended maintenance practices for all BMPs are in Chapter
6 of this manual. During design, the following should be
considered to ensure ease of maintenance over the long-term:
Do not put a filter sock on the underdrain. This is not
necessary and can cause the BMP to clog.
The best surface cover for a rain garden is full vegetation. Do
not use rock mulch within the rain garden because sediment
build-up on rock mulch tends to inhibit infiltration and require
frequent cleaning or removal and replacement. Wood mulch
handles sediment build-up better than rock mulch; however,
wood mulch floats and may clog the overflow depending on
the configuration of the outlet, settle unevenly, or be
transported downstream. Some municipalities may not allow wood mulch for this reason.
Consider all potential maintenance requirements such as mowing (if applicable) and replacement of
the growing medium. Consider the method and equipment for each task required. For example, in a
large rain garden where the use of hand tools is not feasible, does the shape and configuration of the
rain garden allow for removal of the growing medium using a backhoe?
Provide pre-treatment when it will reduce the extent and frequency of maintenance necessary to
maintain function over the life of the BMP. For example, if the site is larger than 2 impervious acres,
prone to debris or the use of sand for ice control, consider a small forebay.
Make the rain garden as shallow as possible. Increasing the depth unnecessarily can create erosive
side slopes and complicate maintenance. Shallow rain gardens are also more attractive.
Design and adjust the irrigation system (temporary or permanent) to provide appropriate water for the
establishment and maintenance of selected vegetation.
Design Procedure and Criteria
The following steps outline the design procedure and criteria, with Figure B-1 providing a corresponding
cross-section.
1. Basin Storage Volume: Provide a storage volume based on a 12-hour drain time.
Find the required WQCV (watershed inches of runoff). Using the imperviousness of the tributary
area (or effective imperviousness where LID elements are used upstream), use Figure 3-2 located
in Chapter 3 of this manual to determine the WQCV based on a 12-hour drain time.
Calculate the design volume as follows: 𝑉𝑉 = �WQCV12�𝐴𝐴 Equation B-1
Where:
V= design volume (ft3)
Is Pretreatment Needed
Designing the inflow gutter to
the rain garden at a minimal
slope of 0.5% can facilitate
sediment and debris deposition
prior to flows entering the BMP.
Be aware, this will reduce
maintenance of the BMP, but
may require more frequent
sweeping of the gutter to ensure
that the sediment does not
impede flow into the rain
garden.
T-3 Bioretention
B-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Benefits of Shredded Paper in Rain Garden Growing Media
Shredded paper, similar to other woody materials, captures nutrients from the compost and
slowly releases them as the paper decomposes. Compost alone will leach more nutrients than
desired.
As the paper decomposes, nutrients stored in the material are available to the vegetation.
Paper temporarily slows the infiltration rate of the media and retains moisture, providing
additional time for a young root system to benefit from moisture in the growing media.
A = area of watershed tributary to the rain garden (ft2)
2. Basin Geometry: A maximum WQCV ponding depth of 12 inches is recommended to maintain
vegetation properly. Provide an inlet or other means of overflow at this elevation. Depending on the
type of vegetation planted, a greater depth may be utilized to detain larger (more infrequent) events.
The bottom surface of the rain garden, also referred to here as the filter area, should be flat. Sediment
will reside on the filter area of the rain garden; therefore, if the filter area is too small, it may clog
prematurely. Increasing the filter area will reduce clogging and decrease the frequency of
maintenance. Equation B-2 provides a minimum filter area allowing for some of the volume to be
stored beyond the area of the filter (i.e., above the sideslopes of the rain garden).
Note that the total surcharge volume provided by the design must also equal or exceed the
design volume. Use vertical walls or slope the sides of the basin to achieve the required volume.
Use the rain garden growing medium described in design step 3 only on the filter area because this
material is more erosive than typical site soils. Sideslopes should be no steeper than 4:1
(horizontal:vertical). 𝐴𝐴≥(2/3)V 1 foot Equation B-2
Where:
V= design volume (ft3)
A = minimum filter area (flat surface area) (ft2)
The one-foot dimension in this equation represents the maximum recommended WQCV depth in the
rain garden. The actual design depth may differ; however, it is still appropriate to use a value of one
foot when calculating the minimum filter area.
3. Growing Medium: For partial and no infiltration sections, provide a minimum of 18 inches of
growing medium to enable establishment of the roots of the vegetation (see Figure B-1). Previous
versions of this manual recommended a mix of 85% sand and 15% peat (by volume). Peat is a
material that typically requires import to Colorado and mining peat has detrimental impacts to the
environment (Mazerolle 2002). UDFCD partnered with the University of Colorado to perform a
study to find a sustainable material to replace peat. The study was successful in finding a
replacement that performed well for filtering ability, clogging characteristics, as well as seed
germination. This mixture consists of 85% coarse sand and a 15% compost/shredded paper mixture
(by volume). The study used thin (approximately 1/4 inch) strips of loosely packed shredded paper
mixed with an equal volume of compost. Based on conversations with local suppliers, compost
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Urban Storm Drainage Criteria Manual Volume 3
containing shredded paper is not an uncommon request, although not typically provided in the
proportions recommended in this BMP Fact Sheet. Compost suppliers have access to shredded paper
through document destruction companies and can provide a mixture of Class 1 compost and shredded
paper. The supplier should provide the rain garden compost mixture premixed with coarse sand. On-
site mixing is not recommended.
Rain Garden Compost Mixture (by volume)
50% Class 1 STA registered compost (approximate bulk density 1000 lbs/CY)
50% loosely packed shredded paper (approximate bulk density 50 to 100 lbs/CY)
When using diamond cut shredded paper or tightly packed paper, use the bulk densities provided to
mix by weight.
The supplier should premix the rain garden compost mixture (above) with coarse sand, in the
following proportions, prior to delivery to the site:
Rain Garden Growing Medium
15% rain garden compost mixture described above (by volume)
85% coarse sand (either Class C Filter Material per Table B-2 or sand meeting ASTM C-33) (by
volume)
Table B-1 provides detailed information on Class 1 compost. Be aware, regular testing is not
required to allow a compost supplier to refer to a product as a specific STA class. However, regular
testing is required and performed through the United States Compost Council (USCC) Seal of Testing
Assurance (STA) Program to be a STA registered compost. To ensure Class 1 characteristics, look
for a Class 1 STA registered compost.
Other Rain Garden Growing Medium Amendments
The growing medium described above is designed for filtration ability, clogging characteristics, and
vegetative health. It is important to preserve the function provided by the rain garden growing
medium when considering additional materials for incorporation into the growing medium or into the
standard section shown in Figure B-1. When desired, amendments may be included to improve water
quality or to benefit vegetative health as long as they do not add nutrients, pollutants, or modify the
infiltration rate. For example, a number of products, including steel wool, capture and retain
dissolved phosphorus (Erickson 2009). When phosphorus is a target pollutant, proprietary materials
with similar characteristics may be considered. Do not include amendments such as top soil, sandy
loam, and additional compost.
Full Infiltration Sections
A full infiltration section retains the WQCV onsite. For this section, it is not necessary to use the
prescribed rain garden growing medium. Amend the soils to provide adequate nutrients to establish
vegetation. Typically, 3 to 5 cubic yards of soil amendment (compost) per 1,000 square feet, tilled 6
inches into the soil, is required for vegetation to thrive. Additionally, inexpensive soil tests can be
conducted to determine required soil amendments. (Some local governments may also require proof
of soil amendment in landscaped areas for water conservation reasons.)
T-3 Bioretention
B-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table B-1. Class 1 Compost
Characteristic Criteria
Minimum Stability Indicator (Respirometry) Stable to Very Stable
Maturity Indicator Expressed as
Ammonia N / Nitrate N Ratio < 4
Maturity Indicator Expressed as
Carbon to Nitrogen Ratio < 12
Maturity Indicator Expressed as
Percentage of Germination/Vigor 80+ / 80+
pH – Acceptable Range 6.0 – 8.4
Soluble Salts – Acceptable Range
(1:5 by weight) 0 – 5 mmhos/cm
Testing and Test Report Submittal Requirement
Seal of Testing Assurance (STA)/Test
Methods for the Examination of
Composting and Compost (TMECC)
Chemical Contaminants
Equal or better than US EPA Class A
Standard, 40 CFR 503.13, Tables 1 & 3
levels
Pathogens Meet or exceed US EPA Class A standard,
40 CFR 503.32(a) levels
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-7
Urban Storm Drainage Criteria Manual Volume 3
4. Underdrain System: Underdrains are often necessary
and should be provided if infiltration tests show
percolation drawdown rates slower than 2 times the rate
needed to drain the WQCV over 12 hours, or where
required to divert water away from structures as
determined by a professional engineer. Percolation tests
should be performed or supervised by a licensed
professional engineer and conducted at a minimum depth
equal to the bottom of the bioretention facility.
Additionally, underdrains are required where
impermeable membranes are used. Similar to the
terminology used for permeable pavement sections, there
are three basic sections for bioretention facilities:
No-Infiltration Section: This section includes an
underdrain and an impermeable liner that does not
allow for any infiltration of stormwater into the
subgrade soils. It is appropriate to use a no-
infiltration system when either of the following is
true:
o Land use or activities could contaminate
groundwater when stormwater is allowed to
infiltrate, or
o The BMP is located over potentially expansive
soils or bedrock and is adjacent (within 10 feet) to
structures.
Partial Infiltration Section: This section does not
include an impermeable liner and, therefore; allows
for some infiltration. Stormwater that does not
infiltrate will be collected and removed by an
underdrain system.
Full Infiltration Section: This section is designed to
infiltrate all of the water stored into the subgrade below.
Overflows are managed via perimeter drainage to a
downstream conveyance element. UDFCD recommends
a minimum infiltration rate of 2 times the rate needed to
drain the WQCV over 12 hours.
When using an underdrain system, provide a control orifice
sized to drain the design volume in 12 hours or more (see
Equation B-3). Use a minimum orifice size of 3/8 inch to
avoid clogging. This will provide detention and slow release
of the WQCV, providing water quality benefits and reducing
impacts to downstream channels. Space underdrain pipes a
maximum of 20 feet on center. Provide cleanouts to enable
maintenance of the underdrain. Cleanouts can also be used to
conduct an inspection (by camera) of the underdrain system to
Important Design Considerations
The potential for impacts to adjacent
buildings can be significantly reduced
by locating the bioretention area at
least 10 feet away from the building,
beyond the limits of backfill placed
against the building foundation walls,
and by providing positive surface
drainage away from the building.
The BMP should not restrict surface
water from flowing away from the
buildings. This can occur if the top of
the perimeter wall for the BMP
impedes flow away from the building.
Always adhere to the slope
recommendations provided in the
geotechnical report. In the absence
of a geotechnical report, the following
general recommendations should be
followed for the first 10 feet from a
building foundation.
1) Where feasible, provide a slope of
10% for a distance of 10 feet away
from a building foundation.
2) In locations where non-expansive
soil or bedrock conditions exist,
the slope for the surface within 10
feet of the building should be at
least 5% away from the building
for unpaved (landscaped) surfaces.
3) In locations where potentially
expansive soil or bedrock
conditions exist, the design slope
should be at least 10% away from
the building for unpaved
(landscaped) surfaces.
4) For paved surfaces, a slope of at
least 2% away from the building is
adequate. Where accessibility
requirements or other design
constraints do not apply, use an
increased minimum design slope
for paved areas (2.5% where non-
expansive soil or bedrock
conditions exist).
T-3 Bioretention
B-8 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
ensure that the pipe was not crushed or disconnected during construction.
Calculate the diameter of the orifice for a 12-hour drain time using Equation B-3 (Use a minimum orifice
size of 3/8 inch to avoid clogging.):
𝐷𝐷12 hour drain time =�𝑉𝑉1414 𝑦𝑦0.41 Equation B-3
Where:
D = orifice diameter (in)
y = distance from the lowest elevation of the storage volume
(i.e., surface of the filter) to the center of the orifice (ft)
V = volume (WQCV or the portion of the WQCV in the rain garden)
to drain in 12 hours (ft3)
In previous versions of this manual, UDFCD recommended that the underdrain be placed in an
aggregate layer and that a geotextile (separator fabric) be placed between this aggregate and the
growing medium. This version of the manual replaces that section with materials that, when used
together, eliminate the need for a separator fabric.
The underdrain system should be placed within an 6-inch-thick section of CDOT Class C filter
material meeting the gradation in Table B-2. Use slotted pipe that meets the slot dimensions provided
in Table B-3.
Table B-2. Gradation Specifications for CDOT Class C Filter Material
(Source: CDOT Table 703-7)
Sieve Size Mass Percent Passing
Square Mesh Sieves
19.0 mm (3/4”) 100
4.75 mm (No. 4) 60 – 100
300 µm (No. 50) 10 – 30
150 µm (No. 100) 0 – 10
75 µm (No. 200) 0 - 3
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-9
Urban Storm Drainage Criteria Manual Volume 3
Table B-3. Dimensions for Slotted Pipe
Pipe Diameter Slot
Length1
Maximum Slot
Width
Slot
Centers1 Open Area1
(per foot)
4” 1-1/16” 0.032” 0.413” 1.90 in2
6” 1-3/8” 0.032” 0.516” 1.98 in2
1 Some variation in these values is acceptable and is expected from various pipe
manufacturers. Be aware that both increased slot length and decreased slot centers
will be beneficial to hydraulics but detrimental to the structure of the pipe.
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric: For no-infiltration sections,
install a 30 mil (minimum) PVC geomembrane liner, per Table B-5, on the bottom and sides of the
basin, extending up at least to the top of the underdrain layer. Provide at least 9 inches (12 inches if
possible) of cover over the membrane where it is attached to the wall to protect the membrane from
UV deterioration. The geomembrane should be field-seamed using a dual track welder, which allows
for non-destructive testing of almost all field seams. A small amount of single track and/or adhesive
seaming should be allowed in limited areas to seam around pipe perforations, to patch seams removed
for destructive seam testing, and for limited repairs. The liner should be installed with slack to
prevent tearing due to backfill, compaction, and settling. Place CDOT Class B geotextile separator
fabric above the geomembrane to protect it from being punctured during the placement of the filter
material above the liner. If the subgrade contains angular rocks or other material that could puncture
the geomembrane, smooth-roll the surface to create a suitable surface. If smooth-rolling the surface
does not provide a suitable surface, also place the separator fabric between the geomembrane and the
underlying subgrade. This should only be done when necessary because fabric placed under the
geomembrane can increase seepage losses through pinholes or other geomembrane defects. Connect
the geomembrane to perimeter concrete walls around the basin perimeter, creating a watertight seal
between the geomembrane and the walls using a continuous batten bar and anchor connection
(see Figure B-3). Where the need for the impermeable membrane is not as critical, the membrane can
be attached with a nitrile-based vinyl adhesive. Use watertight PVC boots for underdrain pipe
penetrations through the liner (see Figure B-2).
T-3 Bioretention
B-10 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table B-4. Physical Requirements for Separator Fabric1
Table B-5. Physical Requirements for Geomembrane
Property
Thickness
0.76 mm
(30 mil)
Test Method
Thickness, % Tolerance ±5 ASTM D 1593
Tensile Strength, kN/m (lbs/in) width 12.25 (70) ASTM D 882, Method B
Modulus at 100% Elongation, kN/m (lbs/in) 5.25 (30) ASTM D 882, Method B
Ultimate Elongation, % 350 ASTM D 882, Method A
Tear Resistance, N (lbs) 38 (8.5) ASTM D 1004
Low Temperature Impact, °C (°F) -29 (-20) ASTM D 1790
Volatile loss, % max. 0.7 ASTM D 1203, Method A
Pinholes, No. Per 8 m2 (No. per 10 sq. yds.) max. 1 N/A
Bonded Seam Strength, % of tensile strength 80 N/A
Property
Class B
Test Method Elongation
< 50%2
Elongation
> 50%2
Grab Strength, N (lbs) 800 (180) 510 (115) ASTM D 4632
Puncture Resistance, N (lbs) 310 (70) 180 (40) ASTM D 4833
Trapezoidal Tear Strength, N (lbs) 310 (70) 180 (40) ASTM D 4533
Apparent Opening Size, mm
(US Sieve Size) AOS < 0.3mm (US Sieve Size No. 50) ASTM D 4751
Permittivity, sec-1 0.02 default value,
must also be greater than that of soil
ASTM D 4491
Permeability, cm/sec k fabric > k soil for all classes ASTM D 4491
Ultraviolet Degradation at 500
hours
50% strength retained for all classes ASTM D 4355
1 Strength values are in the weaker principle direction
2 As measured in accordance with ASTM D 4632
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-11
Urban Storm Drainage Criteria Manual Volume 3
Designing for Flood Protection
Provide the WQCV in rain gardens that direct excess flow into to a landscaped area providing the
flood control volume. Design the flood control outlet to meter the major event (100-year event) and
slowly release the difference in volume between the EURV and the WQCV. (This assumes that the
runoff treated by the rain gardens is routed directly into the outlet or infiltrates.) Providing
treatment in this manner will reduce inundation in the landscaped area to a few times per year,
resulting in an area better suited for multipurpose uses.
6. Inlet/Outlet Control: In order to
provide the proper drain time, the
bioretention area can be designed
without an underdrain (provided it
meets the requirements in step 4) or
the outlet can be controlled by an
orifice plate. Equation B-3 is a
simplified equation for sizing an
orifice plate for a 12-hour drain time.
7. How flow enters and exits the BMP
is a function of the overall drainage
concept for the site. Inlets at each
rain garden may or may not be
needed. Curb cuts can be designed
to both allow stormwater into the rain
garden as well as to provide release of
stormwater in excess of the WQCV.
Roadside rain gardens located on a
steep site might pool and overflow
into downstream cells with a single curb cut, level spreader, or outlet structure located at the most
downstream cell. When selecting the type and location of the outlet structure, ensure that the runoff
will not short-circuit the rain garden. This is a frequent problem when using a curb inlet located
outside the rain garden for overflow.
For rain gardens with concentrated points of inflow, provide for energy dissipation. When rock is
used, provide separator fabric between the rock and growing medium to minimize subsidence.
8. Vegetation: UDFCD recommends that the filter area be vegetated with drought tolerant species that
thrive in sandy soils. Table B-6 provides a suggested seed mix for sites that will not need to be
irrigated after the grass has been established.
All seed must be well mixed and broadcast, followed by hand raking to cover seed and then mulched.
Hydromulching can be effective for large areas. Do not place seed when standing water or snow is
present or if the ground is frozen. Weed control is critical in the first two to three years, especially
when starting with seed.
Do not use conventional sod. Conventional sod is grown in clay soil that will seal the filter area,
greatly reducing overall function of the BMP. Several successful local installations have started with
seed.
Photograph B-2. The curb cut shown allows flows to enter this
rain garden while excess flows bypass the facility. Note: trees are
not recommended inside a rain garden
T-3 Bioretention
B-12 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
When using an impermeable liner, select plants with diffuse (or fibrous) root systems, not taproots.
Taproots can damage the liner and/or underdrain pipe. Avoid trees and large shrubs that may
interfere with restorative maintenance. Trees and shrubs can be planted outside of the area of
growing medium. Use a cutoff wall to ensure that roots do not grow into the underdrain or place trees
and shrubs a conservative distance from the underdrain.
9. Irrigation: Provide spray irrigation at or above the WQCV elevation or place temporary irrigation
on top of the rain garden surface. Do not place sprinkler heads on the flat surface. Remove
temporary irrigation when vegetation is established. If left in place this will become buried over time
and will be damaged during maintenance operations.
Irrigation schedules should be adjusted during the growing season to provide the minimum water
necessary to maintain plant health and to maintain the available pore space for infiltration.
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EPSGROUPINC.COM | 970.221.4158 SWMP: 300 E. Mountain Ave
FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX C
LANDSCAPE PLAN APPENDIX C
PERMITS / APPLICATIONS
For Agency Use Only
Permit Number Assigned
COR03-
Date Received /_ /_
Month Day Year
COLORADO DISCHARGE PERMIT SYSTEM (CDPS)
ST ORM WAT ER DISCHARGE ASSOCIATED WITH CONSTRUCTION ACTIVITIES APPLICATION
PHOTO COPIES, FAXED COPIES, PDF COPIES OR EM AILS WILL NOT BE ACCEPTED.
Please print or type. Original signatures are required. All item s m ust be com pleted accurately and in their entirety for
the application to be deem ed com plete. Incom plete applications will not be processed until all inform ation is received
which will ultim ately delay the issuance of a perm it. If m ore space is required to answer any question, please attach
additional sheets to the application form . Applications m ust be subm itted by m ail or hand delivered to:
Colorado Department of Public Health and Environment
Water Quality Control Division
4300 Cherry Creek Drive South
WQCD-P-B2
Denver, Colorado 80246-1530
Any additional inform ation that you would lik e the Division to consider in developing the perm it should be provided with
the application. Exam ples include effluent data and/or m odeling and planned pollutant rem oval strategies.
PERM IT INFORM ATION
Reason for Application: NEW CERT
RENEW CERT EXISTING CERT #
Applicant is: Property Owner Contractor/Operator
A. CONTACT INFORMATION - NOT ALL CONTACT TYPES MAY APPLY * indicates required
*PERMITTEE (If more than one please add additional pages)
*ORGANIZATION FORMAL NAME:
1) *PERMITTEE the person authorized to sign and certify the permit application. This person receives all
permit correspondences and is legally responsible for compliance with the permit.
Responsible Position (Title):
Currently Held By (Person):
Telephone No:_
email address
Organization:
Mailing Address:
City:_ State: Zip:
This form must be signed by the Permittee (listed in item 1) to be considered complete.
Per Regulation 61 In all cases, it shall be signed as follows:
a) In the case of corporations, by a responsible corporate officer. For the purposes of this section, the responsible
corporate officer is responsible for the overall operation of the facility from which the discharge described in the
application originates.
b) In the case of a partnership, by a general partner.
c) In the case of a sole proprietorship, by the proprietor.
d) In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking elected offic ial
page 1 of 5 revised April 2011
2) DMR COGNIZANT OFFICIAL (i.e. authorized agent) the person or position authorized to sign and certify reports required
by the Division including Discharge Monitoring Reports *DMR’s, Annual Reports, Compliance Schedule submittals,
and other information requested by the Division. The Division will transmit pre-printed reports (ie. DMR’s) to this person.
If more than one, please add additional pages. Same As 1) Permittee
Responsible Position (Title):
Currently Held By (Person):
Telephone No:_
email address
Organization:
Mailing Address:
City:_ State: Zip:
Per Regulation 61 : All reports required by permits, and other information requested by the Division shall be signed by
the permittee or by a duly authorized representative of that person. A person is a duly authorized representative only if:
(i) The authorization is made in writing by the permittee
(ii) The authorization specifies either an individual or a position having responsibility for the overall operation of the
regulated facility or activity such as the position of plant manager, operator of a well or a well field, superintendent,
position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters
for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a
named position); and
(iii) The written authorization is submitted to the Division
3) *SITE CONTACT local contact for questions relating to the facility & discharge authorized by this permit
for the facility.
Same As 1) Permittee
Responsible Position (Title):
Currently Held By (Person):
Telephone No:_
email address
Organization:
Mailing Address:
City:_ State: Zip:
4) * BILLING CONTACT if different than the permittee
Responsible Position (Title):
Currently Held By (Person):
Telephone No:_
email address
Organization:
Mailing Address:
City:_ State: Zip:
Page 2 of 5 revised April 2011
5) OTHER CONTACT TYPES (check below) Add pages if necessary:
ResponsiblePosition (Title):
Currently Held By (Person):
Telephone No:_
email address
Organization:
Mailing Address:
City:_ State: Zip:
o Pretreatment
Coordinator
o Environmental Contact
o Biosolids Responsible
Party
o Property Owner
Inspection Facility Contact
Consultant
Compliance Contact
Stormwater MS4 Responsible
Person
Stormwater Authorized
Representative
Other
B. Permitted Project/Facility Information
Project/Facility Name
Street Address or cross streets
(e.g., “S. of Park St. between 5th Ave. and 10th Ave.”, or “W. side of C.R. 21, 3.25 miles N. of Hwy 10”; A street name without an address,
intersection, mile marker, or other identifying information describing the location of the project is not adequate. For linear projects,
the route of the project should be described as best as possible with the location more accurately indicated by a map.)
City, Zip Code County
Facility Latitude/Longitude— (approxim ate center of site to nearest 15 seconds using one of
following f orm ats
001A Latitude . Longitude . (e.g., 39.703°, 104.933°’)
degrees (to 3 decimal places) degrees (to 3 decimal places)
or
001A Latitude º ’ " Longitude º ’ " (e.g., 39°46'11"N, 104°53'11"W )
degrees minutes seconds degrees minutes seconds
For the approximate center point of the property, to the nearest 15 seconds. The latitude and longitude must be provided as
either degrees, minutes, and seconds, or in decimal degrees with three decimal places. This information may be obtained from
a variety of sources, including:
o Surveyors or engineers for the project should have, or be able to calculate, this information.
o EPA maintains a web-based siting tool as part of their Toxic Release Inventory program that uses interactive maps and
aerial photography to help users get latitude and longitude. The siting tool can be accessed at
www.epa.gov/tri/report/siting_tool/index.htm
o U.S. Geological Survey topographical map(s), available at area map stores.
o Using a Global Positioning System (GPS) unit to obtain a direct reading.
Note: the latitude/longitude required above is not the directional degrees, minutes, and seconds provided on a site legal
description to define property boundaries.
C. MAP (Attachment) If no map is submitted, the permit will not be issued.
Map: Attach a map that indicates the site location and that CLEARLY shows the boundaries of the area that will be
disturbed. Maps must be no larger than 11x17 inches.
D. LEGAL DESCRIPTION
Legal description: If subdivided, provide the legal description below, or indicate that it is not applicable (do not supply
Township/Range/Section or metes and bounds description of site)
Subdivision(s): Lot(s): Block(s):
OR
Not applicable (site has not been subdivided)
page 3 of 5 revised April 2011
E. AREA OF CONSTRUCTION SIT E
Total area of project site (acres): Area of project site to undergo disturbance (acres):
Note: aside from clearing, grading and excavation activities, disturbed areas also include areas receiving
overburden (e.g., stockpiles), demolition areas, and areas with heavy equipment/vehicle traffic and storage
that disturb existing vegetative cover
Total disturbed area of Larger Common Plan of Development or Sale, if applicable:
(i.e., total, including all phases, filings, lots, and infrastructure not covered by this application)
Provide both the total area of the construction site, and the area that will undergo disturbance, in acres. Note: aside
from clearing, grading and excavation activities, disturbed areas also include areas receiving overburden (e.g.,
stockpiles), demolition areas, and areas with heavy equipment/vehicle traffic and storage that disturb existing
vegetative cover (see construction activity description under the APPLICABILITY section on page 1).
If the project is part of a larger common plan of development or sale (see the definition under the APPLICABILITY
section on page 1), the disturbed area of the total plan must also be included.
F. NATURE OF CONST RUCTION ACTIVIT Y
Check the appropriate box(s) or provide a brief description that indicates the general nature of the construction activities.
(The full description of activities must be included in the Stormwater Management Plan.)
Single Family Residential Development
Multi-Family Residential Development
Commercial Development
Oil and Gas Production and/or Exploration (including pad sites and associated infrastructure)
Highway/Road Development (not including roadways associated with commercial or residential development)
Other – Description:
G. ANTICIPAT ED CONSTRUCT ION SCHEDULE
Construction Start Date: ___________________________ Final Stabilization Date: _____________________________
Construction Start Date - This is the day you expect to begin ground disturbing activities, including grubbing, stockpiling, excavating,
demolition, and grading activities.
Final Stabilization Date - in terms of permit coverage, this is when the site is finally stabilized. This means that all ground surface
disturbing activities at the site have been completed, and all disturbed areas have been either built on, paved, or a uniform vegetative
cover has been established with an individual plant density of at least 70 percent of pre-disturbance levels. Permit coverage must be
maintained until the site is finally stabilized. Even if you are only doing one part of the project, the estimated final stabilization
date must be for the overall project. If permit coverage is still required once your part is completed, the permit certification may be
transferred or reassigned to a new responsible entity(s).
H. RECEIVING WAT ERS (If discharge is to a ditch or storm sewer, include the name of the ultimate receiving waters)
Immediate Receiving Water(s):
Ultimate Receiving Water(s):
Identify the receiving water of the stormwater from your site. Receiving waters are any waters of the State of Colorado. This includes
all water courses, even if they are usually dry. If stormwater from the construction site enters a ditch or storm sewer system, identify
that system and indicate the ultimate receiving water for the ditch or storm sewer. Note: a stormwater discharge permit does not
allow a discharge into a ditch or storm sewer system without the approval of the owner/operator of that system.
page 4 of 5 revised April 2011
I. REQUIRED SIGNAT URES (Both parts i. and ii. must be signed)
Signature of Applicant: The applicant must be either the owner and/or operator of the constr uction site. Refer to Part B of the instructions for additional information.
The application must be signed by the applicant to be considered complete. In all cases, it shall be signed as follows: (Regulation 61.4 (1ei)
a) In the case of corporations, by the responsible corporate officer is responsible for the overall operation of the facility from which the discharge
described in the form originates
b) In the case of a partnership, by a general partner.
c) In the case of a sole proprietorship, by the proprietor.
d) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking elected officia l, (a principal executive officer
has responsibility for the overall operation of the facility from which the discharge originates).
STOP!: A Stormwater Management Plan must be completed prior to signing the following certifications!
i. ST ORM WAT ER M ANAGEMENT PLAN CERTIFICATION
“I certify under penalty of law that a complete Stormwater Management Plan, has been prepared for my activity. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the information, the Stormwater Management Plan is, to the best of
my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for falsely certifying the completion of said SWMP,
including the possibility of fine and imprisonment for knowing violations.”
XX
Signature of Legally Responsible Person or Authorized Agent (submission must include original signature) Date Signed
Name (printed) Title
ii. SIGNAT URE OF PERMIT LEGAL CONT ACT
"I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons
who manage the system, or those persons directly responsible for gathering the information, the information submitted is to t he best of my
knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the
possibility of fine and imprisonment for knowing violations."
“I understand that submittal of this application is for coverage under the State of Colorado General Permit for Stormwater Discharges Associated with
Construction Activity for the entirety of the construction site/project described and applied for, until such time as the application is amended or the
certification is transferred, inactivated, or expired.”
XX
Signature of Legally Responsible Person (submission must include original signature) Date Signed
Name (printed Title
DO NOT INCLUDE A COPY OF THE STORMWATER MANAGEMENT PLAN
DO NOT INCLUDE PAYMENT – AN INVOICE WILL BE SENT AFTER THE CERTIFICATION IS ISSUED.
page 5 of 5 revised April 2011
COLORADO DISCHARGE PERMIT SYSTEM (CDPS)
For Agency Use Only
Permit Number Assigned
COG07-______________
Date Received ____/____/____
Month Day Year
CONSTRUCTION DEWATERING INDUSTRIAL WASTEWATER DISCHARGE APPLICATION
PHOTO COPIES, FAXED COPIES, PDF COPIES OR EMAILS WILL NOT BE ACCEPTED.
Please print or type. Original signatures are required. All items must be completed accurately and in their entirety
for the application to be deemed complete. Incomplete applications will not be processed until all information is received
which will ultimately delay the issuance of a permit. If more space is required to answer any question, please attach
additional sheets to the application form. Applications must be submitted by mail or hand delivered to:
Colorado Department of Public Health and Environment
Water Quality Control Division
4300 Cherry Creek Drive South
WQCD-P-B2
Denver, Colorado 80246-1530
Any additional information that you would like the Division to consider in developing the permit should be provided with
the application. Examples include effluent data and/or modeling and planned pollutant removal strategies.
PERMIT INFORMATION
Reason for Application: NEW CERT
RENEW CERT EXISTING CERT #____________________
Applicant is: Property Owner Contractor/Operator
A. Contact Information
Permittee (If more than one please add additional pages)
Organization Formal Name: ___________________________________________________________
1. Permittee the person authorized to sign and certify the permit application. This person receives all permit
correspondences and is legally responsible for compliance with the permit.
Responsible Position (Title): ______________________________________________________________
Currently Held By (Person): _______________________________________________________________
Telephone No:__________________________________________________________________________
email address__________________________________________________________________________
Organization: ___________________________________________________________________________
Mailing Address: ________________________________________________________________________
City:_______________________________ State: ______________________ Zip: ____________________
This form must be signed by the Permittee to be considered complete.
Per Regulation 61: In all cases the permit application shall be signed as follows:
a) In the case of corporations, by a responsible corporate officer. For the purposes of this section, the
responsible corporate officer is responsible for the overall operation of the facility from which the discharge
described in the application originates.
b) In the case of a partnership, by a general partner.
c) In the case of a sole proprietorship, by the proprietor.
d) In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking
elected official
Page 1 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
2. DMR Cognizant Official (i.e. authorized agent)—the person or position authorized to sign and certify reports
required by permits including Discharge Monitoring Reports [DMR’s], Annual Reports, Compliance Schedule
submittals, and other information requested by the Division. The Division will send pre-printed reports (e.g. DMR’s) to
this person. If more than one, please add additional pages. Same as 1) Permittee
Responsible Position (Title): _______________________________________________________
Currently Held By (Person): ________________________________________________________
Telephone No:___________________________________________________________________
Email address____________________________________________________________________
Organization: ____________________________________________________________________
Mailing Address: _________________________________________________________________
City:______________________________ State: ______________ Zip: ______________________
Per Regulation 61: All reports required by permits, and other information requested by the Division shall be
signed by the permittee or by a duly authorized representative of that person. A person is a duly authorized
representative only if:
(i) The authorization is made in writing by the permittee;
(ii) The authorization specifies either an individual or a position having responsibility for the overall operation of
the regulated facility or activity such as the position of plant manager, operator of a well or a well field,
superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for
environmental matters for the company. (A duly authorized representative may thus be either a named
individual or any individual occupying a named position); and
(iii) The written authorization is submitted to the Division.
3. Site/Local Contact—contact for questions regarding the facility & discharges authorized by this permit
Same as Permittee—Item 1
Responsible Position (Title): ________________________________________________________
Currently Held By (Person): _________________________________________________________
Telephone No:____________________________________________________________________
Email address_____________________________________________________________________
Organization: _____________________________________________________________________
Mailing Address: __________________________________________________________________
City:______________________________ State: ______________ Zip: _______________________
4. Operator in Responsible Charge Same as Permittee—Item 1
Responsible Position (Title): __________________________________________________________
Currently Held By (Person): ___________________________________________________________
Telephone No:______________________________________________________________________
Email address______________________________________________________________________
Organization: _______________________________________________________________________
Mailing Address: ____________________________________________________________________
City:_______________________________ State: ______________ Zip: ________________________
Certification Type____________________Certification Number________________________________
Page 2 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
5. Billing Contact (if different than the permittee)
Responsible Position (Title): _____________________________________________________________
Currently Held By (Person): ______________________________________________________________
Telephone No:_________________________________________________________________________
Email address_________________________________________________________________________
Organization: __________________________________________________________________________
Mailing Address: _______________________________________________________________________
City:______________________________ State: ______________ Zip: ____________________________
6. Other Contact Types (check below) Add pages if necessary:
Responsible Position (Title): ______________________________________________________________
Currently Held By (Person): _______________________________________________________________
Telephone No:__________________________________________________________________________
Email address__________________________________________________________________________
Organization: ___________________________________________________________________________
Mailing Address: ________________________________________________________________________
City:______________________________________ State: ______________ Zip: _____________________
Pretreatment Coordinator
Environmental Contact
Biosolids Responsible Party
Property Owner
Inspection Facility Contact
Consultant
Compliance Contact
Stormwater MS4 Responsible
Person
Stormwater Authorized
Representative
Other ____________________
B. Permitted Project/Facility Information
1. Project/Facility Name ____________________________________________________________________________
Street Address or cross streets_____________________________________________________________________
City, State and Zip Code _____________________________________________County _____________________
Type of Facility Ownership
City Government Corporation Private Municipal or Water District
State Government Mixed Ownership _________________________________
2. Facility Latitude/Longitude—List the latitude and longitude of the excavation(s) resulting in the discharge(s). If the exact excavation
location(s) are not known, list the latitude and longitude of the center point of the construction project. If using the center point, be
sure to specify that it is the center point of construction activity.
001A Latitude __________ . _________ Longitude ___________ . _____________ (e.g., 39.703°, 104.933°’)
degrees (to 3 decimal places) degrees (to 3 decimal places)
or
001A Latitude _____ º _____’ _____" Longitude _____ º _____’ _____" (e.g., 39°46'11"N, 104°53'11"W )
degrees minutes seconds degrees minutes seconds
Horizontal Collection Method: GPS Unspecified Interpolation Map – Map Scale Number__________
Reference Point: Project/Facility Entrance Project/Facility Center/Centroid
Horizontal Accuracy Measure (WQCD Requires use of NAD83 Datum for all references)___________________
(add additional pages if necessary)
Page 3 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
B. Permitted Project/Facility Information Continued…
3. Facility Activity and Anticipated Schedule
Dewatering will begin (date) _______________
Estimate how long dewatering will last: Years____________Months_______________Days_________________
Describe Activity e.g., highway bridge and tunnel construction, storm drain expansion, etc. and a description of activities
being performed, including construction schedule and months of operation. Specify source(s) of wastewater to be discharged
(i.e.well, foundation excavation, trenching, etc).
4. Will the discharge go to a ditch or storm sewer? YES NO
If YES, in the appropriate table below include the name of the ultimate receiving waters where the ditch or storm sewer
discharges.
If YES, applicant must contact the owner of the ditch or storm sewer system (prior to discharging) to verify local ordinances
and to determine whether or not additional requirements are going to be imposed by the owner.
5. What type of discharge will this be? Defined Discharge Undefined Discharge
A Defined Discharge is a discharge where the dewatering discharge locations and number of outfalls are known at the time of permit
application.
If discharge is Defined – enter information in table C for Defined Discharges
An Undefined Discharge is a discharge where the exact dewatering discharge locations are unknown at the time of permit application.
The permit applicant must request the maximum number of potential outfalls (dis charges) for the permitted facility.
If discharge is Undefined – enter information in table D for Undefined Discharges
Note: For undefined discharges, the site specific sampling and monitoring parameters will be selected based on the potential
pollutant sources found within the entire permitted project area and will be applied to all outfall(s). The most stringent of the
surface water limitations for each identified site specific parameter will be applied to each permitted outfall.
C. Information for Defined Discharge Location(s):
1. In the following table, include the following information for the discharge:
Include the number of discharge points (outfalls);
Include the name of the receiving stream for each Outfall Number. If the discharge is to groundwater fill out discharge
information located next to G001A, G002A, etc.—Please review the Division’s Low Risk Discharge Guidance for
Discharges of Uncontaminated Groundwater to Land to determine if discharges to groundwater can be allowed under
the Guidance in lieu of obtaining a Construction Dewatering Permit.;
Include the approximate location of the discharge (e.g. ―discharge will occur between 5th Avenue and 20th Avenue‖, or ―the
discharge will enter the storm sewer located at the corn er of Speer Blvd and 8th Ave., which eventually flows to Cherry Creek‖ ;
Include the maximum anticipated flow rate of the discharge; this can be based on pump capacity or other applicable measure.
Add more pages if necessary
Page 4 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
D. Information for Undefined Discharge Location(s):
1. In the following table include the following information for the discharge:
Include the maximum number of potential outfalls (discharges) for the permitted facility/project;
Include the maximum anticipated flow rate of the discharge; this can be based on pump capacity or other applicable measure ;
Include the name of all potential receiving streams for the entire project. I f the discharge is to groundwater fill out discharge
information located next to G001A, G002A, etc.—Please review the Division’s Low Risk Discharge Guidance for
Discharges of Uncontaminated Groundwater to Land to determine if discharges to groundwater can be allowed under
the Guidance in lieu of obtaining a Construction Dewatering Permit.
Note: For undefined discharges, the site specific sampling and monitoring parameters will be selected based on the potential
pollutant sources found within the entire permitted project area and will be applied to all outfall(s). The most stringent of the surface
water limitations for each identified site specific parameter will be applied to each permitted outfall.
Add more pages if necessary
Sampling and Reporting Requirements for Defined and Undefined Discharges: Sampling must occur at every end-of-
pipe dewatering location (after going through your choice of BMP, if necessary). The permittee will be issued Discharge
Monitoring Report (DMR) forms for all requested outfall numbers. The permittee will be required to submit the DMR forms
for each requested outfall number monthly. For the outfall numbers(s) where no discharge occurred for a given month, the
permittee shall mark ―No Discharge‖ on the DMR forms. The sampling results must be maintained by the permittee.
E. A Location Map for Defined and Undefined Discharges—designating the location of the project/facility, the location of the
discharge point(s)/outfalls—applicable only to defined discharges, and the receiving water(s) listed in Items C & D. A north
arrow shall be shown. This map must be on paper that can be folded to 8 ½ x 11 inches.
F. A Legible Sketch of the Site
1. For Defined Discharges—A legible site sketch shall be submitted and must include: the location of the end of pipe
dewatering discharges at the site (e.g. where the flow will be discharged from the pump or BMP), the BMP(s) that will be
used to treat the discharge(s), and the sampling location(s). Refer to the instructions for additional guidance specific to
sites with multiple potential dewatering locations. This map must be on paper that can be folded to 8 ½ x 11 inches.
OR
2. For Undefined Discharges—A legible site sketch shall be submitted and must include: the limits of the construction site
boundary to include street names (if applicable) or landmarks; description of the BMPs to be implemented; and location of
all potential receiving waters. This map must be on paper that can be folded to 8 ½ x 11 inches.
G. Potential Groundwater Contamination
1. Is this operation located within one mile of a landfill, abandoned landfill or any mine or mill tailings? YES NO
2. Has the dewatering discharge been analyzed for any parameters (pH, Oil and Grease, Metals, Organics, etc.)?
YES NO If YES, please attach a copy of the sampling results.
Page 5 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
Note to the applicant: Upon review of the application, the Division may request characterization of the water to be
discharged or analysis of certain parameters once the application has been reviewed. If the Division requests a
representative analysis of the water to be discharged, the application processing time may be lengthened.
3. Has the dewatering area been checked for possible groundwater contamination, such as plumes from leaking
underground storage tanks, mine tailings,etc –or- has a Phase I or Phase II been conducted on the site?
YES NO
If YES, show location of the landfill, tailings, or possible groundwater contamination on the location map or general sketch
map. (Explain the location, extent of contamination, and possible effect on the groundwater pumping from this facility). Or
include a copy of the phase I or Phase II report. If the reports are not available, submit a summary of the results of the
report. If any sampling results are available, please attach a copy of all data.
Note: Contact Water Quality Control Division for the proper water chemistry parameters to report.
H. Additional Information
1. Does the applicant have a Stormwater Permit for Construction Activities? YES NO PENDING
If Yes, Stormwater Construction Permit Number _________________________________
WATER RIGHTS
The State Engineers Office (SEO) has indicated that any discharge that does not return water directly to surface
waters (i.e.land application, rapid infiltration basins, etc.) has the potential for material injury to a water right. As a
result, the SEO needs to determine that material injury to a water right will not occur from such activities. To make
this judgment, the SEO requests that a copy of all documentation demonstrating that the requirements of Colorado
water law have been met, be submitted to their office for review. The submittal should be made as soon as possible
to the following address:
Colorado Division of Water Resources
1313 Sherman Street, Room 818
Denver, Colorado 80203
Should there be any questions on the issue of water rights, the SEO can be contacted at (303) 866-3581. It is
important to understand that any CDPS permit issued by the Division does not constitute a water right. The issuance
of a CDPS permit does not negate the need to also have the necessary water rights in place. Additionally, if the
activity has an existing CDPS permit, there is no guarantee that the proper water rights are in place.
I. Required Certification Signature [Reg 61.4(1)(h)]
"I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in
accordance with a system designed to assure that qualified personnel properly gather and evaluate the information
submitted. Based on my inquiry of the person or p ersons who manage the system, or those persons directly responsible for
gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and
complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine
and imprisonment for knowing violations."
―I understand that submittal of this application is for coverage under the State of Colorado General Permit for Discharges
Associated with Construction Dewatering for the entirety of the construction site/project described and applied for,
until such time as the application is amended or the certification is transferred, inactivated, or expired .‖
Signature (Legally Responsible Party)_________________________________________Date ________________
Name (printed) _____________________________________________Title______________________________
Page 6 of 6 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
Construction Dewatering Application Instructions
Item A- Contact Information
Permit Applicant: Provide the company, corporation, or organization name
1. Permittee—Identify the title and name of the individual who is the legally responsible for the permit. The requirement of
who can be listed as the legally responsible party is included in the permit application. Include all requested information such
as the legal party‘s phone number, email address and mailing address. The individual identified here must sign the permit
application—Part I.
2. DMR Cognizant Official—Identify the title and individual‘s name
3. Site Contact—Identify the title and name of individual who is familiar with the day to day operations of the site. This
person will have first-hand information regarding the construction site, discharges occurring on site, and implementation of
BMPs.
4. Operator in Responsible Charge— Identify the title and individual‘s name if there is an Operator in Charge (Not
required)
5. Billing Contact— Identify the title and individual‘s name
6. Other Contacts – Identify the title and individual‘s name for any of the listed descriptions (Not required)
Item B – Permitted Project/Facility Information
1. Name of the project/facility and location; include the name of the project/facility and include a description of the locatio n
of the project/facility. The location may be a physical address or if the exact address is not available you may use an
approximate address such as: the nearest intersection or boundary streets including directional identifiers (e.g., ―South of 14th
Avenue between Sherman St. and Logan St.‖, or ―West side of C.R. 21, 3.25 miles North of Hwy 10‖) or other identifying
information. A street name without an address, intersection, mile marker or other identifying information is not adequate.
2. Latitude/Longitude: For each excavation resulting in a discharge/outfall provide the Latitude/Longitude of the excavation.
If the exact location of the disturbance resulting in discharge is not known, provide the lat/long of the center point of the
construction activity. If identifying the center point of construction activity, make sure to write in ―center point‘ next to
lat/long. The lat/long may be provided as decimal degrees or degrees, minutes, seconds format. This information can be
obtained from a variety of sources, including:
Various Websites: http://terraserver.microsoft.com, http://geocoder.us/, or
www.epa.gov/tri/reports/siting_tool/index.htm
U.S Geological Survey topographical map, available at area map stores
Surveyors or engineers for the construction project should have, or be able to calculate this information using a
Global Positioning System (GPS) unit
Specify whether the Latitude/Longitude information was collected either by using a GPS unit or through Map interpolation.
3. Facility Activity and Schedule: Include the anticipated start date of construction dewatering and provide the length of
time dewatering is anticipated to last. Provide a description of the general nature of the construction activities th at are
requiring the dewatering. Also describe if the dewatering discharge is from an open excavation, such as a trench or foundation,
or from groundwater lowering wells. Examples of activity descriptions may include: ‗open trench excavation for installation
of 4,000 linear feet of new water lines‘, or ‗a series of shallow groundwater wells will be installed around the perimeter of the
construction site in order to lower the water table for construction of a new 5,000 square foot music shop—all wells will be
piped to one manifold resulting in one discharge location as indicated on our site sketch.
4. Discharges to ditches and storm sewers: Indicate by checking yes or no whether or not the immediate effluent will be
discharged to a ditch or storm sewer. If yes is marked, the applicant must contact the owner of the ditch or storm sewer
system prior to discharge to verify if the owner will allow a discharge to their system. The owner of the ditch/storm sewer
system may impose additional requirements. Storm drainage systems are typically owned by the city or county they are located
within, and therefore contacting the local city/county is the appropriate place to start. If yes is marked, in Table C or Table D
be sure to include the location of the system and the ultimate receiving waters.
5. Defined or Undefined Discharge: Identify whether the applicant is applying for a Defined or Undefined discharge.
A Defined Discharge is a discharge where the dewatering discharge locations are known at the time of permit application.
If discharge is Defined – enter discharge information in Table C
Page 1 of 3—Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
An Undefined Discharge is a discharge where the exact dewatering discharge locations are unknown at the time of permit
application. The permit applicant must request the maximum number of potential outfalls (discharges) for the permitted
facility/project. If discharge is Undefined – enter discharge information in Table D. The applicant must identify all
potential receiving streams for the entire project.
If the applicant is requesting undefined discharges, the site specific sampling and monitoring parameters will be selected
based on the potential pollutant sources found within the entire permitted project area and will be applied to all outfall(s).
The most stringent of the surface water limitations for each identified site specific parameter will be applied to each
permitted outfall. For example, if the undefined project includes installation of 8 miles of linear pipeline and leaking
underground storage tanks are expected to present in one section of the project, sampling and monitoring for Benzene,
Toluene, Ethyl benzene, and Xylenes will be required for all requested outfall(s).
Item C- Information for Defined Discharge Location(s).
1. If Defined Discharge was marked in Section B.5 fill out Table C. Table C requires the following information:
Number of discharge(s) (outfalls)—Identify the number of outfalls requested in Table C, this includes
discharges to surface water and groundwater. If there are more than two requested discharges to surface water,
attach a separate piece of paper including all requested information.
Name of the receiving water(s)—If the discharge is to a ditch, identify the ditch and the ultimate receiving
water(s). Receiving waters are any waters of the state of Colorado, even if the natural drainage is usually dry. If
discharge is to groundwater, then fill out the appropriate information within Table C next to G001A, G001A. If
there are more than two discharges to groundwater, attach a sepa rate piece of paper including all requested
information. If the applicant is requesting a discharge to groundwater, please review the Division‘s Low Risk
Discharge Guidance for Discharges of Uncontaminated Groundwater to Land .
http://www.cdphe.state.co.us/wq/PermitsUnit/policyguidancefactsheets/policyandguidance/lowriskgwdischargeto
land.pdf
Discharges performed in accordance with the Guidance for Discharges of Uncontaminated Groundwater to Land
do not require a separate construction dewatering permit.
Narrative description of the approximate location of the discharge—Include a narrative description of the
discharge path. For example, ―the dewatering discharge will enter the storm sewer located at 6th Avenue and
Sheridan which flows to Bear Creek‖ or ―the dewatering will discharge to a field located at 66th and Farmers
Road with potential to runoff to Sanders Creek‖. If there is more than one known discharge, include this
descriptive information for all known discharges.
Maximum anticipated flow rate of the discharge (in gallons per minute)—Do not leave this section blank.
Include the maximum flow rate. You may estimate the flow contribution based on pump capacity if data is not
available.
Latitude/Longitude of each discharge location—Include the latitude/longitude of each discharge location. See
the instructions B.2 for information on how to obtain latitude/longitude information.
Item D- Information for Undefined Discharge Location(s).
1. If Undefined Discharge was marked in Section B.5 fill out Table D. Table D requires the flowing information:
Maximum number of potential outfalls (discharges) for the permitted facility—The applicant must identify the
maximum number of discharge locations (outfalls) for the entire construction project. If more than 5 outfalls are
requested, attach a separate piece of paper. DMRs will be sent to the permittee for each requested ou tfall.
Maximum anticipated flow rate of the discharge (in gallons per minute)—Do not leave this section blank. The
flow rate may be estimated based on pump capacity if data is not available.
Name(s) of the all potential receiving stream(s)—Identify all potential receiving streams for the entire project.
If the discharge is to groundwater then fill out the information in Table D next to G001A, G002A, etc.
Page 2 of 3 Revised April 2011
Industrial Wastewater Discharge Permit – Construction Dewatering www.coloradowaterpermits.com
Item E – Location Map—A location map is required to be submitted with all applications for both defined and undefined
discharges. The location map must include the location of the project/facility, the approximate location of each defined discharge
points, and the identified receiving water(s) listed in Items C or D. The map must have a minimum scale of 1:24000 (the scale of a
USGS 7.5 minute map). A legible submittal is required on paper that can be folded to8 ½ by 11 inches.
Item F- Detailed Sketch of the Site—If a defined discharge is requested please submit a detailed site sketch which includes
the information requested in F.1. If an undefined discharge is requested please submit a detailed site sketch which includes
the information requested in F.2.
1. Detailed Sketch of the Site for Defined Discharges—Must included a detailed sketch of the site showing the location of
end of pipe dewatering discharge(s) at the site —to include the flow line of each requested dewatering discharge. The
location and identification of the structural Best Management Practices (BMPs) used to treat the effluent prior to discharge.
The map shall also include the sampling locations for each requested outfall. A legible submittal is required on paper that
can be folded to 8 ½ by 11 inches.
2. Detailed Sketch of the Site for Undefined Discharges—This map must include the boundary of the construction site
where all potential dewatering could occur. The boundaries should include a northern boundary, an eastern boundary, a
southern boundary and a western boundary. The map must highlight or call out street names that border the project
boundary. If streets are not available, landmarks or mile-markers must be identified. The map must highlight all potential
receiving streams. The map must also include the identification of the structural BM Ps used to treat the effluent prior to
discharge. A legible submittal is required on paper that can be folded to 8 ½ by 11 inches.
Item G—Potential Groundwater Contamination
1. Dewatering on/near Landfills, Mines, or Mill Tailings: If the dewatering project is located within one mile of a landfill,
abandoned landfill, mine or mill tailings check yes. In addition, provide as much detail as possible regarding the extent of
contamination and attach all sampling data. Indicate the location of the landfill, m ine, etc. on the Location and Detail Maps.
Contamination plume information can be obtained from the following source:
http://www.cdphe.state.co.us/hm/HMSiteCover.htm
2. Sampling Data: If any sampling data is available that is representative of the prop osed discharge mark yes. Attach a copy
of all sampling results to the application. If the data was collected for another agency or private company include a brief
description as to why the data was collected.
3. Additional Sources of Contamination: Mark yes if the proposed construction site resulting in a dewatering discharge has
been evaluated for any additional sources of contamination. Additional sources include underground storage tanks, dry
cleaners, voluntary clean-up sites, etc. Also mark yes, if a Phase I or Phase II has been conducted on the property or adjacent
properties. Attach a copy of all records (phase I, phase II, sampling efforts) that could help characterized the water to be
discharged.
Contamination plume information can be obtained from the following source:
http://www.cdphe.state.co.us/hm/HMSiteCover.htm
Item H—Additional Information
1. Stormwater Permit for Construction Activities: If the applicant holds a stormwater permit for construction related
activities (parcels > 1 acre) include the stormwater permit number. If you have applied, or intend to apply but have not yet
obtained coverage and your certification number, indicate ―Pending‖ for this item.
Item I—Signature Requirements—The permit applicant listed in Part A.1 must sign the permit application. Signatures must
meet the requirements established in Regulation 61.4(1)(h).
Page 3 of 3—Revised April 2011
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EPSGROUPINC.COM | 970.221.4158 SWMP: 300 E. Mountain Ave
FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX D
INSPECTION LOGS
Page 1 of 6 CDOT Form #1176 2/21
COLORADO DEPARTMENT OF TRANSPORTATION STORMWATER FIELD INSPECTION REPORT - ACTIVE CONSTRUCTION
(1) Project Name:(2) Project Contractor:(3) SWMP Administrator (Qualified Stormwater Manager)
/Erosion Control Inspector:
(4) CDOT Project Engineer/CDOT Designee:(5) Other Attendee(s) (Name and Title):
(6) CDOT Project Number:(7) Project Code (Sub Account #):(8) CDPS-SCP
Certification#:
(12)REASON FOR INSPECTION / EXCLUSION
❑Routine Inspection: (A routine erosion control inspection shall be conducted at a minimum, once every 7 Calendar Days)❑Runoff Event: (Post-storm event inspections must be conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface
erosion. If no construction activities will occur following a storm event, post-storm event inspections shall be conducted prior to re-commencing construction
activities, but no later than 72 hours following the storm event. The occurrence of any such delayed inspection must be documented in the inspection
record.) Routine inspections still must be conducted every 7 calendar days.
Storm Start Date: Approximate End Time of Storm (hrs): ❑Third Party Request: Winter Conditions Inspections Exclusion: Inspections are not required at sites where construction activities are temporarily
halted, snow cover exists over the entire site for an extended period, and melting conditions posing a risk of surface erosion do not exist. This
exception is applicable only during the period where melting conditions do not exist, and applies to the routine 7-day inspections, as well as the post-
storm-event inspections. If visual inspection of the site verifies that all of these conditions are satisfied, document the conditions in section 17 (General
Notes) and proceed to section 18 (Inspection Certification). Documentation must include: dates when snow cover existed, date when construction activities
ceased, and date when melting conditions began.❑
(13)SWMP MANAGEMENT
Yes No N/A (g) Reason for N/A
(a) Is the SWMP located on site?
(b) Are changes to the SWMP documents noted and approved?
(c) Are the inspection reports retained in the SWMP?
(d) Are corrective actions from the last inspection completed?
(e) Is the Spill Response Plan updated in the SWMP?
(f) Is a list of potential pollutants updated in the SWMP?
(14)CURRENT CONSTRUCTION ACTIVITIES
(a)Describe current phase of construction activities
(b)Estimate of disturbed area at the time of the inspection, use guidance found in 208.04 (e):
(c) Has the SWMP Phased Control Measure Implementation Matrix been updated? ❑ Yes ❑No
Page 2 of 5 CDOT Form #1176 2/21
(15)CONSTRUCTION SITE ASSESSMENT & CORRECTIVE ACTIONS **Off-site Pollutant Discharges are a Violation of the Permit and Reason for Immediate Project Suspension**
The Construction Site Boundary/Limits of Construction (LOC), all disturbed areas, designated haul roads, material and/or waste storage areas that are exposed to precipitation,
discharge locations, and locations where vehicles exit the site shall be inspected for evidence of, or the potential for, pollutants leaving the LOC, entering the stormwater
drainage system, or discharging to State waters. If there is evidence of sediment or other pollutants discharging from the site, see section 16 (Construction Site Assessment).
All erosion and sediment control practices identified in the SWMP shall be evaluated to ensure that they are maintained and operating correctly. Identify the condition of the
control measure, using more than one letter if necessary: (I) Inadequate control measure; (M) Maintenance is needed; (A) Additional control measure is needed; (R) Remove
control measure. Keep copies of this blank page for additional room if needed.
Continuous maintenance is required on all control measures. As per CDPS-SCP: “Control measures that are not operating effectively, have proven to be inadequate, or
have failed must be addressed as soon as possible, immediately in most cases.”
Location Control
Measure Completed
& Initials
Page 3 of 6 CDOT Form #1176 2/21
(16)CONSTRUCTION SITE ASSESSMENT **Off-site Pollutant Discharges are a Violation of the Permit and Reason for Immediate Project Suspension**
(a) Is there evidence of discharge of sediment or other pollutants from the site?❑Yes ❑ No
*If yes, explain the discharge, the location and the associated corrective actions in section 15 (Construction Site Assessment & Corrective Actions) or section 18 (General Notes).
(b) Has sediment or other pollutants discharging from the site reached State waters? ❑ Yes ❑ No
*If yes, see subsection 208.03(c) and Part I.L.6 of the permit for reporting requirements.
(17)GENERAL NOTES
(18)INSPECTION CERTIFICATION
By signing this form, I certify that I attended the inspection in accordance with specification 208.03.
Contractor’s SWMP Administrator (Qualified Stormwater Manager)
Print Name: Signature Required: Date:
Contractor’s Erosion Control Inspector (If Needed):
Print Name: Signature (if needed) Date:
(19)COMPLIANCE CERTIFICATION
I verify that, to the best of my knowledge and belief, that if any corrective action items were identified during the inspection, those corrective actions are complete, and the site
is currently in compliance with the permit (Part I.A.3.f.i).
Contractor’s SWMP Administrator/ECI
Print Name: Signature Required: Date
Contractor’s Superintendent/Approved Designee
Print Name: Signature Required: Date:
CDOT Project Engineer/CDOT Designee
Print Name: Signature Required: Date:
Page 4 of 6 CDOT Form #1176 2/21
Stormwater Management Field Inspection Report Instructions
State waters are defined to be any and all surface and subsurface waters which are contained in or flow through the state,
including, streams, rivers, lakes, drainage ditches, storm drains, ground water, and wetlands, but not including waters in sewage
systems, waters in treatment works of disposal systems, waters in potable water distribution systems, and all water withdrawn for
use until use and treatment have been completed. (Per subsection 107.25 and 25-8-103 (19) CRS)
(3)SWMP Administrator (Qualified Stormwater Manager) and Erosion Control Inspector: Indicate the name(s) of
the individual responsible for implementing, maintaining and revising the SWMP. An Erosion Control Inspector(s) may
be the SWMP Administrator in projects with not more than 40 acres of disturbance (see 208.03(c)).
(4)CDOT Project Engineer/CDOT Designee: Indicate the name of the CDOT representative performing the inspection
with the SWMP Administrator/Erosion Control Inspector(s). This person should be the Project Engineer or an
authorized representative.
(9) CDPS-SCP Certification #: Indicate the Colorado Discharge Permit System (CDPS) Stormwater Construction Permit (SCP)
(for Stormwater Discharges Associated with Construction Activities) certification number, issued by CDPHE, for the project
which the report is being completed. Certification number can be found on the first page of the SCP.
(12)Reason(s) for Inspection / Exclusion: Indicate the purpose for the inspection or exclusion. These inspections are
required to comply with the CDOT Specifications and the CDPS-SCP.
❑Routine Inspections. These inspections are required at least every 7 calendar days during active construction.
Suspended projects require the 7 calendar day inspection unless snow cover exists over the entire site for an extended
period of time, and melting conditions do not exist (see, Winter Conditions Inspections Exclusions). ❑ Runoff Event
Inspection for Active Sites. See page 1 for definition.
❑Third Party Request. Indicate the name of the third party requesting the inspection and, if known, the reason the request
was made.
❑Winter Conditions Inspections Exclusions. See page 1 for definition. An inspection does not need to be completed, but
use this form to document the conditions that meet the Exclusion. ❑ Other. Specify any other reason(s) that resulted in
the inspection.
(13)SWMP Management: Review the SWMP records and documents and use a ✔ to answer the question. To comply with
CDOT Standard Specifications and the CDPS-SCP, all of the items identified must be adhered to. If No is checked,
indicate the necessary corrective action in section 15 (Construction Site Assessment & Corrective Actions). Specification
208.03(d).
a)A copy of the SWMP must be retained on site, unless another location (specified by the permit) is approved by the
Division.
b)Indicate all changes that have been made to any portion of the SWMP documents during construction. Changes shall
be dated and signed at the time of occurrence. Amendments may include items listed in subsection 208.03(d).
c)The SWMP Administrator shall keep a record of inspections. Inspection reports must identify any incidents of
noncompliance with the terms and conditions of the CDOT specifications or the CDPS-SCP. Inspection records must
be retained for three years from expiration or inactivation of permit coverage.
d)Are corrective actions from the last inspection completed? Is a description of the corrective action(s), the date(s) of
the corrective action(s), and the measure(s) taken to prevent future violations (including changes to the SWMP, as
necessary) documented?
e)Subsection 208.06(c) requires that a Spill Response Plan be developed and implemented to establish operating
procedures and that the necessary employee training be provided to minimize accidental releases of pollutants that
can contaminate stormwater runoff. Records of spills, leaks or overflows that result in the discharge of pollutants must
be documented and maintained. Information that should be recorded for all occurrences include the time and date,
weather conditions, reasons for spill, etc. Some spills may need to be reported to the Water Quality Control Division
immediately.
f)(f) Subsection 107.25(b)6 requires the Erosion Control Supervisor to identify and describe all potential pollutant
sources, including materials and activities, and evaluate them for the potential to contribute pollutants to stormwater
discharge.
g)(g) If N/A is checked for any of the items (a) through (f), indicate why in the space provided, if additional space is
needed indicate in section 17 (General Notes).
Page 5 of 6 CDOT Form #1176 2/21
Stormwater Management Field Inspection Report Instructions (continued)
(14) Current Construction Activities:
a)Provide a short description of the current construction activities/phase at the project site; include summary of grading
activities, installation of utilities, paving, excavation, landscaping, etc.
(1)Estimate of disturbed area at the time of the inspection, use guidance found in 208.04 (e). Estimate the acres of
disturbed area at the time of the inspection. Include clearing, grading, excavation activities, areas receiving overburden
(e.g. stockpiles), demolition areas and areas with heavy equipment/vehicle traffic, installation of new or improved haul
roads and access roads, staging areas, borrow areas and storage that will disturb existing vegetative cover, (Areas that
have been: hard armored or paved should not be counted for total disturbance).
b)Has the Phased control measure Implementation Matrix on the SWMP been updated? As part of the inspection the
Phased control measure Implementation matrix for both the structural and non-structural control measures found at
the beginning of the SWMP sheets must be reviewed to ensure that “In use on site” box is checked for control
measures currently in use at the time of the inspection.
(15) Construction Site Assessment & Corrective Actions: Inspect the construction site and indicate where control measure
feature(s) identified in section 13 (SWMP Management), require corrective action. Erosion and sediment control practices
identified in the SWMP shall be evaluated to ensure that they are operating correctly.
•Condition. Identify the condition of the control measure, using more than one letter (identified in section 15) if necessary.
•Location. Site location (e.g., project station number, mile marker, intersection quadrant, etc.).
•Control measure. Indicate the type of control measure at this location that requires corrective action (e.g., silt fence,
erosion logs, soil retention blankets, etc.).
•Date Completed & Initials. Date and initial when the corrective action was completed and the preventative measure
statement finished.
•Description of Corrective Action and Preventative Measure Taken. Provide the proposed corrective action needed to bring
the area or control measure into compliance. Once corrective actions are completed, state the measures taken to prevent
future violations and ensure that the control measures are operating correctly, including the required changes made to the
•SWMP.
Inadequate control measure: Is any control measure that is not designed or implemented in accordance with the
requirements of the permit and/or any control measure that is not implemented to operate in accordance with its design, this
includes control measures that have not been implemented for pollution sources. If it is infeasible to install or repair the
control measure immediately after discovering the deficiency the reason must be documented and a schedule included to
return the control measure to effective operating condition as soon as possible.
Control measures requiring routine maintenance: Any control measure that is still operating in accordance with its
design and the requirements of the permit, but requires maintenance to prevent a breach of the control measure. These
items are not subject to the corrective action requirements as specified in Part I.b.1.c of the permit.
Additional: Any control measure inadequate for its application or an area with insufficient control measure(s). If it is
infeasible to install revised or additional control measure(s) immediately after discovering the deficiency the reason must be
documented and a schedule included to return the control measure to effective operating condition as soon as possible.
Remove: Control measure no longer necessary
(16) Construction Site Assessment: Was there any off site discharge of sediment at this site since the last inspection?
a)Is there evidence of discharge of sediment or other pollutants from the site? Off-site pollutant discharges are a
violation of the permit. (The construction site perimeter, all disturbed areas, material and/or waste storage areas that
are exposed to precipitation, discharge locations, and locations where vehicles access the site shall be inspected for
evidence of, or the potential for, pollutants leaving the construction site boundaries, entering the stormwater drainage
system).
b)Are pollutants discharging to State water?
c)Has sediment or other pollutants discharging from the site reached State waters? Off-site pollutant discharges are a
violation of the permit. If off site discharge has occurred, explain the discharge and the corrective actions in section
15 (Construction Site Assessment & Corrective Actions) or section 17 (General Notes).
Page 6 of 6 CDOT Form #1176 2/21
(17)General Notes: Indicate any additional notes that add detail to the inspection; this may include positive practices noted on
the project.
(18)Inspection Certification: In accordance with 208.03, required personnel shall sign to verify that they were in attendance.
(19)Compliance Certification: After all corrections have been made, this signature must be completed in accordance with Part
I.A.3.f of the CDPS-SCP.
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX E
CONTRACTOR INSERTS
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX F
REFERENCE MATERIAL
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FORT COLLINS | GREELEY | MESA | TUCSON | GOODYEAR | PHOENIX | FORT WORTH APPENDIX
APPENDIX G
NATURAL RESOURCES CONSERVATION RESOURCES