HomeMy WebLinkAboutBANNER HEALTH MEDICAL CAMPUS - FDP - FDP130020 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTMay 22, 2013
FINAL DRAINAGE AND
EROSION CONTROL REPORT
BANNER HEALTH MEDICAL CAMPUS
Fort Collins, Colorado
Prepared for:
Banner Health
1801 16th Street
Greeley, CO 80631
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 306-003
This Drainage Report is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy is absolutely necessary, we recommend double-sided printing.
May 22, 2013
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Final Drainage and Erosion Control Report for
BANNER HEALTH MEDICAL CAMPUS
Dear Staff:
Northern Engineering is pleased to submit this Final Drainage and Erosion Control Report for your
review. This report accompanies the Project Development Plan submittal for the proposed
Banner Health Medical Campus development.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed project. We
understand that review by the City is to assure general compliance with standardized criteria
contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Aaron Cvar, PE
Project Engineer
Banner Health Medical Campus
Preliminary Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION .................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain ......................................................................................................................................... 4
II. DRAINAGE BASINS AND SUB-BASINS ........................................................................ 4
A. Major Basin Description .................................................................................................................... 4
B. Sub-Basin Description ....................................................................................................................... 4
III. DRAINAGE DESIGN CRITERIA .................................................................................... 5
A. Regulations ........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 5
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 6
F. Floodplain Regulations Compliance .................................................................................................. 6
G. Modifications of Criteria ................................................................................................................... 6
IV. DRAINAGE FACILITY DESIGN ..................................................................................... 6
A. General Concept ............................................................................................................................... 6
B. Master Drainage Concepts ................................................................................................................ 9
C. Specific Details .................................................................................................................................. 9
V. CONCLUSIONS ........................................................................................................ 10
A. Compliance with Standards ............................................................................................................ 10
B. Drainage Concept ............................................................................................................................ 10
References ......................................................................................................................... 11
APPENDICES:
APPENDIX A – Hydrologic Computations
APPENDIX B – Hydraulic Computations
B.1 – Storm Sewers
B.2 – Inlets
B.3 – Riprap
APPENDIX C – Water Quality Design Computations
APPENDIX D – SWMM Analysis
APPENDIX E –Erosion Control Report
Banner Health Medical Campus
Preliminary Drainage Report
LIST OF TABLES AND FIGURES:
Figure 1 – Aerial Photograph .................................................................................................. 2
Figure 2 – Proposed Site Plan ................................................................................................. 3
Figure 3 – Existing Floodplains ............................................................................................... 4
Table 1 – Pond Summary…………………………………………………………………………………9
MAP POCKET:
Drainage Exhibits
Banner Health Medical Campus
Final Drainage and Erosion Control Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the northwest quarter of Section 4, Township 6 South,
Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado.
3. The project site is located just southeast of the intersection of East Harmony Road
and Lady Moon Drive.
4. The project site lies within the East Harmony portion of the McClellands Creek Master
Drainage Basin. Per the “East Harmony Portion of the McClellands Creek Master
Drainage Plan Update”, by Icon Engineering, August 1999 (Ref. 6), onsite detention
is required with a release rate of 0.5 cfs per acre in the 100-year storm event.
5. Areas directly adjacent to the project site on the west, south and east are currently
undeveloped. The existing Hewlett Packard campus is located just north of the
project site on the north side of Harmony Road.
Banner Health Medical Campus
Final Drainage and Erosion Control Report 2
B. Description of Property
1. The subject property is approximately 33 net acres.
Figure 1 – Aerial Photograph
2. The subject property currently consists of vacant ground. The ground cover generally
consists of open pasture and some native seeding. Existing ground slopes are
generally mild (i.e., 1 to 5±%) through the interior of the property. General
topography slopes from west to east towards the Fossil Creek Reservoir Inlet Ditch.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey, the site consists of Paoli fine sandy loam,
which falls into Hydrologic Soil Group B.
4. The proposed project will develop the majority of the existing site, constructing a
medical campus. Parking areas and associated utilities will be constructed.
Detention/water quality ponds will be constructed at the northeast and southeast
corners of the site.
Banner Health Medical Campus
Final Drainage and Erosion Control Report 3
Figure 2– Proposed Site Plan
5. The Fossil Creek Reservoir Inlet Ditch is located roughly 1400 feet east of the project
site, and runs parallel to the site from north to south. There are no other major
irrigation ditches or related facilities in the vicinity of the project site.
6. The proposed land use is comprised entirely of a medical campus.
Banner Health Medical Campus
Final Drainage and Erosion Control Report 4
C. Floodplain
1. The Cache La Poudre River 100-year floodplain lies approximately 2000 feet offsite
to the east. No portion of the subject property is encroached by any City or FEMA
jurisdictional floodplain.
Figure 3 – Existing Floodplains
2. It is noted that the vertical datum utilized for site survey work is the City of Fort
Collins Benchmark #7-01 (Elevation=4911.33, Ft. Collins NGVD 29).
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site is located within the East Harmony portion of the McClellands Creek
Master Drainage Basin.
B. Sub-Basin Description
2. The subject property historically drains overland towards the Fossil Creek Reservior
Inlet Ditch, located roughly 1400 feet east of the project site. A more detailed
description of the project drainage patterns follows in Section IV.A.4., below.
3. Areas to the east of the site drain into an existing storm line within Lady Moon Drive
and are conveyed south in the existing storm system. Drainage from East Harmony
Road to the north of the site is conveyed east via the roadside ditch running along the
south side of East Harmony Road. There is an existing storm line that begins just
west of Cinquefoil Lane and runs roughly 500 feet east which conveys drainage from
the roadside ditch.
PROJECT
SITE
Banner Health Medical Campus
Final Drainage and Erosion Control Report 5
III. DRAINAGE DESIGN CRITERIA
A. Regulations
There are no optional provisions outside of the FCSCM proposed with the proposed
project.
B. Four Step Process
The overall stormwater management strategy employed with the proposed project utilizes
the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters.
The following is a description of how the proposed development has incorporated each
step.
Step 1 – Employ Runoff Reduction Practices
Several techniques have been utilized with the proposed development to facilitate the
reduction of runoff peaks, volumes, and pollutant loads as the site is developed by
implementing multiple Low Impact Development (LID) strategies including:
Conserving existing amenities in the site including the existing vegetated areas.
Providing vegetated open areas throughout the site to reduce the overall impervious
area and to minimize directly connected impervious areas (MDCIA).
Routing flows, to the extent feasible, through vegetated swales to increase time of
concentration, promote infiltration and provide initial water quality.
Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with
Slow Release
The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban
development of this intensity will still generate stormwater runoff that will require
additional BMPs and water quality treatment. All stormwater runoff from the site will
ultimately be routed to onsite water quality ponds, where it will be treated prior to exiting
the site and entering the storm collection system.
Step 3 – Stabilize Drainageways
There are no major drainageways within the subject property. While this step may not
seem applicable to proposed development, the project indirectly helps achieve stabilized
drainageways nonetheless. By providing water quality where none previously existed,
sediment with erosion potential is removed from the downstream drainageway systems
and receiving Fossil Creek Reservoir Inlet Ditch. Furthermore, this project will pay one-
time stormwater development fees, as well as ongoing monthly stormwater utility fees,
both of which help achieve City-wide drainageway stability.
Step 4 – Implement Site Specific and Other Source Control BMPs.
The proposed project will require the need for site specific source controls including:
Localized trash enclosures throughout the site for the disposal of waste products.
C. Development Criteria Reference and Constraints
The subject property is bounded on several sides by currently developed properties
and existing public streets. As such, several constraints have been identified during
the course of this analysis that will impact the proposed drainage system including:
Banner Health Medical Campus
Final Drainage and Erosion Control Report 6
Existing elevations along property lines will generally be maintained.
Overall drainage patterns of the existing site will be maintained.
Elevations of existing downstream facilities that the subject property will release to
will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above the subject property is not located in a FEMA regulatory floodplain.
4. The proposed project does not propose to modify any natural drainageways.
F. Floodplain Regulations Compliance
1. As previously mentioned, all structures are located outside of any FEMA 100-year
floodplain, and thus the structures are not subject to any floodplain regulations.
G. Modifications of Criteria
1. The proposed development is not requesting any modifications to criteria at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of the project drainage design are to maintain existing drainage
patterns, ensure no adverse impacts to any adjacent properties, and to maintain the
detention concepts as outlined in the “Harmony Portion of the McClellands Creek
Master Drainage Plan Update”, by Icon Engineering, August 1999 (Ref. 6).
2. Areas to the west of the site are intercepted by a storm line system within Lady Moon
Banner Health Medical Campus
Final Drainage and Erosion Control Report 7
Drive and do not flow through the site. East Harmony Road and areas to the north of
the site drain into a roadside swale along the south side of East Harmony Road and
do not drain through the site.
3. A list of tables and figures used within this report can be found in the Table of
Contents at the front of the document. The tables and figures are located within the
sections to which the content best applies.
4. The drainage patterns anticipated for proposed drainage basins are described below.
Basin 1
Basin 1 consists of landscaped and paved parking areas, and drains into the proposed
Pond 1.
Basin 2
Basin 2 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 3
Basin 2 consists of landscaped, paved parking areas and drives, and a proposed
helipad. This basin drains into the proposed Pond 1.
Basin 4
Basin 4 consists of landscaped areas, paved drives, and public street. Flows area
captured and conveyed via Storm Line 1 into Pond 3.
Basin 5
Basin 5 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 6
Basin 6 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 7
Basin 7 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 8
Basin 8 consists of landscaped areas, a proposed helipad, and a paved drive. Flows
area captured and conveyed via Storm Line 2 into Pond 1.
Basin 9a
Basin 9a consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 9b
Basin 9b consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 10
Basin 10 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Banner Health Medical Campus
Final Drainage and Erosion Control Report 8
Basin 11
Basin 11 consists of landscaped area and drains into the proposed Pond 1.
Basin 12
Basin 12 consists of rooftop, and drains partially into the proposed Pond 1 and
partially into the proposed Pond 2.
Basin 13
Basin 13 is currently shown to be an overlot grading area; however, all drainage
calculations have been done anticipating future fully developed conditions (please see
Rational Method Calculations for anticipated C-Values, % Imperviousness, and other
assumed parameters for fully developed conditions). This basin drains into the
proposed Pond 2.
Basin 14
Basin 14 is currently shown partially to be an overlot grading area; however, all
drainage calculations have been done anticipating future fully developed conditions
(please see Rational Method Calculations for anticipated C-Values, % Imperviousness,
and other assumed parameters for fully developed conditions). This basin drains into
the proposed Pond 3 via Storm Line 1.
Basin 15
Basin 15 consists of landscaped areas, and public street. Flows are captured and
conveyed via Storm Line 1 into Pond 3.
Basin 16
Basin 16 consists of landscaped area and drains into the proposed Pond 1.
Basin 17
Basin 17is currently shown to be an overlot grading area; however, all drainage
calculations have been done anticipating future fully developed conditions (please see
Rational Method Calculations for anticipated C-Values, % Imperviousness, and other
assumed parameters for fully developed conditions). This basin drains into the
proposed Pond 2.
Basin 18
Basin 18 is currently shown to be an overlot grading area; however, all drainage
calculations have been done anticipating future fully developed conditions (please see
Rational Method Calculations for anticipated C-Values, % Imperviousness, and other
assumed parameters for fully developed conditions). This basin drains into the
proposed Pond 2.
Basin 19
Basin 19 is currently shown partially to be an overlot grading area as well as including
the proposed Pond 2; however, all drainage calculations have been done anticipating
future fully developed conditions (please see Rational Method Calculations for
anticipated C-Values, % Imperviousness, and other assumed parameters for fully
developed conditions). All runoff from this basin is captured in the proposed Pond 2.
Banner Health Medical Campus
Final Drainage and Erosion Control Report 9
Basin 20
Basin 20 consists of 1.05 acres; partially Lady Mood Drive R.O.W. (0.57 acres), and
partially landscaped areas within the proposed site (0.48 acres). This basin drains
into the existing storm collection system within Lady Moon Drive.
Basin 21
Basin 11 consists of 0.21 acres of LeFever Drive R.O.W. and drains into the existing
storm collection system within Lady Moon Drive.
Basin 22
Basin 12 consists of 0.76 acres of LeFever Drive R.O.W. Drainage is collected in a
storm collection system with Cinquefoil Lane, and directed east into the proposed
Pond 3.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report.
B. Master Drainage Concepts
1. The intent of the master drainage plan done with this FDP submittal is to show the
the overall drainage concept for adjacent sites as well as the current project site. The
currently proposed detention ponds have been demonstrated to work in conjunction for
both the current development conditions and fully developed future conditions. The
computer model EPA SWMM 5 has been utilized to model the overall drainage
system. Table 1, below, summarizes master drainage SWMM modeling results.
SWMM output is provided in the Appendix of this report. A full-size copy of the
Master Drainage Exhibit can be found in the Map Pocket at the end of this report.
Table 1 – Detention/Water Quality Pond Summary
Pond Detention Water Quality Total Volume
Water
Quality 100-yr Peak
Volume Capture Volume
WSEL WSEL Release Rate
(AC-FT) (AC-FT) (AC-FT) (FT) (FT) (CFS)
1 3.71 0.30 4.01 4897.80 4902.40 0.70
2 1.19 0.38 1.57 4901.00 4903.40 39.70
3 9.73 1.05 10.78 4884.40 4888.40 29.50
C. Specific Details
1. Water quality treatment is being provided for the proposed development in the form of
extended detention as previously described. Additionally, a PLD bottom is being
provided within each of the detention ponds.
Final design details, construction documentation, and Standard Operating
Procedures (SOP) Manual shall be provided to the City of Fort Collins for
review prior to Final Development Plan approval. A final copy of the approved
SOP manual shall be provided to City and must be maintained on-site by the
entity responsible for the facility maintenance. Annual reports must also be
prepared and submitted to the City discussing the results of the maintenance
program (i.e. inspection dates, inspection frequency, volume loss due to
Banner Health Medical Campus
Final Drainage and Erosion Control Report 10
sedimentation, corrective actions taken, etc.).
2. Table 1, above, summarizes the water quality information for the proposed water
quality ponds.
3. Proper maintenance of the drainage facilities designed with the proposed
development is a critical component of their ongoing performance and effectiveness.
4. The drainage features associated with the proposed project are all private facilities,
located on private property, with the exception of the pond outfalls. Pond outfalls for
Ponds 1 and 2 will be within Cinquefoil Land R.O.W. The outfall for Regional Pond 3
will be within the R.O.W. of Fossil Creek Reservoir Inlet Ditch.
V. CONCLUSIONS
A. Compliance with Standards
1. The drainage design proposed with the proposed project complies with the City of Fort
Collins’ Stormwater Criteria Manual.
2. The drainage design proposed with this project complies with the “East Harmony
Portion of the McClellands Creek Master Drainage Plan Update”, by Icon Engineering,
August 1999 (Ref. 6)
3. There are no regulatory floodplains within the proposed development.
4. The drainage plan and stormwater management measures proposed with the
proposed development are compliant with all applicable State and Federal regulations
governing stormwater discharge.
B. Drainage Concept
1. The drainage design proposed with this project will effectively limit any potential
damage associated with its stormwater runoff by providing an extended detention
component within all detention ponds.
2. The drainage concept for the proposed development is consistent with the “East
Harmony Portion of the McClellands Creek Master Drainage Plan Update”, by Icon
Engineering, August 1999 (Ref. 6)
Banner Health Medical Campus
Final Drainage and Erosion Control Report 11
References
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
6. East Harmony Portion of the McClellands Creek Master Drainage Plan Update, Icon
Engineering, August 1999.
7. Final Drainage and Erosion Control Report for Presidio Apartments, Northern Engineering,
December 2009.
APPENDIX A
HYDROLOGIC COMPUTATIONS
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 306-003
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC
Asphalt, Concrete ……....……………...……….....…...……………….… 0.95 100% Date:
Gravel ……….…………………….….…………………………..………… 0.50 40%
Roofs …….…….………………..……………….…………………………… 0.95 90%
Pavers…………………………...………………..………………………… 0.40 22%
Lawns and Landscaping
Sandy Soil ……..……………..……………….…………………………… 0.15 0%
Clayey Soil ….….………….…….…………..……………………………… 0.25 0% 2-year Cf
= 1.00 100-year Cf = 1.25
Basin ID
Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt,
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1 148231 3.40 0.510 0.000 0.000 2.892 0.36 0.36 0.44 15%
2 110932 2.55 2.088 0.000 0.000 0.458 0.82 0.82 1.00 82%
3 25244 0.58 0.504 0.000 0.000 0.075 0.86 0.86 1.00 87%
4 21710 0.50 0.359 0.000 0.000 0.140 0.75 0.75 0.94 72%
5 28259 0.65 0.590 0.000 0.000 0.058 0.89 0.89 1.00 91%
6 28041 0.64 0.618 0.000 0.000 0.026 0.92 0.92 1.00 96%
7 14159 0.33 0.153 0.000 0.000 0.172 0.58 0.58 0.72 47%
8 20480 0.47 0.202 0.000 0.000 0.268 0.55 0.55 0.69 43%
9a 46922 1.08 0.980 0.000 0.000 0.097 0.89 0.89 1.00 91%
9b 24109 0.55 0.515 0.000 0.000 0.039 0.90 0.90 1.00 93%
10 25901 0.59 0.529 0.000 0.000 0.065 0.87 0.87 1.00 89%
11 16811 0.39 0.158 0.000 0.000 0.228 0.54 0.54 0.67 41%
12 71971 1.65 0.000 1.652 0.000 0.000 0.95 0.95 1.00 90%
Overland Flow, Time of Concentration:
Project: 306-003
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = Ti + Tt (Equation RO-2)
Velocity (Gutter Flow), V = 20·S½
Velocity (Swale Flow), V = 15·S½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Is Length
>500' ?
C*Cf
(2-yr
Cf=1.00)
C*Cf
(10-yr
Cf=1.00)
C*Cf
(100-yr
Cf=1.25)
Length,
L
(ft)
Slope,
S
(%)
Ti
2-yr
(min)
Ti
10-yr
(min)
Ti
100-yr
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
2-yr
Tc
Rational Method Equation: Project: 306-003
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 3.40 14 14 13 0.36 0.36 0.44 1.95 3.34 7.04 2.4 4.0 10.6
2 2 2.55 7 7 5 0.82 0.82 1.00 2.52 4.31 9.95 5.3 9.0 25.3
3 3 0.58 6 6 5 0.86 0.86 1.00 2.67 4.56 9.95 1.3 2.3 5.8
4 4 0.50 5 5 5 0.75 0.75 0.94 2.85 4.87 9.95 1.1 1.8 4.7
5 5 0.65 5 5 5 0.89 0.89 1.00 2.85 4.87 9.95 1.6 2.8 6.5
6 6 0.64 5 5 5 0.92 0.92 1.00 2.85 4.87 9.95 1.7 2.9 6.4
7 7 0.33 7 7 5 0.58 0.58 0.72 2.60 4.44 9.95 0.5 0.8 2.3
8 8 0.47 10 10 8 0.55 0.55 0.69 2.26 3.86 8.59 0.6 1.0 2.8
9a 9a 1.08 5 5 5 0.89 0.89 1.00 2.85 4.87 9.95 2.7 4.7 10.7
9b 9b 0.55 5 5 5 0.90 0.90 1.00 2.85 4.87 9.95 1.4 2.4 5.5
10 10 0.59 5 5 5 0.87 0.87 1.00 2.85 4.87 9.95 1.5 2.5 5.9
11 11 039 8 8 6 054 054 067 246 421 931 05 09 24
DEVELOPED RUNOFF COMPUTATIONS
C100
Design
Point
Flow,
Q100
(cfs)
Flow,
Q2
(cfs)
10-yr
Tc
(min)
2-yr
Tc
(min)
C2
Flow,
Q10
(cfs)
Intensity,
i100
(in/hr)
Basin(s)
ATC
May 15, 2013
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
Q C f C i A
11 11 0.39 8 8 6 0.54 0.54 0.67 2.46 4.21 9.31 0.5 0.9 2.4
12 12 1.65 5 5 5 0.95 0.95 1.00 2.85 4.87 9.95 4.5 7.6 16.4
13 13 3.44 10 10 8 0.88 0.88 1.00 2.26 3.86 8.38 6.8 11.7 28.9
APPENDIX B
HYDRAULIC COMPUTATIONS
B.1 – Storm Sewers
B.2 – Inlets
B.3 – Riprap Calculations
APPENDIX B.1
STORM SEWERS
Hydraflow Plan View
Project File: stm1-import.stm No. Lines: 17 05-21-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 PIPE 1-1 102.0 48 c 51.9 4884.59 4884.80 0.405 4887.58 4888.11 0.89 4889.00 End
2 PIPE 1-2 102.0 48 c 383.7 4884.80 4886.34 0.401 4889.28* 4890.93* 1.02 4891.96 1
3 PIPE 1-3B 2.00 15 c 67.3 4898.07 4898.40 0.490 4898.64 4898.97 0.21 4899.18 2
4 Pipe 1-3 92.30 42 c 89.6 4886.34 4886.79 0.503 4891.96* 4892.60* 1.43 4894.03 2
5 Pipe 1-4-NEW 78.80 42 c 323.5 4886.79 4888.41 0.501 4894.42* 4896.11* 1.04 4897.15 4
6 Pipe 1-5 64.80 42 c 371.8 4892.49 4894.35 0.500 4897.49* 4898.80* 0.71 4899.51 5
7 PIPE 1-6A 39.70 30 c 86.3 4895.89 4896.75 0.997 4899.51* 4900.20* 1.02 4901.22 6
8 PIPE 1-6 25.10 24 c 182.0 4894.55 4895.46 0.500 4899.51* 4901.42* 0.99 4902.41 6
9 PIPE 1-5A 10.00 18 c 38.5 4896.66 4897.05 1.012 4897.87 4898.26 0.67 4898.26 5
10 PIPE 1-5B 4.00 18 c 17.5 4896.66 4896.84 1.027 4898.09 4898.09 0.10 4898.19 5
11 PIPE 1-4A 9.50 18 c 38.5 4896.59 4896.98 1.013 4897.77 4898.16 n/a 4898.16 4
12 PIPE 1-4B 4.00 18 c 17.0 4896.59 4896.76 0.999 4897.35 4897.52 n/a 4897.52 4
13 Pipe 1-3A 7.70 24 c 163.4 4891.52 4892.34 0.502 4892.89 4893.32 n/a 4893.32 j 2
14 Pipe - (85) 7.00 15 c 195.9 4892.89 4893.87 0.500 4893.95* 4895.97* 0.51 4896.48 13
15 Pipe - (88) 4.70 15 c 36.5 4894.07 4894.25 0.494 4896.76* 4896.92* 0.23 4897.15 14
16 Pipe - (86) 2.30 15 c 21.8 4894.07 4894.18 0.505 4896.93* 4896.95* 0.05 4897.01 14
17 Pipe 1-4 0.70 15 c 139.6 4893.09 4893.79 0.502 4893.71 4894.13 n/a 4894.13 j 13
Project File: stm1-import.stm Number of lines: 17 Run Date: 05-21-2013
NOTES: c = cir; e = ellip; b = box; Return period = 2 Yrs. ; *Surcharged (HGL above crown). ; j - Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 48 102.0 4884.59 4887.58 2.99 10.07 10.13 1.60 4889.17 0.522 51.9 4884.80 4888.11 3.31 11.13 9.17 1.31 4889.42 0.422 0.472 0.245 0.68 0.89
2 48 102.0 4884.80 4889.28 4.00 12.56 8.12 1.02 4890.31 0.430 384 4886.34 4890.93 4.00 12.57 8.12 1.02 4891.96 0.430 0.430 1.649 1.00 1.02
3 15 2.00 4898.07 4898.64 0.57* 0.54 3.70 0.21 4898.85 0.461 67.3 4898.40 4898.97 0.57** 0.54 3.68 0.21 4899.18 0.452 0.457 0.307 1.00 0.21
4 42 92.30 4886.34 4891.96 3.50 9.62 9.60 1.43 4893.39 0.717 89.6 4886.79 4892.60 3.50 9.62 9.59 1.43 4894.03 0.717 0.717 0.642 1.00 1.43
5 42 78.80 4886.79 4894.42 3.50 9.62 8.19 1.04 4895.46 0.523 324 4888.41 4896.11 3.50 9.62 8.19 1.04 4897.15 0.523 0.523 1.691 1.00 1.04
6 42 64.80 4892.49 4897.49 3.50 9.62 6.74 0.71 4898.20 0.354 372 4894.35 4898.80 3.50 9.62 6.74 0.71 4899.51 0.353 0.354 1.315 1.00 0.71
7 30 39.70 4895.89 4899.51 2.50 4.91 8.09 1.02 4900.53 0.799 86.3 4896.75 4900.20 2.50 4.91 8.09 1.02 4901.22 0.798 0.799 0.689 1.00 1.02
8 24 25.10 4894.55 4899.51 2.00 3.14 7.99 0.99 4900.50 1.050 182 4895.46 4901.42 2.00 3.14 7.99 0.99 4902.41 1.049 1.050 1.910 1.00 0.99
9 18 10.00 4896.66 4897.87 1.21* 1.52 6.56 0.67 4898.54 0.800 38.5 4897.05 4898.26 1.21** 1.52 6.56 0.67 4898.93 0.800 0.800 n/a 1.00 0.67
10 18 4.00 4896.66 4898.09 1.43 1.73 2.31 0.08 4898.17 0.107 17.5 4896.84 4898.09 1.25 1.57 2.54 0.10 4898.19 0.120 0.114 0.020 1.00 0.10
11 18 9.50 4896.59 4897.77 1.18* 1.49 6.39 0.63 4898.40 0.760 38.5 4896.98 4898.16 1.18** 1.49 6.39 0.63 4898.79 0.760 0.760 n/a 1.00 n/a
12 18 4.00 4896.59 4897.35 0.76* 0.90 4.43 0.30 4897.66 0.466 17.0 4896.76 4897.52 0.76** 0.90 4.43 0.30 4897.83 0.466 0.466 n/a 1.00 n/a
13 24 7.70 4891.52 4892.89 1.37 2.29 3.36 0.18 4893.06 0.150 163 4892.34 4893.32 j 0.98** 1.54 5.01 0.39 4893.71 0.419 0.285 n/a 0.76 0.30
14 15 7.00 4892.89 4893.95 1.06* 1.11 6.31 0.62 4894.57 0.947 196 4893.87 4895.97 1.25 1.23 5.70 0.51 4896.48 1.001 0.974 1.909 1.00 0.51
15 15 4.70 4894.07 4896.76 1.25 1.23 3.83 0.23 4896.98 0.452 36.5 4894.25 4896.92 1.25 1.23 3.83 0.23 4897.15 0.451 0.451 0.165 1.00 0.23
16 15 2.30 4894.07 4896.93 1.25 1.23 1.87 0.05 4896.98 0.108 21.8 4894.18 4896.95 1.25 1.23 1.87 0.05 4897.01 0.108 0.108 0.024 1.00 0.05
17 15 0.70 4893.09 4893.71 0.62 0.61 1.16 0.02 4893.73 0.041 140 4893.79 4894.13 j 0.33** 0.26 2.65 0.11 4894.23 0.406 0.224 n/a 1.00 0.11
Project File: stm1-import.stm Number of lines: 17 Run Date: 05-21-2013
Notes: * Critical depth assumed.; ** Critical depth.; j-Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: stm2-import.stm No. Lines: 1 05-20-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe - (53) 2.80 15 c 132.4 4896.53 4897.19 0.499 4897.20 4897.87 0.27 4898.13 End
Project File: stm2-import.stm Number of lines: 1 Run Date: 05-20-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs.
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 15 2.80 4896.53 4897.20 0.67 0.67 4.18 0.27 4897.47 0.507 132 4897.19 4897.87 0.68** 0.68 4.13 0.27 4898.13 0.494 0.500 0.662 1.00 0.27
Project File: stm2-import.stm Number of lines: 1 Run Date: 05-20-2013
Notes: ; ** Critical depth.
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: stm3-import.stm No. Lines: 19 05-20-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe 3-1 64.00 42 c 95.5 4897.34 4897.82 0.503 4900.14 4900.28 1.15 4901.43 End
2 Pipe - (57) 12.70 24 c 46.5 4900.11 4900.34 0.495 4902.40* 4902.52* 0.25 4902.77 1
3 Pipe - (58) 4.00 12 c 135.0 4901.34 4903.37 1.503 4902.77 4904.22 n/a 4904.22 j 2
4 Pipe - (59) 4.00 12 c 69.1 4903.37 4904.41 1.505 4904.31 4905.26 n/a 4905.26 j 3
5 Pipe - (60) (1) 6.40 15 c 95.5 4900.54 4901.02 0.503 4902.77* 4903.57* 0.42 4904.00 2
6 Pipe - (60) 2.30 15 c 10.0 4900.54 4900.59 0.497 4902.97* 4902.98* 0.05 4903.04 2
7 Pipe 3-2 51.30 36 c 157.1 4897.82 4898.60 0.497 4901.83* 4902.62* 0.82 4903.44 1
8 Pipe 3-2 (1) 40.00 36 c 184.0 4898.60 4899.52 0.500 4903.76* 4904.33* 0.50 4904.82 7
9 Pipe 3-3 40.00 30 c 40.5 4899.50 4899.70 0.494 4904.82* 4905.15* 0.15 4905.31 8
10 Pipe 3-4 33.50 30 c 190.5 4899.70 4900.66 0.504 4905.62* 4906.70* 0.11 4906.81 9
11 Pipe 3-5 22.80 30 c 96.0 4900.66 4901.14 0.500 4907.20* 4907.45* 0.34 4907.78 10
12 Pipe 3-5 (1) 14.50 24 c 85.5 4901.14 4901.56 0.491 4907.79* 4908.09* 0.05 4908.14 11
13 Pipe 3-6 9.00 24 c 51.6 4901.56 4901.82 0.503 4908.34* 4908.41* 0.13 4908.54 12
14 Pipe - (56) 4.00 12 c 154.3 4902.82 4903.59 0.499 4908.54* 4910.20* 0.06 4910.26 13
15 Pipe - (56) (1) 4.00 12 c 52.1 4903.59 4903.85 0.500 4910.26* 4910.82* 0.40 4911.22 14
16 Pipe - (69) 8.30 15 c 126.3 4901.89 4902.52 0.499 4907.78* 4909.56* 0.11 4909.67 11
17 Pipe - (70) 8.30 15 c 18.5 4902.52 4902.61 0.486 4909.67* 4909.93* 0.18 4910.12 16
18 Pipe - (71) 2.40 15 c 91.9 4902.61 4903.07 0.501 4910.77* 4910.88* 0.06 4910.94 17
19 Pipe - (68) 11.30 12 c 9.5 4900.60 4900.65 0.525 4903.44* 4904.26* 3.22 4907.48 7
Project File: stm3-import.stm Number of lines: 19 Run Date: 05-20-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs. ; *Surcharged (HGL above crown). ; j - Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 42 64.00 4897.34 4900.14 2.80 8.25 7.76 0.94 4901.08 0.361 95.5 4897.82 4900.28 2.46** 7.22 8.87 1.22 4901.50 0.488 0.424 0.405 0.94 1.15
2 24 12.70 4900.11 4902.40 2.00 3.14 4.04 0.25 4902.65 0.269 46.5 4900.34 4902.52 2.00 3.14 4.04 0.25 4902.77 0.269 0.269 0.125 1.00 0.25
3 12 4.00 4901.34 4902.77 1.00 0.79 5.09 0.40 4903.18 1.075 135 4903.37 4904.22 j 0.85** 0.71 5.63 0.49 4904.71 1.015 1.045 n/a 0.15 n/a
4 12 4.00 4903.37 4904.31 0.94 0.77 5.23 0.42 4904.73 0.929 69.1 4904.41 4905.26 j 0.85** 0.71 5.63 0.49 4905.75 1.015 0.972 n/a 1.00 n/a
5 15 6.40 4900.54 4902.77 1.25 1.23 5.22 0.42 4903.20 0.837 95.5 4901.02 4903.57 1.25 1.23 5.22 0.42 4904.00 0.837 0.837 0.799 1.00 0.42
6 15 2.30 4900.54 4902.97 1.25 1.23 1.87 0.05 4903.03 0.108 10.0 4900.59 4902.98 1.25 1.23 1.87 0.05 4903.04 0.108 0.108 0.011 1.00 0.05
7 36 51.30 4897.82 4901.83 3.00 7.07 7.26 0.82 4902.65 0.504 157 4898.60 4902.62 3.00 7.07 7.26 0.82 4903.44 0.504 0.504 0.792 1.00 0.82
8 36 40.00 4898.60 4903.76 3.00 7.07 5.66 0.50 4904.26 0.307 184 4899.52 4904.33 3.00 7.07 5.66 0.50 4904.82 0.307 0.307 0.564 1.00 0.50
9 30 40.00 4899.50 4904.82 2.50 4.91 8.15 1.03 4905.86 0.811 40.5 4899.70 4905.15 2.50 4.91 8.15 1.03 4906.19 0.811 0.811 0.328 0.15 0.15
10 30 33.50 4899.70 4905.62 2.50 4.91 6.83 0.72 4906.34 0.569 190 4900.66 4906.70 2.50 4.91 6.82 0.72 4907.42 0.569 0.569 1.083 0.15 0.11
11 30 22.80 4900.66 4907.20 2.50 4.91 4.65 0.34 4907.53 0.263 96.0 4901.14 4907.45 2.50 4.91 4.64 0.34 4907.78 0.263 0.263 0.253 1.00 0.34
12 24 14.50 4901.14 4907.79 2.00 3.14 4.62 0.33 4908.12 0.350 85.5 4901.56 4908.09 2.00 3.14 4.62 0.33 4908.42 0.350 0.350 0.299 0.15 0.05
13 24 9.00 4901.56 4908.34 2.00 3.14 2.87 0.13 4908.47 0.135 51.6 4901.82 4908.41 2.00 3.14 2.86 0.13 4908.54 0.135 0.135 0.070 1.00 0.13
14 12 4.00 4902.82 4908.54 1.00 0.79 5.09 0.40 4908.94 1.075 154 4903.59 4910.20 1.00 0.79 5.09 0.40 4910.60 1.075 1.075 1.659 0.15 0.06
15 12 4.00 4903.59 4910.26 1.00 0.79 5.09 0.40 4910.66 1.075 52.1 4903.85 4910.82 1.00 0.79 5.09 0.40 4911.22 1.075 1.075 0.560 1.00 0.40
16 15 8.30 4901.89 4907.78 1.25 1.23 6.76 0.71 4908.50 1.408 126 4902.52 4909.56 1.25 1.23 6.76 0.71 4910.27 1.408 1.408 1.778 0.15 0.11
17 15 8.30 4902.52 4909.67 1.25 1.23 6.76 0.71 4910.38 1.408 18.5 4902.61 4909.93 1.25 1.23 6.76 0.71 4910.64 1.408 1.408 0.260 0.26 0.18
18 15 2.40 4902.61 4910.77 1.25 1.23 1.96 0.06 4910.83 0.118 91.9 4903.07 4910.88 1.25 1.23 1.96 0.06 4910.94 0.118 0.118 0.108 1.00 0.06
19 12 11.30 4900.60 4903.44 1.00 0.79 14.39 3.22 4906.66 8.583 9.5 4900.65 4904.26 1.00** 0.79 14.39 3.22 4907.48 8.579 8.581 0.814 1.00 3.22
Project File: stm3-import.stm Number of lines: 19 Run Date: 05-20-2013
Notes: ; ** Critical depth.; j-Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: stm4-import.stm No. Lines: 9 05-20-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe - (63) 49.50 36 c 54.6 4899.87 4900.14 0.494 4902.11 4902.58 0.94 4903.51 End
2 Pipe - (62) 20.60 30 c 222.8 4900.14 4901.26 0.503 4904.25* 4904.73* 0.27 4905.00 1
3 Pipe - (64) 4.00 15 c 216.5 4902.51 4903.59 0.499 4905.11* 4905.82* 0.02 4905.84 2
4 Pipe - (64) (1) 3.00 15 c 134.1 4903.59 4904.26 0.500 4905.92* 4906.16* 0.09 4906.26 3
5 Pipe - (65) 2.00 6 c 52.2 4905.01 4905.27 0.499 4906.26* 4911.91* 1.61 4913.52 4
6 Pipe - (66) 1.00 6 c 9.9 4905.27 4905.32 0.504 4914.73* 4915.00* 0.06 4915.06 5
7 Pipe - (67) 1.00 4 c 31.6 4905.32 4905.48 0.507 4915.06* 4922.51* 2.04 4924.55 6
8 Pipe - (61) 16.60 24 c 46.7 4901.26 4901.49 0.493 4905.00* 4905.22* 0.43 4905.65 2
9 Pipe - (72) 28.90 30 c 37.8 4902.14 4902.33 0.503 4903.98 4904.23 0.81 4905.04 1
Project File: stm4-import.stm Number of lines: 9 Run Date: 05-20-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs. ; *Surcharged (HGL above crown).
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 36 49.50 4899.87 4902.11 2.24 5.67 8.73 1.19 4903.30 0.569 54.6 4900.14 4902.58 2.44 6.14 8.06 1.01 4903.58 0.478 0.523 0.286 0.93 0.94
2 30 20.60 4900.14 4904.25 2.50 4.91 4.20 0.27 4904.52 0.215 223 4901.26 4904.73 2.50 4.91 4.20 0.27 4905.00 0.215 0.215 0.479 1.00 0.27
3 15 4.00 4902.51 4905.11 1.25 1.23 3.26 0.17 4905.28 0.327 217 4903.59 4905.82 1.25 1.23 3.26 0.17 4905.98 0.327 0.327 0.708 0.15 0.02
4 15 3.00 4903.59 4905.92 1.25 1.23 2.45 0.09 4906.01 0.184 134 4904.26 4906.16 1.25 1.23 2.44 0.09 4906.26 0.184 0.184 0.247 1.00 0.09
5 6 2.00 4905.01 4906.26 0.50 0.20 10.19 1.61 4907.87 10.845 52.2 4905.27 4911.91 0.50** 0.20 10.19 1.61 4913.52 10.840 10.842 5.655 1.00 1.61
6 6 1.00 4905.27 4914.73 0.50 0.20 5.09 0.40 4915.14 2.711 9.9 4905.32 4915.00 0.50 0.20 5.09 0.40 4915.41 2.710 2.711 0.268 0.15 0.06
7 4 1.00 4905.32 4915.06 0.33 0.09 11.46 2.04 4917.11 23.573 31.6 4905.48 4922.51 0.33** 0.09 11.46 2.04 4924.55 23.564 23.569 7.448 1.00 2.04
8 24 16.60 4901.26 4905.00 2.00 3.14 5.28 0.43 4905.44 0.459 46.7 4901.49 4905.22 2.00 3.14 5.28 0.43 4905.65 0.459 0.459 0.214 1.00 0.43
9 30 28.90 4902.14 4903.98 1.84 3.88 7.45 0.86 4904.85 0.530 37.8 4902.33 4904.23 1.90 3.99 7.24 0.81 4905.04 0.496 0.513 0.194 1.00 0.81
Project File: stm4-import.stm Number of lines: 9 Run Date: 05-20-2013
Notes: ; ** Critical depth.
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: stm5-import.stm No. Lines: 1 05-20-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe - (73) 23.20 24 c 47.4 4901.96 4902.20 0.507 4903.68 4904.20 0.85 4905.05 End
Project File: stm5-import.stm Number of lines: 1 Run Date: 05-20-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs.
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 24 23.20 4901.96 4903.68 1.72 2.87 8.07 1.01 4904.69 0.830 47.4 4902.20 4904.20 2.00 3.14 7.39 0.85 4905.05 0.870 0.850 0.403 1.00 0.85
Project File: stm5-import.stm Number of lines: 1 Run Date: 05-20-2013
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: stm6-import.stm No. Lines: 3 05-20-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe - (76) 8.00 18 c 38.0 4899.00 4899.19 0.500 4900.08 4900.42 0.09 4900.52 End
2 Pipe - (75) 8.00 18 c 370.5 4899.19 4901.05 0.502 4900.61 4902.26 0.43 4902.69 1
3 Pipe - (74) 4.00 12 c 286.4 4901.55 4906.13 1.599 4902.71 4906.98 n/a 4906.98 j 2
Project File: stm6-import.stm Number of lines: 3 Run Date: 05-20-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs. ; j - Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 18 8.00 4899.00 4900.08 1.08 1.36 5.87 0.54 4900.62 0.656 38.0 4899.19 4900.42 1.23 1.55 5.15 0.41 4900.83 0.492 0.574 0.218 0.23 0.09
2 18 8.00 4899.19 4900.61 1.42 1.73 4.62 0.33 4900.94 0.428 371 4901.05 4902.26 1.21 1.52 5.25 0.43 4902.69 0.512 0.470 1.741 1.00 0.43
3 12 4.00 4901.55 4902.71 1.00 0.79 5.09 0.40 4903.11 1.075 286 4906.13 4906.98 j 0.85** 0.71 5.63 0.49 4907.47 1.015 1.045 n/a 1.00 n/a
Project File: stm6-import.stm Number of lines: 3 Run Date: 05-20-2013
Notes: ; ** Critical depth.; j-Line contains hyd. jump.
Hydraflow Storm Sewers 2005
Hydraflow Plan View
Project File: outlet-import.stm No. Lines: 3 05-21-2013
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 Pipe - (34) 29.50 24 c 58.7 4866.89 4867.48 1.005 4868.75* 4869.63* 0.74 4870.37 End
Project File: outlet-import.stm Number of lines: 1 Run Date: 05-21-2013
NOTES: c = cir; e = ellip; b = box; Return period = 100 Yrs. ; *Surcharged (HGL above crown).
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 24 29.50 4866.89 4868.75 1.86 3.04 9.69 1.46 4870.21 1.254 58.7 4867.48 4869.63 2.00 3.14 9.39 1.37 4871.00 1.450 1.352 0.794 0.54 0.74
Project File: outlet-import.stm Number of lines: 1 Run Date: 05-21-2013
Hydraflow Storm Sewers 2005
APPENDIX B.2
INLETS
Project: 306‐003
By: ATC
Date: 5/20/13
Inlet Inlet Design Design Design
ID Type Point Storm Flow Inlet Capacity
(CFS) (CFS)
INLET CAPACITY SUMMARY
2‐1 Sump‐Single Combo 8 100‐yr 2.80 9.20
3‐1.1A Sump‐Single Combo 7 100‐yr 2.30 9.20
3‐1.1B Sump‐Single Combo 6 100‐yr 6.40 9.20
3‐2 Sump‐Double Combo 2,3 10‐yr 11.30 21.40
3‐4 Sump‐Single Combo 5 100‐yr 6.50 9.20
3‐5 Sump‐Double Combo 9a 100‐yr 10.70 21.40
3‐7 Sump‐Single p g Combo 9b 100‐yr y 5.50 9.20
3‐6.1 Sump‐Single Combo 10 100‐yr 3.00 9.20
3‐6.2 Sump‐Single Combo 10 100‐yr 2.90 9.20
3‐6.3 Slotted Manhole Cover 11 100‐yr 2.40 5.10
Project =
Inlet ID =
Design Information (Input) MINOR MAJOR
Type of Inlet Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal
= 2.00 2.00 inches
Number of Unit Inlets (Grate or Curb Opening) No = 1 1
Water Depth at Flowline (outside of local depression) Flow Depth = 6.0 12.0 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo
(G) = 3.00 3.00 feet
Width of a Unit Grate Wo
= 2.00 2.00 feet
Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio
= 0.31 0.31
Warning 3 Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf
(G) = 0.50 0.50
Grate Weir Coefficient (typical value 2.15 - 3.60) Cw
(G) = 3.60 3.60
Grate Orifice Coefficient (typical value 0.60 - 0.80) Co
(G) = 0.60 0.60
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo
(C) = 3.00 3.00 feet
Height of Vertical Curb Opening in Inches Hvert
= 6.50 6.50 inches
Height of Curb Orifice Throat in Inches Hthroat
= 5.25 5.25 inches
Angle of Throat (see USDCM Figure ST-5) Theta = 0.00 0.00 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet) Wp
= 2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10) Cf
(C) = 0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.6) Cw
(C) = 3.70 3.70
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co
(C) = 0.66 0.66
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition) Q
a = 4.0 9.2 cfs
WARNING: Inlet Capacity less than Q Peak for Minor and Major Storms Q
PEAK REQUIRED = 6.0 16.0 cfs
Warning 1: Dimension entered is not a typical dimension for inlet type specified.
Warning 3: Clogging factor is not in the recommended value for inlet type specified.
INLET IN A SUMP OR SAG LOCATION
306-003
Combo Inlet - Single
Denver No. 16 Combination
H-Vert
H-Curb
W
Lo (C)
Lo (G)
Wo
WP
UD Inlet 3.1-comboinlet, Inlet In Sump 5/20/2013, 4:33 PM
Project =
Inlet ID =
Design Information (Input) MINOR MAJOR
Type of Inlet Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal
= 2.00 2.00 inches
Number of Unit Inlets (Grate or Curb Opening) No = 2 2
Water Depth at Flowline (outside of local depression) Flow Depth = 6.0 12.0 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo
(G) = 3.00 3.00 feet
Width of a Unit Grate Wo
= 2.00 2.00 feet
Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio
= 0.31 0.31
Warning 3 Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf
(G) = 0.50 0.50
Grate Weir Coefficient (typical value 2.15 - 3.60) Cw
(G) = 3.60 3.60
Grate Orifice Coefficient (typical value 0.60 - 0.80) Co
(G) = 0.60 0.60
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo
(C) = 3.00 3.00 feet
Height of Vertical Curb Opening in Inches Hvert
= 6.50 6.50 inches
Height of Curb Orifice Throat in Inches Hthroat
= 5.25 5.25 inches
Angle of Throat (see USDCM Figure ST-5) Theta = 0.00 0.00 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet) Wp
= 2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10) Cf
(C) = 0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.6) Cw
(C) = 3.70 3.70
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co
(C) = 0.66 0.66
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition) Q
a = 6.2 21.4 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q PEAK) Q
PEAK REQUIRED = 6.0 16.0 cfs
Warning 1: Dimension entered is not a typical dimension for inlet type specified.
Warning 3: Clogging factor is not in the recommended value for inlet type specified.
INLET IN A SUMP OR SAG LOCATION
306-003
Combo Inlet - Double
Denver No. 16 Combination
H-Vert
H-Curb
W
Lo (C)
Lo (G)
Wo
WP
UD Inlet 3.1-comboinlet, Inlet In Sump 5/20/2013, 4:35 PM
Area Inlet Performance Curve:
Manhole ID: 3-6.3
Governing Equations:
At low flow depths, the inlet will act like a weir governed by the following equation:
* where P = 3.1416*Dia.of grate
* where H corresponds to the depth of water above the flowline
At higher flow depths, the inlet will act like an orifice governed by the following equation:
* where A equals the open area of the inlet grate
* where H corresponds to the depth of water above the centroid of the cross-sectional area (A)
The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown.
However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation
will cross at a certain flow depth. The two curves can be found below:
If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir.
Input Parameters:
Type of Grate: PERFORATED MANHOLE COVER
Diameter of Grate (ft): 2
Open Area of Grate (ft2): 1.88
Flowline Elevation (ft): 0.000
Reduction Factor: 50%
Depth vs. Flow:
Depth Above Inlet (ft)
Elevation
(ft)
Shallow
Weir Flow
(cfs)
Orifice
Flow
(cfs)
Actual
Flow
(cfs)
0.00 0.00 0.00 0.00 0.00
0.10 0.10 0.30 1.60 0.30
0.20 0.20 0.84 2.26 0.84
0.30 0.30 1.55 2.77 1.55
0.40 0.40 2.38 3.20 2.38
0.50 0.50 3.33 3.57 3.33
0.60 0.60 4.38 3.91 3.91
0.70 0.70 5.52 4.23 4.23
0.80 0.80 6.74 4.52 4.52
0.90 0.90 8.05 4.79 4.79
1.00 1.00 9.42 5.05 5.05
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Discharge (cfs)
Stage (ft)
Stage - Discharge Curves
Weir Flow
Orifice Flow
Q 3 . 0 P H 1 . 5
APPENDIX B.3
RIPRAP CALCULATIONS
Circular
D or Da,
Pipe
Diameter
(ft)
H or Ha,
Culvert
Height
(ft)
W,
Culvert
Width
(ft)
Yt/D Q/D
1.5
Q/D
2.5 Y
t/H Q/WH
0.5
Storm Line 1 81.68 4.00 1.60 0.40 10.21 2.55 N/A N/A 5.00 2.55 16.34 31.05 Type L 32.00 23.00 1.5
Storm Line 2 2.80 1.25 0.50 0.40 2.00 1.60 N/A N/A 6.10 1.60 0.56 ‐0.79 Type L 5.00 5.00 1.5
Storm Line 3 64.00 3.50 1.40 0.40 9.77 2.79 N/A N/A 4.70 2.79 12.80 26.52 Type L 28.00 21.00 1.5
Storm Line 4 49.50 3.00 1.20 0.40 9.53 3.18 N/A N/A 4.20 3.18 9.90 22.05 Type L 22.00 18.00 1.5
Storm Line 5 23.20 2.00 0.80 0.40 8.20 4.10 N/A N/A 3.30 4.10 4.64 12.54 Type L 14.00 12.00 1.5
Storm Line 6 8.00 1.50 0.60 0.40 4.35 2.90 N/A N/A 4.40 2.90 1.60 5.13 Type L 6.00 8.00 1.5
Pond 3 Outfall 29.50 2.00 0.80 0.40 10.43 5.21 N/A N/A 2.20 5.21 5.90 11.83 Type L 12.00 12.00 1.5
Culvert 3.00 1.00 0.40 0.40 3.00 3.00 N/A N/A 4.50 3.00 0.60 2.25 Type L 5.00 5.00 1.5
Yt,
Tailwater
Depth
(ft)
Culvert Parameters
At=Q/V (ft)
INPUT CALCULATE
Date: 5/15/13
Expansion
Factor
1/(2tanq)
(From
Figure
MD‐23 or
MD‐24)
Storm
Line/Culvert
Label
Design
Discharge
(cfs)
By: ATC
OUTPUT
Spec
Length
of
Riprap
(ft)
Box Culvert
CALCULATIONS FOR RIPRAP PROTECTION AT PIPE OUTLETS
Circular
Pipe
(Figure MD‐21)
APPENDIX C
WATER QUALITY DESIGN COMPUTATIONS
WATER QUALITY POND DESIGN CALCULATIONS
POND 1
Project: 306-003
By: ATC
Date: 5.15.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 13.880 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 65.89 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.6589 <-- CALCULATED
WQCV (watershed inches) = 0.258 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.298 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 1.600 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = 0.915 <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = 1 <-- INPUT from Figure 5
number of rows = 5
t (in) = 0.500 <-- INPUT from Figure 5
number of rows = 1.000 <-- CALCULATED from WQ Depth and row spacing
WATER QUALITY POND DESIGN CALCULATIONS
POND 2
Project: 306-003
By: ATC
Date: 5.15.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 13.000 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 82.79 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.8279 <-- CALCULATED
WQCV (watershed inches) = 0.347 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.375 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 2.200 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = 0.977 <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = 1 1/9 <-- INPUT from Figure 5
number of rows = 7
t (in) = 0.500 <-- INPUT from Figure 5
number of rows = 1.000 <-- CALCULATED from WQ Depth and row spacing
WATER QUALITY POND DESIGN CALCULATIONS
POND 3
Project: 306-003
By: ATC
Date: 5.15.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 34.790 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 85.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.8500 <-- CALCULATED
WQCV (watershed inches) = 0.362 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 1.050 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 2.200 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = 2.436 <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = 1 3/4 <-- INPUT from Figure 5
number of rows = 7
t (in) = 0.500 <-- INPUT from Figure 5
number of rows = 1.000 <-- CALCULATED from WQ Depth and row spacing
APPENDIX D
SWMM ANALYSIS
1
2
3
4
5
5
6
7
8
out1
out2 out3
mh2
mh3 mh5
mh4
FCRID
pond1
pond2
pond3
FtCollins-100yr
11/21/2012 00:15:00
SWMM 5 Page 1
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022)
--------------------------------------------------------------
*********************************************************
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
*********************************************************
****************
Analysis Options
****************
Flow Units ............... CFS
Process Models:
Rainfall/Runoff ........ YES
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... YES
Ponding Allowed ........ NO
Water Quality .......... NO
Infiltration Method ...... HORTON
Flow Routing Method ...... KINWAVE
Starting Date ............ NOV-21-2012 00:00:00
Ending Date .............. NOV-21-2012 06:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 18.856 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 1.305 0.254
Surface Runoff ........... 17.263 3.359
Final Surface Storage .... 0.429 0.084
Continuity Error (%) ..... -0.750
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 17.263 5.625
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 8.352 2.722
Internal Outflow ......... 4.645 1.514
Storage Losses ........... 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 4.266 1.390
Continuity Error (%) ..... -0.001
********************************
Highest Flow Instability Indexes
********************************
Link out2 (34)
Link 6 (32)
Link 8 (31)
Link 7 (16)
*************************
Routing Time Step Summary
SWMM 5 Page 1
*************************
Minimum Time Step : 30.00 sec
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.12
***************************
Subcatchment Runoff Summary
***************************
--------------------------------------------------------------------------------------------------------
Total Total Total Total Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10^6 gal CFS
--------------------------------------------------------------------------------------------------------
1 3.67 0.00 0.00 0.50 3.13 1.18 111.11 0.852
2 3.67 0.00 0.00 0.24 3.37 1.19 119.14 0.919
3 3.67 0.00 0.00 0.14 3.47 2.24 216.06 0.945
4 3.67 0.00 0.00 0.21 3.40 0.47 47.21 0.928
5 3.67 0.00 0.00 0.21 3.40 0.55 54.75 0.928
******************
Node Depth Summary
******************
---------------------------------------------------------------------
Average Maximum Maximum Time of Max
Depth Depth HGL Occurrence
Node Type Feet Feet Feet days hr:min
---------------------------------------------------------------------
mh2 JUNCTION 0.14 0.16 101.16 0 02:24
mh3 JUNCTION 0.49 1.00 100.00 0 00:16
mh5 JUNCTION 0.26 0.39 98.39 0 02:24
mh4 JUNCTION 3.66 10.00 111.00 0 00:13
FCRID OUTFALL 0.00 0.00 96.00 0 00:00
pond1 STORAGE 2.28 2.61 107.61 0 02:24
pond2 STORAGE 0.53 2.92 107.92 0 00:50
pond3 STORAGE 1.69 2.36 99.36 0 01:55
*******************
Node Inflow Summary
*******************
-------------------------------------------------------------------------------------
Maximum Maximum Lateral Total
Lateral Total Time of Max Inflow Inflow
Inflow Inflow Occurrence Volume Volume
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal
-------------------------------------------------------------------------------------
mh2 JUNCTION 0.00 0.65 0 02:24 0.000 0.092
mh3 JUNCTION 0.00 3.15 0 02:23 0.000 0.241
mh5 JUNCTION 0.00 3.09 0 02:24 0.000 0.240
mh4 JUNCTION 47.21 79.71 0 00:40 0.471 1.661
FCRID OUTFALL 0.00 23.27 0 01:55 0.000 2.721
pond1 STORAGE 111.11 111.11 0 00:40 1.178 1.178
pond2 STORAGE 119.14 119.14 0 00:40 1.191 1.191
pond3 STORAGE 270.81 273.40 0 00:40 2.785 3.025
**********************
Node Surcharge Summary
**********************
Surcharging occurs when water rises above the top of the highest conduit.
---------------------------------------------------------------------
Max. Height Min. Depth
Hours Above Crown Below Rim
SWMM 5 Page 2
Node Type Surcharged Feet Feet
---------------------------------------------------------------------
mh4 JUNCTION 2.15 9.000 0.000
pond1 STORAGE 6.01 2.606 7.394
pond2 STORAGE 6.01 2.920 7.080
*********************
Node Flooding Summary
*********************
Flooding refers to all water that overflows a node, whether it ponds or not.
--------------------------------------------------------------------------
Total Maximum
Maximum Time of Max Flood Ponded
Hours Rate Occurrence Volume Volume
Node Flooded CFS days hr:min 10^6 gal 1000 ft3
--------------------------------------------------------------------------
mh4 2.15 76.83 0 00:40 1.514 0.000
**********************
Storage Volume Summary
**********************
--------------------------------------------------------------------------------------------
Average Avg E&I Maximum Max Time of Max Maximum
Volume Pcnt Pcnt Volume Pcnt Occurrence Outflow
Storage Unit 1000 ft3 Full Loss 1000 ft3 Full days hr:min CFS
--------------------------------------------------------------------------------------------
pond1 127.501 6 0 152.799 7 0 02:24 0.65
pond2 6.467 1 0 53.320 9 0 00:49 40.41
pond3 146.838 3 0 252.572 5 0 01:54 23.27
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg. Max. Total
Freq. Flow Flow Volume
Outfall Node Pcnt. CFS CFS 10^6 gal
-----------------------------------------------------------
FCRID 97.23 17.31 23.27 2.721
-----------------------------------------------------------
System 97.23 17.31 23.27 2.721
********************
Link Flow Summary
********************
-----------------------------------------------------------------------------
Maximum Time of Max Maximum Max/ Max/
|Flow| Occurrence |Veloc| Full Full
Link Type CFS days hr:min ft/sec Flow Depth
-----------------------------------------------------------------------------
5 CONDUIT 0.65 0 02:26 2.44 0.00 0.02
6 CONDUIT 3.09 0 02:24 3.12 0.00 0.04
7 CONDUIT 3.09 0 02:24 5.64 0.00 0.03
8 CONDUIT 2.50 0 00:16 4.02 1.08 1.00
out1 DUMMY 0.65 0 02:24
out2 DUMMY 40.41 0 00:50
out3 DUMMY 23.27 0 01:55
*************************
Conduit Surcharge Summary
*************************
SWMM 5 Page 3
----------------------------------------------------------------------------
Hours Hours
--------- Hours Full -------- Above Full Capacity
Conduit Both Ends Upstream Dnstream Normal Flow Limited
----------------------------------------------------------------------------
8 2.08 2.14 2.10 2.13 2.14
Analysis begun on: Tue May 21 13:51:34 2013
Analysis ended on: Tue May 21 13:51:34 2013
Total elapsed time: < 1 sec
SWMM 5 Page 4
POND RATING
POND 1
PROJECT: 306‐003
DATE: 5.15.13
BY: ATC
Contour
Elevation (FT)
Contour
Area (SF)
Depth
(FT)
Incremental
Volume (CF)
Cumulative
Volume (CF)
Cumulative
Volume (AC‐FT)
4896.20 186.71 N/A N/A 0.00 0.00
4896.40 1686.81 0.20 162.32 162.32 0.00
4896.60 4230.32 0.20 572.56 734.88 0.02
4896.80 7183.63 0.20 1128.44 1863.31 0.04
4897.00 9962.29 0.20 1707.04 3570.35 0.08
4897.20 11610.97 0.20 2155.22 5725.57 0.13
4897.40 13014.75 0.20 2461.24 8186.81 0.19
4897.60 14452.25 0.20 2745.45 10932.26 0.25
4897.80 15907.45 0.20 3034.81 13967.06 0.32
4898.00 17390.57 0.20 3328.70 17295.76 0.40
4898.20 18910.48 0.20 3629.04 20924.81 0.48
4898.40 20496.22 0.20 3939.61 24864.41 0.57
4898.60 22190.20 0.20 4267.52 29131.94 0.67
4898.80 23919.54 0.20 4609.89 33741.83 0.77
4899.00 25717.38 0.20 4962.61 38704.44 0.89
4899.20 27597.47 0.20 5330.38 44034.82 1.01
4899.40 29499.24 0.20 5708.62 49743.43 1.14
4899.60 31431.03 0.20 6092.01 55835.44 1.28
4899.80 33409.10 0.20 6483.01 62318.44 1.43
4900.00 35250.79 0.20 6865.17 69183.61 1.59
4900.20 37457.72 0.20 7269.74 76453.34 1.76
4900.40 38569.71 0.20 7602.47 84055.82 1.93
4900.60 39649.33 0.20 7821.66 91877.47 2.11
4900.80 40701.73 0.20 8034.88 99912.35 2.29
4901.00 41727.83 0.20 8242.74 108155.09 2.48
4901.20 42732.82 0.20 8445.87 116600.96 2.68
4901.40 43722.69 0.20 8645.36 125246.32 2.88
4901.60 44712.92 0.20 8843.38 134089.70 3.08
4901.80 45708.72 0.20 9041.98 143131.68 3.29
4902.00 46705.60 0.20 9241.25 152372.93 3.50
4902.20 47703.39 0.20 9440.72 161813.65 3.71
4902.40 48702.09 0.20 9640.38 171454.03 3.94
4902.60 49702.26 0.20 9840.27 181294.29 4.16
4902.80 50705.57 0.20 10040.62 191334.91 4.39
4903.00 51712.25 0.20 10241.62 201576.52 4.63
4903.20 52722.29 0.20 10443.29 212019.82 4.87
4903.40 53728.51 0.20 10644.92 222664.74 5.11
POND RATING
POND 2
PROJECT: 306‐003
DATE: 5.15.13
BY: ATC
Contour
Elevation (FT)
Contour
Area (SF)
Depth
(FT)
Incremental
Volume (CF)
Cumulative
Volume (CF)
Cumulative
Volume (AC‐FT)
4898.80 248.01 N/A N/A 0.00 0.00
4899.00 1468.84 0.20 154.69 154.69 0.00
4899.20 2875.17 0.20 426.60 581.30 0.01
4899.40 4050.81 0.20 689.25 1270.54 0.03
4899.60 5320.16 0.20 934.22 2204.76 0.05
4899.80 6733.98 0.20 1202.64 3407.40 0.08
4900.00 8088.69 0.20 1480.20 4887.60 0.11
4900.20 9443.61 0.20 1751.48 6639.08 0.15
4900.40 10707.63 0.20 2013.80 8652.89 0.20
4900.60 12069.03 0.20 2276.31 10929.20 0.25
4900.80 13534.42 0.20 2558.95 13488.14 0.31
4901.00 14901.76 0.20 2842.52 16330.66 0.37
4901.20 16215.10 0.20 3110.76 19441.42 0.45
4901.40 17542.93 0.20 3374.93 22816.36 0.52
4901.60 18816.23 0.20 3635.17 26451.53 0.61
4901.80 20093.33 0.20 3890.26 30341.79 0.70
4902.00 21373.49 0.20 4146.02 34487.81 0.79
4902.20 22656.04 0.20 4402.33 38890.14 0.89
4902.40 23924.99 0.20 4657.53 43547.67 1.00
4902.60 25004.82 0.20 4892.58 48440.25 1.11
4902.80 25957.38 0.20 5095.92 53536.17 1.23
4903.00 26862.08 0.20 5281.69 58817.86 1.35
4903.20 27851.25 0.20 5471.03 64288.89 1.48
4903.40 28935.42 0.20 5678.32 69967.22 1.61
4903.60 29674.93 0.20 5860.88 75828.10 1.74
4903.80 30413.09 0.20 6008.65 81836.75 1.88
4904.00 31155.49 0.20 6156.71 87993.46 2.02
4904.20 31902.13 0.20 6305.61 94299.07 2.16
4904.40 32653.00 0.20 6455.37 100754.44 2.31
4904.60 33408.10 0.20 6605.97 107360.40 2.46
4904.80 34258.96 0.20 6766.53 114126.93 2.62
POND RATING
POND 3
PROJECT: 306‐003
DATE: 5.15.13
BY: ATC
Contour
Elevation (FT)
Contour
Area (SF)
Depth
(FT)
Incremental
Volume (CF)
Cumulative
Volume (CF)
Cumulative
Volume (AC‐FT)
4882.20 782.09 N/A N/A 0.00 0.00
4882.40 3049.28 0.20 358.38 358.38 0.01
4882.60 5841.51 0.20 874.08 1232.46 0.03
4882.80 9112.03 0.20 1483.29 2715.75 0.06
4883.00 12812.25 0.20 2181.94 4897.69 0.11
4883.20 16865.89 0.20 2958.54 7856.24 0.18
4883.40 21215.23 0.20 3799.81 11656.04 0.27
4883.60 25880.82 0.20 4701.88 16357.92 0.38
4883.80 30990.51 0.20 5679.47 22037.39 0.51
4884.00 36702.11 0.20 6761.22 28798.61 0.66
4884.20 43098.28 0.20 7971.48 36770.09 0.84
4884.40 50261.84 0.20 9326.84 46096.93 1.06
4884.60 58258.70 0.20 10842.22 56939.14 1.31
4884.80 65962.07 0.20 12414.11 69353.25 1.59
4885.00 73153.91 0.20 13905.40 83258.65 1.91
4885.20 80413.42 0.20 15351.01 98609.66 2.26
4885.40 87749.72 0.20 16810.98 115420.64 2.65
4885.60 95170.44 0.20 18287.00 133707.63 3.07
4885.80 102692.33 0.20 19781.51 153489.14 3.52
4886.00 110490.57 0.20 21313.53 174802.68 4.01
4886.20 112423.22 0.20 22291.10 197093.77 4.52
4886.40 114253.78 0.20 22667.45 219761.23 5.05
4886.60 116088.50 0.20 23033.98 242795.21 5.57
4886.80 117927.92 0.20 23401.40 266196.61 6.11
4887.00 119771.83 0.20 23769.74 289966.35 6.66
4887.20 121619.94 0.20 24138.94 314105.29 7.21
4887.40 123472.62 0.20 24509.02 338614.31 7.77
4887.60 125329.60 0.20 24879.99 363494.30 8.34
4887.80 127190.97 0.20 25251.83 388746.13 8.92
4888.00 129056.88 0.20 25624.56 414370.69 9.51
4888.20 130927.11 0.20 25998.17 440368.87 10.11
4888.40 132801.98 0.20 26372.69 466741.55 10.71
4888.60 134681.23 0.20 26748.10 493489.65 11.33
4888.80 136564.88 0.20 27124.39 520614.05 11.95
4889.00 138453.31 0.20 27501.60 548115.65 12.58
4889.20 140346.09 0.20 27879.73 575995.38 13.22
4889.40 142243.60 0.20 28258.76 604254.13 13.87
4889.60 144146.16 0.20 28638.77 632892.90 14.53
4889.80 146053.37 0.20 29019.74 661912.64 15.20
4890.00 147965.55 0.20 29401.68 691314.33 15.87
APPENDIX E
EROSION CONTROL REPORT
STORMWATER MANAGEMENT PLAN (SWMP)
Banner Health Medical Campus
May 22, 2013
Prepared for:
Banner Health
1801 16th Street
Greeley, CO 80631
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 306-003
ADDRESS:
200 S. College Ave. Suite 10
Fort Collins, CO 80524
PHONE: 970.221.4158
FAX: 970.221.4159
WEBSITE:
www.northernengineering.com
May 22, 2013
Encompass Technologies
324 Jefferson Street
Fort Collins, CO 80524
RE: Stormwater Management Plan
Banner Health Medical Campus
Fort Collins, CO
To whom it may concern:
Northern Engineering Services, Inc. is pleased to submit this Stormwater Management Plan and Erosion
Control Report for the Banner Health Medical Campus project. This report outlines Best Management
Practices (BMPs) to be implemented with the proposed construction in order 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). Please note: this Stormwater Management plan (including the Site Maps) 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,
NORTHERN ENGINEERING SERVICES, INC.
Aaron Cvar,PE
Project Engineer
Banner Health Medical Campus
Stormwater Management Plan
TABLE OF CONTENTS
Vicinity Map
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 .......................................................................................... 2
2.1 Existing Site Description .............................................................................................. 2
2.2 Nature of Construction Activity ..................................................................................... 2
2.3 Sequence of Major Activities ......................................................................................... 2
2.4 Site Disturbance ......................................................................................................... 2
2.5 Existing Vegetation ...................................................................................................... 2
2.6 Potential Pollution Sources ........................................................................................... 3
2.7 Non-stormwater discharges .......................................................................................... 3
2.8 Receiving Waters ........................................................................................................ 3
3.0 Stormwater Management Controls .............................................................................. 4
3.1 SWMP Administrator ................................................................................................... 4
3.2 Best Management Practices (BMP’s) for Stormwater Pollution Prevention .......................... 4
3.3 Structural Practices for Erosion and Sediment Control ..................................................... 4
3.4 Phased BMP Installationl ............................................................................................. 5
3.5 Nonstructural Practices for Erosion and Sediment Control ................................................ 8
3.6 Material Handling and Spill Prevention ........................................................................ 11
3.7 Dedicated Concrete or Asphalt Batch Plant .................................................................. 11
3.8 Vehicle Tracking Control ............................................................................................ 11
3.9 Waste Management and Disposal ............................................................................... 11
3.10 Groundwater and Stormwater Dewatering .................................................................... 11
4.0 Final Stabilization and Long-Term Stormwater Management ........................................ 12
4.1 Final Stabilization ..................................................................................................... 12
4.2 Long-Term Stormwater Management ........................................................................... 12
5.0 Inspection, Maintenance and Record Keeping ............................................................ 13
5.1 BMP Inspection ........................................................................................................ 13
5.2 BMP Maintenance .................................................................................................... 13
5.3 Record Keeping ........................................................................................................ 13
6.0 Additional SWMP and BMP Resources ...................................................................... 15
References 16
Banner Health Medical Campus
Stormwater Management Plan
APPENDICES:
APPENDIX A – Phasing Plan, Site Maps
APPENDIX B – Erosion Control Details
APPENDIX C – Copies of Permits/Applications (to be provided by contractor)
APPENDIX D – Stormwater Management Plan Inspection Logs
APPENDIX E – Contractor Inserts (as needed)
APPENDIX F – Reference Material
Banner Health Medical Campus
Stormwater Management Plan 1
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
to describe the practices that will be used to reduce the pollutants in stormwater discharges from
the site. The SWMP must be completed and implemented at the time the project breaks ground,
and revised as necessary as construction proceeds to accurately reflect the conditions and practices
at the site.
This report summarizes the Stormwater Management Plan for the construction activity that will
occur with the Banner Health Medical Campus development project in Fort Collins, CO. 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 aforementioned construction site to allow for maintenance
and inspection updates, and for 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, which are 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 BMP’s – Practices to REMOVE sediment from runoff, such as sediment basins,
silt fence, or inlet protection.
Non-structural BMP’s – 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 BMP’s – 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 that is issued by the Water
Quality Control Division of the CDPHE. Additional Environmental permitting not described in this
report will likely be required as a part of this project. An example is the Construction Dewatering
Permit for groundwater, which will be discussed later. Another example is the Air Pollution
Emission Notice (APEN). The CDPHE website contains links to both of these permits, as well as
many other potential permits. The Contractor is responsible for ensuring the proper permits are
acquired.
Banner Health Medical Campus
Stormwater Management Plan 2
2.0 Narrative Site Description
2.1 Existing Site Description
The project site is located in the northwest quarter of Section 4, Township 6 South, Range 68 West
of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. The project
site is located just southeast of the intersection of East Harmony Road and Lady Moon Drive. Areas
directly adjacent to the project site on the west, south and east are currently undeveloped. The
existing Hewlett Packard campus is located just north of the project site on the north side of
Harmony Road.
The subject property currently consists of vacant ground. The ground cover generally consists of
open pasture and some native seeding. Existing ground slopes are generally mild (i.e., 1 to 5±%)
through the interior of the property. General topography slopes from west to east towards the Fossil
Creek Reservoir Inlet Ditch.
According to the United States Department of Agriculture (USDA) Natural Resources Conservation
Service (NRCS) Soil Survey, the site consists of Paoli fine sandy loam, which falls into Hydrologic
Soil Group B.
2.2 Nature of Construction Activity
The proposed project will develop the majority of the existing site, constructing a medical campus.
Parking areas and associated utilities will be constructed. Detention/water quality ponds will be
constructed at the northeast and southeast corners of the site.
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 installation of utilities will occur
next, including water, sewer, and storm sewer. 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 throughout the project,
followed by asphalt paving of the parking areas. Vertical construction of the buildings is expected to
commence once the public infrastructure has been inspected by the city. Fine grading of the areas
around the buildings, and the installation of landscaping throughout the project will follow. The
final stage of construction will be the construction of the buildings, along detailed grading around
each building and installation of landscaping.
2.4 Site Disturbance
The entire project boundary / total disturbance area is approximately 27 acres.
2.5 Existing Vegetation
The existing site vegetation consists primarily of sparse grasses. In general, the site has an
estimated 60% vegetative cover. It is highly recommended that pre-construction photos be taken
by the contractor to clearly document vegetative conditions prior any disturbance activities.
Banner Health Medical Campus
Stormwater Management Plan 3
2.6 Potential Pollution Sources
As is typical with most construction sites, there are a number of potential pollution sources which
could affect water quality. It is not possible for this report to identify all materials that will be 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)
2.7 Non-stormwater discharges
The Stormwater Construction Permit only covers discharges composed entirely of stormwater.
Exceptions include emergency fire fighting activities, landscape irrigation return flow,
uncontaminated springs, construction dewatering (caused by storm events) and concrete washout
water. Proper treatment and use of BMPs is still required for these exceptions when available.
The discharge of pumped stormwater, ONLY, from excavations, ponds, depressions, etc. to surface
waters, or to a municipal storm sewer system is allowed by the Stormwater Construction Permit, as
long as the dewatering activity and associated BMPs are identified in the SWMP 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.
2.8 Receiving Waters
Stormwater runoff from the project area will generally flow into the Fossil Creek Reservoir Inlet
Ditch, which is located along the east boundary of the development site. The proposed post-
development drainage pattern generally follows the historic drainage course.
Banner Health Medical Campus
Stormwater Management Plan 4
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 authority to adequately manage and direct day-to-day stormwater quality
management activities at the site.
Please note: It is the responsibility of the SWMP Administrator to evaluate the proposed BMPs as
shown on the Stormwater Management Plan and modify the Plan as necessary throughout the
construction process. The final decision on where all BMPs will be located and when they will be
installed shall be made by the SWMP Administrator. All documentation throughout the
construction process shall also be the responsibility of the SWMP Administrator.
The SWMP Administrator for this site is (to be filled in by the SWMP Administrator, when
selected):
Name:
Company:
Phone:
E-mail:
3.2 Best Management Practices (BMP’s) for Stormwater Pollution Prevention
Beginning from mobilization, and throughout the entire construction of the buildings, 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 responsibility of the Contractor to make the ultimate determination as to what practices should
be employed and when. In the event that a review agency deems onsite erosion control measure to
be insufficient, it shall be the responsibility of the contractor to implement modifications as directed.
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 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 that are implemented to prevent erosion from happening or to
limit erosion once it occurs. These devices can be temporary or permanent, and installation of
individual components will vary depending on the stage of construction. Please refer to the
Stormwater Management Plan (Appendix A) for the proposed location of all BMPs. Construction
Details for Temporary BMPs are located in the Appendix for reference. As noted above, it is the
Banner Health Medical Campus
Stormwater Management Plan 5
responsibility of SWMP Administrator to evaluate the proposed BMPs as shown on the Stormwater
Management Plan and modify the plan as necessary throughout the construction process.
3.4 Phased BMP Installation
It is important to recognize the four (4) major Development Phases as 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 July, 2013 I
Overlot Grading August, 2013 August, 2013 I
Utility Installation August, 2013 September, 2013 II
Building Construction
September,
2013 May, 2014 III
Final Stabilization May, 2014 July, 2014 IV
Included in the back map pockets are the Site Plans: a “Static” Site Plan and a “Dynamic” Site
Plans (one for each phase of construction). The “Static” plan serves to display the overall
management plan all at once. However, proper implementation of BMPs does not occur at once,
and certain BMPs may move location in the construction process; therefore, the “Dynamic” Site
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.
Banner Health Medical Campus
Stormwater Management Plan 6
Silt Fencing (Phase I)
Silt fencing shall be provided to prevent migration of sediment off-site or into adjacent
properties. All silt fencing shall be installed prior to any land disturbing activity (stockpiling,
stripping, grading, etc.). Silt fencing is to be installed prior to site excavation or earthwork
activities.
Inspections of the silt fence should identify tears or holes in the material, 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 silt fence 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 prior to any land disturbing activity (stockpiling, stripping, grading, etc.). Location
of vehicle tracking control pads will be located at any and 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 prior to 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.
Sediment Control Log – aka “Straw Wattles” (Phase I)
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 can be used in many instances. Examples include perimeter control
for stockpiles, as part of inlet protection designs, as check dams in small drainage ways, or
on disturbed slopes to shorten flow lengths.
Sediment Control Logs should be inspected for excess sediment accumulation. Sediment
should be removed prior to reaching half the height of the log.
At a minimum, Sediment Control Logs should be used around soil stockpiles and for inlet
protection in unpaved areas of the site.
Curb Inlet Protection (Phase I & II)
Curb inlet protection shall be provided for existing curb inlets to prevent sediment transport
from adjacent earthwork disturbance. Installation of these filters shall occur before adjacent
earthmoving activities (Phase I implementation). Wattle type filters are to be implemented
for new and existing inlets where asphalt is not yet installed. For these inlets, if 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 responsibility of the Contractor 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 discretion of the
Contractor as to whether replacement of any inlet filter is necessary.
Inlet protection should be inspected regularly for tears that can result in sediment entering
Banner Health Medical Campus
Stormwater Management Plan 7
an inlet. Inlet protection should also be inspected for sediment accumulation upstream of
the inlet, and sediment should be removed when the less than half of the capacity is
available, or per manufacturer specifications.
Erosion Control Blankets (Phase II)
A temporary degradable rolled erosion control product composed of natural flexible fibers
shall be used on all seeded slopes 3:1 and greater (excluding mulched shrub bed areas).
Erosion control blankets should be utilized to provide erosion control and to facilitate
vegetation establishment. During installation, it is important to ensure that no gaps or voids
exist under the material and that all corners of the material are secured using stakes and
trenching. Stakes should be made of materials that are biodegradable. Continuous contact
between the product and the soil is necessary to avoid failure.
Erosion Control Blankets should be inspected regularly for signs of erosion, including
beneath the mat. If voids are apparent, they should be filled with suitable soil. Inspections
should also identify loose or damaged stakes, as well as loose portions of the blanket. If
deficiencies are found, they should be repaired or replaced.
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 a minimum of 400 feet
from any natural drainage way or body of water, and at least 1000 feet from any wells or
drinking water sources. Washout areas should not be located in an area where shallow
groundwater may be present. Contractor shall clearly show the desired location and access
to the Concrete Washout Area on the Stormwater Management Plan - Dynamic Site Plan.
Contractor shall place a Vehicle Tracking Pad if the selected location for the Concrete
Washout Area is detached from 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 that 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.
Sediment Trap (Phase II)
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.
Sediment Traps should be inspected for stability and seepage. Accumulated sediment
should be removed as needed to maintain the effectiveness of the sediment trip, typically
when the sediment depth is half the height of the outflow embankment.
A Sediment Trap shall be installed at the outlet structure of the Water Quality Pond as soon
as possible upon completion of the outlet structure, and will remain in place until the project
site has been stabilized. The Sediment Trap will help reduce sediment discharge into the
receiving drainage way by filtering at the pond outlet.
Riprap (Phase II)
Considered a permanent BMP, riprap pads will be provided to prevent long term erosion and
scour at the outlets of storm lines and other critical scour locations. Riprap pads will be
Banner Health Medical Campus
Stormwater Management Plan 8
placed at specified storm sewer outfalls and other critical locations as soon as possible
following construction of the respective facility. The riprap pads will be inspected regularly
and any required maintenance will be performed as discussed in subsequent sections.
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.
3.5 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 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 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.
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 drip-line 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 drip-line 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 how to care for the tree. If a tree is damage beyond repair,
the City Forester should be consulted on remediation measures.
At a minimum, trees located along the canal realignment should be protected, as should the
existing vegetation found in the wetland areas on the north side of the site.
Banner Health Medical Campus
Stormwater Management Plan 9
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 a minimum of 100 feet from
any drainage way and 50 feet from any storm sewer 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.
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 for temporary stabilization of areas that cannot be
reseeded due to seasonal constraints. The most common type of mulch used is hay or grass
that is 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.
In the case that hydraulic mulching is utilized, the Contractor shall use wood cellulose fibers
mixed with water at two thousands 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 BMP’s help to keep soil particles from entering the air as a
result of land disturbing construction activities. Examples include use of 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 to ensure that sufficient
water is applied is crucial to ensuring soil particles don’t become airborne. Equally
important is monitoring for overwatering, as too much water can lead to increased erosion.
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, establishing proper equipment/vehicle fueling and
maintenance practices. 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.
Street Sweeping and Vacuuming – Street sweeping and vacuuming should be used to
Banner Health Medical Campus
Stormwater Management Plan 10
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.
3.6 Material Handling and Spill Prevention
Potential pollution sources, as discussed in earlier sections, are to be to be identified by the
Contractor. Spill prevention procedures are to be determined and put in place prior to construction
by the Contractor. A spill and flooding response procedure must also be determined and put in
place prior to 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 by 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 waters of the State of Colorado (which include
surface water, ground water, and dry gullies or storm sewers leading to surface water) must be
reported immediately to the Division’s emergency spill reporting line at (877) 518-5608. All
spills that will require cleanup, even if the spill is minor and does not need to be reported to the
state, should still be reported to the City of Fort Collins.
While not expected with this project, it will be the responsibility of the Contractor to designate a
fueling area and take the necessary precautions to ensure that no stormwater pollution occurs in the
event that a fueling area is needed. Fueling areas shall be located a minimum 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.
Banner Health Medical Campus
Stormwater Management Plan 11
3.7 Dedicated Concrete or Asphalt Batch Plant
There are not any dedicated concrete or asphalt batch plants anticipated with this project. In the
event that a plant is needed, the Contractor should be aware that additional permitting will be
required. In particular, an Air Pollutant Emission Notice (APEN) will need to be obtained from
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 be
used to minimize the transmission of sediment from the site due to vehicles leaving the site. The
use of gravel parking areas and wash racks can also be implemented to ensure minimal vehicle
tracking from the site. Minimizing or limiting the number of vehicles accessing the site by providing
designated delivery areas, or by restricting deliveries when the site is muddy, is also encouraged.
3.9 Waste Management and Disposal
It will be the responsibility of the Contractor to designate a concrete truck chute washout area and
to 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 to enter a storm drain system or
stream. Upon completion of construction activities the concrete washout material shall be removed
and properly disposed of prior to 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 as to not 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, in order 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 as to prevent dispersion of waste materials from wind. It shall also be the responsibility
of the Contractor to maintain a clean jobsite as to prevent 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, prior to the water being 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 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.
Banner Health Medical Campus
Stormwater Management Plan 12
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. As defined by the Colorado
Department of Public Health and Environment 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.”
4.2 Long-Term Stormwater Management
The primary method of long-term stormwater management will be the use of a concrete outlet
structure and a water quality pond. The outlet structure shall be designed in a manner that allows
smaller, more frequent rainfall events to be detained and released over an extended amount of time.
This extended detention allows suspended sediment and pollutants to settle from the water prior to
entering drainage facilities downstream of the site.
In addition to the water quality pond, riprap will be placed at the outlets of all storm sewer pipes,
curb cuts, drainage pans, and similar concentrated discharge points in order to prevent erosion. All
disturbed areas will receive permanent paving or will be vegetated per the Landscape Plan. All
stormwater runoff from paved surfaces and rooftops is released through a vegetated swale prior to
reaching the water quality pond. Therefore, the disconnection of impervious areas combined with
the detention pond design, offer significant water quality enhancement, and will serve the long-term
stormwater management goals for this project.
Banner Health Medical Campus
Stormwater Management Plan 13
5.0 Inspection, Maintenance and Record Keeping
5.1 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 in order 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, to keep records of site conditions and inspections, and to
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 that are 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 that they are
operating correctly. Particular attention should be paid to areas that have a 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.
5.2 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,
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 Fort Collins;
etc.) upon request.
Preventative maintenance of all temporary and permanent erosion control BMPs shall be provided
in order 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 with Appendix B.
5.3 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 BMP’s that need to be maintained
Location(s) of BMP’s that failed to operate as designed or proved inadequate
Locations(s) where additional BMP’s 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
Banner Health Medical Campus
Stormwater Management Plan 14
The report shall contain a signed statement indicating the site is in compliance 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 the record
keeping of BMP inspections and maintenance. Photographs, field notebooks, drawings and maps
should be included 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. A record of other spills that are responded to, even if they do not result in a
discharge of pollutants, 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 immediately. Specifically, a release of any chemical, oil, petroleum
product, sewage, etc., which may enter waters of the State of Colorado (which include surface
water, ground water and dry gullies or storm sewers leading to surface water) must be reported to
the CDPHE.
The Stormwater Management Plan is intended to be a “living document” where the SWMP
Administrator can hand write the location of BMPs as they are installed to appropriately reflect the
current site conditions.
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 takes place.
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.
Banner Health Medical Campus
Stormwater Management Plan 15
6.0 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 BMP’s
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
Banner Health Medical Campus
Stormwater Management Plan 16
References
1. Final Drainage Drainage and Erosion Control Report, Banner Health Medical Campus,
Northern Engineering Services, May 22, 2013 (NES Project No. 306-003).
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 1-3, Urban Drainage and Flood Control
District, Water Resources Publications, LLC., Denver, Colorado, Updated November 2010.
APPENDIX A
SITE MAPS
APPENDIX B
EROSION CONTROL DETAILS
APPENDIX C
COPIES OF PERMITS/APPLICATIONS (TO BE PROVIDED BY CONTRACTOR)
APPENDIX D
INSPECTION LOGS
STORM WATER MANAGEMENT PLAN
INSPECTION TABLE
BMP Name/ Desc. Date Erosion Control Measures Effective Brief Revision Description
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
1
STORM WATER MANAGEMENT PLAN
INSPECTION TABLE
BMP Name/ Desc. Date Erosion Control Measures Effective Brief Revision Description
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
2
STORM WATER MANAGEMENT PLAN
INSPECTION TABLE
BMP Name/ Desc. Date Erosion Control Measures Effective Brief Revision Description
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
___ Yes ____ No ____ Yes (w/Rev)
3
APPENDIX E
CONTRACTOR INSERTS
APPENDIX F
REFERENCE MATERIAL
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
Common
a
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 wheatgrass
d
Agropyron cristatum
'Ephriam' Cool Sod 175,000 1.5
Oahe Intermediate wheatgrass Agropyron intermedium
'Oahe' Cool Sod 115,000 5.5
Vaughn sideoats grama
e
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
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
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
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
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 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
MAP POCKET
DRAINAGE EXHIBITS
(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.
Rectangular
Pipe
(Figure MD‐22) Spec
Width
of
Riprap
(ft)
2*d50,
Depth
of
Riprap
(ft)
for L/2
Froude
Parameter
Q/D
2.5
Max 6.0
or
Q/WH
1.5
Max 8.0
Riprap
Type
(From
Figure
MD‐21 or
MD‐22)
Project: 306‐003
Urban Drainage
pg MD‐107
L=
1/(2tanq)*
[At/Yt)‐W]
(ft)
Q 0 . 67 A ( 2 gH ) 0 . 5
14 14 2.57 10 10 8 0.88 0.88 1.00 2.21 3.78 8.38 5.0 8.5 21.5
15 15 1.61 7 7 6 0.88 0.88 1.00 2.60 4.44 9.63 3.7 6.3 15.5
16 16 0.50 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 1.3 2.1 5.0
17 17 4.01 6 6 5 0.88 0.88 1.00 2.76 4.72 9.95 9.7 16.6 39.9
18 18 2.33 6 6 5 0.88 0.88 1.00 2.76 4.72 9.95 5.7 9.7 23.2
19 19 1.56 9 9 8 0.46 0.46 0.58 2.30 3.93 8.59 1.7 2.8 7.7
20 20 1.05 16 16 14 0.81 0.81 1.00 1.84 3.14 6.82 1.6 2.7 7.2
21 21 0.21 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 0.5 0.9 2.1
22 22 0.76 11 11 10 0.88 0.88 1.00 2.17 3.71 7.88 1.5 2.5 6.0
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
11No0.36 0.36 0.44 78 2.00% 9.8 9.8 8.6 0 0.50% N/A N/A 361 1.00% 1.50 4.0 14 14 13
22No0.82 0.82 1.00 120 2.00% 4.5 4.5 1.6 224 0.50% 1.41 2.6 0 N/A N/A N/A 7 7 5
33No0.86 0.86 1.00 139 2.00% 4.2 4.2 1.7 180 0.50% 1.41 2.1 0 N/A N/A N/A 6 6 5
44No0.75 0.75 0.94 45 2.00% 3.4 3.4 1.6 280 3.00% 3.46 1.3 0 N/A N/A N/A 5 5 5
55No0.89 0.89 1.00 126 2.00% 3.5 3.5 1.7 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
66No0.92 0.92 1.00 195 2.00% 3.7 3.7 2.1 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
77No0.58 0.58 0.72 49 2.00% 5.4 5.4 3.9 103 0.50% 1.41 1.2 0 N/A N/A N/A 7 7 5
88No0.55 0.55 0.69 121 2.00% 9.0 9.0 6.7 80 0.50% 1.41 0.9 0 N/A N/A N/A 10 10 8
9a 9a No 0.89 0.89 1.00 128 2.00% 3.6 3.6 1.7 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
May 15, 2013
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
Ti C Cf L
9b 9b No 0.90 0.90 1.00 87 2.00% 2.8 2.8 1.4 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
10 10 No 0.87 0.87 1.00 84 2.00% 3.1 3.1 1.4 56 0.50% 1.41 0.7 0 N/A N/A N/A 5 5 5
11 11 No 0.54 0.54 0.67 90 2.00% 7.9 7.9 6.0 0 0.50% N/A N/A 0 N/A N/A N/A 8 8 6
12 12 No 0.95 0.95 1.00 50 2.00% 1.6 1.6 1.0 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
13 13 No 0.88 0.88 1.00 108 2.00% 3.4 3.4 1.5 0 0.50% N/A N/A 587 1.00% 1.50 6.5 10 10 8
14 14 No 0.88 0.88 1.00 125 2.00% 3.7 3.7 1.7 539 0.50% 1.41 6.4 0 N/A N/A N/A 10 10 8
15 15 No 0.88 0.88 1.00 20 2.00% 1.5 1.5 0.7 435 0.50% 1.41 5.1 0 N/A N/A N/A 7 7 6
16 16 No 0.88 0.88 1.00 93 2.00% 3.1 3.1 1.4 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
17 17 No 0.88 0.88 1.00 120 2.00% 3.6 3.6 1.6 200 0.50% 1.41 2.4 0 N/A N/A N/A 6 6 5
18 18 No 0.88 0.88 1.00 120 2.00% 3.6 3.6 1.6 200 0.50% 1.41 2.4 0 N/A N/A N/A 6 6 5
19 19 No 0.46 0.46 0.58 60 2.00% 7.4 7.4 6.0 150 0.50% 1.41 1.8 0 N/A N/A N/A 9 9 8
20 20 No 0.81 0.81 1.00 60 2.00% 3.3 3.3 1.1 1066 0.50% 1.41 12.6 0 N/A N/A N/A 16 16 14
21 21 No 0.88 0.88 1.00 20 2.00% 1.5 1.5 0.7 156 0.50% 1.41 1.8 0 N/A N/A N/A 5 5 5
22 22 No 0.88 0.88 1.00 20 2.00% 1.5 1.5 0.7 768 0.50% 1.41 9.1 0 N/A N/A N/A 11 11 10
13 150033 3.44 3.100 0.000 0.000 0.344 0.88 0.88 1.00 90%
14 111783 2.57 2.310 0.000 0.000 0.257 0.88 0.88 1.00 90%
15 70132 1.61 1.449 0.000 0.000 0.161 0.88 0.88 1.00 90%
16 21750 0.50 0.449 0.000 0.000 0.050 0.88 0.88 1.00 90%
17 174741 4.01 3.610 0.000 0.000 0.401 0.88 0.88 1.00 90%
18 101437 2.33 2.096 0.000 0.000 0.233 0.88 0.88 1.00 90%
19 67963 1.56 0.468 0.000 0.000 1.092 0.46 0.46 0.58 30%
20 45847 1.05 0.842 0.000 0.000 0.211 0.81 0.81 1.00 80%
21 9177 0.21 0.190 0.000 0.000 0.021 0.88 0.88 1.00 90%
22 33083 0.76 0.684 0.000 0.000 0.076 0.88 0.88 1.00 90%
DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I.
10-year Cf = 1.00
May 15, 2013