HomeMy WebLinkAboutLOAF N JUG - PDP - PDP180004 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE REPORT
Loaf N Jug #810 – I25 & HWY392
Fort Collins, Colorado
Prepared for:
Loaf ‘N’ Jug
c/o Jimmy Cruz
442 Keeler Parkway
Pueblo, CO 81001
Phone: (719) 948-3071
Prepared by:
Galloway & Company, Inc.
6162 S. Willow Drive, Suite 320
Greenwood Village, Colorado 80111
Phone: (970) 770-8884
Contact: Phil Dalrymple, PE
Original Preparation: March 26th, 2018
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TABLE OF CONTENTS
TABLE OF CONTENTS.......................................................................................................................... 1
I. CERTIFICATIONS .......................................................................................................................... 2
II. GENERAL LOCATION AND DESCRIPTION .................................................................................. 3
III. DRAINAGE BASINS AND SUB-BASINS ........................................................................................ 5
IV. DRAINAGE DESIGN CRITERIA ..................................................................................................... 6
V. DRAINAGE FACILITY DESIGN .................................................................................................... 11
VI. EROSION AND SEDIMENT CONTROL MEASURES ................................................................... 13
VII. CONCLUSIONS ............................................................................................................................ 20
VIII. REFERENCES .............................................................................................................................. 23
APPENDIX A - REFERENCE MATERIALS
VICINITY MAP
NRCS SOILS MAP
FEMA FIRMETTE
APPENDIX B - HYDROLOGY CALCULATIONS
PROPOSED COMPOSITE RUNOFF CALCULATIONS
APPENDIX C - HYDRAULIC CALCULATIONS
UDFCD SAND FILTER BMP CALCULATIONS
SAND FILTER MEDIA SPECIFICATIONS
MODIFIED FAA METHOD EXTENDED DETENTION CALCULATIONS
UDFCD DETENTION & OUTLET STRUCTURE CALCULATIONS
APPENDIX D – DRAINAGE MAPS
DEVELOPED CONDITION DRAINAGE MAP
APPENDIX E – EROSION CONTROL MAP
EROSION CONTROL PLAN
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I. CERTIFICATIONS
CERTIFICATION OF ENGINEER
“I hereby certify that this report for the final drainage design of Loaf N Jug #810 was prepared
by me (or under my direct supervision) in accordance with the provisions of the Fort Collins
Stormwater Criteria Manual for the owners thereof.”
______________________________________
Phil Dalrymple, PE
Registered Professional Engineer
State Of Colorado No. 41171
For and on behalf of Galloway & Company, Inc.
CERTIFICATION OF OWNER
“Loaf N Jug hereby certifies that the drainage facilities for the Loaf N Jug #810 shall be
constructed according to the design presented in this report. We understand that the City of
Fort Collins does not and will not assume liability for drainage facilities designed and/or
certified by our engineer. We also understand that the City of Fort Collins relies on the
representation of others to establish that drainage facilities are designed and constructed in
compliance with City of Fort Collins guidelines, standards, or specifications. Review by the City
of Fort Collins can therefore in no way limit or diminish any liability, which we or any other party
may have with respect to the design or construction of such facilities.”
____________________________________
Loaf N Jug
Attest:
___________________________________
(Name of Responsible Party)
__________________________________
Notary Public
__________________________________
Authorized Signature
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II. GENERAL LOCATION AND DESCRIPTION
LOCATION
Loaf ‘N’ Jug Fort Collins (hereafter referred to as “the site” or “project site”) will be located
northwest of the intersection of Interstate Highway I-25 and State Highway 392, also known as
Carpenter Road. It is bounded on the north and west by the SW Frontage Road; on the south
by State Highway 392; and on the east by the southbound off-ramp from I-25. Swede Lake, a
small bay off the southeast corner of Fossil Creek Reservoir, is located northwest of the site.
More specifically, the site is located in the Southwest Quarter of Section 15, Township 6 North,
Range 68 West in the City of Fort Collins, County of Larimer and State of Colorado. Refer to
Appendix A for a Vicinity Map.
DESCRIPTION OF PROPERTY
The project site consists of approximately 2.84 acres. It is currently a vacant and undeveloped
lot of land. The existing grades slope down towards the site at an average of twenty five
percent. The existing runoff generally flows from south to north on the site lot where it is then
directed to a series of drainage swales. Swales along the East and West carry a majority of
offsite runoff and the existing swale along the East side of the Frontage Road currently collects
storm water from the site. These swales carry runoff north toward Fossil Creek Reservoir and
the Cache la Poudre River.
There are no major drainage ways passing through the project site.
According to the USDA NRCS Web Soil Survey, ‘Wiley silt loam, 3 to 5 percent slopes’ covers
roughly the entire project site. This soil is associated with Hydrologic Soil Group (HSG) ‘B’.
HSG ‘B’ soils have a moderately slow infiltration rate when thoroughly wet, and consist chiefly
of soils that allow unimpeded downward water transmission. These soils have a moderate rate
of water transmission. The remainder of the site consists of similar HSG ‘B’ soils. Refer to
Appendix A for additional soils information.
Terracon conducted a geotechnical investigation on March 13, 2018. The results of the
preliminary geotechnical investigation are summarized in Geotechnical Engineering Report,
Windsor Loaf ‘N’ Jug, Windsor, Colorado (Terracon Project No. 20175104, Dated: March 13,
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2018). The soils encountered across the site, “generally consisted of about 20 to 24 feet of
lean clay with various amounts of sand over claystone bedrock.”
The site is situated south of the Fossil Creek Reservoir and west of the Cache La Poudre River
and is incorporated in both Master Drainage Plans. Currently, runoff from the site is directed to
these water bodies via drainage swales which run from south to north around the project site.
During the water quality storm event, excess surface runoff captured by on-site storm drainage
infrastructure will flow into a Sand Filter (SF) basin located on the east side of the site. Treated
discharge will flow into underdrains that outfall into the existing drainage swale north of the
site. During the minor (i.e., 2-year) and major (i.e., 100-year) storm events, runoff volume in
excess of the water quality event will flow out the permanent outlet structure or overtop the
basin and flow into the drainage swales north and east of the basin. Once in the drainage
swales, channelized flows will be conveyed into the Fossil Creek Reservoir and Cache La
Poudre River.
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III. DRAINAGE BASINS AND SUB-BASINS
MAJOR BASIN DESCRIPTION
The project site is located in the Fossil Creek/Cache La Poudre drainage basins. According to
the City of Fort Collins website (http://www.fcgov.com/utilities/what-we-do/stormwater/drainage-basins/fossil-creek-basin),
the Fossil Creek Drainage basin “extends along the south end of Fort Collins, from the foothills
across Interstate 25 past County Road 5. It encompasses 32 square miles in the city of Fort
Collins and Larimer County. Historically, the basin consisted of agricultural land, but the basin
has experienced significant development in the recent past.” The Cache La Poudre River is
tributary to the South Platte River and, due to floodplain restrictions, has a lower development
density and more parks and open space along the river corridor,” (https://www.fcgov.com/utilities/what-we-
do/stormwater/drainage-basins/poudre-river).
The project site is shown on FEMA Map Numbers 08069C1201F (refer to Appendix A for
FEMA Firmette). The map shows the project site outside the 0.2% annual chance floodplain.
Refer to Appendix A for a copy of the Firmette.
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IV. DRAINAGE DESIGN CRITERIA
REGULATIONS
This final drainage design presented herein is prepared in accordance with the Fort Collins
Amendments to the Urban Drainage and Flood Control District Criteria Manual (i.e., Urban
Drainage and Flood Control District Urban Storm Drainage Criteria Manuals Volumes 1, 2 and
3 [Manual]). Together, the requirements are referred to as the Fort Collins Stormwater Criteria
Manual [FCSCM].
DIRECTLY CONNECTED IMPERVIOUS AREA (DCIA)
We developed a strategy for implementing ‘The Four-Step Process’ for stormwater quality
management. Each step is listed below along with a brief narrative describing the
implementation strategy. Refer to Appendix C for the LID sizing calculations. The following
table, which is included on the LID Exhibit, summarizes basic information about each
Stormwater quality strategy. The bold number preceding each strategy keys to its location on
the LID Exhibit.
Step 1 - Employ runoff reduction practices
Several different Stormwater quality strategies were designed with Step 1 in mind. Developed
runoff from the series of onsite basins will flow to a Sand Filter (SF) before entering the
existing drainage swales. The UDFCD defines a Sand Filter as “A stormwater quality BMP
consisting of a sand bed and underdrain system. Above the vegetated sand bed is an
extended detention basin sized to capture the WQCV and EURV. A Sand Filter extended
detention basin provides pollutant removal through settling and filtering and is generally suited
to off-line, on-site configurations where there is no base flow and the sediment load is
relatively low.” Refer to Appendix C for additional design and construction details.
The existing drainage swales also help to reduce runoff as they allow infiltration along the
length of the swale. Existing swale slopes and cross-section sizes will be maintained as much
as possible throughout the construction process for the site, with efforts to minimize impact,
especially regarding site grading, from site development. However, due to project requirements
to develop the site frontage to meet LCUASS standards, a 150 ft portion of the westernmost
swale will be regraded to maintain 3:1 slope criteria throughout the project site.
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During storm events exceeding the water quality event, the sand filter is designed to fill to the
design volume and flow out the permanent outlet structure or overtop the basin and flow into
the drainage swales north and east of the basin. The incoming runoff will spill through a weir
designed to pass the 100-year incoming flows at a flow depth of 0.5’. The downstream face of
the spillway will be protected with North American Green (NAG) SC250 Turf Reinforcement
Mat (TRM). This is a composite TRM of 70% straw and 30% coconut fiber matrix incorporated
into permanent three-dimensional turf reinforcement matting. The spillway and downstream
protection are designed for peak 100-year developed runoff entering the sand filter and
passing through the weir. The downstream spillway slope is exposed because the water
surface elevation in the detention pond has not reached the weir elevation.
Of the total 1.52 acres of newly added impervious area, 1.18 acres are tributary to the sand
filter LID feature. The LID requirement for this site is as follows: 75% of any newly developed
area is required to be treated using LID. The percentage of newly developed area (i.e., added
impervious area per Ordinance No. 152, 2012) treated using an LID is 77.4% (1.18/1.52 AC).
Step 2 - Implement BMPs that provide a Water Quality Capture Volume (WQCV)
The developed runoff from basins A1, A2, A3, R1 and R2 will drain into an Extended Detention
Basin (EDB) designed on top of the sand filter. The UDFCD defines an Extended Detention
Basin as “An engineered basin with an outlet structure designed to slowly release urban runoff
over an extended time period to provide water quality benefits and control peak flows for
frequently occurring storm events. The basins are sometimes called "dry ponds" because they
are designed not to have a significant permanent pool of water remaining between storm
runoff events. Outlet structures for extended detention basins are sized to control more
frequently occurring storm events.”
During storm events exceeding the water quality event, the Extended Detention Basin (EDB) is
designed to fill to the design volume and spill excess runoff into the existing drainage swales.
The permanent outlet structure is designed to collect flows greater than the water quality event
and up to the 100-year event and release those flows downstream into the existing drainage
swales at the historic release rate for the Fossil Creek basin (0.2 cfs/acre). The excess runoff
will spill through a weir designed to pass the 100-year incoming flows at a flow depth of 0.5’.
The downstream face of the spillway will be protected with North American Green (NAG)
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SC250 Turf Reinforcement Mat (TRM). This is a composite TRM of 70% straw and 30%
coconut fiber matrix incorporated into permanent three-dimensional turf reinforcement matting.
The spillway and downstream protection are designed for peak 100-year developed runoff
entering the EDB and passing through the EDB weir. The downstream spillway slope is
exposed because the water surface elevation in the detention pond has not reached the weir
elevation.
Step 3 - Stabilize drainageways
There are no formal drainage ways existing on the site. Existing swales are already stabilized
with vegetation and will remain undisturbed as much as possible. Any areas disturbed during
construction will be stabilized prior to project completion. Additionally, rip rap protection will be
provided to protect the drainage swale receiving outflow from the onsite detention pond.
Step 4 - Implement site specific and other source control BMPS
Because the new development will be a gas station, one site specific source control BMP
implemented for this site is the inclusion of a spill control structure. This spill control is located
down grade of both the service kiosks and underground storage tanks to capture potential
spills from either location and protect downstream facilities from petroleum products and other
pollutants that are stored and handled at gas stations. The capacity of the spill control
structure is 150 gallons. Once stormwater flows through the spill control structure, it will enter
the storm sewer system and head to the proposed detention pond where it will receive further
treatment through extended detention and the sand filter.
DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS
The project site has a natural outfall to the existing drainage swales surrounding the site. In
order to maintain the existing slope and capacity of these swales, site grading and drainage
was constrained by the perimeter existing grades as much as possible. Where necessary,
regrading to accommodate additional offsite improvements was done with efforts made to
minimize impacted drainage swale length.
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HYDROLOGICAL CRITERIA
For urban catchments that are not complex and are generally 160 acres or less in size, it is
acceptable that the design storm runoff be analyzed using the Rational Method. The Rational
Method is often used when only the peak flow rate or total volume of runoff is needed (e.g.,
storm sewer sizing or simple detention basin sizing). The Rational Method was used to
estimate the peak flow at each design point. Routing calculations (i.e., time attenuation) that
aggregate the basins draining to a specific design point are include in the Rational Method
calculations in Appendix B.
The Rational Method is based on the Rational Formula:
Q = CiA
Where:
Q = the maximum rate of runoff, cfs
C = a runoff coefficient that is the ratio between the runoff volume from an area and the
average rate of rainfall depth over a given duration for that area
i = average intensity of rainfall in inches per hour for a duration equal to the Time of
Concentration (Tc)
A = area, acres
The one-hour rainfall Intensity-Duration-Frequency tables for use with the Rational Method of
runoff analysis are provided in Table RA-7 and Table RA-8 (refer to Appendix B).
The 2-year and 100-year storm events serve as the basis for the drainage system design. The
2-year storm is considered the minor storm event. It has a fifty percent probability of
exceedance during any given year. The 100-year storm is considered the major storm event. It
has a one percent probability of exceedance during any given year.
The 2-year drainage system, at a minimum, must be designed to transport runoff from the 2-
year recurrence interval storm event with minimal disruption to the urban environment. The
100-year drainage system, as a minimum, must be designed to convey runoff from the 100-
year recurrence interval flood to minimize life hazards and health, damage to structures, and
interruption to traffic and services.
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HYDRAULIC CRITERIA
The on-site excess developed runoff within each tributary area begins its journey to the
stormwater quality feature and, ultimately, the perimeter swales as overland flow from
commercial lot areas (i.e., roof area, concrete hardscape and landscaping). Runoff then flows
directly into the sand filter or drainage swales, or is intercepted by curb inlets. These inlets
discharge to the on-site Sand Filter (SF).
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V. DRAINAGE FACILITY DESIGN
GENERAL CONCEPT
This final design presents the detailed design of system for collecting and conveying
developed runoff from current and future development at Loaf ‘N’ Jug #810 to the Stormwater
quality feature on-site detention pond.
The existing site runoff drains to an existing drainage swale surrounding the project site on the
north, west, and east sides. These swales facilitate drainage toward Fossil Creek and Cache la
Poudre river. The proposed design matches this existing drainage pattern and includes the
development of a permanent outfall.
Typically, the on-site excess developed runoff will travel overland into the storm sewer system
where it is directed into the on-site water quality and detention basin. Site runoff is treated by
the Sand Filter (SF) detention basin and then collected by an underdrain which flows to the
northernmost drainage swale.
SPECIFIC DETAILS
On-Site Sand Filter Detention Basin
The proposed on-site sand filter was sized using the Urban Drainage Stormwater Best
Management Practice Design Workbook version 3.03, included in Appendix C. The BMP
design workbook considers tributary basin geometry and imperviousness to estimate the water
quality capture volume (WQCV) for the sand filter, as well as required filter surface area.
Based on the workbook calculations, the required WQCV for this site is 0.031 acre-ft. In
addition to the WQCV to be provided for treatment by the sand filter, the extended detention
volume was designed to provide the 100-year volume plus the WQCV. Utilizing the modified
FAA Method, Appendix C, the 100-year storage volume was estimated to be 0.37 acre-ft.
Utilizing the Urban Drainage Detention Design Workbook, version 3.07, a stage-storage
relationship was modeled to provide these required storage volumes within the site area east
of the gas station and drive aisles.
The preliminary design for the sand filter detention basin estimated the WQCV stage to be
0.31 ft above the sand filter media surface elevation (4878.4) and the extended detention
volume (0.37 acre-ft + 0.031 acre-ft) to have a water surface elevation (4881.4). Based on site
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grading surrounding the basin, the stormwater quality features and extended detention
features will function as intended during the minor and major storm event.
The proposed 2.5’ x 2.5’ x 3’ concrete vault will provide an outlet for storm events between the
water quality event and the 100-year event. The structure will provide an outfall pipe with an
orifice restrictor plate to release flows at the historic release rate, 0.2 cfs/ acre. Two 1-inch
underdrains will be provided along the length of the sand filter to collect treated water and tie
into the outlet structure to outfall into the existing drainage swales.
The ultimate outfall, will discharge at ±0.2 cfs/ac (±0.52 cfs) thorugh a 2.8” orifice plate
attached to a headwall. Beyond the headwall, is a 24” RCP outfall system. The system is
designed to outfall to the existing swale system to the north, daylighting at ±4875.2 elevation.
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VI. EROSION AND SEDIMENT CONTROL MEASURES
The existing site condition is fully vegetated with native grasses. An existing drainage swale
surrounds the project site on the north, west, and east sides, facilitating drainage north toward
Fossil Creek and Cache la Poudre river. A total area of approximately 3.6 acres (2.8 onsite,
0.8 surrounding offsite) will be disturbed during the construction of the Loaf N Jug site.
POTENTIAL POLLUTANT SOURCES
Potential pollutant sources for this site include:
· Disturbed and stored soils: The site will be grubbed and overlot graded prior to major
utility and roadway construction. This will be a one time activity and should be
completed relatively early in the project timeline. The areas of grading that will not
require additional disturbance shall receive final landscaping within 30 days of
substantial completion of site work and building construction and prior to certificate of
occupancy. Otherwise temporary seeding and mulching will be required within 7 days
of last disturbance if no further disturbance is anticipated for at least 14 days. Any soil
stock piles utilized during construction will be covered with a tarpaulin when not in
active use and will have silt fence installed along the base of the slope.
· Vehicle tracking of sediments: There is potential for tracking of soils between the
beginning of the grading process and the final stabilization of the site. Vehicle tracking
control is to be installed prior to land disturbance activities and sweeping is to take
place as needed. Vehicle access to the exposed and disturbed subgrade will be limited
primarily to roll on/off earthmoving equipment and heavy materials delivery trucks. The
SWMP Administrator is responsible for insuring that access to exposed subgrade is
limited, both in quantity and in timing relative to the tracking susceptibility of the soil as
it relates to moisture content. The administrator must keep the adjacent parking areas
and public rights-of-way free from mud and other tracked debris from the site.
· Loading and unloading operations: All loading and unloading operations of
equipment shall be accomplished in areas protected by erosion and sediment controls.
It is recommended that all equipment be cleaned on-site and within protected areas
prior to exiting the site.
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· Hazardous Material Management and Spill Reporting Plan: Any hazardous or
potentially hazardous material that is brought onto the construction site will be handled
properly in order to reduce the potential for storm water pollution. All materials used on
this construction site will be properly stored including the use of secondary containment
measures, handled, dispensed and disposed of following all applicable label directions.
Flammable and combustible liquids will be stored and handled according to 29 CFR
1926.152. Only approved containers and portable tanks shall be used for storage and
handling of flammable and combustible liquids.
In the event of an accidental spill, immediate action will be undertaken by the General
Contractor to contain and remove the spilled material. All hazardous materials will be
disposed of by the Contractor in the manner specified by federal, state and local
regulations and by the manufacturer of such products. As soon as possible, the spill
will be reported to the appropriate agencies. As required under the provisions of the
Clean Water Act, any spill or discharge entering waters of the United States will be
properly reported. The General Contractor will prepare a written record of all spills and
associated clean-up and will also notify the City of Fort Collins. The General Contractor
will provide notice to Owner immediately upon identification of a reportable spill.
Any spills of petroleum products or hazardous materials in excess of Reportable
Quantities as defined by EPA or the state or local agency regulations, shall be
immediately reported to the EPA National Response Center (1-800-424-8802), the
Colorado Department of Public Health and Environment (CDPHE) (1-877-518-5608),
and the City of Fort Collins (970-221-6700).
The State reportable quantity for petroleum products is 25 gallons or more (or that
cause a sheen on nearby surface waters). Spills from regulated aboveground and
underground fuel storage tanks must be reported to the State Oil Inspector within 24
hours (after-hours contact CDPHE Emergency Spill Reporting Line). This includes
spills from fuel pumps. Spills or releases of hazardous substances from regulated
storage tanks in excess of the reportable quantity (40 CFR Part 302.6) must be
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reported to the National Response Center, the local fire authority immediately, the State
Oil Inspector, the City of Brighton, and Adams County within 24 hours.
The reportable quantity for hazardous materials can be found in 40 CFR 302 at:
http://ecfr.gpoaccess.gov/cgi/t/text/text-
idx?c=ecfr&tpl=/ecfrbrowse/Title40/40cfr302_main_02.tpl
In order to minimize the potential for a spill of petroleum product or hazardous materials
to come in contact with storm water, the following steps will be implemented:
a) All materials with hazardous properties (such as pesticides, petroleum
products, fertilizers, detergents, construction chemicals, acids, paints, paint
solvents, additives for soil stabilization, concrete, curing compounds and
additives, etc.) will be stored including secondary containment measures in a
secure location, under cover, when not in use.
b) The minimum practical quantity of all such materials will be kept on the
job site and scheduled for delivery as close to time of use as practical.
c) A spill control and containment kit (containing for example, absorbent
material such as kitty litter or sawdust, acid neutralizing agent, brooms, dust
pans, mops, rags, gloves, goggles, plastic and metal trash containers, etc.) will
be provided on the construction site and location(s) shown on Site Maps. The
kit should be inspected for completeness as a part of weekly stormwater
inspections.
d) All of the product in a container will be used before the container is
disposed of. All such containers will be triple rinsed, with water prior to disposal.
The rinse water used in these containers will be disposed of in a manner in
compliance with state and federal regulations and will not be allowed to mix with
storm water discharges.
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e) All products will be stored in and used from the original container with
the original product label.
f) All products will be used in strict compliance with instructions on the
product label.
The disposal of excess or used products will be in strict compliance with instructions on
the products label and local regulations.
The contractor is responsible for the Spill Prevention and Control Plan (SPCP). The
SPCP shall clearly state measures to stop the source of a spill, contain the spill, clean
up the spill, dispose of contaminated materials, and train personnel to prevent and
control future spills. In addition, the SPCP must include contact and documentation
requirements for each of the Minor, Significant, and Hazardous spill magnitudes.
Further requirements are listed below in the equipment fueling section.
· Fueling of equipment: Temporary on-site fuel tanks for construction vehicles shall
meet all state and federal regulations. Tanks shall have approved spill containment
with the capacity required by the applicable regulations. From NFPA 30: All tanks shall
be provided with secondary containment (i.e. containment external to and separate
from primary containment). Secondary containment shall be constructed of materials of
sufficient thickness, density, and composition so as not to be structurally weakened as
a result of contact with the fuel stored and capable of containing discharged fuel for a
period of time equal to or longer than the maximum anticipated time sufficient to allow
recovery of discharged fuel. It shall be capable of containing 110% of the volume of the
primary tank if a single tank is used, or in the case of multiple tanks, 150% of the
largest tank or 10% of the aggregate, whichever is larger.
The tanks shall be in sound condition free of rust or other damage which might
compromise containment. Fuel storage areas will meet all EPA, OSHA and other
regulatory requirements for signage, fire extinguisher, etc. Hoses, valves, fittings, caps,
filler nozzles, and associated hardware shall be maintained in proper working condition
at all times. The location of fuel tanks shall be shown on the Site Maps and shall be
located to minimize exposure to weather and surface water drainage features.
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A Spill Prevention, Control and Countermeasure (SPCC) Plan must be developed if
aboveground oil storage capacity at the construction site exceeds 1,320-gallons or as
specified by state. Containers with a storage capacity of 55-gallons or less are not
included when calculating site storage capacity. The General Contractor shall develop
and implement a SPCC Plan in accordance with the Oil Pollution Prevention regulation
at Title 40 of the Code of Federal Regulations, Part 112, (40 CFR 112).
· Maintenance of equipment used for construction: If equipment is to be maintained
and stored in an open area this area should not be within the drip line of trees and not
be within 100 feet of a watercourse or wetland. Runoff should be diverted away from
watercourses and wetlands. Maintenance should be done on impervious areas
surrounded with impervious berms. Where this is not possible, use pads designed to
contain the pollutants which may leak or spill during maintenance operations.
Impervious pads are particularly important on sandy and other course soils where
spilled materials can easily leach into the groundwater. Equipment shall be checked
before and after each use and, minimally, during the weekly stormwater inspection if
otherwise idle. Periodic checks of the equipment wash areas shall be performed to
ensure proper operation.
· Concrete washout: Concrete washout area shall be installed prior to any concrete
placement on site. Signs shall be placed at the construction entrance(s), at the washout
area, and elsewhere as necessary to clearly indicate the location of the concrete
washout area. The washout area shall be repaired and enlarged or cleaned out as
necessary to maintain capacity for wasted concrete. Concrete and concrete wash water
shall be removed from the site and disposed of at an accepted waste facility.
· Worker’s trash: The site shall be policed at the end of each work day to be kept free of
trash and debris resulting from workers day to day activities. If necessary utilize clearly
marked and protected containers for trash and debris at convenient locations
throughout the site. Burying of waste on site is prohibited. Trash must be properly
contained at the end of each day.
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· Portable toilets: All personnel involved with construction activities must comply with
state and local sanitary or septic system regulations. Temporary sanitary facilities will
be provided at the site throughout the construction phase. They must be utilized by all
construction personnel and must be serviced weekly by a commercial operator. The
location of sanitary facilities shall be shown on the Site Maps. Portable toilets must be
securely anchored a minimum of 10’ behind curbs, and are not allowed within 50’ of
inlets or within 50’ of a water of the State or the municipal storm drain system.
BMP’S FOR STORMWATER POLLUTION PREVENTION
A General Permit for Stormwater Discharge Associated with Construction Activities issued by
the Colorado Department of Public Health and Environment (CDPHE), Water Quality Control
Division (WQCD), will be acquired for the site. A Stormwater Management Plan (SWMP)
should be prepared to identify the Best Management Practices (BMPs) which, when
implemented, will meet the requirements of said General Permit. Below is a summary of
SWMP requirements which may be implemented on-site as well as a sequencing chart of BMP
installation (modified from Urban Drainage and Flood Control District, Urban Storm Drainage
Criteria Manual Volume 3, Construction Phasing/Sequencing). Specific locations for erosion
control BMPs are presented in the erosion control plan in Appendix E.
The following temporary BMPs may be installed and maintained to control on-site erosion and
prevent sediment from traveling off-site during construction:
· Silt Fence – a woven synthetic fabric that filters runoff. The silt fence is a temporary
barrier that is placed at the base of a disturbed area.
· Vehicle Tracking Control – a stabilized stone pad located at points of ingress and
egress on a construction site. The stone pad is designed to reduce the amount of mud
transported onto public roads by construction traffic.
· Inlet protection – Inlet protection will be used on all existing and proposed storm inlets
to help prevent debris from entering the storm sewer system. Inlet protection generally
consists of straw wattles or block and gravel filters.
· Concrete washout – Concrete washout area shall be installed prior to any concrete
placement on site. Signs shall be placed at the construction entrance(s), at the washout
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area, and elsewhere as necessary to clearly indicate the location of the concrete
washout area. The washout area shall be repaired and enlarged or cleaned out as
necessary to maintain capacity for wasted concrete. Concrete and concrete wash water
shall be removed from the site and disposed of at an accepted waste facility.
· Stabilized Staging Area – This is a clearly designated area where construction
equipment and vehicles, stockpiles, waste bins, and other construction-related
materials are stored. The stabilized storage area consists of a stabilized surface,
covered with 3-inch diameter aggregate or larger.
Permanent stabilization of the site will include establishment of native seeded areas in the
ROW and on-site disturbed area and pavement placement. Final site stabilization is achieved
when perennial vegetative cover provides permanent stabilization with a density greater than
70 percent over the entire area to be stabilized by vegetative cover.
CONSTRUCTION SEQUENCING CHART
Project Phase BMP’s
Pre-disturbance/Pre-
Construction Phase
· Install sediment controls downgradient of access point
(including inlet protection of existing inlets and drainage
facilities, see erosion control plan)
· Establish vehicle tracking control at entrance to paved frontage
road
· Use construction fencing to define the boundaries of the project
and limit access to areas of the site that are not to be disturbed
· Install perimeter controls (silt fence) as needed on
downgradient perimeter of site (see erosion control plan for
location)
Construction Phase · Create stabilization staging area
· Locate portable toilets on flat surfaces away from drainage
paths
· Construct concrete washout area and provide signage (see
erosion control plan for location)
· Establish waste disposal areas
`
20
· Provide inlet protection as inlets are constructed (see erosion
control plan for location)
· Protect and repair BMPs, as necessary
· Perform street sweeping as needed
· Remove excess or waste materials
Final Stabilization In addition to the above BMPs:
· Seed and mulch (see landscape plan for additional detail)
· Construct permanent outlet protection (rip rap) at constructed
outlets
· Remove all temporary BMPs when site has reached final
stabilization
CONSTRUCTION MATERIALS & EQUIPMENT
The contractor shall store all construction materials and equipment and shall provide
maintenance and fueling of equipment on confined areas on-site from which runoff will be
contained and filtered.
MAINTENANCE
The temporary BMPs will be inspected by the contractor at a minimum of once every two
weeks and after each significant storm event. The property owner will be responsible for
routine and non-routine maintenance of the temporary BMPs. Routine maintenance includes:
· Remove sediment from the bottom of the temporary sediment basin when accumulated
sediment occupies about 20% of the design volume or when sediment accumulation
results in poor drainage.
· Debris and litter removal to minimize outlet clogging and improve aesthetics as
necessary.
· Inspection of the facility annually to ensure that it functions as initially intended.
· Cleaning and repair of BMP’s is required when sediment has built up or the BMP is not
working properly.
`
21
SWMP ADMINISTRATOR
The SWMP Administrator is responsible for developing, implementing, maintaining, and
revising the SWMP. The Contractor shall designate a SWMP Administrator which will be the
contact for all SWMP related issues and the person responsible for its accuracy,
completeness, and implementation. The SWMP Administrator should be a person with
authority to adequately manage and direct day-to-day stormwater quality management
activities at the site.
The SWMP Administrator is responsible for holding a weekly storm water meeting attended by
the General Contractor with all contractors and subcontractors involved in ground-disturbing
activities to review the requirements of the Permit(s), the SWMP, and address any problems
that have arisen in implementing the SWMP or maintaining the BMPs. Contractor shall
maintain a log of all weekly meetings and document the issues addressed in the meetings.
The name and contact information for the SWMP Administrator is:
Name: ________________________________________ Phone: ___________________
`
22
VII. CONCLUSIONS
COMPLIANCE WITH STANDARDS
The design presented in this final drainage report for Loaf N Jug #810 has been prepared in
accordance with the design standards and guidelines presented in the Fort Collins Stormwater
Criteria Manual.
VARIANCES
No variances are being requested with the proposed improvements described herein.
DRAINAGE CONCEPT
The proposed Loaf N Jug storm drainage improvements should provide adequate protection
for the developed site. The proposed drainage design for the site should not negatively impact
the existing downstream storm drainage system.
`
23
VII. REFERENCES
1. Fort Collins Stormwater Criteria Manual (Addendum to the Urban Storm Drainage
Criteria Manuals Volumes 1, 2 and 3), prepared by City of Fort Collins.
2. Urban Drainage and Flood Control District, Drainage Criteria Manual Volumes 1 and 2,
prepared by Wright-McLaughlin Engineers, dated June 2001 (revised April 2008), and
the Volume 3, prepared by Wright-McLaughlin Engineers, dated September 1992 and
revised November 2010.
APPENDIX A – REFERENCE MATERIALS
VICINITY MAP
Loaf ‘N’ Jug #810 Vicinity Map
Not to Scale
Loaf ‘N’ Jug
Project Site
Fossil Creek
Reservoir
Cache La Poudre
River
NRCS SOILS MAP
9
Custom Soil Resource Report
Soil Map
4480950 4480990 4481030 4481070 4481110 4481150 4481190 4481230 4481270
4480950 4480990 4481030 4481070 4481110 4481150 4481190 4481230 4481270
500430 500470 500510 500550 500590 500630 500670
500430 500470 500510 500550 500590 500630 500670
40° 28' 55'' N
104° 59' 41'' W
40° 28' 55'' N
104° 59' 31'' W
40° 28' 45'' N
104° 59' 41'' W
40° 28' 45'' N
104° 59' 31'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 20 40 80 120
Meters
Map Scale: 1:1,610 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
118 Wiley silt loam, 1 to 3 percent
slopes
0.1 0.7%
119 Wiley silt loam, 3 to 5 percent
slopes
13.7 99.3%
Totals for Area of Interest 13.8 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
Custom Soil Resource Report
11
FEMA FIRMETTE
PROJECT SITE
APPENDIX B – HYDROLOGY CALCULATIONS
PROPOSED COMPOSITE RUNOFF
CALCULATIONS
Table 3.4-1. IDF Table for Rational Method
Duration 2-year 10-year 100-year
min in/hr in/hr in/hr
5 2.85 4.87 9.95
6 2.67 4.56 9.31
7 2.52 4.31 8.80
8 2.40 4.10 8.38
9 2.30 3.93 8.03
10 2.21 3.78 7.72
11 2.13 3.63 7.42
12 2.05 3.50 7.16
13 1.98 3.39 6.92
14 1.92 3.29 6.71
15 1.87 3.19 6.52
16 1.81 3.08 6.30
17 1.75 2.99 6.10
18 1.70 2.90 5.92
19 1.65 2.82 5.75
20 1.61 2.74 5.60
21 1.56 2.67 5.46
22 1.53 2.61 5.32
23 1.49 2.55 5.20
24 1.46 2.49 5.09
25 1.43 2.44 4.98
26 1.40 2.39 4.87
27 1.37 2.34 4.78
28 1.34 2.29 4.69
29 1.32 2.25 4.60
30 1.30 2.21 4.52
31 1.27 2.16 4.42
32 1.24 2.12 4.33
33 1.22 2.08 4.24
34 1.19 2.04 4.16
35 1.17 2.00 4.08
36 1.15 1.96 4.01
37 1.16 1.93 3.93
38 1.11 1.89 3.87
39 1.09 1.86 3.80
40 1.07 1.83 3.74
41 1.05 1.80 3.68
42 1.04 1.77 3.62
43 1.02 1.74 3.56
44 1.01 1.72 3.51
45 0.99 1.69 3.46
46 0.98 1.67 3.41
47 0.96 1.64 3.36
48 0.95 1.62 3.31
49 0.94 1.60 3.27
50 0.92 1.58 3.23
51 0.91 1.56 3.18
52 0.90 1.54 3.14
53 0.89 1.52 3.10
54 0.88 1.50 3.07
55 0.87 1.48 3.03
56 0.86 1.47 2.99
57 0.85 1.45 2.96
58 0.84 1.43 2.92
59 0.83 1.42 2.89
60 0.82 1.40 2.86
65 0.78 1.32 2.71
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0 10 20 30 40 50 60 70 80 90 100 110 120
Rainfall Intensity (in/hr)
Storm Duration (Minutes)
Table RA-7 | City of Fort Collins
Rainfall Intensity - Duration - Frequency (IDF)
2-Year 10-Year 100-Year
Designer:
Company: 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr
Date: 1-hour rainfall depth, P1 (in) = 0.88 1.16 1.47 1.99 2.49 3.05 4.68
Project: a b c
Location: Rainfall Intensity Equation Coefficients = 28.50 10.00 0.786
2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr
Overland
Flow Length
Li
(ft)
U/S Elevation
(ft)
(Optional)
D/S Elevation
(ft)
(Optional)
Overland
Flow Slope
Si
(ft/ft)
Overland
Flow Time
ti
(min)
Channelized
Flow Length
Lt
(ft)
U/S Elevation
(ft)
(Optional)
D/S Elevation
(ft)
(Optional)
Channelized
Flow Slope
St
(ft/ft)
NRCS
Conveyance
Factor K
Channelized
Flow Velocity
Vt
(ft/sec)
Channelized
Flow Time
tt
(min)
Computed
tc
(min)
Regional
tc
(min)
Selected
tc
(min)
2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr
0.71 0.73 0.76 0.79 0.81 0.83 0.85 11.09
APPENDIX C – HYDRAULIC CALCULATIONS
UDFCD SAND FILTER BMP CALCULATIONS
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 59.0 %
(100% if all paved and roofed areas upstream of sand filter)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.590
C) Water Quality Capture Volume (WQCV) Based on 12-hour Drain Time WQCV = 0.19 watershed inches
WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including sand filter area) Area = 86,250 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 1,339 cu ft
VWQCV = WQCV / 12 * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth DWQCV = 0.5 ft
B) Sand Filter Side Slopes (Horizontal distance per unit vertical, Z = 4.00 ft / ft
4:1 or flatter preferred). Use "0" if sand filter has vertical walls.
C) Minimum Filter Area (Flat Surface Area) AMin = 636 sq ft
D) Actual Filter Area AActual = 850 sq ft
E) Volume Provided VT = cu ft
3. Filter Material
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y = 2.0 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = 1,339 cu ft
iii) Orifice Diameter, 3/8" Minimum DO = 13 / 16 in
City of Fort Collins BSM
Fort Collins, Colorado
Design Procedure Form: Sand Filter (SF)
Galloway & Company, Inc.
March 7, 2018
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" CDOT Class B or C Filter Material
Other (Explain):
YES
NO
LNJ810_UD-BMP_v3.06.xlsm, SF 3/7/2018, 12:55 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6-7. Inlet / Outlet Works
A) Describe the type of energy dissipation at inlet points and means of
conveying flows in excess of the WQCV through the outlet
Notes:
Design Procedure Form: Sand Filter (SF)
Galloway & Company, Inc.
March 7, 2018
Fort Collins, Colorado
Choose One
YES NO
LNJ810_UD-BMP_v3.06.xlsm, SF 3/7/2018, 12:55 AM
SAND FILTER MEDIA SPECIFICATIONS
March 19, 2011
BIORETENTION SAND MEDIA SPECIFICATION 1
CITY OF FORT COLLINS
BIORETENTION SAND MEDIA SPECIFICATION
PART 1 - GENERAL
A. Bioretention Sand Media (BSM) shall be uniformly mixed, uncompacted, free of stones,
stumps, roots, or other similar objects larger than two inches. No other materials or
substances shall be mixed or dumped within the bioretention area that may be harmful to plant
growth or prove a hindrance to the facility’s function and maintenance.
B. BSM shall be free of plant or seed material of non-native, invasive species, or weeds.
C. Fully mixed BSM shall be tested prior to installation and meet the following criteria:
1. P-Index of less than 30
2. pH of 5.5-6.5. Should pH fall outside of the acceptable range, it may be modified with
lime (to raise) or iron sulfate plus sulfur (to lower). The lime or iron sulfate must be mixed
uniformly into the BSM prior to use in the bioretention facility.
3. Cation Exchange Capacity (CEC) greater than 10
4. Phosphorous (Phosphate, P2O5) not to exceed 69 ppm
5. BSM that fails to meet the minimum requirements shall be replaced at the Contractor’s
expense.
D. BSM shall be delivered fully mixed in a drum mixer. Onsite mixing of piles will not be allowed.
Mixing of the BSM to a homogeneous consistency shall be done to the satisfaction of the
Owner.
PART 2 - SOIL MATERIALS
A. Sand
1. BSM shall consist of 60-70% sand by volume meeting ASTM C-33.
B. Shredded Paper
1. BSM shall consist of 5-10% shredded paper by volume.
2. Shredded paper shall be loosely packed, approximate bulk density of 50-100 lbs/CY.
3. Shredded paper shall consist of loose leaf paper, not shredded phone books, and shall
be thoroughly and mechanically mixed to prevent clumping.
C. Topsoil
1. BSM shall consist of 5-10% topsoil by volume.
2. Topsoil shall be classified as sandy loam, loamy sand, or loam per USDA textural triangle
with less than 5% clay material.
3. Onsite, native material shall not be used as topsoil.
4. Textural analysis shall be performed on topsoil, preferably at its source, prior to including
topsoil in the mix. Topsoil shall be free of subsoil, debris, weeds, foreign matter, and any
other material deleterious to plant health.
5. Topsoil shall have a pH range of 5.5 to 7.5 and moisture content between 25-55%.
6. Contractor shall certify that topsoil meets these specifications.
D. Leaf Compost
1. BSM shall consist of 10-20% leaf compost by volume.
2. Leaf compost shall consist of Class 1 organic leaf compost consisting of aged leaf mulch
resulting from biological degradation and transformation of plant-derived materials under
controlled conditions designed to promote aerobic decomposition.
March 19, 2011
BIORETENTION SAND MEDIA SPECIFICATION 2
3. The material shall be well composted, free of viable weed seeds and contain material of a
generally humus nature capable of sustaining growth of vegetation, with no materials
toxic to plant growth.
4. Compost shall be provided by a local US Composting Council Seal of Testing Assurance
(STA) member. A copy of the provider’s most recent independent STA test report shall
be submitted to and approved by the Owner prior to delivery of BSM to the project site.
5. Compost material shall also meet the following criteria:
a. 100 percent of the material shall pass through a 1/2 inch screen
b. PH of the material shall be between 6.0 and 8.4
c. Moisture content shall be between 35 and 50 percent
d. Maturity greater than 80 percent (maturity indicator expressed as percentage of
germination/vigor, 80+/80+)
e. Maturity indicator expressed as Carbon to Nitrogen ration < 12
f. Maturity indicator expressed as AmmoniaN/NitrateN Ratio <4
g. Minimum organic matter shall be 40 percent dry weight basis
h. Soluble salt content shall be no greater than 5500 parts per million or 0-5
mmhos/cm
i. Phosphorus content shall be no greater than 325 parts per million
j. Heavy metals (trace) shall not exceed 0.5 parts per million
k. Chemical contaminants: meet or exceed US EPA Class A standard, 40 CFR
503.13, Tables 1 & 3 levels
l. Pathogens: meet or exceed US EPA Class A standard, 40 CFR 503.32(a) levels
PART 3 - EXECUTION
A. General
1. Refer to project specifications for excavation requirements.
B. Placement Method
1. BSM material shall be spread evenly in horizontal layers.
2. Thickness of loose material in each layer shall not exceed 9-inches.
3. Compaction of BSM material is not required.
MODIFIED FAA METHOD EXTENDED
DETENTION CALCULATIONS
Project Number: LNJ810 Date: 3/7/2018
Project Location: Fort Collins, Colorado
Calculations By: H. Feissner
Pond Description: Detention Pond
User Input Cell: Blue Text
100-year 16128
0.75 0.37
2
0.52
minutes seconds in/hr cubic feet cubic feet cubic feet acre-feet
5 300 9.95 4478 156 4322 0.099
10 600 7.72 6948 312 6636 0.152
15 900 6.52 8802 468 8334 0.191
20 1200 5.60 10080 624 9456 0.217
25 1500 4.98 11205 780 10425 0.239
30 1800 4.52 12204 936 11268 0.259
35 2100 4.08 12852 1092 11760 0.270
40 2400 3.74 13464 1248 12216 0.280
45 2700 3.46 14013 1404 12609 0.289
50 3000 3.23 14535 1560 12975 0.298
55 3300 3.03 14999 1716 13283 0.305
60 3600 2.86 15444 1872 13572 0.312
65 3900 2.71 15854 2028 13826 0.317
70 4200 2.59 16317 2184 14133 0.324
75 4500 2.48 16740 2340 14400 0.331
80 4800 2.38 17136 2496 14640 0.336
85 5100 2.29 17519 2652 14867 0.341
90 5400 2.21 17901 2808 15093 0.346
95 5700 2.13 18212 2964 15248 0.350
100 6000 2.06 18540 3120 15420 0.354
105 6300 2.00 18900 3276 15624 0.359
110 6600 1.94 19206 3432 15774 0.362
115 6900 1.88 19458 3588 15870 0.364
120 7200 1.84 19872 3744 16128 0.370
Storage
Volume
Modified FAA Method- Storage Volume Calculations
Inputs | Tributary Area Output | Detention Volume
Storm Duration Time Rainfall
Intensity Inflow Volume
Catchment 'C':
Catchment Drainage Area, ac:
Return Period for Detention Control: Required Storage, cubic feet:
Required Storage, ac-ft:
Release Rate, cfs:
Average
Outflow
Storage
Volume
UDFCD DETENTION & OUTLET STRUCTURE
CALCULATIONS
Project:
Basin ID:
Depth Increment = 0.1 ft
Required Volume Calculation Media Surface 0.00 125.5 31.4 3,938 0.090
Selected BMP Type = SF 0.10 126.3 32.2 4,064 0.093 400 0.009
Watershed Area = 1.98 acres 0.20 127.0 32.9 4,179 0.096 771 0.018
Watershed Length = 350 ft 0.30 127.8 33.7 4,307 0.099 1,195 0.027
Watershed Slope = 0.015 ft/ft Zone 1 (WQCV) 0.33 128.1 34.0 4,359 0.100 1,369 0.031
Watershed Imperviousness = 59.0% percent 0.40 128.6 34.5 4,437 0.102 1,633 0.037
Percentage Hydrologic Soil Group A = 0% percent 0.50 129.4 35.3 4,568 0.105 2,083 0.048
Percentage Hydrologic Soil Group B = 100% percent 0.60 130.2 36.1 4,701 0.108 2,546 0.058
Percentage Hydrologic Soil Groups C/D = 0% percent 0.70 131.0 36.9 4,834 0.111 3,023 0.069
Desired WQCV Drain Time = 12 hours 0.80 131.8 37.7 4,969 0.114 3,513 0.081
Location for 1-hr Rainfall Depths = User Input 0.90 132.6 38.5 5,106 0.117 4,017 0.092
Water Quality Capture Volume (WQCV) = 0.031 acre-feet 1.00 133.4 39.3 5,243 0.120 4,534 0.104
Excess Urban Runoff Volume (EURV) = 0.127 acre-feet 1.10 134.2 40.1 5,382 0.124 5,066 0.116
2-yr Runoff Volume (P1 = 0.88 in.) = 0.077 acre-feet 0.88 inches Zone 2 (EURV) 1.18 134.9 40.8 5,508 0.126 5,556 0.128
5-yr Runoff Volume (P1 = 1.16 in.) = 0.108 acre-feet 1.16 inches 1.20 135.0 40.9 5,522 0.127 5,611 0.129
10-yr Runoff Volume (P1 = 1.47 in.) = 0.154 acre-feet 1.47 inches 1.30 135.8 41.7 5,664 0.130 6,170 0.142
25-yr Runoff Volume (P1 = 1.99 in.) = 0.241 acre-feet 1.99 inches 1.40 136.6 42.5 5,806 0.133 6,744 0.155
50-yr Runoff Volume (P1 = 2.49 in.) = 0.315 acre-feet 2.49 inches 1.50 137.4 43.3 5,950 0.137 7,331 0.168
100-yr Runoff Volume (P1 = 3.05 in.) = 0.411 acre-feet 3.05 inches 1.60 138.2 44.1 6,095 0.140 7,934 0.182
500-yr Runoff Volume (P1 = 4.68 in.) = 0.679 acre-feet 4.68 inches 1.70 139.0 44.9 6,242 0.143 8,550 0.196
Approximate 2-yr Detention Volume = 0.072 acre-feet 1.80 139.8 45.7 6,390 0.147 9,182 0.211
Approximate 5-yr Detention Volume = 0.102 acre-feet 1.90 140.6 46.5 6,539 0.150 9,828 0.226
Approximate 10-yr Detention Volume = 0.143 acre-feet 2.00 141.4 47.3 6,689 0.154 10,490 0.241
Approximate 25-yr Detention Volume = 0.183 acre-feet 2.10 142.3 48.2 6,856 0.157 11,235 0.258
Approximate 50-yr Detention Volume = 0.212 acre-feet 2.20 143.1 49.0 7,009 0.161 11,928 0.274
Approximate 100-yr Detention Volume = 0.254 acre-feet 2.30 143.9 49.8 7,163 0.164 12,637 0.290
2.40 144.7 50.6 7,319 0.168 13,361 0.307
Stage-Storage Calculation 2.50 145.5 51.4 7,476 0.172 14,100 0.324
Zone 1 Volume (WQCV) = 0.031 acre-feet 2.60 146.3 52.2 7,634 0.175 14,856 0.341
Zone 2 Volume (EURV - Zone 1) = 0.096 acre-feet 2.70 147.1 53.0 7,793 0.179 15,627 0.359
Zone 3 Volume (User Defined - Zones 1 & 2) = 0.285 acre-feet 2.80 147.9 53.8 7,954 0.183 16,415 0.377
Total Detention Basin Volume = 0.412 acre-feet 2.90 148.7 54.6 8,116 0.186 17,218 0.395
Initial Surcharge Volume (ISV) = N/A ft^3 Zone 3 (User) 2.99 149.4 55.3 8,263 0.190 17,955 0.412
Initial Surcharge Depth (ISD) = N/A ft 3.00 149.5 55.4 8,279 0.190 18,038 0.414
Total Available Detention Depth (Htotal
) = 3.00 ft
3.10 150.3 56.2 8,444 0.194 18,874 0.433
Depth of Trickle Channel (HTC
) = N/A ft
3.20 151.1 57.0 8,610 0.198 19,727 0.453
Slope of Trickle Channel (STC
) = N/A ft/ft
3.30 151.9 57.8 8,777 0.201 20,596 0.473
Slopes of Main Basin Sides (Smain
) = 4 H:V
3.40 152.7 58.6 8,945 0.205 21,482 0.493
Basin Length-to-Width Ratio (RL/W
) = 4 3.50 153.5 59.4 9,115 0.209 22,385 0.514
3.60 154.3 60.2 9,286 0.213 23,305 0.535
Initial Surcharge Area (AISV
) = 0 ft^2
3.70 155.1 61.0 9,458 0.217 24,242 0.557
Surcharge Volume Length (LISV
) = 0.0 ft
3.80 155.9 61.8 9,631 0.221 25,197 0.578
Surcharge Volume Width (WISV
) = 0.0 ft
0 User Defined Stage-Area Boolean for Message
0 Equal Stage-Area Inputs Watershed L:W
1 CountA
0 Calc_S_TC
H_FLOOR
125.5069 L_FLOOR_OTHER
0.00 ISV 0.00 ISV
0.00 Floor 0.00 Floor
0.33 Zone 1 (WQCV) 0.33 Zone 1 (WQCV)
1.18 Zone 2 (EURV) 1.18 Zone 2 (EURV)
2.99 Zone 3 (User) 2.99 Zone 3 (User)
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
UD-Detention, Version 3.07 (February 2017)
0.000
0.660
1.320
1.980
2.640
0.000
0.130
0.260
0.390
0.520
0.00 2.50 5.00 7.50 10.00
Volume (ac-ft)
Area (acres)
Stage (ft.)
Area (acres) Volume (ac-ft)
0
5500
11000
16500
22000
0
55
110
165
220
0.00 2.50 5.00 7.50 10.00
Area (sq.ft.)
Length, Width (ft.)
Stage (ft)
Length (ft) Width (ft) Area (sq.ft.)
LNJ810 Detention and SF-UD-Detention_v3.07-TEST.xlsm, Basin 3/13/2018, 1:58 PM
Project:
Basin ID:
Stage (ft) Zone Volume (ac-ft) Outlet Type
Zone 1 (WQCV) 0.33 0.031 Filtration Media
Zone 2 (EURV) 1.18 0.096 Orifice Plate
Zone 3 (User) 2.99 0.285 Weir&Pipe (Circular)
0.412 Total
User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP) Calculated Parameters for Underdrain
Underdrain Orifice Invert Depth = 2.50 ft (distance below the filtration media surface) Underdrain Orifice Area = 0.0 ft
2
Underdrain Orifice Diameter = 0.80 inches Underdrain Orifice Centroid = 0.03 feet
User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate
Invert of Lowest Orifice = 0.33 ft (relative to basin bottom at Stage = 0 ft) WQ Orifice Area per Row = N/A ft
2
Depth at top of Zone using Orifice Plate = 1.18 ft (relative to basin bottom at Stage = 0 ft) Elliptical Half-Width = N/A feet
Orifice Plate: Orifice Vertical Spacing = 3.40 inches Elliptical Slot Centroid = N/A feet
Orifice Plate: Orifice Area per Row = sq. inches Elliptical Slot Area = N/A ft
2
User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest)
Row 1 (required) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional)
Stage of Orifice Centroid (ft) 0.33 0.61 0.90
Orifice Area (sq. inches) 0.00 0.00 0.00
Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional)
Stage of Orifice Centroid (ft)
Orifice Area (sq. inches)
User Input: Vertical Orifice (Circular or Rectangular) Calculated Parameters for Vertical Orifice
Not Selected Not Selected Not Selected Not Selected
Invert of Vertical Orifice = N/A N/A ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Area = N/A N/A ft
2
Depth at top of Zone using Vertical Orifice = N/A N/A ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Centroid = N/A N/A feet
Vertical Orifice Diameter = N/A N/A inches
User Input: Overflow Weir (Dropbox) and Grate (Flat or Sloped) Calculated Parameters for Overflow Weir
Zone 3 Weir Not Selected Zone 3 Weir Not Selected
Overflow Weir Front Edge Height, Ho = 0.53 N/A ft (relative to basin bottom at Stage = 0 ft) Height of Grate Upper Edge, Ht
= 0.53 N/A feet
Overflow Weir Front Edge Length = 2.50 N/A feet Over Flow Weir Slope Length = 2.50 N/A feet
Overflow Weir Slope = 0.00 N/A H:V (enter zero for flat grate) Grate Open Area / 100-yr Orifice Area = 102.31 N/A should be > 4
Horiz. Length of Weir Sides = 2.50 N/A feet Overflow Grate Open Area w/o Debris = 4.38 N/A ft
2
Overflow Grate Open Area % = 70% N/A %, grate open area/total area Overflow Grate Open Area w/ Debris = 2.19 N/A ft
2
Debris Clogging % = 50% N/A %
.
User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice) Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate
Zone 3 Circular Not Selected Zone 3 Circular Not Selected
Depth to Invert of Outlet Pipe = 2.50 N/A ft (distance below basin bottom at Stage = 0 ft) Outlet Orifice Area = 0.04 N/A ft
2
Circular Orifice Diameter = 2.80 N/A inches Outlet Orifice Centroid = 0.12 N/A feet
Half-Central Angle of Restrictor Plate on Pipe = N/A N/A radians
User Input: Emergency Spillway (Rectangular or Trapezoidal) Calculated Parameters for Spillway
Spillway Invert Stage= 3.00 ft (relative to basin bottom at Stage = 0 ft) Spillway Design Flow Depth= 0.51 feet
Spillway Crest Length = 5.00 feet Stage at Top of Freeboard = 4.51 feet
Spillway End Slopes = 4.00 H:V Basin Area at Top of Freeboard = 0.25 acres
Freeboard above Max Water Surface = 1.00 feet
Routed Hydrograph Results
Design Storm Return Period = WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year
One-Hour Rainfall Depth (in) = 0.53 1.07 0.88 1.16 1.47 1.99 2.49 3.05 4.68
Calculated Runoff Volume (acre-ft) = 0.031 0.127 0.077 0.108 0.154 0.241 0.315 0.411 0.679
OPTIONAL Override Runoff Volume (acre-ft) =
Inflow Hydrograph Volume (acre-ft) = 0.031 0.126 0.076 0.108 0.153 0.241 0.315 0.411 0.678
COUNTA for Basin Tab = 1 Ao Dia WQ Plate Type Vert Orifice 1 Vert Orifice 2
Count_Underdrain = 1 0.11(diameter = 3/8 inch) 2 1 1
Count_WQPlate = 0 0.14(diameter = 7/16 inch)
Count_VertOrifice1 = 0 0.18(diameter = 1/2 inch) Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean
Count_VertOrifice2 = 0 0.24(diameter = 9/16 inch) 2 1 5yr, <72hr 0
Count_Weir1 = 1 0.29(diameter = 5/8 inch) >5yr, <120hr 0
Count_Weir2 = 0 0.36 (diameter = 11/16 inch) Max Depth Row
Count_OutletPipe1 = 1 0.42(diameter = 3/4 inch) WQCV 28 Watershed Constraint Check
Count_OutletPipe2 = 0 0.50 (diameter = 13/16 inch) 2 Year 60 Slope 0.015
COUNTA_2 (Standard FSD Setup)= 1 0.58(diameter = 7/8 inch) EURV 91 Shape 1.42
MaxPondDepth_Error? FALSE 0.(67 diameter = 15/16 inch) 5 Year 79
Hidden Parameters & Calculations 0.76 (diameter = 1 inch) 10 Year 110 Spillway Depth
(diameter 0.86 = 1-1/16 inches) 25 Year 168 0.51
WQ Plate Flow at 100yr depth = 0.00 0.(diameter 97 = 1-1/8 inches) 50 Year 213
CLOG #1= 35% (diameter 1.08 = 1-3/16 inches) 100 Year 267 1 Z1_Boolean
Cdw #1
= 1.15 1.(diameter 20 = 1-1/4 inches) 500 Year 336 0 Z2_Boolean
Cdo #1
= 1.07 (diameter 1.32 = 1-5/16 inches) Zone3_Pulldown Message 1 Z3_Boolean
Overflow Weir #1 Angle = 0.000 1.(diameter 45 = 1-3/8 inches) 1 Opening Message
CLOG #2= #VALUE! (diameter 1.59 = 1-7/16 inches) Draintime Running
Cdw #2
= #VALUE! 1.(diameter 73 = 1-1/2 inches) Outlet Boolean Outlet Rank Total (1 to 4)
Cdo #2
= #VALUE! (diameter 1.88 = 1-9/16 inches) Vertical Orifice 1 0 0 1
Overflow Weir #2 Angle = #VALUE! 2.(diameter 03 = 1-5/8 inches) Vertical Orifice 2 0 0 Boolean
Underdrain Q at 100yr depth = 0.04 (diameter 2.20 = 1-11/16 inches) Overflow Weir 1 1 1 0 Max Depth
VertOrifice1 Q at 100yr depth = 0.00 2.(diameter 36 = 1-3/4 inches) Overflow Weir 2 0 0 0 500yr Depth
VertOrifice2 Q at 100yr depth = 0.00 (diameter 2.54 = 1-13/16 inches) Outlet Pipe 1 1 1 0 Freeboard
EURV_draintime_user = 32 2.(diameter 72 = 1-7/8 inches) Outlet Pipe 2 0 0 1 Spillway
Count_User_Hydrographs 0 (diameter 2.90 = 1-15/16 inches) 0 Spillway Length
CountA_3 (EURV & 100yr) = 0 3.09(diameter = 2 inches) Button Visibility Boolean FALSE Time Interval
CountA_4 (100yr Only) = 1 (use 3.29 rectangular openings) 1 Button_Trigger
1 Underdrain
0 WQCV Plate
1 EURV-WQCV Plate
0 EURV-WQCV VertOrifice
0 Outlet 90% Qpeak
1 Outlet Undetained
S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis
minimum bound
maximum bound
UD-Detention, Version 3.07 (February 2017)
Detention Basin Outlet Structure Design
0
2
4
6
8
10
12
14
0.1 1 10
FLOW [cfs]
TIME [hr]
500YR IN
500YR OUT
100YR IN
100YR OUT
50YR IN
Outflow Hydrograph Workbook Filename:
Storm Inflow Hydrographs
The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program.
SOURCE WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK
Time Interval TIME WQCV [cfs] EURV [cfs] 2 Year [cfs] 5 Year [cfs] 10 Year [cfs] 25 Year [cfs] 50 Year [cfs] 100 Year [cfs] 500 Year [cfs]
4.70 min 0:00:00
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0:04:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Hydrograph 0:09:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Constant 0:14:06 0.03 0.10 0.06 0.09 0.13 0.19 0.25 0.33 0.53
1.064 0:18:48 0.07 0.28 0.17 0.24 0.33 0.52 0.67 0.88 1.43
0:23:30 0.18 0.71 0.43 0.61 0.86 1.34 1.73 2.25 3.67
0:28:12 0.49 1.96 1.19 1.68 2.36 3.67 4.77 6.19 10.08
0:32:54 0.57 2.28 1.38 1.96 2.75 4.31 5.61 7.30 11.98
0:37:36 0.54 2.16 1.31 1.86 2.61 4.10 5.34 6.96 11.43
0:42:18 0.48 1.96 1.19 1.69 2.38 3.73 4.86 6.33 10.41
0:47:00 0.42 1.74 1.05 1.49 2.10 3.31 4.32 5.64 9.30
0:51:42 0.36 1.48 0.89 1.27 1.80 2.84 3.71 4.86 8.03
0:56:24 0.31 1.30 0.78 1.11 1.57 2.48 3.24 4.24 6.99
1:01:06 0.28 1.17 0.70 1.00 1.42 2.24 2.94 3.84 6.34
1:05:48 0.23 0.95 0.57 0.81 1.16 1.83 2.40 3.15 5.23
1:10:30 0.18 0.76 0.45 0.65 0.93 1.48 1.95 2.56 4.28
1:15:12 0.13 0.57 0.33 0.49 0.70 1.12 1.48 1.96 3.30
1:19:54 0.09 0.41 0.24 0.35 0.51 0.82 1.09 1.45 2.46
1:24:36 0.07 0.30 0.18 0.26 0.37 0.60 0.80 1.05 1.78
1:29:18 0.06 0.24 0.14 0.20 0.29 0.47 0.62 0.82 1.38
1:34:00 0.05 0.20 0.12 0.17 0.24 0.39 0.51 0.68 1.13
1:38:42 0.04 0.17 0.10 0.14 0.21 0.33 0.44 0.57 0.96
1:43:24 0.04 0.15 0.09 0.13 0.18 0.29 0.38 0.50 0.84
1:48:06 0.03 0.14 0.08 0.12 0.17 0.26 0.35 0.46 0.76
1:52:48 0.03 0.13 0.08 0.11 0.15 0.24 0.32 0.42 0.70
1:57:30 0.02 0.09 0.06 0.08 0.11 0.18 0.24 0.31 0.51
2:02:12 0.02 0.07 0.04 0.06 0.08 0.13 0.17 0.23 0.38
2:06:54 0.01 0.05 0.03 0.04 0.06 0.10 0.13 0.17 0.28
2:11:36 0.01 0.04 0.02 0.03 0.04 0.07 0.09 0.12 0.20
2:16:18 0.01 0.02 0.01 0.02 0.03 0.05 0.07 0.09 0.15
2:21:00 0.00 0.02 0.01 0.01 0.02 0.03 0.05 0.06 0.10
2:25:42 0.00 0.01 0.01 0.01 0.01 0.02 0.03 0.04 0.07
2:30:24 0.00 0.01 0.00 0.01 0.01 0.02 0.02 0.03 0.05
2:35:06 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.03
2:39:48 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01
2:44:30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2:49:12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2:53:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2:58:36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:03:18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:08:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:12:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:17:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:22:06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:26:48 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:31:30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:36:12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:40:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:45:36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:50:18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:59:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:04:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:09:06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Summary Stage-Area-Volume-Discharge Relationships
The user can create a summary S-A-V-D by entering the desired stage increments and the remainder of the table will populate automatically.
The user should graphically compare the summary S-A-V-D table to the full S-A-V-D table in the chart to confirm it captures all key transition points.
Stage Area Area Volume Volume
Total
Outflow
[ft] [ft^2] [acres] [ft^3] [ac-ft] [cfs]
UD-Detention, Version 3.07 (February 2017)
Detention Basin Outlet Structure Design
Stage - Storage
Description
For best results, include the
stages of all grade slope
changes (e.g. ISV and Floor)
from the S-A-V table on
Sheet 'Basin'.
Also include the inverts of all
outlets (e.g. vertical orifice,
overflow grate, and spillway,
where applicable).
APPENDIX D – DRAINAGE MAPS
DEVELOPED CONDITION DRAINAGE MAP
LOT 1
INTERSTATE LAND HOLDINGS MINOR LAND
DIVISION
FILE NO. 12-S3124
OWNER: INTERSTATE LAND HOLDINGS LLC
SW FRONTAGE ROAD
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
CARPENTER ROAD
(CO-HWY 392)
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
EXIT 262 NW
NW I-25 OFF RAMP
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
UE
UE
STM
STM STM STM STM
STM STM STM
STM
STM
4875
4875
4880
4885
4890
4895
4890
4895
4900
4905
4910
4915
4920
4885
4890
4895
4900
4905
4880
4885
4879
4881
4882
4883
4884
4886
4887
4888
4880
4880
4885
2.49%
A4
0.34
0.86
0.89
A2
0.69
0.01
0.44
APPENDIX E – EROSION CONTROL MAP
EROSION CONTROL PLAN
SW FRONTAGE ROAD
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
CARPENTER ROAD
(CO-HWY 392)
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
EXIT 262 NW
NW I-25 OFF RAMP
(PUBLIC RIGHT OF WAY - WIDTH VARIES)
4875
4875
4880
4885
4890
4895
4890
4895
4900
4905
4910
4915
4920
4885
4890
4895
4900
4905
4880
4885
4879
4881
4882
4883
4884
4886
4887
4888
4880
4880
4885
4885
4885
4885
83
84
84 84
86
87
88
X
X X X
X
X
X
X
X
X
X
X
X
X
X X
X X
X
X
X
X X
X
X
X
X
X X X X
X
X X
X
X X
X
X X
X
X X X
X
X
X
X
X
X X X X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X X
X
X
X
X X X X
X
X
X X X
X
X
X
X
X
X
X X X
X
X
X
X
X
LOD
LOD
LOD
LOD
LOD
SF
SF
VTC
CWA
SSA
SP
PT
IP
IP
SF
SF
IP
IP
IP
SF
SF
SF
LS
LS
LS
# Date Issue / Description
STAMP
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884
Planning. Architecture. Engineering.
O
www.gallowayUS.com
C 2016. Galloway & Company, Inc. All Rights Reserved
Init.
Date:
Drawn By:
Project No:
Checked By:
H:\Loaf N Jug\CO, Fort Collins - LNJ000810 - I-25 & Hwy 392\CADD\2 Plan\LNJ810_P_11-EROS.dwg - Cayla Cappello - 2015-04-16
LOAF N JUG #810
UTILITY PLANS
NWC OF I-25 AND HIGHWAY 392
FORT COLLINS, COLORADO
THESE PLANS ARE AN INSTRUMENT OF
SERVICE AND ARE THE PROPERTY OF
GALLOWAY, AND MAY NOT BE DUPLICATED,
DISCLOSED, OR REPRODUCED WITHOUT
THE WRITTEN CONSENT OF GALLOWAY.
COPYRIGHTS AND INFRINGEMENTS WILL
BE ENFORCED AND PROSECUTED.
COPYRIGHT
LNJ000810
442 Keeler Parkway
Pueblo, Colorado 81001
719-948-3071
1 03/28/18 1ST PLANNING SUBMITTAL
CAC
PJD
03/14/18
OF 10
8
EROSION CONTROL PLAN
SCALE: 1"=40'
0 20 40
BASIS OF BEARING
BEARINGS ARE BASED ON EAST LINE OF LOT 2, INTERSTATE LAND HOLDINGS MINOR LAND
DIVISION FILE NO. 12-S3124, MONUMENTED ON THE NORTH END BY A BLUE PLASTIC CAP
(ILLEGIBLE) AND SOUTH END BY A REBAR WITH A BLUE PLASTIC CAP STAMPED "PLS 34174", AND IS
CONSIDERED TO BEAR, S08°15'04"W.
BENCHMARK
ELEVATIONS FOR THE SITE WERE BASED ON THE NATIONAL GEODETIC SURVEY (NGS) MONUMENT
'PEPEK', PID "AE3938", WHICH HAS AN ELEVATION OF 4927 FEET (NAVD 88) .
THE STATION IS LOCATED ABOUT 3.5 MI (5.6 KM) SOUTH-SOUTHEAST OF TIMNATH, 3.2 MI (5.1 KM)
WEST OF WINDSOR AND 1 MI (1.6 KM) WEST OF THE LARIMER-WELD COUNTY LINE, IN THE
SOUTHEAST 1/4 OF SECTION 14, T 6 N, R 68 W, AT STATE HIGHWAY 392 MILEPOST 1.4.
OWNERSHIP--COLORADO DEPT. OF TRANSPORTATION RIGHT-OF-WAY TO REACH THE STATION
FROM THE INTERSECTION OF STATE HIGHWAY 392 AND STATE HIGHWAY 257 IN WINDSOR, GO
WEST ON STATE HIGHWAY 392 FOR 3.0 MI (4.8 KM) TO THE INTERSECTION OF LARIMER COUNTY
ROAD 3 AND THE STATION IN THE NORTHWEST CORNER OF THE INTERSECTION ON TOP OF A
SMALL HILL. TO DRIVE TO THE STATION FROM THE INTERSECTION, GO NORTH ON COUNTY ROAD
3 FOR 0.1 MI (0.2 KM) TO THE ENTRANCE TO A SUBDIVISION. TURN LEFT, WEST, FOR ABOUT 30 M
(98.4 FT) TO AN INTERSECTION. TURN LEFT, SOUTH, FOR ABOUT 30 M (98.4 FT) TO THE FIRST
PLACE ON THE LEFT TO DRIVE UP TO THE TOP OF A SMALL HILL AND THE STATION THE MARK IS A
STANDARD DISK SET IN THE TOP OF A 0.5 M (1.6 FT) ROUND BY 1.7 M (5.6 FT) DEEP CONCRETE
POST PROJECTING 5 CM ABOVE THE GROUND. IT IS 67.5 M (221.5 FT) WEST FROM THE CENTER
LINE OF LARIMER COUNTY ROAD 3, 46.7 M (153.2 FT) NORTHWEST FROM THE CENTER LINE OF
STATE HIGHWAY 392, 3.4 M (11.2 FT) SOUTHEAST FROM THE TOP CENTER OF A TELEPHONE
PEDISTAL, 2.55 M (8.37 FT) SOUTHEAST FROM A PROPERTY CORNER LS NUMBER 22564, 0.7 M (2.3
FT) NORTHEAST FROM A WITNESS POST AND 0.7 M (2.3 FT) SOUTHWEST FROM A WITNESS POST.
CAUTION - NOTICE TO CONTRACTOR
1. ALL UTILITY LOCATIONS SHOWN ARE BASED ON MAPS PROVIDED
BY THE APPROPRIATE UTILITY COMPANY AND FIELD SURFACE
EVIDENCE AT THE TIME OF SURVEY AND IS TO BE CONSIDERED
AN APPROXIMATE LOCATION ONLY. IT IS THE CONTRACTOR'S
RESPONSIBILITY TO FIELD VERIFY THE FIELD LOCATION OF ALL
UTILITIES, PUBLIC OR PRIVATE, WHETHER SHOWN ON THE PLANS
OR NOT, PRIOR TO CONSTRUCTION. REPORT ANY
DISCREPANCIES TO THE ENGINEER PRIOR TO CONSTRUCTION.
2. WHERE A PROPOSED UTILITY CROSSES AN EXISTING UTILITY, IT
IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE
HORIZONTAL AND VERTICAL LOCATION OF SUCH EXISTING
UTILITY, EITHER THROUGH POTHOLING OR ALTERNATIVE
METHOD. REPORT INFORMATION TO THE ENGINEER PRIOR TO
CONSTRUCTION.
CITY ENGINEER DATE
DATE
DATE
DATE
DATE
STORMWATER UTILITY
PARKS & RECREATION
TRAFFIC ENGINEER
DATE
APPROVED:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
WATER & WASTEWATER UTILITY
CITY OF FORT COLLINS, COLORADO
UTILITY PLAN APPROVAL
ENVIRONMENTAL PLANNER
EROSION CONTROL LEGEND
X X X SILT FENCE
EXISTING STORM SEWER
EXISTING CONTOUR
PROPOSED CONTOUR
PROPOSED STORM SEWER (12" AND LARGER)
INLET GRAVEL FILTER
VEHICLE TRACKING CONTROL
CONSTRUCTION ENTRANCE
GRAVEL SOCK INLET PROTECTION
CONCRETE WASHOUT AREA
GRAVEL SOCK IN GUTTER
LIMITS OF DISTURBANCE (~3.6 ACRES)
FLOW ARROW
VTC
SF
IP
GS
SB
CWA
CONTRACTOR STAGING AREA
(APPROXIMATE)
SCL SEDIMENT CONTROL LOG
SSA
PROPOSED LANDSCAPE (SEE LANDSCAPING PLANS)
PT PORTABLE TOILET
SP SITE POSTING (CONTACTS AND PERMITS)
PROPOSED STORM SEWER (LESS THAN 12")
EXISTING CONTOUR
PROPOSED CONTOUR
LS
All changes, addendums, additions, deletions and
modifications to these drawings must be approved,
in writing, by the Fort Collins-Loveland
Water District and the South Fort Collins Sanitation District.
Mr. Terry Farrill, P.E., District Engineer Date
FORT COLLINS - LOVELAND
WATER DISTRICT
SOUTH FORT COLLINS
SANITATION DISTRICT
LOD
R1
0.12
0.76
0.84
R2
0.16
0.76
0.84
A1
0.79
0.73
0.83
A3
0.22
0.86
0.89
A5
0.33
0.01
0.44
A6
0.21
0.01
0.44
# Date Issue / Description
STAMP
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884
Planning. Architecture. Engineering.
O
www.gallowayUS.com
C 2016. Galloway & Company, Inc. All Rights Reserved
Init.
Date:
Drawn By:
Project No:
Checked By:
H:\Loaf N Jug\CO, Fort Collins - LNJ000810 - I-25 & Hwy 392\CADD\2 Plan\LNJ810_P_10-DRAN.dwg - Cayla Cappello - 2015-04-16
LOAF N JUG #810
UTILITY PLANS
NWC OF I-25 AND HIGHWAY 392
FORT COLLINS, COLORADO
THESE PLANS ARE AN INSTRUMENT OF
SERVICE AND ARE THE PROPERTY OF
GALLOWAY, AND MAY NOT BE DUPLICATED,
DISCLOSED, OR REPRODUCED WITHOUT
THE WRITTEN CONSENT OF GALLOWAY.
COPYRIGHTS AND INFRINGEMENTS WILL
BE ENFORCED AND PROSECUTED.
COPYRIGHT
LNJ000810
442 Keeler Parkway
Pueblo, Colorado 81001
719-948-3071
1 03/28/18 1ST PLANNING SUBMITTAL
BASIS OF BEARING
BEARINGS ARE BASED ON EAST LINE OF LOT 2, INTERSTATE LAND HOLDINGS MINOR LAND
DIVISION FILE NO. 12-S3124, MONUMENTED ON THE NORTH END BY A BLUE PLASTIC CAP
(ILLEGIBLE) AND SOUTH END BY A REBAR WITH A BLUE PLASTIC CAP STAMPED "PLS 34174", AND IS
CONSIDERED TO BEAR, S08°15'04"W.
CAC
PJD
03/14/18
OF 12
7
DRAINAGE PLAN
CAUTION - NOTICE TO CONTRACTOR
1. ALL UTILITY LOCATIONS SHOWN ARE BASED ON MAPS PROVIDED
BY THE APPROPRIATE UTILITY COMPANY AND FIELD SURFACE
EVIDENCE AT THE TIME OF SURVEY AND IS TO BE CONSIDERED
AN APPROXIMATE LOCATION ONLY. IT IS THE CONTRACTOR'S
RESPONSIBILITY TO FIELD VERIFY THE FIELD LOCATION OF ALL
UTILITIES, PUBLIC OR PRIVATE, WHETHER SHOWN ON THE PLANS
OR NOT, PRIOR TO CONSTRUCTION. REPORT ANY
DISCREPANCIES TO THE ENGINEER PRIOR TO CONSTRUCTION.
2. WHERE A PROPOSED UTILITY CROSSES AN EXISTING UTILITY, IT
IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE
HORIZONTAL AND VERTICAL LOCATION OF SUCH EXISTING
UTILITY, EITHER THROUGH POTHOLING OR ALTERNATIVE
METHOD. REPORT INFORMATION TO THE ENGINEER PRIOR TO
CONSTRUCTION.
CITY ENGINEER DATE
DATE
DATE
DATE
DATE
STORMWATER UTILITY
PARKS & RECREATION
TRAFFIC ENGINEER
DATE
APPROVED:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
WATER & WASTEWATER UTILITY
CITY OF FORT COLLINS, COLORADO
UTILITY PLAN APPROVAL
ENVIRONMENTAL PLANNER
SCALE: 1"=40'
0 20 40
SITE LEGEND
ADJACENT PROPERTY BOUNDARY LINE
PROPERTY BOUNDARY LINE
PROPOSED CURB & GUTTER
EXISTING CURB & GUTTER TO REMAIN
PROPOSED INLET
EASEMENT BOUNDARY LINE
STREET LIGHT
EXISTING TO BE REMOVED
GRADING LEGEND
EXISTING STORM SEWER
PROPOSED STORM SEWER
STS
45 PROPOSED CONTOUR
5245 EXISTING CONTOUR
STS
STS PROPOSED STORM SEWER (LESS THAN 12")
DRAINAGE LEGEND
PROPOSED BASIN BOUNDARY LINE
DESIGN POINT
BASIN AREA IN ACRES
100-YEAR RUNOFF COEFFICIENT
BASIN DESIGNATION
A 5-YEAR RUNOFF COEFFICIENT
0.00
0.00
0.00
FLOW ARROW
CITY OF FORT COLLINS DRAINAGE NOTES
1. ALL STREET, SANITARY SEWER, STORM SEWER AND WATER CONSTRUCTION SHALL CONFORM TO CITY STANDARDS
AND SPECIFICATIONS CURRENT AT THE DATE OF EXECUTION OF THE DEVELOPMENT AGREEMENT PERTAINING TO
THIS DEVELOPMENT. ANY CONSTRUCTION OCCURRING THREE YEARS AFTER THE EXECUTION OF THE
DEVELOPMENT AGREEMENT SHALL REQUIRE RE-EXAMINATION OF THE PLANS BY THE DIRECTOR WHO MAY
REQUIRE THAT THEY BE MADE TO CONFORM TO STANDARDS AND SPECIFICATIONS CURRENT AT THAT TIME.
2. THE TYPE, SIZE, LOCATION, AND NUMBER OF ALL KNOWN UNDERGROUND UTILITIES ARE APPROXIMATE AS SHOWN ON THE
DRAWINGS. IT SHALL BE THE RESPONSIBILITY OF THE CONTRACTOR TO VERIFY THE EXISTENCE AND LOCATION OF ALL
UNDERGROUND UTILITIES ALONG THE ROUTE OF THE WORK. BEFORE COMMENCING NEW CONSTRUCTION, THE CONTRACTOR
SHALL BE RESPONSIBLE FOR LOCATING UNKNOWN UNDERGROUND UTILITIES.
3. THESE PLANS HAVE BEEN REVIEWED BY THE CITY FOR CONCEPT ONLY. THE REVIEW DOES NOT IMPLY RESPONSIBILITY BY
THE REVIEWING DEPARTMENT, THE CITY ENGINEER, OR THE CITY FOR ACCURACY OR CORRECTNESS OF THE CALCULATIONS.
FURTHERMORE, THE REVIEW DOES NOT IMPLY THAT THE QUANTITIES OF THE ITEMS ON THE PLANS ARE THE FINAL
QUANTITIES REQUIRED. THE REVIEW SHALL NOT BE CONSTRUED IN ANY REASON AS ACCEPTANCE OF FINANCIAL
RESPONSIBILITY BY THE CITY FOR ADDITIONAL QUANTITIES OF ITEMS SHOWN THAT MAY BE REQUIRED DURING THE
CONSTRUCTION PHASE.
4. PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION, THE CONTRACTOR MUST GIVE THE CITY ENGINEERING
DEPARTMENT (970-221-6605) AND THE EROSION CONTROL INSPECTOR (970-221-6700) TWENTY-FOUR (24) HOURS
ADVANCE-NOTICE. INITIAL EROSION CONTROL MEASURES MUST BE INSTALLED AND A SITE INSPECTION BY THE EROSION
CONTROL INSPECTOR IS REQUIRED BEFORE COMMENCING CONSTRUCTION ACTIVITIES.
5. MAINTENANCE OF ONSITE DRAINAGE FACILITIES SHALL BE THE RESPONSIBILITY OF THE PROPERTY OWNERS.
6. ALL RECOMMENDATIONS OF THE FINAL DRAINAGE AND EROSION CONTROL STUDY FOR THIS DEVELOPMENT BY (ENGINEERING
FIRM) MUST BE MET.
7. PRIOR TO FINAL INSPECTION AND ACCEPTANCE BY THE CITY, CERTIFICATION OF THE DRAINAGE FACILITIES BY A COLORADO
REGISTERED PROFESSIONAL ENGINEER MUST BE SUBMITTED TO AND APPROVED BY THE CITY STORMWATER DEPARTMENT.
FOR COMMERCIAL AND MULTI-FAMILY DEVELOPMENTS, CERTIFICATION OF ALL DRAINAGE FACILITIES SHALL BE SUBMITTED TO
THE CITY STORMWATER DEPARTMENT AT LEAST TWO WEEKS PRIOR TO THE RELEASE OF A CERTIFICATE OF OCCUPANCY.
INDIVIDUAL LOT CERTIFICATION, ELEVATION CERTIFICATION, OR FLOODPROOFING CERTIFICATION, AS SPECIFIED IN THE
DEVELOPMENT AGREEMENT, MUST BE SUBMITTED TO THE CITY STORMWATER DEPARTMENT AT LEAST TWO WEEKS PRIOR TO
THE RELEASE OF A CERTIFICATE OF OCCUPANCY FOR SUCH LOT.
8. IF DEWATERING IS USED TO INSTALL UTILITIES, AND DISCHARGE WILL BE INTO THE STREET, GUTTER, STORM SEWER,
CHANNEL, IRRIGATION DITCH, OR ANY WATERS OF THE STATE A STATE CONSTRUCTION DEWATERING INDUSTRIAL
WASTEWATER DISCHARGE PERMIT IS REQUIRED.
9. ALL LAND DISTURBING ACTIVITIES GREATER THAN OR EQUAL TO ONE ACRE MUST COMPLY WITH THE STATE OF COLORADO
PERMITTING PROCESS FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY. FOR MORE
INFORMATION CONTACT THE COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, WATER QUALITY CONTROL
DIVISION, AT 303-692-3500 OR REFER TO THE WEB SITE AT HTTP://WWW.CDPHE.STATE.CO.US/WQ/PERMITSUNIT/ .
10. BENCHMARK: NATIONAL GEODETIC SURVEY BENCHMARK "C322 RESET 1959"
NAVD 88 ELEVATION: 4989.40
A STANDARD 3 1/2 INCH U.S. CONSTRUCTION AND GEODETIC SURVEY BRASS BENCHMARK DISK SET IN THE TOP OF
A CONCRETE WALL ON THE NORTH SIDE OF SPRING CREEK. LOCATED 47 FEET WEST OF THE CENTERLINE OF
COLLEGE AVENUE (AKA U.S. HIGHWAY 287) AND 3,566 FEET NORTH OF THE CENTERLINE OF DRAKE STREET.
11. IF FILL OR DREDGED MATERIAL IS DISCHARGED INTO WATERS OF THE UNITED STATES, A USACE 404 PERMIT IS REQUIRED.
12. IF CONSTRUCTION AFFECTS ANY COLORADO HIGHWAY, A COLORADO DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY
PERMIT IS REQUIRED.
GENERAL DRAINAGE NOTES
1. NO BUILDING, STRUCTURE, OR FILL WILL BE PLACED IN THE DETENTION AREAS AND
CHANGES OR ALTERATIONS AFFECTING THE HYDRAULIC CHARACTERISTICS OF THE
DETENTION AREAS WILL BE MADE WITHOUT THE APPROVAL OF THE CITY ENGINEER.
2. MAINTENANCE AND OPERATION OF THE DETENTION AND WATER QUALITY AREAS IS THE
RESPONSIBILITY OF PROPERTY OWNER. IF OWNER FAILS IN THIS RESPONSIBILITY, THE
CITY HAS THE RIGHT TO ENTER THE PROPERTY, MAINTAIN THE DETENTION AREAS, AND BE
REIMBURSED FOR COSTS INCURRED.
3. DETENTION POND VOLUMES, ALL DRAINAGE APPURTENANCES, AND BASIN BOUNDARIES
SHALL BE VERIFIED. AS-BUILT DRAWINGS SHALL BE PREPARED BY A REGISTERED
PROFESSIONAL ENGINEER PRIOR TO ISSUANCE OF CERTIFICATE OF OCCUPANCY.
4. PERMISSION TO REPRODUCE THESE PLANS IS HEREBY GIVEN TO THE CITY OF LITTLETON
FOR CITY PURPOSES ASSOCIATED WITH PLAN REVIEW, APPROVAL, PERMITTING,
INSPECTION AND CONSTRUCTION OF THE WORK.
5. ALL PROPOSED CURB AND GUTTER FOR THE SITE SHALL BE 6" VERTICAL CURB AND
GUTTER W/ A 1' PAN.
VICINITY MAP
NOT TO SCALE
SITE
RUNOFF SUMMARY TABLE
DESIGN
POINT BASIN
AREA
(AC)
PERCENT
IMPERVIOUS
Q5
(CFS)
Q100
(CFS)
1 A1 0.79 86.7 2.27 6.75
2 A2 0.69 2 0.03 3.12
3 A3 0.22 100 0.73 1.99
4 A4 0.34 100 1.16 3.17
5 A5 0.33 2 0.02 1.48
6 A6 0.21 2 0.01 0.93
1 R1 0.12 90 0.37 1.09
1 R2 0.16 90 0.47 1.38
All changes, addendums, additions, deletions and
modifications to these drawings must be approved,
in writing, by the Fort Collins-Loveland
Water District and the South Fort Collins Sanitation District.
Mr. Terry Farrill, P.E., District Engineer Date
FORT COLLINS - LOVELAND
WATER DISTRICT
SOUTH FORT COLLINS
SANITATION DISTRICT
OF 10
4:13:48 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:18:30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:23:12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:27:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:32:36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:37:18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:42:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:46:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:51:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:56:06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:00:48 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:05:30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:10:12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:14:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:19:36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:24:18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:29:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:33:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:38:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
UD-Detention, Version 3.07 (February 2017)
Detention Basin Outlet Structure Design
50YR OUT
25YR IN
25YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
EURV IN
EURV OUT
WQCV IN
WQCV OUT
0
0.5
1
1.5
2
2.5
3
3.5
4
0.1 1 10 100
PONDING DEPTH [ft]
DRAIN TIME [hr]
500YR
100YR
50YR
25YR
10YR
5YR
2YR
EURV
WQCV
0.00
1,000.00
2,000.00
3,000.00
4,000.00
5,000.00
6,000.00
0
50,000
100,000
150,000
200,000
250,000
300,000
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00
OUTFLOW [cfs]
AREA [ft^2], VOLUME [ft^3]
PONDING DEPTH [ft]
User Area [ft^2]
Interpolated Area [ft^2]
Summary Area [ft^2]
Volume [ft^3]
Summary Volume [ft^3]
Outflow [cfs]
Summary Outflow [cfs]
Predevelopment Unit Peak Flow, q (cfs/acre) = 0.00 0.00 0.01 0.02 0.19 0.71 1.10 1.61 2.93
Predevelopment Peak Q (cfs) = 0.0 0.0 0.0 0.0 0.4 1.4 2.2 3.2 5.8
Peak Inflow Q (cfs) = 0.6 2.3 1.4 2.0 2.8 4.3 5.6 7.3 12.0
Peak Outflow Q (cfs) = 0.0 0.4 0.4 0.4 0.4 0.4 0.4 0.46 4.4
Ratio Peak Outflow to Predevelopment Q = N/A N/A N/A 10.6 1.0 0.3 0.2 0.1 0.8
Structure Controlling Flow = Filtration Media Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Spillway
Max Velocity through Grate 1 (fps) = N/A 0.08 0.07 0.1 0.1 0.1 0.1 0.1 0.1
Max Velocity through Grate 2 (fps) = N/A N/A N/A N/A N/A N/A N/A N/A N/A
Time to Drain 97% of Inflow Volume (hours) = 14 25 24 24 25 26 27 29 27
Time to Drain 99% of Inflow Volume (hours) = 14 26 25 25 26 29 30 32 33
Maximum Ponding Depth (ft) = 0.28 0.91 0.60 0.79 1.10 1.68 2.12 2.66 3.35
Area at Maximum Ponding Depth (acres) = 0.10 0.12 0.11 0.11 0.12 0.14 0.16 0.18 0.20
Maximum Volume Stored (acre-ft) = 0.026 0.095 0.058 0.080 0.116 0.195 0.261 0.352 0.483
Detention Basin Outlet Structure Design
UD-Detention, Version 3.07 (February 2017)
Example Zone Configuration (Retention Pond)
3.90 156.7 62.6 9,806 0.225 26,168 0.601
Depth of Basin Floor (HFLOOR
) = 0.00 ft
4.00 157.5 63.4 9,982 0.229 27,158 0.623
Length of Basin Floor (LFLOOR
) = 125.5 ft
4.10 158.3 64.2 10,160 0.233 28,165 0.647
Width of Basin Floor (WFLOOR
) = 31.4 ft
4.20 159.1 65.0 10,338 0.237 29,190 0.670
Area of Basin Floor (AFLOOR
) = 3,938 ft^2
4.30 159.9 65.8 10,518 0.241 30,233 0.694
Volume of Basin Floor (VFLOOR
) = 0 ft^3
4.40 160.7 66.6 10,699 0.246 31,294 0.718
Depth of Main Basin (HMAIN
) = 3.00 ft
4.50 161.5 67.4 10,882 0.250 32,373 0.743
Length of Main Basin (LMAIN
) = 149.5 ft
4.60 162.3 68.2 11,066 0.254 33,470 0.768
Width of Main Basin (WMAIN
) = 55.4 ft
4.70 163.1 69.0 11,251 0.258 34,586 0.794
Area of Main Basin (AMAIN
) = 8,279 ft^2
4.80 163.9 69.8 11,437 0.263 35,720 0.820
Volume of Main Basin (VMAIN
) = 17,927 ft^3
4.90 164.7 70.6 11,624 0.267 36,873 0.846
Calculated Total Basin Volume (Vtotal
) = 0.412 acre-feet
5.00 165.5 71.4 11,813 0.271 38,045 0.873
5.10 166.3 72.2 12,003 0.276 39,236 0.901
5.20 167.1 73.0 12,195 0.280 40,446 0.929
5.30 167.9 73.8 12,388 0.284 41,675 0.957
5.40 168.7 74.6 12,582 0.289 42,923 0.985
5.50 169.5 75.4 12,777 0.293 44,191 1.014
5.60 170.3 76.2 12,973 0.298 45,479 1.044
5.70 171.1 77.0 13,171 0.302 46,786 1.074
5.80 171.9 77.8 13,370 0.307 48,113 1.105
5.90 172.7 78.6 13,571 0.312 49,460 1.135
6.00 173.5 79.4 13,772 0.316 50,827 1.167
6.10 174.3 80.2 13,975 0.321 52,215 1.199
6.20 175.1 81.0 14,180 0.326 53,622 1.231
6.30 175.9 81.8 14,385 0.330 55,051 1.264
6.40 176.7 82.6 14,592 0.335 56,499 1.297
6.50 177.5 83.4 14,800 0.340 57,969 1.331
6.60 178.3 84.2 15,009 0.345 59,459 1.365
6.70 179.1 85.0 15,220 0.349 60,971 1.400
6.80 179.9 85.8 15,432 0.354 62,503 1.435
6.90 180.7 86.6 15,645 0.359 64,057 1.471
7.00 181.5 87.4 15,859 0.364 65,632 1.507
7.10 182.3 88.2 16,075 0.369 67,229 1.543
7.20 183.1 89.0 16,292 0.374 68,848 1.581
7.30 183.9 89.8 16,511 0.379 70,488 1.618
7.40 184.7 90.6 16,730 0.384 72,150 1.656
7.50 185.5 91.4 16,951 0.389 73,834 1.695
7.60 186.3 92.2 17,173 0.394 75,540 1.734
7.70 187.1 93.0 17,397 0.399 77,268 1.774
7.80 187.9 93.8 17,621 0.405 79,019 1.814
7.90 188.7 94.6 17,847 0.410 80,793 1.855
8.00 189.5 95.4 18,075 0.415 82,589 1.896
8.10 190.3 96.2 18,303 0.420 84,408 1.938
8.20 191.1 97.0 18,533 0.425 86,249 1.980
8.30 191.9 97.8 18,764 0.431 88,114 2.023
8.40 192.7 98.6 18,996 0.436 90,002 2.066
8.50 193.5 99.4 19,230 0.441 91,914 2.110
8.60 194.3 100.2 19,465 0.447 93,848 2.154
8.70 195.1 101.0 19,701 0.452 95,807 2.199
8.80 195.9 101.8 19,939 0.458 97,789 2.245
8.90 196.7 102.6 20,178 0.463 99,795 2.291
9.00 197.5 103.4 20,418 0.469 101,824 2.338
9.10 198.3 104.2 20,659 0.474 103,878 2.385
9.20 199.1 105.0 20,902 0.480 105,956 2.432
9.30 199.9 105.8 21,145 0.485 108,058 2.481
9.40 200.7 106.6 21,391 0.491 110,185 2.530
9.50 201.5 107.4 21,637 0.497 112,337 2.579
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
Optional
Override
Area (ft^2)
Length
(ft)
Optional
Override
Stage (ft)
Stage
(ft)
Stage - Storage
Description
Area
(ft^2)
Width
(ft)
UD-Detention, Version 3.07 (February 2017)
Volume
(ft^3)
Volume
(ac-ft)
Area
(acre)
Optional User Override
1-hr Precipitation
Example Zone Configuration (Retention Pond)
LNJ810 Detention and SF-UD-Detention_v3.07-TEST.xlsm, Basin 3/13/2018, 1:58 PM
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 1.66 2.27 2.97 4.22 5.40 6.75 10.66
0.01 0.01 0.07 0.26 0.34 0.44 0.54 20.54
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.02 0.03 0.25 1.22 1.98 3.12 5.97
0.84 0.86 0.86 0.88 0.89 0.89 0.90 3.80
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.54 0.73 0.93 1.28 1.62 1.99 3.10
0.84 0.86 0.86 0.88 0.89 0.89 0.90 4.23
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.86 1.16 1.48 2.04 2.58 3.17 4.93
0.01 0.01 0.07 0.26 0.34 0.44 0.54 4.02
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.01 0.02 0.12 0.58 0.94 1.48 2.84
0.01 0.01 0.07 0.26 0.34 0.44 0.54 14.38
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.01 0.01 0.08 0.37 0.59 0.93 1.79
0.74 0.76 0.78 0.81 0.83 0.84 0.87 12.63
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.27 0.37 0.49 0.68 0.87 1.09 1.71
0.74 0.76 0.78 0.81 0.83 0.84 0.87 5.80
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 0.35 0.47 0.62 0.87 1.11 1.38 2.17
0.40 0.43 0.49 0.58 0.63 0.67 0.73
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 3.41 4.85 6.94 11.26 15.09 19.92 33.17
0.45 0.48 0.53 0.62 0.66 0.70 0.75
5.00 2.98 3.93 4.99 6.75 8.45 10.35 15.87 2.66 3.76 5.26 8.27 10.98 14.33 23.61
B 2.0
300.00 0.011
Rainfall Intensity, I (in/hr)
75.00 0.011 11.82
Peak Flow, Q (cfs)
Calculation of Peak Runoff using Rational Method
Runoff Coefficient, C Overland (Initial) Flow Time Channelized (Travel) Flow Time Time of Concentration
Subcatchment
Name
Area
(ac)
NRCS
Hydrologic
Soil Group
Percent
Imperviousness
A1 0.79 B 86.7
Select UDFCD location for NOAA Atlas 14 Rainfall Depths from the pulldown list OR enter your own depths obtained from the NOAA website (click this link)
Cells of this color are for required user-input
Cells of this color are for optional override values
Cells of this color are for calculated results based on overrides
CAC
Galloway
3/7/2018
LNJ000810.20
Fort Collins, CO
Version 2.00 released May 2017
A3 0.22 B 100.0 30.00 0.003 165.00 0.020
A2 0.69 250.00 0.035
9.21
A5 0.33 B 2.0 35.00 0.250
9.85
A4 0.34 B 100.0 170.00 0.025 45.00 0.025
R1 0.12 B 90.0 95.00 0.001
A6 0.21 B 2.0 155.00 0.050
12.34
TOTAL 2.86 B 53.2
R2 0.16 B 90.0 20.00 0.001 150.00 0.005
SF Tributary 1.98 B 59.0
I ��/�� =
a ∗ P�
b + t�
�
t�
=
0.395 1.1 − C�
L�
S�
�.��
t�
=
L�
60K S�
=
L�
60V�
Computed t�
= t�
+ t�
Regional t�
= 26 − 17i +
L�
60 14i + 9 S�
Selected t�
= max t�������
,min Computed t�
,Regional t�
t�������
= 5 (urban)
t�������
= 10 (non-urban)
Q ��� = CIA
70 0.73 1.25 2.59
75 0.70 1.19 2.48
80 0.66 1.14 2.38
85 0.64 1.09 2.29
90 0.61 1.05 2.21
95 0.58 1.01 2.13
100 0.56 0.97 2.06
105 0.54 0.94 2.00
110 0.52 0.91 1.94
115 0.51 0.88 1.88
120 0.49 0.86 1.84
Frequency and Intensity
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 12, Oct 10, 2017
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Mar 20, 2015—Oct
15, 2016
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10