HomeMy WebLinkAboutMONTAVA - PHASE E - TOWN CENTER RESIDENTIAL - BDR220003 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORT
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Preliminary Development Plan (PDP)
Final Drainage Report
For
Montava Subdivision Phase E: Town Center
November 29, 2022
submitted to:
City of Fort Collins,
Colorado
748 Whalers Way
November 29, 2021
Mr. Wes Lamarque
City of Fort Collins
Development Review Engineer
700 Wood Street
Fort Collins, CO 80521
Re: Montava Subdivision Phase E: Town Center
Final Design Drainage Report
Project No. 1230.0005.00
Dear Ms. Lamarque:
TST, Inc. Consulting Engineers (TST) is pleased to submit this Preliminary
Design Drainage Report for the Montava Subdivision Phase E: Town Center
project to the City of Fort Collins (City) for review and approval.
The purpose of this drainage report is to evaluate the drainage conditions of the
above-referenced proposed Montava Subdivision Phase E: Town Center project
site. The Fort Collins Stormwater Criteria Manual (referred to as FCSCM).
Please review the attached report and provide any questions or comments at your
earliest convenience. We appreciate the opportunity to be of continued service to
the city and look forward to receiving your comments and moving forward on this
important project.
Sincerely,
TST, INC. CONSULTING ENGINEERS
Bryston Anthony M. Gartner, E.I. Jonathan F. Sweet, P.E.
BAMG JFS
I hereby attest that this report for the preliminary drainage design for the Montava
Subdivision Phase E: Town Center was prepared by me or under my direct
supervision, in accordance with the provisions of the Fort Collins Stormwater
Criteria Manual. I understand that the City of Fort Collins does not and will not
assume liability for drainage facilities designed by others
______________________________
Jonathan F. Sweet
Registered Professional Engineer
State of Colorado No. 40341
748 Whalers Way
Suite 200
Fort Collins, CO 80525
970.226.0557 main
970.226.0204 fax
ideas@tstinc.com
www.tstinc.com
Table of Contents
Preliminary Design Drainage Report
Montava Subdivision Phase E: Town Center
Page i
1.0 - GENERAL LOCATION AND DESCRIPTION ......................................................... 1
1.1 Project Location and Description ..................................................................... 1
1.2 Description of Property ..................................................................................... 2
2.0 - DRAINAGE BASINS AND SUB-BASINS .............................................................. 4
2.1 Major Basin Description .................................................................................... 4
2.2 Existing Conditions ........................................................................................... 4
2.3 Proposed Conditions ......................................................................................... 4
3.0 - DRAINAGE DESIGN CRITERIA ............................................................................ 8
3.1 Hydrological and Hydraulic Criteria ................................................................. 8
4.0 - CONCLUSIONS .................................................................................................... 10
5.0 - REFERENCES ...................................................................................................... 12
6.0 - APPENDICES ....................................................................................................... 13
List of Figures
1.1 Vicinity Map ....................................................................................................................... 2
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 1
1.0 - General Location and Description
The purpose of this Final Drainage Report is to present the drainage design for the Montava
Subdivision Phase E: Town Center (Hereinafter referred to as the “Phase E”) project site to
the City of Fort Collins (hereinafter referred to as the “City”) for review and approval.
The design objectives for this drainage report are to present:
Hydrologic analysis of the proposed improvements and surrounding off-site areas to
determine the location and magnitude of the site’s storm runoff.
Hydrologic data used to design storm runoff collection and conveyance facilities.
Hydraulic analysis of proposed on-site and existing downstream storm infrastructure to
ensure sufficient conveyance of stormwater runoff to the existing and proposed
detention areas.
Detention analysis and design of the existing and proposed stormwater detention areas.
Best Management Practices (BMPs) used to prevent erosion and sedimentation before,
during, and after construction of the stormwater infrastructure.
Overall storm drainage plan that meets previously approved drainage plans and the
FCSCM.
The drainage system was designed using the Fort Collins Stormwater Criteria Manual
(collectively referred as FCSCM).
1.1 Project Location and Description
The Phase E project site is located in Section 32, Township 8 North, Range 68 West of the 6th
Principal Meridian, within the City of Fort Collins, Larimer County, Colorado. The proposed site
is bounded on the north by farmland and Future Montava Subdivision phases, on the east by
farmland, N. Giddings Road, and Future Montava Subdivision phases, on the south by Mountain
Vista Drive and farmland, on the west by the Number 8 Outlet Ditch and Montava Subdivision
Phase. A vicinity map illustrating the project location is provided in Figure 1.1.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 2
Figure 1.1: Vicinity Map
1.2 Description of Property
The Montava Subdivision Phase E project site contains approximately 48 acres and consisting
of the Multi-Family, Mixed-Use, and Open Space. The Montava Subdivision Phase E: Town
Center is currently zoned as Low-Density Mixed-Use Neighborhood District Zone (LMN).
According to Flood Insurance Rate Map (FIRM) #08069C0982F eff. 12/19/2006 prepared by the
Federal Emergency Management Agency (FEMA), the Montava Subdivision Phase E is located
in unshaded Zone X. Zone X indicates areas determined to be outside of 500-year or 0.2%
annual chance floodplain, meaning it is not designated as a special flood hazard zone. Copies
of the FEMA maps that apply to the Montava Subdivision Phase E are included in Appendix B.
The types of soils found on the Montava Subdivision Phase E site consist of:
Aquepts, loamy (5).
Ascalon sandy loam (7) – 0 to 3 percent slops.
Caruso Clay loam (22) - 0 to 1 percent slope.
Fort Collins loam (35) – 0 to 3 percent slopes.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 3
Kim loam (53) – 0 to 3 percent slopes.
Kim loam (54) – 3 to 5 percent slopes.
Satanta loam (94) – 0 to 1 percent slopes.
Satanta loam (95) – 1 to 3 percent slopes.
Satanta Variant clay loam (98) – 0 to 3 percent slopes.
Stoneham loam (101) – 1 to 3 percent slopes.
Stoneham loam (102) – 3 to 5 percent slopes.
Stoneham loam (103) – 5 to 9 percent slopes.
The characteristics of the soil found on the project site include:
Moderate infiltration rate when thoroughly wet.
Moderately fine texture to moderately coarse texture.
Moderate rate of water transmission.
Majority of the site has a wind erodibility rating of 6 (8 being the least susceptible)
These soils consist of the following hydrologic soil groups as defined in the United States
Department of Agriculture (USDA), Web Soil Survey:
Group B – 16.40%.
Group C – 33.50%.
Group D – 50.10%.
The USDA web soil survey report is included in Appendix C.
The following reports were utilized in the drainage analysis and design of Montava Subdivision
Phase E.
Montava Master Drainage Study Fort Collins, Colorado, prepared by Martin/Martin, Inc.,
dated January 23, 2019.
Hydrologic and hydraulic information was referenced from this report to analyze off-site
areas and conveyance links downstream from the Montava Subdivision Phase E and site.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 4
2.0 - Drainage Basins and Sub-Basins
2.1 Major Basin Description
According to the FCSCM, Phase E is located within the Upper Cooper Slough Basin. According
to the basin master planning states that the Number 8 Ditch is in need of improvements which
will be implemented for the reach that is through the site and Phase G. All Number 8 Ditch
improvements will be handled and designed by others in Phase G and Montava Master
Drainage Plan. The Upper Cooper Slough Basin stormwater generally flows from north to south
which is ultimately being captured by the Larimer and Weld Canal. According to the Montava
Master Drainage Study, Phase E is primarily located in Basin F, Basin G1, and Basin G2.
2.2 Existing Conditions
The Phase E site is located in an undeveloped lot west of the Anheuser Busch property. The
current land is being used for agricultural purposes and undeveloped land. The land currently
consists of native grasses, bare ground, and crops. Runoff from the undeveloped site has two
flow paths, split by a ridge, and both ends up in the Larimer and Weld Canal that is located
south of the site. The majority of Montava Phase E, northeast of the ridge, sheet flows
southeast into an inadvertent detention area which will overtop Mountain Vista Drive, and
eventually into the Larimer and Weld Canal. The other flow path, southwest of the ridge, sheet
flows southwest into the Number 8 Outlet Ditch and eventually into the Larimer and Weld Canal.
The Number 8 Outlet Ditch is located to the west of the site and conveys offsite flows and
improvements to the ditch will be completed by others.
The existing site does not have any existing ponds or drainage facilities. A pond has been built
with Phase G to the northwest of the site and an irrigation pond is built north of the site. The
pond built with Phase G does not discharge onto the site and the irrigation pond discharges to
the northwest of the site. The site has an inadvertent detention area near Giddings Road and
Mountain Vista Drive. All water that is generated on the existing site sheet flows and ends up in
one of the major waterways that are located close to the site.
There are two major drainage ways that are being utilized for Montava Subdivision Phase E.
One is the Larimer and Weld Canal, which is the waterway that all the water from the proposed
site ends up. The second is the Number 8 Ditch, which is being realigned in a pipe that is
directed around the proposed Timberline Road. This Number 8 Ditch improvement is being
designed by others with Montava Phase G Plans.
2.3 Proposed Conditions
The proposed Montava Subdivision Phase E development generally maintains existing drainage
patterns. To conform to the Master Drainage Plan for the area the proposed site will be broken
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 5
into three basins that have been outlined in the Montava Master Drainage Plan. The portion of
Phase E located in Basin F will generally flow southeast into a pond designed by others with the
Master Drainage Study. The portion of Phase E located with Basin G1 will generally flow
southeast and into an interim pond proposed by others with the Master Drainage Study. The
portion of Phase E located in Basin G2 will generally flow southwest into a pond proposed by
others with the Master Drainage Study and outfall directly into the Number 8 Ditch.
The following basins were delineated for the Montava Subdivision Phase E site plan, using the
Montava Master Drainage Basins:
P Basin F is a portion of Basin F from the Montava Master Drainage Plan. P Basin F is made up
of proposed streets, single family development, and future commercial development. This basin
is approximately 16.83 acres with an approximate composite imperviousness of roughly 65.8%.
P Basin F is an overall basin that is broken up into subbasins that all end up in the proposed
Pond F, designed by others. The majority of the basin is directed south and east through
various storm infrastructure and into a raingarden that is located off the north corner of Pond F.
After that water has been treated in the Rain Garden, it will discharge into the water quality and
detention Pond F. The other portion of the basin is directed east and south through various
storm infrastructure and into the water quality and detention Pond F, designed by others.
P Basin G1 is a portion of Basin G1 from the Montava Master Drainage Plan. P Basin G1 is
made up of proposed streets, single family development, and future commercial development.
This basin is approximately 16.40 acres with an approximate composite imperviousness of
roughly 53.0%. P Basin G1 is an overall basin that is broken up into subbasins that all end up in
the proposed Interim Pond 427, designed by others. The majority of the basin is directed toward
various low points across the basin and into the storm line that directs it to the interim Pond 427,
designed by others.
P Basin G2 is a portion of Basin G1 from the Montava Master Drainage Plan. P Basin G2 is
made up of proposed streets and future commercial development. This basin is approximately
8.32 acres with an approximate composite imperviousness of roughly 30.7%. P Basin G2 is an
overall basin that is broken up into subbasins that all end up in the proposed Water Quality
Pond G2. The majority of the basin is directed southwest through various storm infrastructure
and into raingardens located at the end of the proposed storm lines. After that water has been
treated in the Rain Garden, it will discharge into the water Pond G2 ultimately spilling into the
piped section of the Number 8 Ditch.
Pond F Basin is a portion of Basin F from the Montava Master Drainage Plan. Pond F Basin is
made up of proposed Pond F (designed by others), future recreation center, and future sports
fields. This basin is approximately 8.29 acres with an approximate composite imperviousness
of roughly 24.8%. The entirety of the basin sheet flows directly into the pond or into a Rain
Garden that ultimately ends up in Pond F.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 6
Off-Site Basins
Basin D from Montava Master Drainage Plan is made up of existing irrigation and detention
pond, future school, future park, future mixed-use lots, and future streets. This basin is
approximately 42.34 acres with an approximate composite imperviousness of roughly 60%.
Generally, runoff will be directed south to the existing irrigation and detention pond. Future
development will have to implement some sort of LID before the runoff will be captured by the
pond. This basin was not analyzed for runoff or conformance to the LID section of the FCSCM.
The only information used from this basin is the outfall of the pond, which is the only offsite
contributing flow for the whole site. The flow that is coming into Phase E is 8.6 cfs under
Timberline Road and into a drainage swale that ends up in Pond F.
2.4 Low Impact Development (LID)
Per City of Fort Collins criteria, Low Impact Development (LID) features are proposed to treat
50% of the newly developed single family, and 75% of the newly developed multifamily within
Phase E. Timberline Right-of-Way Adjacent to Phase E is discharging to the proposed LID
systems and was included in the overall treatment percentage.
One LID system is being proposed for Phase E, Bioretention (Rain Gardens). The location of
hese systems is described in Section 2.3 showing the percentage of newly developed area
treated by these systems is included in the Appendix B.
The proposed LID systems, water quality, and detention facilities will be located in tracts owned
and maintained by the Montava Metropolitan District.
2.5 MDCIA “Four Step Process”
Step 1 – Employee Runoff Reduction Practices
Montava Phase E is providing LID treatment for 50% of the single-family development and 75%
of the multifamily development, excluding the future commercial, through various Bioretention
(Rain Gardens). The LID systems have been placed throughout the site to minimize directly
connected impervious areas.
Step 2 – Implement BMPs That Provide a WQCV with Slow Release
The remaining single and multifamily development throughout the site not being treated by the
LID described is being treated through traditional water quality control volume extended
drainage basins designed to release the water quality event within a minimum if 40 hours.
Step 3 – Stabilize Streams
Portions of Phase E will be spilling into an improved Number 8 Ditch, improved by other
designing Phase G. Piping of the Number 8 is the preferred solution to minimize public
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 7
interaction with the existing facilities, as well as reducing the downstream sediment load that
was seen with an open irrigation channel. Phase E will also be spilling into a couple of ponds,
designed by others, that are designed to reduce the sediment load to the downstream
properties. Phase E only spills into the improved downstream infrastructure that was designed
to lessen or solve the problems that have been outlined in the 2017 Selected Plan improvement
recommendations.
Step 4 – Implement Site Specific and Other Source Control BMPs
1. The following practices suggested by City of Fort Collins Criteria will be implemented
throughout the design and construction process:
2. Being a single-family development, trash receptacles will be dispersed throughout the
neighborhood and likely be enclosed containers that minimize concentrated and polluted
runoff from entering the storm sewer system or receiving drainageways prior to being
treated.
3. Phase E of Montava Subdivision does not include a dog park, but any future dog parks
shall be located in areas away from detention basins and educational opportunities to
reinforce pick-up practices for dog owners shall be employed.
4. Phase E of Montava Subdivision does not include any community gardens, but future
community gardens shall be located in areas that are outside of the detention basins to
prevent chemical and sediment loading.
5. Construction Best Management Practices (BMPs) will be employed to located material
storage away from drainage facilities.
2.6 Variance Requests
No drainage variances are being requested at this time.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 8
3.0 - Drainage Design Criteria
The drainage design presented in this report has been developed in accordance with the
guidelines established by the FCSCM dated December 2018.
Storm system infrastructure including pipes, culverts, inlets, and drainage swales were sized to
convey the 100-year storm event. In areas of concern, storm system infrastructure was sized to
handle the 100-year and any additional bypass flow from upstream infrastructure.
3.1 Hydrological and Hydraulic Criteria
Design Rainfall & Runoff Calculation Method
The hydrology of the project site for developed conditions was evaluated based on the 2-, 10-
and 100-year storm frequencies as dictated within the FCSCM manual. The Rational Method
was used to determine peak runoff rates for each developed basin. Peak storm runoff values
were used to size on-site drainage facilities including storm culverts, sewers, inlets and
channels for the initial or major design storms as specified in the FCSCM criteria and standards.
Within the criteria and standards, the initial design storm was established as the 2-year minor
storm event and the 100-year storm as the major event.
Inlet Design
All inlets within the project area have been designed to collect and convey the 2-year developed
runoff. In areas where flooding is a concern, inlets were upsized to convey much of the 100-
year developed runoff. As stated in FCSCM, Inlet Functions, Types and Appropriate
Applications, the standard inlets for use on City of Loveland streets are:
Inlet Type Permitted Use
Curb Opening Inlet Type R All street types with 6 inches of vertical curb
Type C Inlet All Alleys with reverse crown and Streets with pan instead of curb
(Montava Drive/ Paseo Drive)
Storm Sewer and Culvert Design
As stated in the FCSCM, the Manning’s roughness coefficient (n) for all storm sewer pipe
capacity calculations shall be 0.013 regardless of pipe material.
The storm sewers and culverts in the project area were designed in accordance with the criteria
and standards of the FCSCM using a minimum pipe diameter of 15 inches. Where applicable,
storm sewers have been sized to convey the 100-year developed runoff to the existing detention
ponds. Peak runoff for storm sewer design was calculated using the Rational Method per the
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 9
FCSCM. All storm sewers were sized using the Urban Drainage program, UD-Sewer 2009
Version 1.4.0. All culverts were sized using the Federal Highway Administration (FHA)
Program, HY-8 Version 7.30.
Riprap Design
Riprap was designed at the outlet of all storm sewers to dissipate energy and prevent erosion in
the 100-year storm per the FCSCM criteria and standards.
Street Capacity
The criteria and standards set forth in the FCSCM were used to check street capacity for both
the minor (2-year) and major (100-year) storm events. The FCSCM requires that stormwater
overtopping curbs should not occur during the minor storms and the flow spread must meet the
following guidelines for each street designation:
Local – flow may spread to crown of road.
Collector - flow spread must leave a minimum of 6 feet (6’) wide clear travel lane on
each side of the centerline.
Arterial (with median) – flow spread must leave a minimum of 12 feet (12’) wide travel
lane in both directions of travel.
Additionally, the following allowable street flow depths were used for the drainage design:
Local – Minor Storm (0.50-ft), Major Storm (0.67-ft)
Collector - Minor Storm (0.50-ft), Major Storm (0.67-ft)
Minor Arterial - Minor Storm (0.50-ft), Major Storm (0.67-ft)
Swale Design
As defined in Chapter 9 of the Fort Collins Stormwater Criteria Manual, open channels are
utilized to preserve, enhance, and restore stream corridors, used in the design of constructed
channels and swales by use of natural concepts.
Per the FCSCM criteria and standards, all open channels must be designed to carry the major
(100-year) storm runoff. The swales were sized to either contain the 100-year developed peak
runoff plus 1 foot of freeboard or 133 percent of the 100-year developed peak runoff.
Drainage swales were designed to be grass-lined, triangular channels with 4:1 side-slopes.
Erosion potential in the swales was analyzed to determine if additional protective measures are
needed within the project area. Based on Froude number calculations.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 10
Detention Discharge and Storage Calculation
Montava Phase E drains to three separate Detention/ Water Quality ponds. Detention Pond F
and Interim Detention Pond 427 are concurrently being designed by others under a separate
title. Water Quality Pond G2 is being designed with this preliminary drainage report. Pond F is
located Pond F Basin and captures the runoff from P Basin F and Pond F Basin. This pond
discharges into a drainage swale that is southeast of the proposed site, this outfall ultimately
ends up in the interim pond 427. Interim Pond 427 is located southeast of the proposed site,
near the intersection of Mountain Vista and Giddings and captures the runoff from P Basin G1.
This pond discharges under Mountain Vista Drive and follows the existing drainage
infrastructure and ultimately ends up in the Larimer and Weld Canal. The remaining area of the
proposed site, P Basin G2, is captured by a water quality pond that is located in the southwest
corner of P Basin G2. This pond discharges directly into the improved piped Number 8 ditch and
ultimately into the Larimer and Weld Ditch.
The SWMM model that was prepared with the Montava Master Drainage Plan has Pond G2
reducing the discharge from the 100-year to the 2-year historic. In the Master Drainage Plan
Pond G2 has a volume of 1.92 ac-ft and a release rate of 1.8 cfs. Due to site constraints a pond
of that size was not possible. Montava Phase E Pond G2 has been designed with a volume of
0.82 ac-ft and a release rate of approximately 10 cfs. According to the Master Drainage Report
the planned upstream diversion drastically reduces the flows through the Number 8 Ditch by
approximately 263 cfs. Since we are diverting approximately 161 cfs from the Number 8 Ditch
and keeping it well below the historic flow, a small increase is being proposed. The proposed
condition will slightly increase the flows through the Number 8 Ditch making the difference
approximately 255 cfs.
The required Water Quality Volume of 0.33 ac-ft was calculated. The outlet structure was
designed to have two stages. The first stage is a water quality orifice plate designed to drain the
WQCV within 40 hours. The second stage is an unrestricted pipe that will drain anything greater
than the WQCV. Refer to Appendix F for more information about the pond sizing and the outlet
structure.
Erosion and Sediment Control
Montava Phase E has been designed to be in compliance with the City of Fort Collins Erosion
Control Criteria and all Erosion Control Materials will be provided with the Final Drainage
Report. Erosion and sedimentation occurring on-site during construction will be controlled by
use of temporary Best Management Practices (BMPs – i.e., silt fence, gravel inlet filters, vehicle
tracking control pads, and straw wattle barriers). A separate Stormwater Management Plan has
been provided with the PDR Submittal.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 11
4.0 - Conclusions
This preliminary drainage report has been prepared in accordance with the City of Fort Collins
Stormwater Criteria Manual for a Project Development Plan (PDP) submittal. The PDP plans
have also been prepared to be in compliance with the city’s current drainage criteria.
The Montava Subdivision Phase E has been designed to safely and effectively capture, convey,
and attenuate stormwater runoff in accordance with the FCSCM, Fort Collins Stormwater
Criteria Manual, and Montava Master Drainage Study. The analysis indicates that the proposed
development has been designed in a way that is consistent with existing drainage patterns of
both FCSCM and Montava Master Drainage Study. 50% of the newly single-family development
and 75% of the newly developed multifamily development will be connected to a LID system,
which will treat storms before the traditional water quality and detention ponds. The traditional
water quality and detention ponds will treat the remaining development of the site. The
proposed drainage infrastructure will attenuate the flow prior to entering the downstream
properties/ infrastructure.
Additionally, areas of future development adjacent to the project area will have to been analyzed
to ensure that adequate facilities will accommodate future development.
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 12
5.0 - References
1. Fort Collins Stormwater Criteria Manual, as adopted by the city of Fort Collins, as
referenced in Section 26-500 of the Code of the City of Fort Collins, December 2018.
2. City of Fort Collins Cooper Slough Alternatives Analysis Update, prepared by Fort
Collins Department of Utilities, prepared by ICON Engineering Inc., October 2017
3. Montava Planned Unit Development Master Drainage Study, by Martin/Martin Inc., dated
January 23, 2019
Montava Subdivision Phase E: Town Center Preliminary Drainage Report
Page 13
6.0 - Appendices
The following appendices are attached to and made part of this final drainage design report:
APPENDIX A HYDROLOGIC ANALYSIS
APPENDIX B LOW IMPACT DEVELOPMENT (LID) CALCULATIONS
APPENDIX C FEMA FLOOD INSURANCE RATE MAP
APPENDIX D USDA HYDROLOGIC SOIL GROUP MAP
APPENDIX E DRAIANGE PLANS
APPENDIX F DETENTION DESIGN
Appendix A
HYDOLOGIC ANALYSIS
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
Composite C
C2 C2 C10 C100
Medium Density 0.50 0.65 50
Streets: Paved 0.26 0.95 90
Lawn, Clayey, >7% Slope 0.05 0.35 2
Medium Density 0.09 0.65 50
Streets: Paved 0.12 0.95 90
Lawn, Sandy, >7% Slope 0.00 0.20 2
Medium Density 0.35 0.65 50
Streets: Paved 0.10 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.07 0.65 50
Streets: Paved 0.06 0.95 90
Lawn, Sandy, >7% Slope 0 0.20 2
Medium Density 0.36 0.65 50
Streets: Paved 0.12 0.95 90
Lawn, Sandy, >7% Slope 0.00 0.20 2
Medium Density 0.17 0.65 50
Streets: Paved 0.05 0.95 90
Lawn, Sandy, >7% Slope 0.03 0.20 2
Medium Density 0.25 0.65 50
Streets: Paved 0.16 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.78 0.65 50
Streets: Paved 0.21 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.35 0.65 50
Streets: Paved 0.21 0.95 90
Lawn, Clayey, >7% Slope 0.25 0.35 2
Medium Density 0.43 0.65 50
Streets: Paved 0.20 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.10 0.65 50
Streets: Paved 0.10 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.45 0.65 50
Streets: Paved 0.39 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.40 0.65 50
Streets: Paved 0.31 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.26 0.65 50
Streets: Paved 0.06 0.95 90
Lawn, Clayey, >7% Slope 0.28 0.35 2
Medium Density 0.26 0.65 50
Streets: Paved 0.08 0.95 90
Lawn, Clayey, >7% Slope 0.29 0.35 2
Medium Density 0.21 0.65 50
Streets: Paved 0.10 0.95 90
Lawn, Clayey, >7% Slope 0.34 0.35 2
Medium Density 0.28 0.65 50
Streets: Paved 1.08 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.00 0.65 50
Streets: Paved 0.52 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.00 0.65 50
Streets: Paved 0.59 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.00 0.65 50
Streets: Paved 0.78 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.00 0.65 50
Streets: Paved 0.66 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.10 0.65 50
Streets: Paved 1.48 0.95 90
Lawn, Clayey, >7% Slope 0.25 0.35 2
Medium Density 0.20 0.65 50
Streets: Paved 0.12 0.95 90
Lawn, Clayey, >7% Slope 0.03 0.35 2
Medium Density 0.35 0.65 50
Streets: Paved 0.19 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.04 0.65 50
Streets: Paved 0.11 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.48 0.65 50
Streets: Paved 0.15 0.95 90
Lawn, Clayey, >7% Slope 0.06 0.35 2
Medium Density 0.31 0.65 50
Streets: Paved 0.24 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Total F Basins 16.82 Avg. % Imp. 65.8%Avg. 100-yr C100 =0.88
1.00
31.0% 0.54 0.54
0.95 0.95 0.95 1.00
0.78 0.78 0.78 0.98
0.68
0.79
0.690.55
0.95
0.66 90.0% 0.95 0.95 0.95 1.00
0.59 90.0%
31.6% 0.54
0.67
1.36 81.8% 0.89 0.89 1.00
F-21
F-14 0.60
F-10 0.63 62.7% 0.75 0.75
F-19
F-17
F-16 0.65
0.54
0.55
0.54
0.89
0.54
F-15 0.63 33.0% 0.55
F-18 0.52 90.0% 0.95 0.95
F-20 0.78 90.0% 0.95 0.95
F-23 0.35 68.7% 0.80
58.9% 0.72 0.72
0.82
0.72
0.79
F-11 0.20 70.0% 0.80
F-9 0.81 45.6% 0.64 0.64
F-8 0.99 58.5% 0.71 0.71
0.80 0.80
0.66
Onsite Basin Composite Runoff Coefficients
Basin/ Sub-
Basin Area (ac) Attribute
59.9%
Attribute Area
(ac)
Composite Runoff CoefficientsRunoff
Coefficient, C
Percent
ImperviousImpervious
0.73 0.73 0.910.73F-1 0.81
F-7 0.41 65.6% 0.77 0.77
F-6 0.25 52.2%
0.79 0.79
0.66
68.5%
F-2 0.21 72.9% 0.82 0.82
F-4 0.13
F-3 0.45
0.66
0.73
0.82
F-13 0.71
F-12 0.84 0.79
0.96
1.00
0.99
67.5% 0.78 0.78 0.98
68.6% 0.79
0.78
0.93
0.89
0.77
0.71
0.64
0.75
0.79
1.00
0.90
0.99
F-5 0.48 60.0% 0.73 0.73 0.91
0.95 1.00
F-22 1.83 75.8% 0.85 0.85 0.85 1.00
0.80 0.80 0.99
F-24 0.54 64.1% 0.76 0.76 0.76 0.94
F-27 0.55 67.5%
F-25 0.15 79.3% 0.87 0.87 0.87 1.00
F-26 0.69 54.5% 0.69 0.69 0.69 0.86
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
Composite C
C2 C2 C10 C100
Medium Density 0.70 0.65 50
Streets: Paved 1.25 0.95 90
Lawn, Clayey, >7% Slope 0.11 0.35 2
Medium Density 0.79 0.65 50
Streets: Paved 0.23 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.83 0.65 50
Streets: Paved 0.47 0.95 90
Lawn, Clayey, >7% Slope 0.02 0.35 2
Medium Density 0.22 0.65 50
Streets: Paved 0.29 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.33 0.65 50
Streets: Paved 0.76 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.25 0.65 50
Streets: Paved 0.32 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.18 0.65 50
Streets: Paved 0.27 0.95 90
Lawn, Clayey, >7% Slope 0.02 0.35 2
Medium Density 0.12 0.65 50
Streets: Paved 0.25 0.95 90
Lawn, Clayey, >7% Slope 0.01 0.35 2
Medium Density 0.10 0.65 50
Streets: Paved 0.10 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.16 0.65 50
Streets: Paved 0.38 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.14 0.65 50
Streets: Paved 0.26 0.95 90
Lawn, Clayey, >7% Slope 0.02 0.35 2
Medium Density 0.26 0.65 50
Streets: Paved -0.12 0.95 90
Lawn, Clayey, >7% Slope 0.04 0.35 2
Medium Density 0.30 0.65 50
Streets: Paved -0.21 0.95 90
Lawn, Clayey, >7% Slope 0.06 0.35 2
Medium Density 0.87 0.65 50
Streets: Paved 0.04 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.02 0.65 50
Streets: Paved 0.05 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.03 0.65 50
Streets: Paved 0.15 0.95 90
Lawn, Clayey, >7% Slope 0.00 0.35 2
Medium Density 0.12 0.65 50
Streets: Paved 0.64 0.95 90
Streets: Permeable Pavers 0.45 0.30 40
Lawn, Clayey, >7% Slope 0.65 0.35 2
Medium Density 0.00 0.65 50
Streets: Paved 0.23 0.95 90
Streets: Permeable Pavers 0.44 0.30 40
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Open Lands, Transition 1.81 0.20 20
Medium Density 0.00 0.65 50
Streets: Paved 0.04 0.95 90
Open Lands, Transition 1.96 0.20 20
Total F Basins 16.41 Avg. % Imp. 53.0%Avg. 100-yr C100 =0.74
Composite C
C2 C2 C10 C100
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Open Lands, Transition 1.45 0.20 20
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Streets: Permeable Pavers 0.25 0.30 40
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Streets: Permeable Pavers 0.19 0.30 40
Medium Density 2.00 0.65 50
Streets: Paved 0.00 0.95 90
Open Lands, Transition 0.89 0.20 20
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Streets: Permeable Pavers 0.38 0.30 40
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Open Lands, Transition 0.50 0.20 20
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Streets: Permeable Pavers 0.59 0.30 40
Medium Density 0.00 0.65 50
Streets: Paved 0.00 0.95 90
Open Lands, Transition 1.97 0.20 20
Total F Basins 8.22 Avg. % Imp. 30.7%Avg. 100-yr C100 =0.38
Medium Density 0.00 0.65 50
Streets: Paved 0.57 0.95 90
Open Lands, Transition 7.72 0.20 20
Total F Basins 8.29 Avg. % Imp. 24.8%Avg. 100-yr C100 =0.31
Basin/ Sub-
Basin Area (ac) Attribute
Attribute Area
(ac)
Runoff
Coefficient, C Impervious Percent
Impervious
Composite Runoff Coefficients
Onsite Basin Composite Runoff Coefficients
Basin/ Sub-
Basin Area (ac) Attribute
Attribute Area
(ac)
Runoff
Coefficient, C Impervious Percent
Impervious
Composite Runoff Coefficients
G1-14 0.91 51.8% 0.66 0.66 0.66 0.83
0.42
0.18
0.15
1.00
G1-2
G1-3
G1-4
G1-5
G1-6
1.00
0.84 1.00
1.00
0.86 0.86 1.00
0.38
40.0% 0.30 0.30 0.30 0.38
40.0% 0.30 0.30 0.30 0.38
40.8% 0.51 0.51
1.0078.6%
0.49 0.49 0.49 0.61
0.86
0.11 0.11
Onsite Basin Composite Runoff Coefficients
G1-13
0.82 1.00
70.9% 0.81 0.81 0.81
G1-8
G1-9
0.57
0.47
0.38
0.20
G2-1 1.45 20.0% 0.20
1.00
1.00
63.5% 0.75 0.75 0.75
72.7% 0.82 0.82 0.82
77.9% 0.86 0.86
0.90
0.94
0.72
0.86
72.5% 0.82 0.82
1.02
1.32
0.51
1.09
0.72 0.72
71.7% 0.82 0.82 0.82
0.51
0.20
G2-2 0.25 40.0% 0.30 0.30 0.30
G1-7
0.86
G1-1 2.06
0.86 0.86
0.80
78.1%G1-10
G1-11
G1-12
0.54
G1-17 1.86 44.6%
59.0%
75.1% 0.84 0.84
70.0% 0.80 0.80
-25.2%
0.82 0.82 0.82 1.00
12.7% 0.38 0.38
G1-16 0.18 83.3% 0.90 0.90 0.90 1.00
0.11 0.14
72.5%
0.48
G1-15 0.07
POND F 8.29 24.8% 0.25 0.25 0.25 0.31
G1-20 2.00 21.4% 0.22 0.22 0.22 0.27
G2-8 1.97 20.0%
0.20
G2-7 0.59
G2-3 0.19
G2-4 2.89
0.20 0.20 0.20 0.25
0.64
0.25
0.38
G2-5 0.38 40.0% 0.30 0.30 0.30 0.38
G2-6 0.50 20.0% 0.20 0.20 0.20 0.25
G1-18 0.67 57.2% 0.52 0.52 0.52 0.65
G1-19 1.81 20.0% 0.20 0.20 0.20 0.25
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
Overland Flow Average Channelized Channel Channel Channelized
Length, D Overland Slope Tov Tov Tov Flow Length Slope Velocity Time (Tt)
(ft) (%) 2-year 10-year 100-year (ft) (%) (ft/s) (min) 2-year 10-year 100-year
F-1 0.73 0.73 0.91 87 0.5 8 8 4 60 0.5 1.5 0.7 9 9 5
F-2 0.82 0.82 1.00 40 0.5 4 4 1 71 0.5 1.5 0.8 5 5 5
F-3 0.72 0.72 0.90 72 0.5 8 8 4 108 0.5 1.5 1.2 9 9 5
F-4 0.79 0.79 0.99 42 0.5 5 5 2 53 0.5 1.5 0.6 6 6 5
F-5 0.73 0.73 0.91 100 0.5 9 9 5 85 0.5 1.5 0.9 10 10 6
F-6 0.66 0.66 0.82 62 0.5 8 8 5 55 0.5 1.5 0.6 9 9 6
F-7 0.77 0.77 0.96 65 0.5 6 6 3 95 0.5 1.5 1.1 7 7 5
F-8 0.71 0.71 0.89 100 0.5 9 9 5 230 0.5 1.5 2.6 12 12 8
F-9 0.64 0.64 0.79 68 0.5 9 9 6 205 0.5 1.5 2.3 11 11 8
F-10 0.75 0.75 0.93 41 0.5 5 5 3 50 0.5 1.5 0.6 6 6 5
F-11 0.80 0.80 1.00 48 0.5 5 5 2 48 0.5 1.5 0.5 6 6 5
F-12 0.79 0.79 0.99 50 0.5 5 5 2 202 0.5 1.5 2.2 7 7 5
F-13 0.78 0.78 0.98 80 0.5 7 7 3 165 0.5 1.5 1.8 9 9 5
F-14 0.54 0.54 0.68 77 0.5 12 12 9 230 0.5 1.5 2.6 15 15 12
F-15 0.55 0.55 0.69 85 0.5 12 12 9 242 0.5 1.5 2.7 15 15 12
F-16 0.54 0.54 0.67 85 0.5 12 12 9 275 0.5 1.5 3.1 15 15 12
F-17 0.89 0.89 1.00 40 0.5 3 3 1 1003 0.5 1.5 11.1 14 14 12
F-18 0.95 0.95 1.00 25 0.5 2 2 1 300 0.5 1.5 3.3 5 5 5
F-19 0.95 0.95 1.00 75 0.5 3 3 2 425 0.5 1.5 4.7 8 8 7
F-20 0.95 0.95 1.00 69 0.5 3 3 2 450 0.5 1.5 5.0 8 8 7
F-21 0.95 0.95 1.00 67 0.5 3 3 2 278 0.5 1.5 3.1 6 6 5
F-22 0.85 0.85 1.00 69 0.5 5 5 2 286 0.5 1.5 3.2 8 8 5
F-23 0.80 0.80 0.99 50 0.5 5 5 2 85 0.5 1.5 0.9 6 6 5
F-24 0.76 0.76 0.94 60 0.5 6 6 3 105 0.5 1.5 1.2 7 7 5
F-25 0.87 0.87 1.00 30 0.5 3 3 1 40 0.5 1.5 0.4 5 5 5
F-26 0.69 0.69 0.86 63 0.5 8 8 4 100 0.5 1.5 1.1 9 9 5
F-27 0.78 0.78 0.98 40 0.5 5 5 2 210 0.5 1.5 2.3 7 7 5
G1-1 0.82 0.82 1.00 65 0.5 5 5 2 782 0.5 1.5 8.7 14 14 11
G1-2 0.72 0.72 0.90 73 0.5 8 8 4 170 0.5 1.5 1.9 10 10 6
G1-3 0.75 0.75 0.94 48 0.5 6 6 3 190 0.5 1.5 2.1 8 8 5
G1-4 0.82 0.82 1.00 53 0.5 5 5 2 316 0.5 1.5 3.5 9 9 6
G1-5 0.86 0.86 1.00 50 0.5 4 4 2 470 0.5 1.5 5.2 9 9 7
G1-6 0.82 0.82 1.00 80 0.5 6 6 2 260 0.5 1.5 2.9 9 9 5
G1-7 0.81 0.81 1.00 42 0.5 4 4 2 101 0.5 1.5 1.1 5 5 5
G1-8 0.84 0.84 1.00 45 0.5 4 4 2 22 0.5 1.5 0.2 5 5 5
G1-9 0.80 0.80 1.00 43 0.5 5 5 2 72 0.5 1.5 0.8 6 6 5
G1-10 0.86 0.86 1.00 83 0.5 5 5 2 260 0.5 1.5 2.9 8 8 5
G1-11 0.82 0.82 1.00 120 0.5 7 7 3 524 0.5 1.5 5.8 13 13 9
G1-12 0.38 0.38 0.48 60 0.5 13 13 11 353 0.5 1.5 3.9 17 17 15
G1-13 0.11 0.11 0.14 120 0.5 26 26 25 1011 0.5 1.5 11.2 37 37 36
G1-14 0.66 0.66 0.83 38 0.5 6 6 4 412 0.5 1.5 4.6 11 11 9
G1-15 0.86 0.86 1.00 38 0.5 3 3 1 412 0.5 1.5 4.6 8 8 6
G1-16 0.90 0.90 1.00 28 0.5 2 2 1 412 0.5 1.5 4.6 7 7 6
G1-17 0.49 0.49 0.61 50 0.5 10 10 8 412 0.5 1.5 4.6 15 15 13
G1-18 0.52 0.52 0.65 28 0.5 7 7 6 412 0.5 1.5 4.6 12 12 11
G1-19 0.20 0.20 0.25 28 0.5 11 11 11 412 0.5 1.5 4.6 16 16 16
G1-20 0.22 0.22 0.27 246 0.5 33 33 31 412 0.5 1.5 4.6 38 38 36
G2-1 0.20 0.20 0.25 212 0.5 31 31 29 20 0.5 1.5 0.2 31 31 29
G2-2 0.30 0.30 0.38 20 0.5 8 8 8 310 0.5 1.5 3.4 11 11 11
G2-3 0.30 0.30 0.38 20 0.5 8 8 8 226 0.5 1.5 2.5 11 11 11
G2-4 0.51 0.51 0.64 210 0.5 20 20 16 230 0.5 1.5 2.6 23 23 19
G2-5 0.30 0.30 0.38 30 0.5 10 10 9 450 0.5 1.5 5.0 15 15 14
G2-6 0.20 0.20 0.25 116 0.5 23 23 22 460 0.5 1.5 5.1 28 28 27
G2-7 0.30 0.30 0.38 30 0.5 10 10 9 20 0.5 1.5 0.2 10 10 9
G2-8 0.20 0.20 0.25 370 0.5 41 41 39 20 0.5 1.5 0.2 41 41 39
POND F 0.25 0.25 0.31 350 0.5 37 37 35 192 0.5 1.5 2.1 39 39 37
Basin Time of Concentration
Frequency Adj. Runoff Coefficients (C*Cf)
C2 C10 C100
Overland Travel Time Time of Concentration
Tc = Tov + Tt (min)Basin
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
2 - year 10 - year 100 - year 2 - year 10 - year 100 - year 2 - Year 10 - Year 100 - Year 2 - Year 10 - Year 100 - Year
F-1 0.81 0.73 0.73 0.91 9 9 5 2.30 3.93 9.95 1.36 2.32 7.33
F-2 0.21 0.82 0.82 1.00 5 5 5 2.85 4.87 9.95 0.49 0.84 2.09
F-3 0.45 0.72 0.72 0.90 9 9 5 2.30 3.93 9.95 0.74 1.27 4.01
F-4 0.13 0.79 0.79 0.99 6 6 5 2.67 4.56 9.95 0.27 0.47 1.27
F-5 0.48 0.73 0.73 0.91 10 10 6 2.21 3.78 9.31 0.77 1.32 4.05
F-6 0.25 0.66 0.66 0.82 9 9 6 2.30 3.93 9.31 0.38 0.64 1.91
F-7 0.41 0.77 0.77 0.96 7 7 5 2.52 4.31 9.95 0.79 1.36 3.91
F-8 0.99 0.71 0.71 0.89 12 12 8 2.05 3.50 8.38 1.45 2.47 7.40
F-9 0.81 0.64 0.64 0.79 11 11 8 2.13 3.63 8.38 1.10 1.87 5.39
F-10 0.63 0.75 0.75 0.93 6 6 5 2.67 4.56 9.95 1.25 2.14 5.84
F-11 0.20 0.80 0.80 1.00 6 6 5 2.67 4.56 9.95 0.43 0.73 1.99
F-12 0.84 0.79 0.79 0.99 7 7 5 2.52 4.31 9.95 1.67 2.86 8.25
F-13 0.71 0.78 0.78 0.98 9 9 5 2.30 3.93 9.95 1.28 2.18 6.90
F-14 0.60 0.54 0.54 0.68 15 15 12 1.87 3.19 7.16 0.61 1.03 2.90
F-15 0.63 0.55 0.55 0.69 15 15 12 1.87 3.19 7.16 0.65 1.11 3.10
F-16 0.65 0.54 0.54 0.67 15 15 12 1.87 3.19 7.16 0.66 1.12 3.14
F-17 1.36 0.89 0.89 1.00 14 14 12 1.92 3.29 7.16 2.32 3.97 9.74
F-18 0.52 0.95 0.95 1.00 5 5 5 2.85 4.87 9.95 1.41 2.41 5.17
F-19 0.59 0.95 0.95 1.00 8 8 7 2.40 4.10 8.80 1.35 2.30 5.19
F-20 0.78 0.95 0.95 1.00 8 8 7 2.40 4.10 8.80 1.78 3.04 6.86
F-21 0.66 0.95 0.95 1.00 6 6 5 2.67 4.56 9.95 1.67 2.86 6.57
F-22 1.83 0.85 0.85 1.00 8 8 5 2.40 4.10 9.95 3.74 6.39 18.21
F-23 0.35 0.80 0.80 0.99 6 6 5 2.67 4.56 9.95 0.74 1.27 3.46
F-24 0.54 0.76 0.76 0.94 7 7 5 2.52 4.31 9.95 1.03 1.76 5.07
F-25 0.15 0.87 0.87 1.00 5 5 5 2.85 4.87 9.95 0.37 0.64 1.49
F-26 0.69 0.69 0.69 0.86 9 9 5 2.30 3.93 9.95 1.09 1.87 5.91
F-27 0.55 0.78 0.78 0.98 7 7 5 2.52 4.31 9.95 1.08 1.85 5.34
G1-1 2.06 0.82 0.82 1.00 14 14 11 1.92 3.29 7.42 3.2 5.5 15.3
G1-2 1.02 0.72 0.72 0.90 10 10 6 2.21 3.78 9.31 1.6 2.8 8.5
G1-3 1.32 0.75 0.75 0.94 8 8 5 2.40 4.10 9.95 2.4 4.1 12.4
G1-4 0.51 0.82 0.82 1.00 9 9 6 2.30 3.93 9.31 1.0 1.6 4.7
G1-5 1.09 0.86 0.86 1.00 9 9 7 2.30 3.93 8.80 2.2 3.7 9.6
G1-6 0.57 0.82 0.82 1.00 9 9 5 2.30 3.93 9.95 1.1 1.8 5.7
G1-7 0.47 0.81 0.81 1.00 5 5 5 2.85 4.87 9.95 1.1 1.9 4.7
G1-8 0.38 0.84 0.84 1.00 5 5 5 2.85 4.87 9.95 0.9 1.6 3.8
G1-9 0.20 0.80 0.80 1.00 6 6 5 2.67 4.56 9.95 0.4 0.7 2.0
G1-10 0.54 0.86 0.86 1.00 8 8 5 2.40 4.10 9.95 1.1 1.9 5.4
G1-11 0.42 0.82 0.82 1.00 13 13 9 1.98 3.39 8.03 0.7 1.2 3.4
G1-12 0.18 0.38 0.38 0.48 17 17 15 1.75 2.99 6.52 0.1 0.2 0.6
G1-13 0.15 0.11 0.11 0.14 37 37 36 1.13 1.93 4.01 0.0 0.0 0.1
G1-14 0.91 0.66 0.66 0.83 11 11 9 2.13 3.63 8.03 1.3 2.2 6.1
G1-15 0.07 0.86 0.86 1.00 8 8 6 2.40 4.10 9.31 0.1 0.2 0.7
G1-16 0.18 0.90 0.90 1.00 7 7 6 2.52 4.31 9.31 0.4 0.7 1.7
G1-17 1.86 0.49 0.49 0.61 15 15 13 1.87 3.19 6.92 1.7 2.9 7.9
G1-18 0.67 0.52 0.52 0.65 12 12 11 2.05 3.50 7.42 0.7 1.2 3.3
G1-19 1.81 0.20 0.20 0.25 16 16 16 1.81 3.08 6.30 0.7 1.1 2.9
G1-20 2.00 0.22 0.22 0.27 38 38 36 1.11 1.89 4.01 0.5 0.8 2.2
G2-1 1.45 0.20 0.20 0.25 31 31 29 1.27 2.16 4.60 0.4 0.6 1.7
G2-2 0.25 0.30 0.30 0.38 11 11 11 2.13 3.63 7.42 0.2 0.3 0.7
G2-3 0.19 0.30 0.30 0.38 11 11 11 2.13 3.63 7.42 0.1 0.2 0.5
G2-4 2.89 0.51 0.51 0.64 23 23 19 1.49 2.55 5.75 2.2 3.8 10.6
G2-5 0.38 0.30 0.30 0.38 15 15 14 1.87 3.19 6.71 0.2 0.4 1.0
G2-6 0.50 0.20 0.20 0.25 28 28 27 1.34 2.29 4.78 0.1 0.2 0.6
G2-7 0.59 0.30 0.30 0.38 10 10 9 2.21 3.78 8.03 0.4 0.7 1.8
G2-8 1.97 0.20 0.20 0.25 41 41 39 1.05 1.80 3.80 0.4 0.7 1.9
POND F 8.29 0.25 0.25 0.31 39 39 37 1.09 1.86 3.93 2.3 3.9 10.2
Table A-3
Basin Peak Discharge
Rainfall Intensity (in/hr) Peak Discharge (cfs)Basin Basin Area
(ac)
Frequency Adj. Runoff Coefficients
P BASIN F
P BASIN G1
P BASIN G2
POND F
Time of Concentration, Tc (min)
Appendix B
LOW IMPACT DEVELOPMENT
(LID) CALCULATIONS
MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report
Basin/ Sub-Basin Total Area (acres)
Multi-Family Area (acres)
75% LID TREATED
Single-Family Area (acres)
50% LID TREATED
Area Remaining 75%
LID TREATED Impervious Area (acres) % Impervious TO BE LID TREATED
PERCENT OF
TOTAL SITE
AREA TO BE
TREATED
F-1 0.81 0.47 0.03 0.31 0.49 59.88%YES 1.63% 0.81
F-2 0.21 0.17 0.00 0.04 0.15 72.86%NO 0.42% 0.00
F-3 0.45 0.19 0.16 0.10 0.27 58.89%NO 0.90% 0.00
F-4 0.13 0.07 0.00 0.06 0.09 68.46%NO 0.26% 0.00
F-5 0.48 0.10 0.27 0.12 0.29 60.00%YES 0.96% 0.48
F-6 0.25 0.17 0.00 0.08 0.13 52.24%YES 0.50% 0.25
F-7 0.41 0.11 0.15 0.16 0.27 65.61%NO 0.82% 0.00
F-8 0.99 0.48 0.30 0.21 0.58 58.48%YES 1.99% 0.99
F-9 0.81 0.35 0.00 0.46 0.37 45.56%YES 1.63% 0.81
F-10 0.63 0.17 0.26 0.19 0.40 62.70%NO 1.26% 0.00
F-11 0.20 0.10 0.00 0.10 0.14 70.00%YES 0.40% 0.00
F-12 0.84 0.68 0.00 0.16 0.58 68.57%NO 1.69% 0.00
F-13 0.71 0.30 0.19 0.22 0.48 67.46%YES 1.42% 0.71
F-14 0.60 0.00 0.26 0.34 0.19 31.60%NO 1.20% 0.60
F-15 0.63 0.00 0.26 0.37 0.21 32.98%YES 1.26% 0.63
F-16 0.65 0.00 0.21 0.44 0.20 31.05%NO 1.30% 0.65
F-17 1.36 0.28 0.00 1.08 1.11 81.76%YES 2.73% 1.36
F-18 0.52 0.00 0.00 0.52 0.47 90.00%NO 1.04% 0.52
F-19 0.59 0.00 0.00 0.59 0.53 90.00%NO 1.18% 0.00
F-20 0.78 0.00 0.00 0.78 0.70 90.00%NO 1.57% 0.00
F-21 0.66 0.00 0.00 0.66 0.59 90.00%NO 1.32% 0.00
F-22 1.83 0.33 0.00 1.50 1.39 75.79%YES 3.67% 0.00
F-23 0.35 0.20 0.00 0.15 0.24 68.74%YES 0.70% 0.35
F-24 0.54 0.08 0.08 0.38 0.35 64.07%YES 1.08% 0.54
F-25 0.15 0.03 0.00 0.12 0.12 79.33%YES 0.30% 0.15
F-26 0.69 0.33 0.16 0.21 0.38 54.52%YES 1.38% 0.69
F-27 0.55 0.28 0.03 0.24 0.37 67.45%YES 1.10% 0.55
Total= 16.82 4.88 2.36 9.58 11.06 65.78%33.75% 10.09
71.49%7.91
G1-1 2.06 0.40 0.27 1.39 1.48 71.71%NO 4.13% 0.00
G1-2 1.02 0.36 0.31 0.36 0.60 59.02%NO 2.05% 0.00
G1-3 1.32 0.48 0.35 0.49 0.84 63.52%NO 2.65% 0.00
G1-4 0.51 0.22 0.00 0.29 0.37 72.75%NO 1.02% 0.00
G1-5 1.09 0.33 0.00 0.76 0.85 77.89%NO 2.19% 0.00
G1-6 0.57 0.25 0.00 0.32 0.41 72.46%NO 1.14% 0.00
G1-7 0.47 0.19 0.00 0.29 0.33 70.94%NO 0.94% 0.00
G1-8 0.38 0.20 0.00 0.18 0.29 75.05%NO 0.76% 0.00
G1-9 0.20 0.10 0.00 0.10 0.14 70.00%NO 0.40% 0.00
G1-10 0.54 0.16 0.00 0.38 0.42 78.15%NO 1.08% 0.00
G1-11 0.42 0.14 0.00 0.28 0.30 72.48%NO 0.84% 0.00
G1-12 0.18 0.14 0.00 0.04 0.02 12.67%NO 0.36% 0.00
G1-13 0.15 0.11 0.00 0.04 -0.04 -25.20%NO 0.30% 0.00
G1-14 0.91 0.32 0.00 0.59 0.47 51.76%NO 1.83% 0.00
G1-15 0.07 0.04 0.00 0.03 0.06 78.57%NO 0.14% 0.00
G1-16 0.18 0.02 0.00 0.16 0.15 83.33%NO 0.36% 0.00
G1-17 1.86 0.15 0.00 1.72 0.83 44.57%NO 3.73% 0.00
G1-18 0.67 0.00 0.00 0.67 0.38 57.16%NO 1.34% 0.00
G1-19 1.81 0.00 0.00 1.86 0.36 20.00%NO 3.63% 0.00
G1-20 2.00 0.00 0.00 2.00 0.43 21.40%
NO 4.01% 0.00
Total= 16.41 3.59 0.93 11.94 8.70 53.01%
32.93% 0.00
73.81%6.42
G2-1 1.45 0.00 0.00 1.45 0.29 20.00%YES 2.91% 1.45
G2-2 0.25 0.00 0.00 0.25 0.10 40.00%YES 0.50% 0.25
G2-3 0.19 0.00 0.00 0.19 0.08 40.00%YES 0.38% 0.19
G2-4 2.89 0.00 0.00 2.89 1.18 40.76%YES 5.80% 2.89
G2-5 0.38 0.00 0.00 0.38 0.15 40.00%YES 0.76% 0.38
G2-6 0.59 0.00 0.00 0.59 0.12 20.00%YES 1.18% 0.59
G2-7 0.59 0.00 0.00 0.59 0.24 40.00%YES 1.18% 0.59
G2-8 1.97 0.00 0.00 1.97 0.39 20.00%YES 3.95% 1.97
Total= 8.31 0.00 0.00 8.31 2.54 30.73%16.68% 8.31
75.00%1.91
POND F 8.29 0.00 0.00 8.29 2.06 24.81%YES (1/4 OF BASIN) 4.16% 2.07
Total= 8.29 0.00 0.00 8.29 2.06 24.81%4.16% 2.07
75.00%1.54
17.78 20.47
*Percent impervious values based on UDFCD Vol 1., Chapter 6, Table 6-3
Low Impact Development (LID)
P BASIN F
BASIN PERCENT TREATMENT REQUIRED IMPERVIOUS AREA REQUIRED TO BE TREATED
BASIN PERCENT TREATMENT REQUIRED IMPERVIOUS AREA REQUIRED TO BE TREATED
Per agreements with the City and adjacent property owner, all LID for the H23 project will be handeled offsite on the adjacent H25 developement.
Total Impervious Area Required to be Treated Using
LID Techniques (acres) =
P BASIN G1
P BASIN G2
P BASIN G2
BASIN PERCENT TREATMENT REQUIRED IMPERVIOUS AREA REQUIRED TO BE TREATED
Total Impervious Area to be Treated Using LID
Techniques (acres) =
BASIN PERCENT TREATMENT REQUIRED IMPERVIOUS AREA REQUIRED TO BE TREATED
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =69.1 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.691
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.22 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 410,525 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =7,414 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 10.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =5671 sq ft
D) Actual Flat Surface Area AActual =8540 sq ft
E) Area at Design Depth (Top Surface Area)ATop =10000 sq ft
F) Rain Garden Total Volume VT=9,270 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN BY POND F (BASIN POND F) - LID 1
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01 - BASIN POND F.xlsm, RG 11/27/2022, 10:21 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =31.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.310
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.12 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 28,314 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =292 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =176 sq ft
D) Actual Flat Surface Area AActual =180 sq ft
E) Area at Design Depth (Top Surface Area)ATop =532 sq ft
F) Rain Garden Total Volume VT=356 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-15) LID 2
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-16.xlsm, RG 11/27/2022, 10:22 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =33.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.330
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.13 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 27,443 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =294 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =181 sq ft
D) Actual Flat Surface Area AActual =195 sq ft
E) Area at Design Depth (Top Surface Area)ATop =551 sq ft
F) Rain Garden Total Volume VT=373 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-15) LID 3
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-15.xlsm, RG 11/27/2022, 10:23 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =31.6 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.316
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.13 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 26,136 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =272 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =165 sq ft
D) Actual Flat Surface Area AActual =180 sq ft
E) Area at Design Depth (Top Surface Area)ATop =532 sq ft
F) Rain Garden Total Volume VT=356 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-14) LID 4
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-14.xlsm, RG 11/27/2022, 10:24 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. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-14) LID 4
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_ST-01_BASIN F-14.xlsm, RG 11/27/2022, 10:24 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =52.2 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.522
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 10,890 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =154 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =114 sq ft
D) Actual Flat Surface Area AActual =116 sq ft
E) Area at Design Depth (Top Surface Area)ATop =460 sq ft
F) Rain Garden Total Volume VT=288 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-6) LID 5
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-6.xlsm, RG 11/27/2022, 10:27 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =45.6 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.456
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.16 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 35,284 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =458 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =322 sq ft
D) Actual Flat Surface Area AActual =330 sq ft
E) Area at Design Depth (Top Surface Area)ATop =1730 sq ft
F) Rain Garden Total Volume VT=1,030 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-9) LID 5
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-9.xlsm, RG 11/27/2022, 10:26 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =59.9 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.599
C) Water Quality Capture Volume (WQCV) for a 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 rain garden area) Area = 35,284 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =555 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =423 sq ft
D) Actual Flat Surface Area AActual =458 sq ft
E) Area at Design Depth (Top Surface Area)ATop =873 sq ft
F) Rain Garden Total Volume VT=666 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-1) LID 6
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_BASIN F-1.xlsm, RG 11/27/2022, 10:29 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =27.7 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.277
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.12 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 358,063 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER =3,440 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 (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =1984 sq ft
D) Actual Flat Surface Area AActual =3107 sq ft
E) Area at Design Depth (Top Surface Area)ATop =4061 sq ft
F) Rain Garden Total Volume VT=3,584 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
BAMG
TST INC. CONSULTING ENGINEERS
November 27, 2022
MONTAVA SUBDIVISION
RAIN GARDEN (BASIN F-15) LID 7
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_ST-01_G2 SOUTH.xlsm, RG 11/27/2022, 10:31 AM
Appendix C
FEMA FLOOD INSURANCE
RATE MAP
National Flood Hazard Layer FIRMette
0 500 1,000 1,500 2,000250
Feet
Ü
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
SPECIAL FLOOD
HAZARD AREAS
Without Base Flood Elevation (BFE)
Zone A, V, A99
With BFE or DepthZone AE, AO, AH, VE, AR
Regulatory Floodway
0.2% Annual Chance Flood Hazard, Areas
of 1% annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mileZone X
Future Conditions 1% Annual
Chance Flood HazardZone X
Area with Reduced Flood Risk due to
Levee. See Notes.Zone X
Area with Flood Risk due to LeveeZone D
NO SCREEN Area of Minimal Flood Hazard Zone X
Area of Undetermined Flood HazardZone D
Channel, Culvert, or Storm Sewer
Levee, Dike, or Floodwall
Cross Sections with 1% Annual Chance
17.5 Water Surface Elevation
Coastal Transect
Coastal Transect Baseline
Profile Baseline
Hydrographic Feature
Base Flood Elevation Line (BFE)
Effective LOMRs
Limit of Study
Jurisdiction Boundary
Digital Data Available
No Digital Data Available
Unmapped
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
authoritative NFHL web services provided by FEMA. This map
was exported on 10/12/2021 at 3:48 PM and does not
reflect changes or amendments subsequent to this date and
time. The NFHL and effective information may change or
become superseded by new data over time.
This map image is void if the one or more of the following map
elements do not appear: basemap imagery, flood zone labels,
legend, scale bar, map creation date, community identifiers,
FIRM panel number, and FIRM effective date. Map images for
unmapped and unmodernized areas cannot be used for
regulatory purposes.
Legend
OTHER AREAS OF
FLOOD HAZARD
OTHER AREAS
GENERAL
STRUCTURES
OTHER
FEATURES
MAP PANELS
8
B 20.2
The pin displayed on the map is an approximate
point selected by the user and does not represent
an authoritative property location.
1:6,000
105°1'53"W 40°36'53"N
105°1'16"W 40°36'25"N
Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020
Appendix D
USDA HYDROLOGIC SOIL
GROUP MAP
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Area, ColoradoNatural
Resources
Conservation
Service
November 26, 2022
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado......................................................................14
5—Aquepts, loamy......................................................................................14
7—Ascalon sandy loam, 0 to 3 percent slopes...........................................15
22—Caruso clay loam, 0 to 1 percent slope...............................................16
35—Fort Collins loam, 0 to 3 percent slopes..............................................18
53—Kim loam, 1 to 3 percent slopes..........................................................19
54—Kim loam, 3 to 5 percent slopes..........................................................20
94—Satanta loam, 0 to 1 percent slopes....................................................22
95—Satanta loam, 1 to 3 percent slopes....................................................23
98—Satanta Variant clay loam, 0 to 3 percent slopes.................................24
101—Stoneham loam, 1 to 3 percent slopes..............................................26
102—Stoneham loam, 3 to 5 percent slopes..............................................27
103—Stoneham loam, 5 to 9 percent slopes..............................................29
Soil Information for All Uses...............................................................................31
Soil Properties and Qualities..............................................................................31
Soil Qualities and Features.............................................................................31
Hydrologic Soil Group.................................................................................31
References............................................................................................................36
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
449550044956004495700449580044959004496000449610044962004496300449550044956004495700449580044959004496000449610044962004496300497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600
497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600
40° 37' 5'' N 105° 2' 2'' W40° 37' 5'' N105° 0' 57'' W40° 36' 33'' N
105° 2' 2'' W40° 36' 33'' N
105° 0' 57'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 100 200 400 600
Meters
Map Scale: 1:6,960 if printed on A landscape (11" x 8.5") 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
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 17, Sep 7, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 2, 2021—Aug 25,
2021
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
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Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
5 Aquepts, loamy 5.0 2.8%
7 Ascalon sandy loam, 0 to 3
percent slopes
0.0 0.0%
22 Caruso clay loam, 0 to 1
percent slope
27.0 15.1%
35 Fort Collins loam, 0 to 3 percent
slopes
49.5 27.6%
53 Kim loam, 1 to 3 percent slopes 0.3 0.2%
54 Kim loam, 3 to 5 percent slopes 1.0 0.6%
94 Satanta loam, 0 to 1 percent
slopes
4.6 2.6%
95 Satanta loam, 1 to 3 percent
slopes
0.0 0.0%
98 Satanta Variant clay loam, 0 to
3 percent slopes
57.9 32.3%
101 Stoneham loam, 1 to 3 percent
slopes
21.3 11.9%
102 Stoneham loam, 3 to 5 percent
slopes
5.9 3.3%
103 Stoneham loam, 5 to 9 percent
slopes
6.6 3.7%
Totals for Area of Interest 179.1 100.0%
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
Custom Soil Resource Report
11
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,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
Custom Soil Resource Report
12
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
13
Larimer County Area, Colorado
5—Aquepts, loamy
Map Unit Setting
National map unit symbol: jpws
Elevation: 4,500 to 6,700 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 39 to 50 degrees F
Frost-free period: 80 to 140 days
Farmland classification: Not prime farmland
Map Unit Composition
Aquepts and similar soils:80 percent
Minor components:20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Aquepts
Setting
Landform:Draws, depressions, stream terraces
Landform position (three-dimensional):Base slope, tread, dip
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Loamy alluvium
Typical profile
H1 - 0 to 60 inches: variable
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Very poorly drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to very
high (0.60 to 99.90 in/hr)
Depth to water table:About 6 to 18 inches
Frequency of flooding:NoneRare
Frequency of ponding:None
Interpretive groups
Land capability classification (irrigated): 5w
Land capability classification (nonirrigated): 3w
Hydrologic Soil Group: A/D
Ecological site: R067BY073CO - Riparian
Hydric soil rating: Yes
Minor Components
Nunn
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Kim
Percent of map unit:5 percent
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Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Stoneham
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Fort collins
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
7—Ascalon sandy loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2swl3
Elevation: 3,870 to 5,960 feet
Mean annual precipitation: 12 to 16 inches
Mean annual air temperature: 46 to 57 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Ascalon and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Ascalon
Setting
Landform:Interfluves
Landform position (two-dimensional):Summit
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Wind-reworked alluvium and/or calcareous sandy eolian deposits
Typical profile
Ap - 0 to 6 inches: sandy loam
Bt1 - 6 to 12 inches: sandy clay loam
Bt2 - 12 to 19 inches: sandy clay loam
Bk - 19 to 35 inches: sandy clay loam
C - 35 to 80 inches: sandy loam
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Custom Soil Resource Report
15
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Sodium adsorption ratio, maximum:1.0
Available water supply, 0 to 60 inches: Moderate (about 7.7 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4c
Hydrologic Soil Group: B
Ecological site: R067BY024CO - Sandy Plains
Hydric soil rating: No
Minor Components
Olnest
Percent of map unit:10 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY024CO - Sandy Plains
Hydric soil rating: No
Vona
Percent of map unit:5 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY024CO - Sandy Plains
Hydric soil rating: No
22—Caruso clay loam, 0 to 1 percent slope
Map Unit Setting
National map unit symbol: jpvt
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Caruso and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
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Description of Caruso
Setting
Landform:Flood-plain steps, stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium
Typical profile
H1 - 0 to 35 inches: clay loam
H2 - 35 to 44 inches: fine sandy loam
H3 - 44 to 60 inches: gravelly sand
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:About 24 to 48 inches
Frequency of flooding:NoneOccasional
Frequency of ponding:None
Calcium carbonate, maximum content:5 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.4 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: D
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Loveland
Percent of map unit:9 percent
Landform:Terraces
Ecological site:R067BY036CO - Overflow
Hydric soil rating: Yes
Fluvaquents
Percent of map unit:6 percent
Landform:Terraces
Hydric soil rating: Yes
Custom Soil Resource Report
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35—Fort Collins loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlnc
Elevation: 4,020 to 6,730 feet
Mean annual precipitation: 14 to 16 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform:Stream terraces, interfluves
Landform position (three-dimensional):Interfluve, tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Pleistocene or older alluvium and/or eolian deposits
Typical profile
Ap - 0 to 4 inches: loam
Bt1 - 4 to 9 inches: clay loam
Bt2 - 9 to 16 inches: clay loam
Bk1 - 16 to 29 inches: loam
Bk2 - 29 to 80 inches: loam
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.20 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:12 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
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Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:10 percent
Landform:Stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Vona
Percent of map unit:5 percent
Landform:Interfluves
Landform position (three-dimensional):Interfluve, side slope
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY024CO - Sandy Plains
Hydric soil rating: No
53—Kim loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpwx
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Kim and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform:Fans
Landform position (three-dimensional):Base slope
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium
Typical profile
H1 - 0 to 7 inches: loam
H2 - 7 to 60 inches: clay loam
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Properties and qualities
Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Fort collins
Percent of map unit:6 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Stoneham
Percent of map unit:3 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Aquic haplustolls
Percent of map unit:1 percent
Landform:Swales
Hydric soil rating: Yes
54—Kim loam, 3 to 5 percent slopes
Map Unit Setting
National map unit symbol: jpwy
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Kim and similar soils:90 percent
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Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform:Fans
Landform position (three-dimensional):Base slope
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium
Typical profile
H1 - 0 to 7 inches: loam
H2 - 7 to 60 inches: clay loam
Properties and qualities
Slope:3 to 5 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Thedalund
Percent of map unit:4 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Stoneham
Percent of map unit:3 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Fort collins
Percent of map unit:2 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Aquic haplustolls
Percent of map unit:1 percent
Landform:Swales
Hydric soil rating: Yes
Custom Soil Resource Report
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94—Satanta loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: 2wz89
Elevation: 3,670 to 5,410 feet
Mean annual precipitation: 10 to 23 inches
Mean annual air temperature: 45 to 52 degrees F
Frost-free period: 105 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Satanta and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta
Setting
Landform:Alluvial fans
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
Ap - 0 to 10 inches: loam
Bt - 10 to 17 inches: clay loam
C - 17 to 79 inches: loam
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20
to 0.60 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Very high (about 12.3 inches)
Interpretive groups
Land capability classification (irrigated): 1
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: C
Ecological site: R072XY111KS - Sandy Plains
Hydric soil rating: No
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Minor Components
Nunn
Percent of map unit:5 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R072XY108KS - Loamy Lowland
Hydric soil rating: No
Fort collins
Percent of map unit:5 percent
Landform:Alluvial fans
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R072XY111KS - Sandy Plains
Hydric soil rating: No
95—Satanta loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2w5f3
Elevation: 3,670 to 5,410 feet
Mean annual precipitation: 14 to 23 inches
Mean annual air temperature: 46 to 54 degrees F
Frost-free period: 130 to 163 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Satanta and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta
Setting
Landform:Paleoterraces
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Eolian sands
Typical profile
Ap - 0 to 9 inches: loam
Bt - 9 to 18 inches: clay loam
C - 18 to 79 inches: loam
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Properties and qualities
Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20
to 0.60 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Very high (about 12.2 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: R067BY024CO - Sandy Plains
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:5 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Fort collins
Percent of map unit:5 percent
Landform:Alluvial fans
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY024CO - Sandy Plains
Hydric soil rating: No
98—Satanta Variant clay loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpyh
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
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Farmland classification: Prime farmland if irrigated
Map Unit Composition
Satanta variant and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta Variant
Setting
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
H1 - 0 to 9 inches: clay loam
H2 - 9 to 22 inches: clay loam
H3 - 22 to 60 inches: loam
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:About 24 to 48 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Gypsum, maximum content:10 percent
Maximum salinity:Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.7 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: D
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Caruso
Percent of map unit:3 percent
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
Loveland
Percent of map unit:2 percent
Ecological site:R067BY036CO - Overflow
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Hydric soil rating: No
101—Stoneham loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jptt
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Stoneham and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Stoneham
Setting
Landform:Benches, terraces
Landform position (three-dimensional):Base slope, tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium and/or eolian deposits
Typical profile
H1 - 0 to 4 inches: loam
H2 - 4 to 10 inches: sandy clay loam
H3 - 10 to 60 inches: clay loam
Properties and qualities
Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Custom Soil Resource Report
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Minor Components
Fort collins
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Kim
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
102—Stoneham loam, 3 to 5 percent slopes
Map Unit Setting
National map unit symbol: 2x0j1
Elevation: 3,500 to 6,500 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 46 to 54 degrees F
Frost-free period: 115 to 155 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Stoneham and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Stoneham
Setting
Landform:Low hills, interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvial and/or eolian tertiary aged pedisediment
Typical profile
Ap - 0 to 4 inches: loam
Bt - 4 to 9 inches: clay loam
Btk - 9 to 13 inches: clay loam
Bk1 - 13 to 18 inches: loam
Bk2 - 18 to 34 inches: loam
C - 34 to 80 inches: loam
Properties and qualities
Slope:3 to 5 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
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Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.20 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:12 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Sodium adsorption ratio, maximum:0.5
Available water supply, 0 to 60 inches: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 4c
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Satanta
Percent of map unit:5 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Kimst
Percent of map unit:5 percent
Landform:Interfluves, low hills
Landform position (two-dimensional):Shoulder, backslope
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Weld
Percent of map unit:5 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Custom Soil Resource Report
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103—Stoneham loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jptw
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Farmland of local importance
Map Unit Composition
Stoneham and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Stoneham
Setting
Landform:Benches, terraces
Landform position (three-dimensional):Side slope, tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium and/or eolian deposits
Typical profile
H1 - 0 to 3 inches: loam
H2 - 3 to 9 inches: clay loam
H3 - 9 to 60 inches: clay loam
Properties and qualities
Slope:5 to 9 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 6e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: R067BY008CO - Loamy Slopes
Hydric soil rating: No
Custom Soil Resource Report
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Minor Components
Kim
Percent of map unit:8 percent
Ecological site:R067BY008CO - Loamy Slopes
Hydric soil rating: No
Larimer
Percent of map unit:5 percent
Ecological site:R067BY008CO - Loamy Slopes
Hydric soil rating: No
Fort collins
Percent of map unit:2 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Custom Soil Resource Report
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Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Hydrologic Soil Group
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
31
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Custom Soil Resource Report
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33
Custom Soil Resource Report
Map—Hydrologic Soil Group
449550044956004495700449580044959004496000449610044962004496300449550044956004495700449580044959004496000449610044962004496300497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600
497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600
40° 37' 5'' N 105° 2' 2'' W40° 37' 5'' N105° 0' 57'' W40° 36' 33'' N
105° 2' 2'' W40° 36' 33'' N
105° 0' 57'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 100 200 400 600
Meters
Map Scale: 1:6,960 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
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
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 17, Sep 7, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 2, 2021—Aug 25,
2021
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
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Table—Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
5 Aquepts, loamy A/D 5.0 2.8%
7 Ascalon sandy loam, 0 to
3 percent slopes
B 0.0 0.0%
22 Caruso clay loam, 0 to 1
percent slope
D 27.0 15.1%
35 Fort Collins loam, 0 to 3
percent slopes
C 49.5 27.6%
53 Kim loam, 1 to 3 percent
slopes
B 0.3 0.2%
54 Kim loam, 3 to 5 percent
slopes
B 1.0 0.6%
94 Satanta loam, 0 to 1
percent slopes
C 4.6 2.6%
95 Satanta loam, 1 to 3
percent slopes
C 0.0 0.0%
98 Satanta Variant clay
loam, 0 to 3 percent
slopes
D 57.9 32.3%
101 Stoneham loam, 1 to 3
percent slopes
B 21.3 11.9%
102 Stoneham loam, 3 to 5
percent slopes
C 5.9 3.3%
103 Stoneham loam, 5 to 9
percent slopes
B 6.6 3.7%
Totals for Area of Interest 179.1 100.0%
Rating Options—Hydrologic Soil Group
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
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References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
36
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
37
Appendix E
DRAINAGE PLANS
842438426POND EPOND A1424430436435OVERFLOW42924274.17477363535297303022925426426_OVER757228POND BPOND D26.1POND F426MAPLE HILLSUBDIVISIONSTORYBOOKSUBDIVISIONSODFARMANHEUSERBUSCHWATERGLENSUBDIVISIONTRAIL HEADSUBDIVISIONL&W CANALNO. 8 DITCHL&W CANALN. GIDDINGS RD.C&S RAILROADI-25RICHARDS LAKE RD. (CR 52)MOUNTAIN VISTA DR. (CR 50)9079099042131.18334357298294317307258418311689143731427.1822427POND C43483424POND A42512499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215303.431.6100 MARTINMARTIN.COMMONTAVAMASTER DRAINAGE PLANDEVELOPED ROUTING SCHEMATICD1
12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215303.431.6100 MARTINMARTIN.COMMONTAVAMASTER DRAINAGE PLANDEVELOPED ROUTING SCHEMATICD2DIVERSION SUMMARYSWMMELEMENTQ100 INFLOW(CFS)Q100 DIVERTED(CFS)Q100REMAINING(CFS)833.1 408 279125842 1000 617384OUTFALL SUMMARYSWMMELEMENTQ100 (CFS)904 138907 385909 729POND SUMMARYSWMM ELEMENTQ100 IN (CFS) Q100 OUT (CFS) VOLUME (AC-FT)425 883 819 47426 1322 760 307429 1000 390 13.6430 231 295.5435 468 41530436 1562 1548 25438 732 0 88426 OVERFLOW 167 138 59POND A 1807 1042 123POND A1 76122.8POND A2 78 3.5 3.0POND B 627.22.3POND C 1077.14.6POND D1728.6 9.0POND E17491 3.2POND F 166 6.4 11.4BASIN SUMMARYBASIN IDAREA (AC)% IMPQ2 (CFS) Q100 (CFS)A112.1801170A213.3 801278B 16.6 50 10 62C1 27.6 50 17 107C2 82.0 50 38 246D 47.3 60 26 172E 83.9 25 25 159F 46.9 60 25 166G1 80.4 80 36 249G2 10.0 80 9 59H 45.6 10 10 53I1 58.2 10 8 49I2 34.8 2 2 11J1 20.5 50 9 58J2 22.2 50 18 101J344.550 25 158K122.8 601173K260.0 6027180L 110.5 60 55 361M 42.02214N 86.6 80 61 400O 60.8 10 12 65P 30.2 2 2 12OS-1 45.0 20 11 7124 33.74544 28029 268.8 29 192 100030 33.5 49 44 23137 34.6 232214838 290.7 542469200 33.6 5 5 46DESIGN POINT SUMMARYSWMM ELEMENTQ100 (CFS)16 152138531 35531.1 33831.2 277427 319427.1 6427.29431 1312434 7437 333439 1043442 53725 513729415730 28822 249829 513831224833 138834 1781841 396891 418CONVEYANCE ELEMENT SUMMARYSWMMELEMENTQ100 (CFS)21 38524725 51226 23926.1 626.2 927 1780284529 41330 2731 35331.1 33831.2 27631.3 27134 104335 46872 22473 13974 12574.1 39675 39177 1000229 513231 1310237 310242 493426 760426_OVERFLOW167CULVERT SIZE BY DESIGN POINTSWMMELEMENTBARRELS-SIZEQ100 (CFS)HEADWATER DEPTH(FT)21 2-8x4 3854.4312-7x4355 4.631.1 2-8x4 338 4.131.2 4-48"D2774.1427 2-6x4 319 4.7427.1 1-18"D 6 1.6427.2 1-18"D 9 2.64311-15x10 & 1-5x121312 7.6434 1-18"D 7 1.9437 3-6x3 333 4.2822 3-48"D 249 4.6831 3-48"D2244.3833 2-48"D 138 4.18344-10X51781 7.38412-5X5396 6.29041-60"D138 13.0
Appendix F
DETENTION DESIGN
Project:
Basin ID:
Design Information (Input):Design Information (Input):
Catchment Drainage Imperviousness Ia = 80.00 percent Catchment Drainage Imperviousness Ia = 80.00 percent
Catchment Drainage Area A = 8.22 acres Catchment Drainage Area A = 8.22 acres
Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D
Return Period for Detention Control T = years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc = 18 minutes Time of Concentration of Watershed Tc = 18 minutes
Allowable Unit Release Rate q = cfs/acre Allowable Unit Release Rate q = 1.18 cfs/acre
One-hour Precipitation P1 = inches One-hour Precipitation P1 = 2.66 inches
Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3
Coefficient One C1 = 28.50 Coefficient One C1 = 28.50
Coefficient Two C2 = 10 Coefficient Two C2 =10
Coefficient Three C3 = 0.789 Coefficient Three C3 = 0.789
Determination of Average Outflow from the Basin (Calculated):Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C = Runoff Coefficient C = 0.74
Inflow Peak Runoff Qp-in = cfs Inflow Peak Runoff Qp-in = 33.27 cfs
Allowable Peak Outflow Rate Qp-out = cfs Allowable Peak Outflow Rate Qp-out =9.70 cfs
Mod. FAA Minor Storage Volume = 0 cubic feet Mod. FAA Major Storage Volume = 35,478 cubic feet
Mod. FAA Minor Storage Volume = 0.000 acre-ft Mod. FAA Major Storage Volume = 0.814 acre-ft
2 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet
(input)(output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output)
0 0.00 0.000 0.00 0 0.00 0.000 0.00 0.00 0.000 0.000
2 0.00 0.000 0.00 2 10.67 0.179 1.00 9.70 0.027 0.152
4 0.00 0.000 0.00 4 9.45 0.317 1.00 9.70 0.053 0.263
6 0.00 0.000 0.00 6 8.51 0.428 1.00 9.70 0.080 0.347
8 0.00 0.000 0.00 8 7.75 0.519 1.00 9.70 0.107 0.413
10 0.00 0.000 0.00 10 7.13 0.598 1.00 9.70 0.134 0.464
12 0.00 0.000 0.00 12 6.62 0.665 1.00 9.70 0.160 0.505
14 0.00 0.000 0.00 14 6.18 0.724 1.00 9.70 0.187 0.537
16 0.00 0.000 0.00 16 5.80 0.777 1.00 9.70 0.214 0.564
18 0.00 0.000 0.00 18 5.47 0.825 1.00 9.70 0.240 0.584
20 0.00 0.000 0.00 20 5.18 0.868 0.95 9.21 0.254 0.614
22 0.00 0.000 0.00 22 4.92 0.907 0.91 8.82 0.267 0.640
24 0.00 0.000 0.00 24 4.69 0.944 0.88 8.49 0.281 0.663
26 0.00 0.000 0.00 26 4.49 0.977 0.85 8.21 0.294 0.683
28 0.00 0.000 0.00 28 4.30 1.008 0.82 7.97 0.307 0.701
30 0.00 0.000 0.00 30 4.13 1.038 0.80 7.76 0.321 0.717
32 0.00 0.000 0.00 32 3.97 1.065 0.78 7.58 0.334 0.731
34 0.00 0.000 0.00 34 3.83 1.091 0.76 7.42 0.347 0.743
36 0.00 0.000 0.00 36 3.70 1.115 0.75 7.27 0.361 0.754
38 0.00 0.000 0.00 38 3.57 1.138 0.74 7.15 0.374 0.764
40 0.00 0.000 0.00 40 3.46 1.160 0.73 7.03 0.387 0.773
42 0.00 0.000 0.00 42 3.36 1.181 0.71 6.93 0.401 0.780
44 0.00 0.000 0.00 44 3.26 1.201 0.70 6.83 0.414 0.787
46 0.00 0.000 0.00 46 3.17 1.220 0.70 6.75 0.428 0.792
48 0.00 0.000 0.00 48 3.08 1.238 0.69 6.67 0.441 0.797
50 0.00 0.000 0.00 50 3.00 1.256 0.68 6.60 0.454 0.801
52 0.00 0.000 0.00 52 2.92 1.273 0.67 6.53 0.468 0.805
54 0.00 0.000 0.00 54 2.85 1.289 0.67 6.47 0.481 0.808
56 0.00 0.000 0.00 56 2.78 1.305 0.66 6.41 0.494 0.810
58 0.00 0.000 0.00 58 2.72 1.320 0.66 6.35 0.508 0.812
60 0.00 0.000 0.00 60 2.65 1.334 0.65 6.30 0.521 0.813
62 0.00 0.000 0.00 62 2.60 1.348 0.65 6.26 0.534 0.814
64 0.00 0.000 0.00 64 2.54 1.362 0.64 6.21 0.548 0.814
66 0.00 0.000 0.00 66 2.49 1.376 0.64 6.17 0.561 0.814
68 0.00 0.000 0.00 68 2.44 1.388 0.63 6.13 0.574 0.814
70 0.00 0.000 0.00 70 2.39 1.401 0.63 6.10 0.588 0.813
72 0.00 0.000 0.00 72 2.34 1.413 0.63 6.06 0.601 0.812
74 0.00 0.000 0.00 74 2.30 1.425 0.62 6.03 0.615 0.811
76 0.00 0.000 0.00 76 2.26 1.437 0.62 6.00 0.628 0.809
78 0.00 0.000 0.00 78 2.22 1.448 0.62 5.97 0.641 0.807
80 0.00 0.000 0.00 80 2.18 1.459 0.61 5.94 0.655 0.804
82 0.00 0.000 0.00 82 2.14 1.470 0.61 5.91 0.668 0.802
84 0.00 0.000 0.00 84 2.10 1.480 0.61 5.89 0.681 0.799
86 0.00 0.000 0.00 86 2.07 1.491 0.60 5.86 0.695 0.796
88 0.00 0.000 0.00 88 2.04 1.501 0.60 5.84 0.708 0.793
90 0.00 0.000 0.00 90 2.00 1.511 0.60 5.82 0.721 0.789
92 0.00 0.000 0.00 92 1.97 1.520 0.60 5.80 0.735 0.785
94 0.00 0.000 0.00 94 1.94 1.530 0.60 5.78 0.748 0.781
96 0.00 0.000 0.00 96 1.91 1.539 0.59 5.76 0.762 0.777
98 0.00 0.000 0.00 98 1.89 1.548 0.59 5.74 0.775 0.773
100 0.00 0.000 0.00 100 1.86 1.557 0.59 5.72 0.788 0.769
102 0.00 0.000 0.00 102 1.83 1.566 0.59 5.71 0.802 0.764
104 0.00 0.000 0.00 104 1.81 1.574 0.59 5.69 0.815 0.759
106 0.00 0.000 0.00 106 1.78 1.582 0.58 5.67 0.828 0.754
108 0.00 0.000 0.00 108 1.76 1.591 0.58 5.66 0.842 0.749
110 0.00 0.000 0.00 110 1.73 1.599 0.58 5.64 0.855 0.744
112 0.00 0.000 0.00 112 1.71 1.607 0.58 5.63 0.868 0.738
114 0.00 0.000 0.00 114 1.69 1.615 0.58 5.62 0.882 0.733
116 0.00 0.000 0.00 116 1.67 1.622 0.58 5.60 0.895 0.727
118 0.00 0.000 0.00 118 1.65 1.630 0.58 5.59 0.909 0.721
120 0.00 0.000 0.00 120 1.63 1.637 0.58 5.58 0.922 0.716
Mod. FAA Minor Storage Volume (cubic ft.) = 0 Mod. FAA Major Storage Volume (cubic ft.) = 35,478
Mod. FAA Minor Storage Volume (acre-ft.) = 0.0000 Mod. FAA Major Storage Volume (acre-ft.) = 0.8145
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.35, Released January 2015
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Montava Subdivision
Pond G2
G2 FAA METHOD.xls, Modified FAA 11/29/2022, 5:59 PM
Project:
Basin ID:
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.35, Released January 2015
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Montava Subdivision
Pond G2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 20 40 60 80 100 120 140Volume (acre-feet)Duration (Minutes)
Inflow and Outflow Volumes vs. Rainfall Duration
Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume
G2 FAA METHOD.xls, Modified FAA 11/29/2022, 5:59 PM
MONTAVA SUBDIVISION PRELIMINARY DRAINAGE REPORT
% Imperviousness 90.00%
WQCV (inches)* =a(0.91i3-1.19i2+0.78i)0.40 inches
Volume = (WQCV/12)xA 0.33 ac-ft
*WQCV in 40-hr drain time a=0.9
from Figure 3-2. Water Quality Capture Volume (WQCV) Based on BMP Drain Time
UDFCD Storm Drainage Criteria Manual Volume 3
Water Quality Capture Volume (WQCV) Offsite Pond
Project:
Basin ID:
Depth Increment = ft
Watershed Information 4994 Top of Micropool -- 0.00 -- -- -- 4,400 0.101
Selected BMP Type =EDB 4995 -- 1.00 -- -- -- 7,154 0.164 5,777 0.133
Watershed Area = 46.90 acres 4996 -- 2.00 -- -- -- 8,696 0.200 13,702 0.315
Watershed Length = 1,700 ft 4997 -- 3.00 -- -- -- 10,640 0.244 23,369 0.536
Watershed Length to Centroid = 850 ft 4998 -- 4.00 -- -- -- 13,592 0.312 35,485 0.815
Watershed Slope =0.020ft/ft -- ------
Watershed Imperviousness = 65.00% percent -- -- -- --
Percentage Hydrologic Soil Group A = percent -- -- -- --
Percentage Hydrologic Soil Group B = percent -- -- -- --
Percentage Hydrologic Soil Groups C/D = percent -- -- -- --
Target WQCV Drain Time = 40.0 hours -- -- -- --
Location for 1-hr Rainfall Depths = Denver - Capitol Building -- -- -- --
-- -- -- --
-- -- -- --
Optional User Overrides -- -- -- --
Water Quality Capture Volume (WQCV) = 0.993 acre-feet acre-feet -- -- -- --
Excess Urban Runoff Volume (EURV) = acre-feet acre-feet -- -- -- --
2-yr Runoff Volume (P1 = 0.83 in.) = acre-feet inches -- -- -- --
5-yr Runoff Volume (P1 = 1.09 in.) = acre-feet inches -- -- -- --
10-yr Runoff Volume (P1 = 1.33 in.) = acre-feet inches -- -- -- --
25-yr Runoff Volume (P1 = 1.69 in.) = acre-feet inches -- -- -- --
50-yr Runoff Volume (P1 = 1.99 in.) = acre-feet inches -- -- -- --
100-yr Runoff Volume (P1 = 2.31 in.) = acre-feet inches -- -- -- --
500-yr Runoff Volume (P1 = 3.14 in.) = acre-feet inches -- -- -- --
Approximate 2-yr Detention Volume = acre-feet -- -- -- --
Approximate 5-yr Detention Volume = acre-feet -- -- -- --
Approximate 10-yr Detention Volume = acre-feet -- -- -- --
Approximate 25-yr Detention Volume = acre-feet -- -- -- --
Approximate 50-yr Detention Volume = acre-feet -- -- -- --
Approximate 100-yr Detention Volume = acre-feet -- -- -- --
-- -- -- --
Define Zones and Basin Geometry -- -- -- --
Select Zone 1 Storage Volume (Required) = acre-feet -- -- -- --
Select Zone 2 Storage Volume (Optional) = acre-feet -- -- -- --
Select Zone 3 Storage Volume (Optional) = acre-feet -- -- -- --
Total Detention Basin Volume = acre-feet -- -- -- --
Initial Surcharge Volume (ISV) = user ft 3 -- -- -- --
Initial Surcharge Depth (ISD) = user ft -- -- -- --
Total Available Detention Depth (Htotal) =userft -- ------
Depth of Trickle Channel (HTC) =userft -- ------
Slope of Trickle Channel (STC) = user ft/ft -- -- -- --
Slopes of Main Basin Sides (Smain) = user H:V -- -- -- --
Basin Length-to-Width Ratio (RL/W) =user -- ------
-- -- -- --
Initial Surcharge Area (AISV) =ft 2 -- -- -- --
Surcharge Volume Length (LISV) =ft -- -- -- --
Surcharge Volume Width (WISV) =ft -- -- -- --
Depth of Basin Floor (HFLOOR) =ft -- -- -- --
Length of Basin Floor (LFLOOR) =ft -- -- -- --
Width of Basin Floor (WFLOOR) =ft -- -- -- --
Area of Basin Floor (AFLOOR) =ft 2 -- -- -- --
Volume of Basin Floor (VFLOOR) =ft 3 -- -- -- --
Depth of Main Basin (HMAIN) =ft -- -- -- --
Length of Main Basin (LMAIN) =ft -- -- -- --
Width of Main Basin (WMAIN) =ft -- -- -- --
Area of Main Basin (AMAIN) =ft 2 -- -- -- --
Volume of Main Basin (VMAIN) =ft 3 -- -- -- --
Calculated Total Basin Volume (Vtotal) =acre-feet -- -- -- --
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After providing required inputs above including 1-hour rainfall
depths, click 'Run CUHP' to generate runoff hydrographs using
the embedded Colorado Urban Hydrograph Procedure.
Volume
(ft 3)
Volume
(ac-ft)
Area
(acre)
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)
Montava Subdivision
Pond G2
MHFD-Detention, Version 4.05 (January 2022)
ExampleZone Configuration (Retention Pond)
Pond G2.xlsm, Basin 11/29/2022, 2:21 PM
1 User Defined Stage-Area Booleans for Message
1 Equal Stage-Area Inputs Watershed L:W
0 CountA Watershed Lc:L
Watershed Slope
0 Calc_S_TC Booleans for CUHP
0 CUHP Inputs Complete
H_FLOOR CUHP Results Calculated
L_FLOOR_OTHER
0.00 ISV 0.00 ISV
0.00 Floor #N/A #N/A
#N/A Zone 1 #N/A #N/A
0.00 Zone 2 #N/A #N/A
0.00 Zone 3 #N/A #N/A
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
MHFD-Detention, Version 4.05 (January 2022)
0.000
0.670
1.340
2.010
2.680
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
5600
11200
16800
22400
0
45
90
135
180
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.)
Pond G2.xlsm, Basin 11/29/2022, 2:21 PM
Project:
Basin ID:
Estimated Estimated
Stage (ft) Volume (ac-ft) Outlet Type
Zone 1 (WQCV) 2.08 0.330 Orifice Plate
Zone 2
Zone 3
Total (all zones) 0.330
User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP)Calculated Parameters for Underdrain
Underdrain Orifice Invert Depth = N/A ft (distance below the filtration media surface) Underdrain Orifice Area = N/A ft2
Underdrain Orifice Diameter = N/A inches Underdrain Orifice Centroid = N/A 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
Centroid of Lowest Orifice = 0.00 ft (relative to basin bottom at Stage = 0 ft) WQ Orifice Area per Row = 1.229E-02 ft2
Depth at top of Zone using Orifice Plate = 2.09 ft (relative to basin bottom at Stage = 0 ft) Elliptical Half-Width = N/A feet
Orifice Plate: Orifice Vertical Spacing = 4.00 inches Elliptical Slot Centroid = N/A feet
Orifice Plate: Orifice Area per Row = 1.77 sq. inches (diameter = 1-1/2 inches) Elliptical Slot Area = N/A ft2
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) 0.00 0.30 0.60 0.90 1.20 1.50 1.80
Orifice Area (sq. inches) 1.77 1.77 1.77 1.77 1.77 1.77 1.77
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 Orifi
Not Selected Not Selected Not Selected Not Selected
Invert of Vertical Orifice = ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Area =
Depth at top of Zone using Vertical Orifice = ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Centroid =
Vertical Orifice Diameter = inches
User Input: Overflow Weir (Dropbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir and No Outlet Pipe) Calculated Parameters for Overflow We
grate Not Selected Not Selected Not Selected Not Selected
Overflow Weir Front Edge Height, Ho = ft (relative to basin bottom at Stage = 0 ft)Height of Grate Upper Edge, Ht =
Overflow Weir Front Edge Length = feet Overflow Weir Slope Length =
Overflow Weir Grate Slope = H:V Grate Open Area / 100-yr Orifice Area =
Horiz. Length of Weir Sides = feet Overflow Grate Open Area w/o Debris =
Overflow Grate Type =Overflow Grate Open Area w/ Debris =
Debris Clogging % = %
User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice)Calculated Parameters for Outlet Pipe w/ Flow Restriction Pla
Not Selected Not Selected Not Selected Not Selected
Depth to Invert of Outlet Pipe = ft (distance below basin bottom at Stage = 0 ft)Outlet Orifice Area =
Circular Orifice Diameter = inches Outlet Orifice Centroid =
Half-Central Angle of Restrictor Plate on Pipe = N/A N/A
User Input: Emergency Spillway (Rectangular or Trapezoidal)Calculated Parameters for Spillway
Spillway Invert Stage= ft (relative to basin bottom at Stage = 0 ft) Spillway Design Flow Depth= feet
Spillway Crest Length = feet Stage at Top of Freeboard = feet
Spillway End Slopes = H:V Basin Area at Top of Freeboard = acres
Freeboard above Max Water Surface = feet Basin Volume at Top of Freeboard = acre-ft
Max Ponding Depth of Target Storage Volume =2.08 feet Discharge at Top of Freeboard = cfs
Routed Hydrograph Results
Design Storm Return Period =WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year
One-Hour Rainfall Depth (in) =N/A N/A 0.83 1.09 1.33 1.69 1.99 2.31
CUHP Runoff Volume (acre-ft) =0.330 0.749 0.483 0.666 0.837 1.103 1.323 1.561
Inflow Hydrograph Volume (acre-ft) =N/A N/A 0.483 0.666 0.837 1.103 1.323 1.561
CUHP Predevelopment Peak Q (cfs) =N/A N/A 0.1 0.4 1.3 3.7 5.1 6.9
OPTIONAL Override Predevelopment Peak Q (cfs) =N/A N/A
Predevelopment Unit Peak Flow, q (cfs/acre) =N/A N/A 0.01 0.05 0.15 0.45 0.62 0.84
Peak Inflow Q (cfs) =N/A N/A 6.6 9.0 11.0 15.1 18.1 21.7
Peak Outflow Q (cfs) =0.4 0.7 0.5 0.6 0.7 0.7 0.7 0.7
Ratio Peak Outflow to Predevelopment Q =N/A N/A N/A 1.6 0.5 0.2 0.1 0.1
Structure Controlling Flow =Plate Plate Plate Plate Plate N/A N/A N/A
Max Velocity through Grate 1 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A
Max Velocity through Grate 2 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A
Time to Drain 97% of Inflow Volume (hours) =34 36 36 36 37 38 40 42
Time to Drain 99% of Inflow Volume (hours) =39 44 42 44 46 49 51 53
Maximum Ponding Depth (ft) =2.08 3.79 2.47 3.16 3.73 4.00 4.00 4.00
Area at Maximum Ponding Depth (acres) =0.20 0.30 0.22 0.25 0.29 0.31 0.31 0.31
Maximum Volume Stored (acre-ft) =0.331 0.751 0.411 0.574 0.730 0.815 0.815 0.815
DETENTION BASIN OUTLET STRUCTURE DESIGN
MHFD-Detention, Version 4.05 (January 2022)
Montava Subdivision
Pond G2
The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table (Columns W through AF).
Example Zone Configuration (Retention Pond)
Pond G2.xlsm, Outlet Structure 11/29/2022, 3:28 PM
ice
ft2
feet
eir
feet
feet
ft2
ft2
ate
ft2
feet
radians
500 Year
3.14
2.171
2.171
11.1
1.35
30.0
0.7
0.1
N/A
N/A
N/A
49
61
4.00
0.31
0.815
).
Pond G2.xlsm, Outlet Structure 11/29/2022, 3:28 PM
COUNTA for Basin Tab = 1 Ao Dia WQ Plate Type Vert Orifice 1Vert Orifice 2
Count_Underdrain = 0 0.11 eter = 3/8 inch) 2 1 1
Count_WQPlate = 1 0.14 ter = 7/16 inch)
Count_VertOrifice1 = 0 0.18 eter = 1/2 inch)Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean
Count_VertOrifice2 = 0 0.24 ter = 9/16 inch) 1 1 5yr, <72hr 0
Count_Weir1 = 0 0.29 eter = 5/8 inch) >5yr, <120hr 0
Count_Weir2 = 0 0.36 er = 11/16 inch) Max Depth Row
Count_OutletPipe1 = 0 0.42 eter = 3/4 inch)WQCV 209
Count_OutletPipe2 = 0 0.50 er = 13/16 inch)2 Year 248
COUNTA_2 (Standard FSD Setup)= 0 0.58 eter = 7/8 inch)EURV 380
Hidden Parameters & Calculations 0.67 er = 15/16 inch) 5 Year 317
MaxPondDepth_Error? FALSE 0.76 meter = 1 inch) 10 Year 374 Spillway Depth
Cd_Broad-Crested Weir 3.00 0.86 = 1-1/16 inches) 25 Year 401
WQ Plate Flow at 100yr depth = 0.73 0.97 = 1-1/8 inches) 50 Year 401
CLOG #1= 100% 1.08 = 1-3/16 inches) 100 Year 401 1 Z1_Boolean
n*Cdw #1 = 0.00 1.20 = 1-1/4 inches) 500 Year 401 1 Z2_Boolean
n*Cdo #1 = 0.00 1.32 = 1-5/16 inches) Zone3_Pulldown Message 1 Z3_Boolean
Overflow Weir #1 Angle = 0.000 1.45 = 1-3/8 inches) Opening Message
CLOG #2= 100% 1.59 = 1-7/16 inches) Draintime Running
n*Cdw #2 = 0.00 1.73 = 1-1/2 inches) Outlet Boolean Outlet Rank Total (1 to 4)
n*Cdo #2 = 0.00 1.88 = 1-9/16 inches)Vertical Orifice 1 000
Overflow Weir #2 Angle = 0.000 2.03 = 1-5/8 inches)Vertical Orifice 2 0 0 Boolean
Underdrain Q at 100yr depth = 0.00 2.20 1-11/16 inches)Overflow Weir 1 00 0Max Depth
VertOrifice1 Q at 100yr depth = 0.00 2.36 = 1-3/4 inches)Overflow Weir 2 0 0 0 500yr Depth
VertOrifice2 Q at 100yr depth = 0.00 2.54 1-13/16 inches)Outlet Pipe 1 0 0 0 Freeboard
2.72 = 1-7/8 inches)Outlet Pipe 2 0 0 0 Spillway
Count_User_Hydrographs 0 2.90 1-15/16 inches) 0 Spillway Length
CountA_3 (EURV & 100yr) = 0 3.09 eter = 2 inches) FALSE Time Interval
CountA_4 (100yr Only) = 0 3.29 gular openings) Button Visibility Boolean
COUNTA_5 (FSD Weir Only)= 0 0 WQCV Underdrain
COUNTA_6 (EURV Weir Only)= 0 1 WQCV Plate
0EURV-WQCV Plate
Outlet1_Pulldown_Boolean 0 EURV-WQCV VertOriice
Outlet2_Pulldown_Boolean 0 Outlet 90% Qpeak
Outlet3_Pulldown_Boolean 0 Outlet Undetained
0 Weir Only 90% Qpeak
0 Five Year Ratio Plate
0 Five Year Ratio VertOrifice
EURV_draintime_user
Spillway Options
Offset
Overlapping
S-A-V-D Chart Axis Default X-axis Left Y-Axis Right Y-Axis
minimum bound 0.00 0 0
maximum bound 4.00 40,000 10
S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis
minimum bound
maximum bound
DETENTION BASIN OUTLET STRUCTURE DESIGN
MHFD-Detention, Version 4.05 (January 2022)
0
5
10
15
20
25
30
35
0.1 1 10FLOW [cfs]TIME [hr]
500YR IN
500YR OUT
100YR IN
100YR OUT
50YR IN
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
4.5
0.1 1 10 100PONDING DEPTH [ft]DRAIN TIME [hr]
500YR
100YR
50YR
25YR
10YR
5YR
2YR
EURV
WQCV
0
1
2
3
4
5
6
7
8
9
10
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 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]
Pond G2.xlsm, Outlet Structure 11/29/2022, 3:28 PM
Outflow Hydrograph Workbook Filename:
Inflow Hydrographs
The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program.
SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP
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]
5.00 min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.41
0:15:00 0.00 0.00 0.30 0.91 1.35 1.04 1.51 1.57 2.67
0:20:00 0.00 0.00 2.37 3.47 4.42 3.10 3.90 4.38 6.53
0:25:00 0.00 0.00 5.49 7.64 9.59 6.92 8.43 9.34 13.45
0:30:00 0.00 0.00 6.64 8.97 11.02 13.50 16.27 18.55 25.90
0:35:00 0.00 0.00 6.28 8.37 10.23 15.13 18.13 21.68 30.04
0:40:00 0.00 0.00 5.74 7.54 9.21 14.68 17.56 20.99 29.03
0:45:00 0.00 0.00 5.05 6.74 8.29 13.36 15.96 19.52 26.94
0:50:00 0.00 0.00 4.45 6.07 7.37 12.24 14.61 17.82 24.59
0:55:00 0.00 0.00 3.91 5.34 6.54 10.78 12.87 15.97 22.03
1:00:00 0.00 0.00 3.48 4.75 5.87 9.46 11.29 14.34 19.77
1:05:00 0.00 0.00 3.21 4.37 5.46 8.40 10.03 13.00 17.93
1:10:00 0.00 0.00 2.88 4.10 5.15 7.46 8.91 11.27 15.56
1:15:00 0.00 0.00 2.57 3.74 4.85 6.69 7.98 9.83 13.57
1:20:00 0.00 0.00 2.30 3.34 4.39 5.84 6.96 8.28 11.42
1:25:00 0.00 0.00 2.03 2.95 3.79 5.05 6.01 6.89 9.50
1:30:00 0.00 0.00 1.78 2.60 3.26 4.23 5.04 5.68 7.83
1:35:00 0.00 0.00 1.58 2.33 2.84 3.51 4.17 4.62 6.37
1:40:00 0.00 0.00 1.47 2.05 2.59 2.94 3.49 3.78 5.21
1:45:00 0.00 0.00 1.41 1.86 2.44 2.60 3.09 3.27 4.52
1:50:00 0.00 0.00 1.38 1.73 2.33 2.37 2.83 2.94 4.07
1:55:00 0.00 0.00 1.23 1.62 2.21 2.23 2.65 2.72 3.76
2:00:00 0.00 0.00 1.10 1.51 2.03 2.12 2.53 2.55 3.53
2:05:00 0.00 0.00 0.86 1.19 1.60 1.67 1.99 1.98 2.74
2:10:00 0.00 0.00 0.67 0.91 1.23 1.28 1.52 1.49 2.06
2:15:00 0.00 0.00 0.51 0.70 0.94 0.97 1.16 1.12 1.56
2:20:00 0.00 0.00 0.39 0.53 0.71 0.74 0.88 0.86 1.18
2:25:00 0.00 0.00 0.30 0.40 0.53 0.56 0.66 0.65 0.89
2:30:00 0.00 0.00 0.22 0.29 0.39 0.41 0.49 0.48 0.67
2:35:00 0.00 0.00 0.16 0.21 0.29 0.30 0.36 0.36 0.50
2:40:00 0.00 0.00 0.12 0.16 0.22 0.23 0.27 0.27 0.37
2:45:00 0.00 0.00 0.08 0.11 0.15 0.16 0.19 0.19 0.27
2:50:00 0.00 0.00 0.05 0.07 0.10 0.11 0.13 0.13 0.18
2:55:00 0.00 0.00 0.03 0.04 0.06 0.07 0.08 0.08 0.11
3:00:00 0.00 0.00 0.01 0.02 0.03 0.03 0.04 0.04 0.06
3:05:00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02
3:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:50:00 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
4:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
6:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
DETENTION BASIN OUTLET STRUCTURE DESIGN
Pond G2.xlsm, Outlet Structure 11/29/2022, 3:28 PM
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]
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).
DETENTION BASIN OUTLET STRUCTURE DESIGN
Stage - Storage
Description
MHFD-Detention, Version 4.05 (January 2022)
Pond G2.xlsm, Outlet Structure 11/29/2022, 3:28 PM