HomeMy WebLinkAboutCHRISTIAN BROTHERS AUTOMOTIVE - PDP - PDP170018 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPrepared For:
CHRISTIAN BROTHERS AUTOMOTIVE CENTER
17725 KATY FREEWAY, SUITE 200
HOUSTON, TX 77094
BLOCK 1– UPLANDS PROSPECT BUSINESS PARK P.U.D.
FORT COLLINS, CO
PDP DRAINAGE REPORT
May 17, 2017
Job #co 15298
PROJECT
SITE
INDEX
ITEM PAGE
GENERAL LOCATION & DESCRIPTION......................................................................... 1
DRAINAGE BASINS & SUB-BASINS............................................................................... 2
DRAINAGE DESIGN CRITERIA...................................................................................... 2
DRAINAGE FACILITY DESIGN........................................................................................ 5
CONCLUSIONS.............................................................................................................. 6
REFERENCES................................................................................................................. 6
ATTACHMENTS
Appendix A: Vicinity Map
Appendix B: Hydrologic Computations
Historic and Developed
Weighted C Factor
Time of Concentration
Peak Runoff
Design Tables
Appendix C: Hydraulic Computations
Appendix D: NRCS Soils Map
Appendix E: Flood Insurance Rate Map
Appendix F: Proposed Drainage Plan
Page | 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. A vicinity map has been provided in Appendix A.
2. The project is located in Block 1, Uplands Prospect Business Park P.U.D. in
the East ½ of Section 18, Township 7 North, Range 68 West of the 6th Prime
Meridian, City of Fort Collins, County of Larimer, State of Colorado.
3. The project site is located at the northeast corner of the intersection of East
Prospect Road and Academy Court.
4. There are no major drainage ways, facilities or easements within or adjacent
to the site.
5. To the northeast, the property is bound by the Great Western Railway, to the
south by East Prospect Road and to the west, Academy Court. Life Church of
Fort Collins and Front Range Community College are located on the west side
of Academy Court, The Coterie Natural Area lies south of East Prospect
Road, and Bath Garden Center and Nursery lies to the east of the site.
B. Description of Property
1. The total area of the Lot is 1.147 acres. The project will impact approximately
0.735 acres of the western lot area. The remaining 0.412 acres is covered by a
35- foot wide Platte River Power Authority and an overall 40.5-foot wide
Utility Easement, minimal disturbance will occur in the easement.
2. The eastern 40.5 feet of the property is an occupied utility easement, storm
and sanitary mains have been installed, and along the eastern edge is a Platte
River Power Authority transmission line. The remainder of the property is
undeveloped and is covered primarily with native grass and vegetation. The
site was over-lot graded at the time of development of the subdivision. The
majority of the site has a slight 1 to 3 percent slope to the northeast; the
eastern edge has a slope of 3 to 5 percent to the east. The NRCS Soil Report
classifies the soil as well drained. A copy of the report is provided in
Appendix D.
3. No major drainage ways directly impact the site. The Cache La Poudre River
lies to the north and Spring Creek lies to the south.
4. The project will include the construction of the service facility, parking,
associated utility installation & landscaping. On-site detention is provided on
the east side of the service facility.
5. There are no irrigation facilities on or near the project site.
6. Proposed land use is for a light automotive repair and service facility. The site
is zoned Industrial District (I) which allows this use.
Page | 2
C. Floodplain Submittal Requirements
1. The site is not in a floodplain.
2. The FEMA FIRM panel number 08069C0983H, revised May 2, 2012, was
reference and a copy is included in Appendix E.
3. A copy of the “City of Fort Collins Floodplain Review Checklist for 50%
Submittals” is included in Appendix E.
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. This project is in the Spring Creek Drainage Basin. A copy of the Spring
Creek Master Drainage Plan was not available from the City of Fort Collins
website, due to a statement that the master plan update is currently underway.
2. The area of the Spring Creek Drainage Basin the project is located in is mostly
developed. The project site is a single lot infill development.
3. No irrigation facilities are known to influence or be influenced by the local
drainage design of this project.
B. Sub-Basin Description
1. Historic drainage patterns for the property are typically from west to east and
northeast. The subdivision currently has internal streets and utility
infrastructure installed.
2. This Lot is protected from offsite flows, on the west and south sides by the
existing curb & gutters of Academy Court and E Prospect Road respectively.
This site slopes away from the existing streets and has no offsite flow impacts.
III. DRAINAGE DESIGN CRITERIA
A. Regulations
1. There are no deviations from the criteria. The site was designed to
accommodate the allowable parking numbers, emergency vehicle easements
with the most efficient layout. Runoff from impervious surfaces is conveyed
in vegetated swales with gentle slopes or overland on landscape surfaces to
the on-site detention pond. The detention pond was designed with Water
Quality Capture Volume (WQCV) in addition to the 100-year storm
developed runoff volume. The outlet structure is designed to slowly release
flows from frequent storm events and release flows up to a 100-year storm
event at no more than the 2-year historic runoff rate.
2. The project site has an existing storm sewer with catch basins installed in the
utility easement along the east boundary. The site’s detained flows will be
released into this existing storm sewer. By releasing site flows up to a 100-
Page | 3
year storm event at the 2-year historic rate into the existing storm sewer, flows
to the existing catch basins will be reduced over current condition events
which exceed a 2-year event.
B. Directly Connected Impervious Area (DCIA) and Four Step Process
Compliance
1. Employ Runoff Reduction Practices: This site uses a vegetated swale to convey site
runoff from the building, drive isle and parking areas to the detention pond.
2. Implement BMPs that provide a WQCV with slow release: This site uses a vegetated
swale in addition to a WQCV. The release rate of the WQCV is 40 hours.
3. Stabilize Drainageways: This site will release developed flows at a 2-yr historic rate
into an existing storm sewer system on the project site.
4. Implement Site Specific and Other Source Control BMPs: A separate Erosion and
Sediment Control Plan has been developed with source control BMPs used from
ground breaking operations to permanent stabilization installations.
C. Development Criteria Reference and Constraints
1. No adjacent drainage studies were available at the time this report was
written. All developed lots in the subject subdivision have on-site detention
ponds. This project site is protected from off-site runoff by existing curb and
gutter on the upslope sides. Developed flow from this site will be detained on-
site and released directly into the existing storm sewer at the 2-year historic
rate.
2. There are no known adjacent drainage studies. The Uplands Prospect Business
Park is bound on the east and west sides by existing railroad tracts. There are
no effects from adjacent drainage studies.
3. This Project Site is an infill development in an older subdivision.
Development of this site will not cause any drainage impact any existing
infrastructure.
D. Hydrological Criteria
1. Rainfall data was obtained from the City of Fort Collins Storm Drainage
Design Criteria Manual, Table RA-8. Rainfall data used for this design is as
follows:
2 year 0.82 in.
10 year 1.40 in.
100 year 2.86 in.
2. The Rational Method was used to calculate runoff. Per the Fort Collins Storm
water Criteria, the runoff coefficients were adjusted for infrequent storms.
Therefore the C100 was applied a frequency factor of Cf=1.25.
Page | 4
3. Detention pond sizing, outlet structure configuration, and discharge rates were
calculated using UDFCD equations and spreadsheets. Results were compared
to the City of Fort Collins, Rational Method Spreadsheet Template. The
detention storage was sized for WQCV plus the 100-year developed flows, the
release rate is the 2-year historic flow. Calculations in this study are based on
the disturbed area of 0.735 acres per discussions with City of Fort Collins
staff.
4. For the purposes of this design, the 2-year storm will be considered the Minor
storm, and the 100-year storm will be considered the Major storm.
5. No other calculation methods were used for this report. A.
E. Hydraulic Criteria
1. Per the Fort Collins Storm water Criteria, detention volume is calculated
using the Rational FAA method and per criteria, increased by 20% to account
for the larger resulting storage volume that would be obtained from SWMM
modeling. Per discussions with City of Fort Collins staff, the volume increase
is not required. This site is also less than 5 acres.
2. No additional drainage facility design criteria were used.
3. No modifications to any 100-year floodplain or floodway are proposed as part
of this project.
4. No modifications to any natural drainage ways are proposed as part of this
project.
F. Floodplain Regulations Compliance
1. A FEMA Map and a completed “City of Fort Collins Floodplain Review
Checklist for 50% Submittals” is included in Appendix E.
G. Modifications of Criteria
1. There is no modification of criteria requested.
H. Modifications of Criteria
2. There is no modification of criteria requested.
Storm Return
Period
Frequency Factor, Cf
2 to 10 1.00
11 to 25 1.10
26 to 50 1.20
51 to 100 1.25
Page | 5
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. Typical drainage patterns for this Lot are generally to the east and northeast,
toward the existing Great Western Railway tracks. Developed flows will be a
combination of sheet flow, concentrated gutter flow and grass swale. The
time of concentration for the project was calculated to the detention pond
outlet.
2. There are no off-site flows to consider on this project site.
3. Input and Output results of the Historic Condition and Developed Condition
UD-Rational analysis are in Appendix B. Input and Output results of the
Modified FAA Volume, WQCV and Stage Storage Table and the Fort
Collins Rational Method Spreadsheet, Detention Volume (Mass Balance) and
WQCV are in Appendix C.
4. The proposed drainage pattern will generally follow these existing drainage
patterns of west to east.
B. Specific Details
1. This site has a triangular shape with the low point being at the narrow end of
the lot and a wide utility easement on the east side of the lot. Detention area
was obtained by moving the building west on the lot to minimize impervious
areas and using the open space between the back of the building and utility
easement.
LID requirements were met by designing a bio-swale above the detention
pond to provide water quality benefits prior to the detention area. This bio-
swale has an area of approximately 10% of the impervious area of the paving
and ½ of the building. The east half of the building will drain directly into the
swale or the detention pond which will provide additional water quality
control for frequent, low intensity storms.
2. Detention storage & outlet design: The calculated 100-yr detention volume
plus Water Quality Capture Volume (WQCV) is 0.222 acre-ft using the UD-
FAA method spreadsheet. The calculated 100-yr detention volume plus
Water Quality Capture Volume (WQCV) is 0.221 acre-ft using the using the
City of Fort Collins Rational Method spreadsheet. This project used the more
conservative volume of 0.222 acre-ft for the project. The outlet will consist
of a single stage structure to release WQCV, then release at the 2-year
historic runoff rate up to the 100-yr plus WQCV elevation. WQCV of 0.030
acre-feet is provided in addition to the bio-swale benifits.
3. An overflow weir is designed to release flows that exceed the 100-yr storm
event runoff volume. The emergency flows will be directed towards existing
inlets installed on the storm sewer on the site.
4. Summary table: The required information can be found in Appendix C of this
report.
Page | 6
5. Maintenance access: The maintenance access will be from the north in the
drainage swale.
6. Easements: No easements are impacted as part of this project.
7. Offsite facilities: No new offsite facilities are required as part of this
project.
V. CONCLUSIONS
A. Compliance with standards
1. This report and drainage design is in compliance with all known criteria
published by the City of Fort Collins.
2. This drainage plan complies with the Spring Creek Master Plan based on
criteria conveyed from the City of Fort Collins. The updated Spring Creek
Master Plan was not available at the time of this study.
3. Compliance w/ City floodplain regulations. No floodplains are impacted as
part of this project.
4. Compliance w/ State & Federal regulations. This project is in compliance
with all known City, State and Federal regulations.
B. Drainage Concept
1. The concepts put forth in this study will be effective in maintaining the
historic flow rates for this site while providing adequate water quality
treatment.
2. This drainage plan complies with the City of Fort Collins Storm water
Criteria Manual and all know Master Drainage Plan recommendations.
VI. REFERENCES
1. City of Fort Collins, Colorado, 2011 and 2013.
2. Urban Storm Drainage Criteria Manual, Vol. 1, 2 and 3, Urban Drainage
and Flood Control District, Denver, Colorado, June 2001.
APPENDIX A
VICINITY MAP
APPENDIX B
HYDROLOGIC COMPUTATIONS
Project Title:
Catchment ID:
Illustration
Instructions: For each catchment subarea, enter values for A and C.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
HISTORIC 0.74 0.12 0.09
I=20% 0.00 0.00 0.00
Sum: 0.74 Sum: 0.09
Area-Weighted Runoff Coefficient (sum CA/sum A) = 0.12
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
Area-Weighting for Runoff Coefficient Calculation
Historic Condition, 2-yr Calcs I=20%
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
15298 UD-Rational HIST.xls, Weighted C 4/28/2017, 3:10 PM
Project Title:
Catchment ID:
I. Catchment Hydrologic Data
Catchment ID = 1
Area = 0.74 Acres
Percent Imperviousness = 20.00 %
NRCS Soil Type = B A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr = 2 years (input return period for design storm)
C1 = 28.50 (input the value of C1)
C2= 10.00 (input the value of C2)
C3= 0.786 (input the value of C3)
P1= 0.82 inches (input one-hr precipitation--see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.12
Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 = 0.20
Overide 5-yr. Runoff Coefficient, C = 0.20 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Nearly Grassed
Type Meadow Field Pasture/ Bare Swales/
Lawns Ground Waterways
Conveyance 2.5 5 7 10 15
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0229 86 0.20 N/A 0.13 11.46
1 0.0265 102 7.00 1.14 1.49
2 0.0209 90 7.00 1.01 1.48
3
4
5
278 Computed Tc = 14.44
Regional Tc = 11.54
User-Entered Tc = 11.54
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 1.90 inch/hr Peak Flowrate, Qp = 0.160 cfs
Rainfall Intensity at Regional Tc, I = 2.09 inch/hr Peak Flowrate, Qp = 0.177 cfs
Rainfall Intensity at User-Defined Tc, I = 2.09 inch/hr Peak Flowrate, Qp = 0.177 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
(Sheet Flow)
20
Shallow Paved Swales
Sum
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Fort Collins CBA Historic
2-yr Calcs I=45%, 100-yr Calcs I=73%
Paved Areas &
15298 UD-Rational HIST.xls, Tc and PeakQ 4/28/2017, 3:11 PM
Project Title:
Catchment ID:
I. Catchment Hydrologic Data
Catchment ID = 1
Area = 0.74 Acres
Percent Imperviousness = 55.00 %
NRCS Soil Type = B A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr = 100 years (input return period for design storm)
C1 = 28.50 (input the value of C1)
C2= 10.00 (input the value of C2)
C3= 0.786 (input the value of C3)
P1= 2.86 inches (input one-hr precipitation--see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.54
Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 = 0.38
Overide 5-yr. Runoff Coefficient, C = 0.20 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Nearly Grassed
Type Meadow Field Pasture/ Bare Swales/
Lawns Ground Waterways
Conveyance 2.5 5 7 10 15
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0229 86 0.20 N/A 0.13 11.46
1 0.0265 102 7.00 1.14 1.49
2 0.0209 90 7.00 1.01 1.48
3
4
5
278 Computed Tc = 14.44
Regional Tc = 11.54
User-Entered Tc = 11.54
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 6.61 inch/hr Peak Flowrate, Qp = 2.636 cfs
Rainfall Intensity at Regional Tc, I = 7.30 inch/hr Peak Flowrate, Qp = 2.911 cfs
Rainfall Intensity at User-Defined Tc, I = 7.30 inch/hr Peak Flowrate, Qp = 2.911 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
(Sheet Flow)
20
Shallow Paved Swales
Sum
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Fort Collins CBA Historic
2-yr Calcs I=45%, 100-yr Calcs I=73%
Paved Areas &
15298 UD-Rational HIST.xls, Tc and PeakQ 4/28/2017, 3:12 PM
Project Title:
Catchment ID:
Illustration
Instructions: For each catchment subarea, enter values for A and C.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
LS 0.25 0.37 0.09
PAVE 0.38 0.81 0.31
ROOF 0.11 0.81 0.09
Sum: 0.735 Sum: 0.49
Area-Weighted Runoff Coefficient (sum CA/sum A) = 0.66
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
Area-Weighting for Runoff Coefficient Calculation
100-yr Coefficients, I=75% (UNADJUSTED)
15298 UD-Rational DEV_Disturbedarea.xls, Weighted C 4/28/2017, 3:13 PM
Project Title:
Catchment ID:
I. Catchment Hydrologic Data
Catchment ID = 1
Area = 0.74 Acres
Percent Imperviousness = 75.00 %
NRCS Soil Type = B A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr = 2 years (input return period for design storm)
C1 = 28.50 (input the value of C1)
C2= 10.00 (input the value of C2)
C3= 0.786 (input the value of C3)
P1= 0.82 inches (input one-hr precipitation--see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.51
Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 = 0.54
Overide 5-yr. Runoff Coefficient, C = 0.54 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Nearly Grassed
Type Meadow Field Pasture/ Bare Swales/
Lawns Ground Waterways
Conveyance 2.5 5 7 10 15
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0200 35 0.54 N/A 0.12 4.76
1 0.0200 26 20.00 2.83 0.15
2 0.0050 228 20.00 1.41 2.69
3
4
5
289 Computed Tc = 7.60
Regional Tc = 11.61
User-Entered Tc = 7.60
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 2.45 inch/hr Peak Flowrate, Qp = 0.914 cfs
Rainfall Intensity at Regional Tc, I = 2.09 inch/hr Peak Flowrate, Qp = 0.778 cfs
Rainfall Intensity at User-Defined Tc, I = 2.45 inch/hr Peak Flowrate, Qp = 0.914 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
(Sheet Flow)
20
Shallow Paved Swales
Sum
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Fort Collins CBA Developed
2-yr Calcs I=75%, 100-yr Calcs I=92%
Paved Areas &
15298 UD-Rational DEV_Disturbedarea.xls, Tc and PeakQ 4/28/2017, 3:16 PM
Project Title:
Catchment ID:
I. Catchment Hydrologic Data
Catchment ID = 1
Area = 0.74 Acres
Percent Imperviousness = 92.00 %
NRCS Soil Type = B A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr = 100 years (input return period for design storm)
C1 = 28.50 (input the value of C1)
C2= 10.00 (input the value of C2)
C3= 0.786 (input the value of C3)
P1= 2.86 inches (input one-hr precipitation--see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.84
Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 = 0.76
Overide 5-yr. Runoff Coefficient, C = 0.54 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Nearly Grassed
Type Meadow Field Pasture/ Bare Swales/
Lawns Ground Waterways
Conveyance 2.5 5 7 10 15
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0200 35 0.54 N/A 0.12 4.76
1 0.0200 26 20.00 2.83 0.15
2 0.0050 228 20.00 1.41 2.69
3
4
5
289 Computed Tc = 7.60
Regional Tc = 11.61
User-Entered Tc = 7.60
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 8.56 inch/hr Peak Flowrate, Qp = 5.256 cfs
Rainfall Intensity at Regional Tc, I = 7.28 inch/hr Peak Flowrate, Qp = 4.473 cfs
Rainfall Intensity at User-Defined Tc, I = 8.56 inch/hr Peak Flowrate, Qp = 5.256 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
(Sheet Flow)
20
Shallow Paved Swales
Sum
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Fort Collins CBA Developed
2-yr Calcs I=75%, 100-yr Calcs I=92%
Paved Areas &
15298 UD-Rational DEV_Disturbedarea.xls, Tc and PeakQ 4/28/2017, 3:14 PM
Runoff Coefficient vs. Watershed Imperviousness
Based on Runoff Coefficient estimating equation published by Urbonas, et.al. (1990) & WEF (1998)
Basic equation for NRCS Soil Types C & D:
C CD
= K CD
+ (0.858*i
3
- 0.786*i
2
+ 0.774*i + 0.04)
Basic equation for NRCS Soil Type A:
C A
= K A
+ (1.31*i
3
- 1.44*i
2
+ 1.135*i - 0.12) in which use values for C A
> 0
in which: i = I a /100, imperviousness ratio
I a = watershed imperviousness in percent
C A
= Runoff Coefficient for NRCS Soil Type A
K A
= Correction factor for C A
when the storm return period is greater than 2-years
C CD
= Runoff Coefficient for NRCS Soil Types C and D
K CD
= Correction factor for C CD
when the storm return period is greater than 2-years
NRCS
Soil Types 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr
C & D 0.00 [-0.10*i +0.11] [-0.18*i +0.21] [-0.28*i +0.33] [-0.33*i +0.40] [-0.39*i +0.46]
A 0.00 [-0.08*i +0.09] [-0.14*i +0.17] [-0.19*i +0.24] [-0.22*i +0.28] [-0.25*i +0.32]
Imperv.
Ratio ( i ) 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr
0.00 0.04 0.15 0.25 0.37 0.44 0.50 -0.12 -0.03 0.05 0.12 0.16 0.20
0.05 0.08 0.18 0.28 0.39 0.46 0.52 -0.07 0.02 0.10 0.16 0.20 0.24
0.10 0.11 0.21 0.30 0.41 0.48 0.53 -0.02 0.06 0.14 0.20 0.24 0.28
0.15 0.14 0.24 0.32 0.43 0.49 0.54 0.02 0.10 0.17 0.23 0.27 0.30
0.20 0.17 0.26 0.34 0.44 0.50 0.55 0.06 0.13 0.20 0.26 0.30 0.33
0.25 0.20 0.28 0.36 0.46 0.52 0.56 0.09 0.16 0.23 0.29 0.32 0.35
0.30 0.22 0.30 0.38 0.47 0.53 0.57 0.13 0.19 0.25 0.31 0.34 0.37
0.35 0.25 0.33 0.40 0.48 0.54 0.57 0.16 0.22 0.28 0.33 0.36 0.39
0.40 0.28 0.35 0.42 0.50 0.55 0.58 0.19 0.25 0.30 0.35 0.38 0.41
0.45 0.31 0.37 0.44 0.51 0.56 0.59 0.22 0.27 0.33 0.37 0.40 0.43
0.50 0.34 0.40 0.46 0.53 0.57 0.60 0.25 0.30 0.35 0.40 0.42 0.45
0.55 0.37 0.43 0.48 0.55 0.59 0.62 0.29 0.33 0.38 0.42 0.45 0.47
0.60 0.41 0.46 0.51 0.57 0.61 0.63 0.33 0.37 0.41 0.45 0.47 0.50
0.65 0.45 0.49 0.54 0.59 0.63 0.65 0.37 0.41 0.45 0.49 0.51 0.53
0.70 0.49 0.53 0.57 0.62 0.66 0.68 0.42 0.45 0.49 0.53 0.54 0.56
0.75 0.54 0.58 0.62 0.66 0.69 0.71 0.47 0.50 0.54 0.57 0.59 0.61
0.80 0.60 0.63 0.66 0.70 0.73 0.74 0.54 0.56 0.60 0.63 0.64 0.66
0.85 0.66 0.68 0.71 0.75 0.78 0.79 0.61 0.63 0.66 0.69 0.70 0.72
0.90 0.73 0.75 0.77 0.80 0.83 0.83 0.69 0.71 0.73 0.76 0.77 0.79
0.95 0.80 0.82 0.84 0.87 0.89 0.89 0.78 0.80 0.82 0.84 0.85 0.86
1.00 0.89 0.90 0.92 0.94 0.96 0.96 0.89 0.90 0.92 0.94 0.95 0.96
Notes: For Type B Soils, use the average of coefficients C
CD and C A
I. One-hr Precipitation Values for Metro Denver Area
Return period in years 2 5 10 50 100
Depth in inches 0.93 1.35 1.61 2.20 2.60
II. Recommended Runoff Coefficients for Metro Denver
Business:
Commercial areas
Neighborhood areas
Residential:
Single-family
Multiunit (detached)
Multiunit (attached)
Half-acre lot or larger
Apartments
Industrial:
Light areas
Heavy areas
Parks, cemeteries:
Playgrounds:
Schools:
Railroad yard areas:
Undeveloped areas:
Historical Flow Analysis
Greenbelts, agricultural
Off-site flow analysis
(when land use not defined)
Streets:
Paved
Gravel (packed)
Driveways and sidewalks:
Roofs:
Lawns, sandy soil
Lawns, clayey soil
*Refer to Figures RO-3 through RO-5 in Runoff Chapter
of USDCM.
0
0
100
40
90
90
50
15
2
45
80
80
90
5
10
85
*
60
75
*
Percent Imper-
viousness
Land Use or Surface Characteristics
95
Page 2
Rational Input Coefficients using UD-Rational Spreadsheet
HISTORIC CONDITIONS with 0.735 acres of Project Disturbed Area
IHISTORIC = 20%
Off-site analysis (when land use not defined) using Table RO-11 from COFC_Amendments_V_1_Chapter
_5_Runoff for Lawns, Heavy Soil: Flat <2%
C100 = .44, Adjusted C100 = 0.55
C5 = .20
C2 = .12
I100 = 55%
I2 = 20%
Q100 = 2.91 cfs
Q2 = 0.18 cfs
DEVELOPED CONDITIONS with 0.735 acres of Project Disturbed Area
IDEVELOPED = 75%
C100 = .66, Adjusted C100 = .0.83
C5 = .54
C2 = .51
I100 = 92%
I2 = 75%
Q100 = 5.26 cfs
Q2 = 0.91 cfs
APPENDIX C
HYDRAULIC COMPUTATIONS
Project:
Basin ID:
Design Information (Input): Design Information (Input):
Catchment Drainage Imperviousness Ia = 92.00 percent Catchment Drainage Imperviousness Ia = 92.00 percent
Catchment Drainage Area A = 0.74 acres Catchment Drainage Area A = 0.736 acres
Predevelopment NRCS Soil Group Type = B A, B, C, or D Predevelopment NRCS Soil Group Type = B A, B, C, or D
Return Period for Detention Control T = 2 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 = 8 minutes Time of Concentration of Watershed Tc = 8 minutes
Allowable Unit Release Rate q = 0.24 cfs/acre Allowable Unit Release Rate q = 0.24 cfs/acre
One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P1 = 2.86 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 = 0.74 Runoff Coefficient C = 0.84
Inflow Peak Runoff Qp-in = 1.32 cfs Inflow Peak Runoff Qp-in = 5.24 cfs
Allowable Peak Outflow Rate Qp-out = 0.18 cfs Allowable Peak Outflow Rate Qp-out = 0.18 cfs
Mod. FAA Minor Storage Volume = 1,298 cubic feet Mod. FAA Major Storage Volume = 8,351 cubic feet
Mod. FAA Minor Storage Volume = 0.030 acre-ft Mod. FAA Major Storage Volume = 0.192 acre-ft
15 <- 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 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000
15 1.84 0.021 0.75 0.13 0.003 0.018 15 6.43 0.082 0.75 0.13 0.003 0.079
30 1.27 0.029 0.63 0.11 0.005 0.024 30 4.44 0.113 0.63 0.11 0.005 0.109
45 0.99 0.033 0.58 0.10 0.006 0.027 45 3.45 0.132 0.58 0.10 0.006 0.126
60 0.82 0.037 0.56 0.10 0.008 0.029 60 2.85 0.146 0.56 0.10 0.008 0.138
75 0.70 0.039 0.55 0.10 0.010 0.029 75 2.45 0.156 0.55 0.10 0.010 0.146
90 0.62 0.042 0.54 0.10 0.012 0.030 90 2.15 0.165 0.54 0.10 0.012 0.153
105 0.55 0.044 0.54 0.10 0.014 0.030 105 1.93 0.172 0.54 0.10 0.014 0.159
120 0.50 0.045 0.53 0.09 0.016 0.030 120 1.75 0.179 0.53 0.09 0.016 0.163
135 0.46 0.047 0.53 0.09 0.017 0.029 135 1.61 0.185 0.53 0.09 0.017 0.167
150 0.43 0.048 0.53 0.09 0.019 0.029 150 1.49 0.190 0.53 0.09 0.019 0.171
165 0.40 0.049 0.52 0.09 0.021 0.028 165 1.39 0.195 0.52 0.09 0.021 0.174
180 0.37 0.050 0.52 0.09 0.023 0.027 180 1.30 0.199 0.52 0.09 0.023 0.176
195 0.35 0.051 0.52 0.09 0.025 0.027 195 1.22 0.203 0.52 0.09 0.025 0.178
210 0.33 0.052 0.52 0.09 0.027 0.026 210 1.16 0.207 0.52 0.09 0.027 0.180
225 0.31 0.053 0.52 0.09 0.028 0.025 225 1.10 0.210 0.52 0.09 0.028 0.182
240 0.30 0.054 0.52 0.09 0.030 0.024 240 1.05 0.214 0.52 0.09 0.030 0.183
255 0.29 0.055 0.51 0.09 0.032 0.023 255 1.00 0.217 0.51 0.09 0.032 0.185
270 0.27 0.056 0.51 0.09 0.034 0.022 270 0.96 0.220 0.51 0.09 0.034 0.186
285 0.26 0.056 0.51 0.09 0.036 0.020 285 0.92 0.223 0.51 0.09 0.036 0.187
300 0.25 0.057 0.51 0.09 0.038 0.019 300 0.88 0.225 0.51 0.09 0.038 0.188
315 0.24 0.058 0.51 0.09 0.039 0.018 315 0.85 0.228 0.51 0.09 0.039 0.189
330 0.24 0.058 0.51 0.09 0.041 0.017 330 0.82 0.230 0.51 0.09 0.041 0.189
345 0.23 0.059 0.51 0.09 0.043 0.016 345 0.79 0.233 0.51 0.09 0.043 0.190
360 0.22 0.059 0.51 0.09 0.045 0.014 360 0.77 0.235 0.51 0.09 0.045 0.190
375 0.21 0.060 0.51 0.09 0.047 0.013 375 0.74 0.237 0.51 0.09 0.047 0.191
390 0.21 0.061 0.51 0.09 0.049 0.012 390 0.72 0.240 0.51 0.09 0.049 0.191
405 0.20 0.061 0.51 0.09 0.050 0.011 405 0.70 0.242 0.51 0.09 0.050 0.191
420 0.20 0.062 0.51 0.09 0.052 0.009 420 0.68 0.244 0.51 0.09 0.052 0.191
435 0.19 0.062 0.51 0.09 0.054 0.008 435 0.66 0.246 0.51 0.09 0.054 0.192
450 0.19 0.063 0.51 0.09 0.056 0.007 450 0.65 0.248 0.51 0.09 0.056 0.192
465 0.18 0.063 0.51 0.09 0.058 0.005 465 0.63 0.249 0.51 0.09 0.058 0.192
480 0.18 0.063 0.51 0.09 0.060 0.004 480 0.61 0.251 0.51 0.09 0.060 0.192
495 0.17 0.064 0.51 0.09 0.061 0.003 495 0.60 0.253 0.51 0.09 0.061 0.192
510 0.17 0.064 0.51 0.09 0.063 0.001 510 0.59 0.255 0.51 0.09 0.063 0.191
Project:
Basin ID:
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.35, Released January 2015
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
Q100=2-yr Hist., C100*1.25, Vmajor*1.20
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 100 200 300 400 500 600 700 800 900 1000
Volume (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
15298UD-Detention_v2.35Disturbedarea.xls, Modified FAA 5/1/2017, 8:19 AM
Detention Volume - Mass Balance Method -100-yr (Major Storm)
Input
1.00
1.00
0.18 cfs
0.74 acres
Results
0.193
0.193
Rainfall Duration
(min)
Rainfall Intensity
(in/hr)
Qin
(cfs) Volumein
(ft
3
) Qout
(cfs) Volumeout
(ft
3
)
Volume detained
(acre-feet)
5 9.96 7.32 2196.18 0.18 54.00 0.049
10 7.74 5.69 3413.34 0.18 108.00 0.076
15 6.52 4.79 4312.98 0.18 162.00 0.095
20 5.61 4.12 4948.02 0.18 216.00 0.109
25 4.97 3.65 5477.22 0.18 270.00 0.120
30 4.52 3.32 5979.96 0.18 324.00 0.130
35 4.08 3.00 6297.48 0.18 378.00 0.136
40 3.74 2.75 6588.54 0.18 432.00 0.141
45 3.45 2.54 6853.14 0.18 486.00 0.146
50 3.23 2.37 7117.74 0.18 540.00 0.151
55 3.03 2.23 7355.88 0.18 594.00 0.155
60 2.86 2.10 7567.56 0.18 648.00 0.159
65 2.71 1.99 7779.24 0.18 702.00 0.162
70 2.59 1.90 7990.92 0.18 756.00 0.166
75 2.48 1.82 8202.60 0.18 810.00 0.170
80 2.38 1.75 8387.82 0.18 864.00 0.173
85 2.29 1.68 8573.04 0.18 918.00 0.176
90 2.21 1.62 8758.26 0.18 972.00 0.179
95 2.13 1.56 8917.02 0.18 1026.00 0.181
100 2.06 1.52 9102.24 0.18 1080.00 0.184
105 2.00 1.47 9261.00 0.18 1134.00 0.187
110 1.94 1.43 9419.76 0.18 1188.00 0.189
115 1.88 1.38 9552.06 0.18 1242.00 0.191
120 1.835 1.35 9710.82 0.18 1296.00 0.193
125 1.78 1.31 9794.27 0.18 1350.00 0.194
130 1.72 1.27 9868.82 0.18 1404.00 0.194
135 1.67 1.22 9918.95 0.18 1458.00 0.194
140 1.61 1.18 9944.69 0.18 1512.00 0.194
145 1.56 1.14 9946.03 0.18 1566.00 0.192
150 1.50 1.10 9922.96 0.18 1620.00 0.191
155 1.44 1.06 9875.49 0.18 1674.00 0.188
160 1.39 1.02 9803.61 0.18 1728.00 0.185
165 1.33 0.98 9707.34 0.18 1782.00 0.182
170 1.28 0.94 9586.66 0.18 1836.00 0.178
175 1.22 0.90 9441.58 0.18 1890.00 0.173
180 1.17 0.86 9272.10 0.18 1944.00 0.168
Project:
Basin ID:
Design Information (Input):
Width of Basin Bottom, W = 25.00 ft Right Triangle OR…
Length of Basin Bottom, L = 60.00 ft Isosceles Triangle X OR…
Dam Side-slope (H:V), Zd = 4.00 ft/ft Rectangle OR…
Circle / Ellipse OR…
Irregular (Use Overide values in cells G32:G52)
MINOR MAJOR
Storage Requirement from Sheet 'Modified FAA': 0.03 0.19 acre-ft.
Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft.
Storage Requirement from Sheet 'Full-Spectrum': acre-ft.
Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes
for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor,
& Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage
Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes
(input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek)
4924.90 (input) 25.00 60.00 750.0 5 0.017 0.000
4925.00 4.00 25.98 62.36 810.2 6 5 0.000 0.000
4925.50 4.00 30.90 74.17 1,146.0 289 79 0.007 0.002
4926.00 4.00 35.82 85.97 1,539.9 980 396 0.022 0.009
WQCV@4926.60 4926.50 4.00 40.74 97.78 1,991.8 1,816 1,095 0.042 0.025 0.030
4927.00 4.00 45.66 109.59 2,501.9 2,545 2,186 0.058 0.050
2-yr+WQCV@4927.15 4927.50 4.00 50.58 121.39 3,070.0 3,169 3,614 0.073 0.083 0.060
4928.00 4.00 55.50 133.20 3,696.2 3,710 5,334 0.085 0.122
4928.50 4.00 60.42 145.00 4,380.5 4,302 7,337 0.099 0.168
WQCV+100-yr @4929.00 4929.00 4.00 65.34 156.81 5,122.8 5,173 9,706 0.119 0.223 0.222
4929.50 4.00 70.26 168.62 5,923.2 6,371 12,592 0.146 0.289
4930.00 4.00 75.18 180.42 6,781.7 7,318 16,014 0.168 0.368
4930.25 4.00 77.64 186.33 7,232.7 7,898 17,916 0.181 0.411
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Project:
Basin ID:
STAGE-STORAGE SIZING FOR DETENTION BASINS
4923.75
4924.75
4925.75
4926.75
4927.75
4928.75
4929.75
4930.75
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45
Stage (ft. elev.)
Storage (acre-feet)
STAGE-STORAGE CURVE FOR THE POND
15298UD-Detention_v2.35Disturbedarea.xls, Basin 5/1/2017, 8:27 AM
Project:
Basin ID:
WQCV Design Volume (Input):
Catchment Imperviousness, Ia
= 92.0 percent
Catchment Area, A = 0.74 acres Diameter of holes, D = 0.287 inches
Depth at WQCV outlet above lowest perforation, H = 2 feet Number of holes per row, N = 1
Vertical distance between rows, h = 4.00 inches OR
Number of rows, NL = 6.00
Orifice discharge coefficient, Co
= 0.67 Height of slot, H = inches
Slope of Basin Trickle Channel, S = 0.010 ft / ft Width of slot, W = inches
Time to Drain the Pond = 40 hours
Watershed Design Information (Input): 2
Percent Soil Type A = %
Percent Soil Type B = 100 %
Percent Soil Type C/D = %
Outlet Design Information (Output):
Water Quality Capture Volume, WQCV = 0.399 watershed inches
Water Quality Capture Volume (WQCV) = 0.025 acre-feet 0.00
Design Volume (WQCV / 12 * Area * 1.2) Vol = 0.030 acre-feet
Outlet area per row, Ao = 0.08 square inches
Total opening area at each row based on user-input above, Ao = 0.06 square inches
Total opening area at each row based on user-input above, Ao = 0.000 square feet
3
Row 1 Row 2 Row 3 Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 Row 19 Row 20 Row 21 Row 22 Row 23 Row 23 S
4924.92 4925.25 4925.59 4925.92 4926.25 4926.59 Flow
4924.90 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.00
4925.15 0.0012 0.0000 0.0000 0.0000 0.0000 0.0000 0.00
4925.40 0.0017 0.0009 0.0000 0.0000 0.0000 0.0000 0.00
4925.65 0.0021 0.0015 0.0006 0.0000 0.0000 0.0000 0.00
4925.90 0.0024 0.0019 0.0013 0.0000 0.0000 0.0000 0.01
4926.15 0.0027 0.0023 0.0018 0.0012 0.0000 0.0000 0.01
4926.40 0.0029 0.0026 0.0022 0.0017 0.0009 0.0000 0.01
4926.65 0.0032 0.0029 0.0025 0.0021 0.0015 0.0006 0.01
4926.90 0.0034 0.0031 0.0028 0.0024 0.0019 0.0013 0.01
4927.15 0.0036 0.0033 0.0030 0.0027 0.0023 0.0018 0.02
4927.40 0.0038 0.0035 0.0033 0.0029 0.0026 0.0022 0.02
4927.65 0.0040 0.0037 0.0035 0.0032 0.0029 0.0025 0.02
4927.90 0.0042 0.0039 0.0037 0.0034 0.0031 0.0028 0.02
4928.15 0.0043 0.0041 0.0039 0.0036 0.0033 0.0030 0.02
4928.40 0.0045 0.0043 0.0041 0.0038 0.0035 0.0033 0.02
4928.65 0.0047 0.0045 0.0042 0.0040 0.0037 0.0035 0.02
4928.90 0.0048 0.0046 0.0044 0.0042 0.0039 0.0037 0.03
4929.15 0.0050 0.0048 0.0046 0.0043 0.0041 0.0039 0.03
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Worksheet Protected
Project:
Basin ID:
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
0.00
1000.00
2000.00
3000.00
4000.00
5000.00
6000.00
0.00 0.01 0.01 0.02 0.02 0.03 0.03
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE
15298UD-Detention_v2.35Disturbedarea.xls, WQCV 5/1/2017, 8:28 AM
Water Quality Capture Volume, WQCV
1. Determine the WQCV in Watershed Inches
WQCV = a (0.91I 3-1.19I 2+0.78I )
Where:
WQCV = Water Quality Capture Volume, watershed inches
a = coefficient corresponding to WQCV drain time
I = Imperviousness (%/100)
Drain Time (hrs) Coefficient (a )
12 0.8
24 0.9
40 1.0
Coefficient, a 1.00
Imperviousness, I 96
WQCV = 0.46 watershed inches
2. Determine the required storage volume in Acre-Feet
V = (WQCV/12)A
Where:
V = Required Storage Volume, acre-feet
A = Tributary catchment area upstream, acres
Area, A 0.74 acres
V = 0.028 acre-feet
Drain Time Coefficients
Project:
Basin ID:
X
1
#1 Vertical #2 Vertical
Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input) Orifice Orifice
Water Surface Elevation at Design Depth Elev: WS = 4,929.00 feet
Pipe/Vertical Orifice Entrance Invert Elevation Elev: Invert = 4,924.90 feet
Required Peak Flow through Orifice at Design Depth Q = 0.18 cfs
Pipe/Vertical Orifice Diameter (inches) Dia = 15.0 inches
Orifice Coefficient Co
= 0.67
Full-flow Capacity (Calculated)
Full-flow area Af = 1.23 sq ft
Half Central Angle in Radians Theta = 3.14 rad
Full-flow capacity Qf = 12.3 cfs
Percent of Design Flow = 6833%
Calculation of Orifice Flow Condition
Half Central Angle (0<Theta<3.1416) Theta = 0.41 rad
Flow area Ao
= 0.02 sq ft
Top width of Orifice (inches) To
= 5.91 inches
Height from Invert of Orifice to Bottom of Plate (feet) Yo
= 0.05 feet
Elevation of Bottom of Plate Elev Plate Bottom Edge = 4,924.95 feet
Resultant Peak Flow Through Orifice at Design Depth Qo
= 0.2 cfs
Width of Equivalent Rectangular Vertical Orifice Equivalent Width = 0.40 feet
Centroid Elevation of Equivalent Rectangular Vertical Orifice Equiv. Centroid El. = 4,924.93 feet
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES
15298UD-Detention_v2.35Disturbedarea.xls, Restrictor Plate 5/1/2017, 8:30 AM
Project:
Basin ID:
Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert.
Circular Opening: Diameter in Inches Dia. = inches
OR
Rectangular Opening: Width in Feet W = 3.00 0.25 ft.
Length (Height for Vertical) L or H = 3.00 0.04 ft.
Percentage of Open Area After Trash Rack Reduction % open = 50 100 %
Orifice Coefficient Co
= 0.67 0.62
Weir Coefficient Cw
= 3.00
Orifice Elevation (Bottom for Vertical) Eo
= 4926.12 4,926.12 ft.
Calculation of Collection Capacity:
Net Opening Area (after Trash Rack Reduction) Ao
= 4.50 0.01 sq. ft.
OPTIONAL: User-Overide Net Opening Area Ao
= sq. ft.
Perimeter as Weir Length Lw
= 9.00 ft.
OPTIONAL: User-Overide Weir Length Lw
= ft.
Top Elevation of Vertical Orifice Opening, Top = 4926.16 ft.
Center Elevation of Vertical Orifice Opening, Cen = 4926.14 ft.
Horizontal Orifices Vertical Orifices
Labels Water WQCV #1 Horiz. #1 Horiz. #2 Horiz. #2 Horiz. #1 Vert. #2 Vert. Total Target Volumes
for WQCV, Minor, Surface Plate/Riser Weir Orifice Weir Orifice Collection Collection Collection for WQCV, Minor,
& Major Storage Elevation Flow Flow Flow Flow Flow Capacity Capacity Capacity & Major Storage
W.S. Elevations ft cfs cfs cfs cfs cfs cfs cfs cfs Volumes
(input) (linked) (User-linked) (output) (output) (output) (output) (output) (output) (output) (link for goal seek)
4926.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4926.25 0.00 1.27 8.72 0.00 0.00 0.02 0.00 0.02
4926.50 0.00 6.32 14.91 0.00 0.00 0.03 0.00 0.03
4926.75 0.00 13.50 19.20 0.00 0.00 0.04 0.00 0.04
4927.00 0.00 22.29 22.70 0.00 0.00 0.05 0.00 0.05
4927.25 0.01 32.43 25.72 0.00 0.00 0.05 0.00 0.05
4927.50 0.01 43.77 28.42 0.00 0.00 0.06 0.00 0.06
4927.75 0.01 56.19 30.89 0.00 0.00 0.06 0.00 0.06
4928.00 0.01 69.60 33.17 0.00 0.00 0.07 0.00 0.07
4928.25 0.01 83.93 35.31 0.00 0.00 0.07 0.00 0.07
4928.50 0.01 99.14 37.33 0.00 0.00 0.08 0.00 0.08
4928.75 0.01 115.16 39.24 0.00 0.00 0.08 0.00 0.08
4929.00 0.02 131.96 41.06 0.00 0.00 0.08 0.00 0.08
4929.25 0.02 149.51 42.81 0.00 0.00 0.09 0.00 0.09
4929.50 0.02 167.78 44.48 0.00 0.00 0.09 0.00 0.09
4929.75 0.02 186.73 46.10 0.00 0.00 0.09 0.00 0.09
4930.00 0.02 206.35 47.66 0.00 0.00 0.10 0.00 0.10
4930.25 0.02 226.62 49.17 0.00 0.00 0.10 0.00 0.10
4930.50 #N/A 247.50 50.64 0.00 0.00 0.10 0.00 #N/A
4930.75 #N/A 268.99 52.06 0.00 0.00 0.11 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
Project:
Basin ID:
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL)
4926
4926.5
4927
4927.5
4928
4928.5
4929
4929.5
4930
4930.5
4931
0 0.02 0.04 0.06 0.08 0.1 0.12
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE OUTLET STRUCTURE
UD-Detention_v2.35.xls, Outlet 4/18/2017, 1:40 PM
Project:
Basin ID:
Status: Culvert Data is valid!
Design Information (Input):
Circular Culvert: Barrel Diameter in Inches D = 15 in.
Circular Culvert: Inlet Edge Type (choose from pull-down list) Square End with Headwall
OR:
Box Culvert: Barrel Height (Rise) in Feet Height (Rise) = ft.
Box Culvert: Barrel Width (Span) in Feet Width (Span) = ft.
Box Culvert: Inlet Edge Type (choose from pull-down list) Square Edge w/ 90-15 deg. Flared Wingwall
Number of Barrels No = 1
Inlet Elevation at Culvert Invert Ielev
= 4924.90 ft. elev.
Outlet Elevation at Culvert Invert Oelev
= 4923.00 ft. elev.
Culvert Length in Feet L = 48.0 ft.
Manning's Roughness n = 0.0130
Bend Loss Coefficient Kb
= 0.00
Exit Loss Coefficient Kx
= 1.00
Design Information (calculated):
Entrance Loss Coefficient Ke
= 0.50
Friction Loss Coefficient Kf
= 1.11
Sum of All Loss Coefficients Ks
= 2.61
Orifice Inlet Condition Coefficient Cd
= 0.86
Minimum Energy Condition Coefficient KElow
= -0.09
Calculations of Culvert Capacity (output):
Water Surface Tailwater Culvert Culvert Flowrate Controlling Inlet
Elevation Surface Inlet-Control Outlet-Control Into Culvert Culvert Equation
From Sheet Elevation Flowrate Flowrate From Sheet Flowrate Used
"Basin" ft cfs cfs "Outlet" cfs
(ft., linked) (input if known) (output) (output) (cfs, linked) (output) (output)
4924.90 4922.50 0.00 0.00 0.00 0.00 No Flow (WS < inlet)
4925.00 4922.50 0.10 5.98 0.00 0.00 Min. Energy. Eqn.
4925.50 4922.50 1.30 6.55 0.00 0.00 Min. Energy. Eqn.
4926.00 4922.50 3.40 7.00 0.00 0.00 Regression Eqn.
4926.50 4922.50 5.50 7.84 0.01 0.01 Regression Eqn.
4927.00 4922.50 7.10 8.61 0.15 0.15 Regression Eqn.
4927.50 4922.50 8.30 9.38 0.17 0.17 Regression Eqn.
4928.00 4922.50 9.40 10.09 0.19 0.19 Regression Eqn.
4928.50 4922.50 10.30 10.73 0.20 0.20 Regression Eqn.
4929.00 4922.50 11.20 11.31 0.22 0.22 Orifice Eqn.
4929.50 4922.50 12.00 11.89 0.23 0.23 Orifice Eqn.
4930.00 4922.50 12.70 12.47 0.24 0.24 Orifice Eqn.
4930.25 4922.50 13.10 12.72 0.25 0.25 Orifice Eqn.
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
Project:
Basin ID:
STAGE-DISCHARGE SIZING OF THE OUTLET CULVERT (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
4926.00
4926.50
4927.00
4927.50
4928.00
4928.50
4929.00
4929.50
4930.00
4930.50
0.00 0.05 0.10 0.15 0.20 0.25 0.30
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE FINAL OUTLET PIPE CULVERT
15298UD-Detention_v2.35Disturbedarea.xls, Culvert 5/1/2017, 8:41 AM
Project:
Basin ID:
75.96
4.00000
Design Information (input):
Bottom Length of Weir L = 10.00 feet
Angle of Side Slope Weir Angle = 75.96 degrees
Elev. for Weir Crest EL. Crest = 4,929.00 feet
Coef. for Rectangular Weir Cw
= 3.00
Coef. for Trapezoidal Weir Ct
= 3.00
Calculation of Spillway Capacity (output):
Water Rect. Triangle Total Total
Surface Weir Weir Spillway Pond
Elevation Flowrate Flowrate Release Release
ft. cfs cfs cfs cfs
(linked) (output) (output) (output) (output)
4924.90 0.00 0.00 0.00 0.00
4925.00 0.00 0.00 0.00 0.00
4925.50 0.00 0.00 0.00 0.00
4926.00 0.00 0.00 0.00 0.00
4926.50 0.00 0.00 0.00 0.01
4927.00 0.00 0.00 0.00 0.15
4927.50 0.00 0.00 0.00 0.17
4928.00 0.00 0.00 0.00 0.19
4928.50 0.00 0.00 0.00 0.20
4929.00 0.00 0.00 0.00 0.22
4929.50 10.61 2.12 12.73 12.96
4930.00 30.00 12.00 42.00 42.24
4930.25 41.93 20.96 62.88 63.13
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
Project:
Basin ID:
STAGE-DISCHARGE SIZING OF THE SPILLWAY
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
4926
4926.5012
4927.0024
4927.5035
4928.0047
4928.5059
4929.0071
4929.5083
4930.0094
4930.5106
0 10 20 30 40 50 60 70
Storage (Acre-Feet)
Stage (feet, elev.)
Pond Discharge (cfs)
STAGE-STORAGE-DISCHARGE CURVES FOR THE POND
TOTAL DISCHARGE SPILLWAY DISCHARGE POND STORAGE
15298UD-Detention_v2.35Disturbedarea.xls, Spillway 5/1/2017, 8:42 AM
Modified FAA Volume, WQCV, Stage Storage Table
Minor Storage Volume = 0.030 acre-ft
Major Storage Volume = 0.192 acre-ft
WQCV = 0.030 acre-ft
WQVC Elevation = 0.030 acre-ft @ 4926.60 ft
2-yr + WQCV = 0.060 acre-ft @ 4927.15 ft
100-ry + WQCV = 0.222 acre-ft @ 4929.00 ft
Fort Collins Rational Method Spreadsheet, Detention Volume (Mass Balance), WQCV
Major Storage Volume = 0.193 acre-ft
WQCV = 0.028 acre-ft
APPENDIX D
NRCS SOILS 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, Colorado
CBA Fort Collins Prospect Site
Natural
Resources
Conservation
Service
March 17, 2017
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
Soil Map.................................................................................................................. 5
Soil Map................................................................................................................6
Legend..................................................................................................................7
Map Unit Legend.................................................................................................. 8
Map Unit Descriptions.......................................................................................... 8
Larimer County Area, Colorado...................................................................... 10
53—Kim loam, 1 to 3 percent slopes.......................................................... 10
54—Kim loam, 3 to 5 percent slopes...........................................................11
60—Larim gravelly sandy loam, 5 to 40 percent slopes..............................12
101—Stoneham loam, 1 to 3 percent slopes.............................................. 14
References............................................................................................................16
4
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.
5
6
Custom Soil Resource Report
Soil Map
4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
496430 496450 496470 496490 496510 496530
496430 496450 496470 496490 496510 496530
40° 34' 6'' N
105° 2' 32'' W
40° 34' 6'' N
105° 2' 26'' W
40° 34' 1'' N
105° 2' 32'' W
40° 34' 1'' N
105° 2' 26'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 35 70 140 210
Feet
0 10 20 40 60
Meters
Map Scale: 1:820 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
53 Kim loam, 1 to 3 percent slopes 0.2 13.4%
54 Kim loam, 3 to 5 percent slopes 0.7 39.8%
60 Larim gravelly sandy loam, 5 to
40 percent slopes
0.6 30.6%
101 Stoneham loam, 1 to 3 percent
slopes
0.3 16.2%
Totals for Area of Interest 1.9 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
Custom Soil Resource Report
8
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
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
9
Larimer County Area, Colorado
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: loam, clay loam, sandy clay loam
H2 - 7 to 60 inches:
H2 - 7 to 60 inches:
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural 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 in profile: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 26.5 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Custom Soil Resource Report
10
Minor Components
Fort collins
Percent of map unit: 6 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 3 percent
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
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: loam, clay loam, sandy clay loam
H2 - 7 to 60 inches:
H2 - 7 to 60 inches:
Properties and qualities
Slope: 3 to 5 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Custom Soil Resource Report
11
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 in profile: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 26.5 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Thedalund
Percent of map unit: 4 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 3 percent
Hydric soil rating: No
Fort collins
Percent of map unit: 2 percent
Hydric soil rating: No
Aquic haplustolls
Percent of map unit: 1 percent
Landform: Swales
Hydric soil rating: Yes
60—Larim gravelly sandy loam, 5 to 40 percent slopes
Map Unit Setting
National map unit symbol: jpx5
Elevation: 4,800 to 6,300 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 47 to 49 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Not prime farmland
Map Unit Composition
Larim and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Custom Soil Resource Report
12
Description of Larim
Setting
Landform: Benches, terraces, fans
Landform position (three-dimensional): Side slope, base slope, riser
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium
Typical profile
H1 - 0 to 4 inches: gravelly sandy loam
H2 - 4 to 15 inches: very gravelly sandy clay loam, very gravelly clay loam
H2 - 4 to 15 inches: very gravelly loamy sand, very gravelly sand
H3 - 15 to 60 inches:
H3 - 15 to 60 inches:
Properties and qualities
Slope: 5 to 40 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
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 in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Low (about 5.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: Gravelly Foothill (R049BY214CO)
Hydric soil rating: No
Minor Components
Midway
Percent of map unit: 8 percent
Hydric soil rating: No
Tassel
Percent of map unit: 7 percent
Hydric soil rating: No
Custom Soil Resource Report
13
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: clay loam, sandy clay loam, loam
H2 - 4 to 10 inches: loam, clay loam, sandy clay loam
H2 - 4 to 10 inches:
H3 - 10 to 60 inches:
H3 - 10 to 60 inches:
H3 - 10 to 60 inches:
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural 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 in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Very high (about 27.5 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Custom Soil Resource Report
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Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Kim
Percent of map unit: 5 percent
Hydric soil rating: No
Fort collins
Percent of map unit: 5 percent
Hydric soil rating: No
Custom Soil Resource Report
15
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
16
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
17
APPENDIX E
FLOOD INSURANCE RATE MAP
and FLOODPLAIN – CHECKLIST 50%
City of Fort Collins Floodplain Review Checklist
50% Development Review Submittals
Instructions: Complete this checklist by marking all boxes that have been adequately
completed. Put an “NA” next to any items that are not applicable to this particular
submittal. Any boxes that are left blank and do not have an “NA” marked next to them
are considered incomplete.
Date of Review:_____________ Reviewer’s Name:____________________________
Plat Map
The following required items are on the plat:
100-year floodplain boundary
City
FEMA
Floodway boundary
City
FEMA
The benchmark number and elevation of benchmark
These items match the FIRM. (FEMA Basin)
These items match the Master Plan. (City Basin)
The benchmark number and elevation match with those published in the City of Fort
Collins benchmark system.
Site Plan
The following required items are on the site plan:
100-year floodplain boundary- FEMA and City
500-year floodplain boundary (if proposed structure is a “critical facility”
and a 500-year floodplain is mapped)
Floodway boundary
Erosion buffer zones
Restriction related to use (i.e. critical facility or no residential use of lower
floor if floodproofed mixed-use structure)
Drainage and/or Grading Plan (or a separate Floodplain Sheet if it is too cluttered on
Drainage and Grading Plan)
The following required items are on the drainage and/or grading plan:
100-year floodplain boundary- FEMA and City
500-year floodplain boundary (if proposed structure is a “critical facility”
and a 500-year floodplain is mapped)
Floodway boundary
Erosion buffer zones
Cross-section locations
BFE lines
Regulatory Flood Protection Elevation for individual lots or groups of lots
if structures are to be built in the floodplain.
The floodplain and floodway boundaries are in the correct location and labeled
properly.
The cross-section and BFE lines are in the correct location and labeled properly.
Elevations are referred to the appropriate datum:
FEMA basins – list in both NGVD 29 and NAVD 88
City basins – list only in NGVD 29
Floodway regulations have been met.
No fill in the floodway unless a hydraulic analysis shows “no-rise”.
No manufactured homes, except in an existing park, can be placed in the
floodway.
No changing a nonconforming non-residential or mixed use structure to a
residential structure.
Landscaping meets requirements for no encroachment in the floodway
without a hydraulic analysis to show “no-rise”.
No storage of materials or equipment.
Critical facilities regulations have been met:
100 year – No life safety, emergency response, or hazardous material
critical facilities
500 year Poudre – No life safety or emergency response critical facilities
Any items in the floodway that can float (Example: picnic tables, bike racks, etc.) are
noted as being anchored.
Erosion Buffer Zone requirements have been met:
Design of any allowed development minimizes disturbance to channel bed
and banks.
No structures allowed.
No additions to existing structures allowed.
Any fencing is split-rail design and break-away, but cabled. Must be
oriented parallel to general flow direction.
No detention or water quality ponds.
No bike or pedestrian paths or trails except as required to cross streams or
waterways.
Road, bicycle and pedestrian bridges must span erosion buffer zone.
No fill.
No outdoor storage of non-residential materials or equipment.
No driveways or parking areas.
No irrigated vegetation and non-native trees, grasses, or shrubs.
No utilities except as necessary to cross streams or waterways.
No grading or excavation except as required for permitted activities in
erosion buffer zone.
No construction traffic except as required for permitted activities in
erosion buffer zone.
Any construction in the erosion buffer zone shows that it will not impact
the channel stability.
Any necessary floodplain modeling has been submitted and approved. All modeling
must follow the City’s floodplain modeling guidelines.
Special Poudre River Regulations
Poudre River Floodway Regulations have been met.
No construction of new residential, non-residential or mixed-use
structures.
No redevelopment of residential, non-residential or mixed-use structures.
No additions to residential, non-residential or mixed-use structures.
No fill unless hydraulic analysis shows “no-rise”.
Poudre River floodplain regulations have been met
No construction of new residential or mixed-use structures
No additions to residential structures
No additions to mixed-use structures if there is an expansion in the
residential-use area of the structure.
No floatable materials on non-residential sites
Information Related to Structures in the Floodplain
The regulatory flood protection elevation shown on the plans is at least 2 ft above the
BFE for the Poudre River and at least 18” above the BFE for new development and
redevelopment, 6” above the BFE for additions, substantial improvement and
accessory structures for all other floodplains.
A note is on the plans that the lowest floor (including basement or crawl space) and
HVAC will be required to be elevated above the regulatory flood protection
elevation. Non-residential structures can be floodproofed instead of elevated to the
regulatory flood protection elevation.
A typical drawing detail is included for each foundation type proposed (slab-on-
grade, basement, crawl space) showing the elevation of the HVAC and lowest floor
elevation (which includes bottom of the basement or crawl space) relative to the BFE.
If garages are not going to be elevated to the regulatory flood protection elevation,
then a note is included stating the following requirements:
There shall be 1 square inch of venting for every 1 square foot of enclosed
area.
The bottom of the venting shall not be higher than 1 foot above grade.
The venting shall be on at least two sides, preferably on upstream and
downstream sides. (Does not have to be divided equally).
For manufactured homes, a note is included stating that all submittal requirements on
separate sheet titled “Installation of a Mobile Home Located in a Floodplain:
Submittal Requirements” shall be met.
A note is on the plans stating that a floodplain use permit will be required for each
structure and each site construction element (detention ponds, bike paths, parking
lots, utilities, etc.) in the floodplain.
A note is on the plans stating that a FEMA elevation or floodproofing certificate will
be completed and approved before the CO is issued for any structures in the
floodplain. This is required even if property is only in a City floodplain.
Drainage Report
The site is described as being in the floodplain. Floodplain name and if the floodplain
is a FEMA or City-designated is described. Any floodway or erosion buffer zones on
the site are described.
The FEMA FIRM panel # and date and/or the Master Plan information is cited.
A copy of the FIRM panel with the site location marked is included in the report.
If a floodplain modeling report has been submitted, that report is referenced. The
reason for the floodplain modeling report is described.
If a FEMA CLOMR or LOMR is going to be needed, the reason for the CLOMR or
LOMR is described.
If a FEMA LOMR is required after construction, this is stated in the report.
The location of the structures relative to the floodplain is described. If there is both a
FEMA and a City floodplain on the site, the location of the structures relative to both
is described.
The use of the structures is described. This is to determine if the structure is
residential, non-residential, or mixed-use. Also, structures in all 100- year and Poudre
River 500-year floodplains cannot be used as a critical facility. (See Chapter 10 of
City Code for definitions.)
The report describes how the development will be in compliance with the applicable
floodplain regulations (Chapter 10 of City Code). (Examples: elevation of lowest
floor above regulatory flood protection elevation, floodproofing, floodway
regulations, erosion buffer zone regulations, no-rise, etc.)
The type of foundation construction for the structures (i.e. slab-on-grade, crawl space,
basement, etc.) is discussed in the report.
The type of foundation matches with the details shown on the grading plan.
The report states that the lowest floor (including basement or crawl space) and HVAC
will be required to be elevated above the regulatory flood protection elevation. Non-
residential structures can be floodproofed instead of elevated to the regulatory flood
protection elevation.
If garages are not going to be elevated to the regulatory flood protection elevation,
then a note is included stating the following requirements:
There shall be 1 square inch of venting for every 1 square foot of enclosed
area.
There bottom of the venting shall not be higher than 1 foot above grade.
The venting shall be on at least two sides, preferably on upstream and
downstream sides. (Does not have to be divided equally).
If a non-residential structure is to be floodproofed, then a note is included stating that
all requirements on separate sheet titled “Floodproofing Guidelines” shall be met.
(Floodproofing guidelines can be obtained at http://fcgov.com/stormwater/pdf/fp-
floodproofing.pdf)
For manufactured homes, a note is included stating that all submittal requirements on
separate sheet titled “Installation of a Mobile Home Located in a Floodplain:
Submittal Requirements” shall be met. (Mobile Home guidelines can be obtained at
http://fcgov.com/stormwater/pdf/fp-mobilhome.pdf)
The report states that a floodplain use permit will be required for each structure and
each site construction element (detention ponds, bike paths, parking lots, utilities,
etc.) in the floodplain.
A note is in the report stating that a FEMA elevation or floodproofing certificate will
be completed and approved before the CO is issued.
In the compliance section, Chapter 10 of City Code is listed.
FEMA CLOMR Approval
If a FEMA CLOMR is required, the necessary modeling has been submitted and
approved by the City.
Additional Comments:
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
Updated 11/29/2007
Terms to Note
Lowest Floor Elevation – Elevation of the lowest floor of the lowest enclosed area
(including bottom of basement or crawlspace). This is not the same as finished floor. The
lowest floor should be distinguished from finished floor on plans and reports.
Regulatory Flood Protection Elevation – For all floodplains except the Poudre River, the
regulatory flood protection elevation is eighteen (18) inches above the base flood
elevation. For the Poudre River floodplain, the regulatory flood protection elevation is
twenty-four (24) inches above the base flood elevation. If there is both a FEMA and a
City BFE, the higher BFE should be used to determine the regulatory flood protection
elevation.
Additional floodplain terminology is defined in Chapter 10 of City Code.
NOTE: Issues specific to individual sites may arise that result in additional
requirements. These will be discussed during initial meetings with the applicant.
APPENDIX F
PROPOSED DRAINAGE PLAN
4,995 SF
AUTOMOTIVE REPAIR FACILITY
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 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr
28, 2011
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
7
#N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A
STAGE-DISCHARGE SIZING OF THE SPILLWAY
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
15298UD-Detention_v2.35Disturbedarea.xls, Spillway 5/1/2017, 8:42 AM
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
STAGE-DISCHARGE SIZING OF THE OUTLET CULVERT (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
15298UD-Detention_v2.35Disturbedarea.xls, Culvert 5/1/2017, 8:41 AM
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
Routing 3: Single Stage - Water flows through WQCV plate and #1 horizontal opening into #1 vertical opening. This flow will be applied
to culvert sheet (#2 vertical & horizontal openings is not used).
STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL)
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
Current Routing Order is #3
W.S. EL. WQ
W.S. EL. Minor
W.S. EL. Major
WQ
H1
H2
V1 V2
Routing Order #1 (Standard)
V1
W.S. EL. WQ
W.S. EL. Design Storm
WQ
H1
Routing Order #3 (Single Stage) Routing Order #4
V2
V1
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ
W.S. EL. Emergency Spillway
Emergency Overflow into Pipe- H2
V2
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ V1
Routing Order #2
UD-Detention_v2.35.xls, Outlet 4/18/2017, 1:40 PM
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A #N/A #N/A #N/A
Override
Area
Row 1
Override
Area
Row 2
Override
Area
Row 3
Override
Area
Row 4
Override
Area
Row 5
Override
Area
Row 6
Override
Area
Row 7
Override
Area
Row 8
Override
Area
Row 9
Override
Area
Row 10
Override
Area
Row 11
Override
Area
Row 12
Override
Area
Row 13
Override
Area
Row 14
Override
Area
Row 15
Override
Area
Row 16
Override
Area
Row 17
Override
Area
Row 18
Override
Area
Row 19
Override
Area
Row 20
Override
Area
Row 21
Override
Area
Row 22
Override
Area
Row 23
Override
Area
Row 24
Central Elevations of Rows of Holes in feet
Collection Capacity for Each Row of Holes in cfs
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
15298UD-Detention_v2.35Disturbedarea.xls, WQCV 5/1/2017, 8:28 AM
#N/A #N/A
STAGE-STORAGE SIZING FOR DETENTION BASINS
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
Check Basin Shape
15298UD-Detention_v2.35Disturbedarea.xls, Basin 5/1/2017, 8:27 AM
185 1.11 0.82 9078.22 0.18 1998.00 0.163
190 1.06 0.78 8859.93 0.18 2052.00 0.156
195 1.00 0.74 8617.24 0.18 2106.00 0.149
200 0.95 0.70 8350.15 0.18 2160.00 0.142
205 0.89 0.66 8058.66 0.18 2214.00 0.134
210 0.84 0.61 7742.76 0.18 2268.00 0.126
215 0.78 0.57 7402.47 0.18 2322.00 0.117
220 0.73 0.53 7037.77 0.18 2376.00 0.107
225 0.67 0.49 6648.66 0.18 2430.00 0.097
230 0.61 0.45 6235.16 0.18 2484.00 0.086
235 0.56 0.41 5797.25 0.18 2538.00 0.075
240 0.50 0.37 5334.94 0.18 2592.00 0.063
City of Fort Collins Criteria (120%)
Runoff Coefficient, C =
Frequency Factor, Cf
=
2-yr Release, Qout
=
Area =
Detention Volume Requirement (acre-feet)
525 0.16 0.065 0.51 0.09 0.065 0.000 525 0.57 0.256 0.51 0.09 0.065 0.191
540 0.16 0.065 0.51 0.09 0.067 -0.002 540 0.56 0.258 0.51 0.09 0.067 0.191
555 0.16 0.066 0.51 0.09 0.069 -0.003 555 0.55 0.260 0.51 0.09 0.069 0.191
570 0.15 0.066 0.51 0.09 0.071 -0.005 570 0.54 0.261 0.51 0.09 0.071 0.191
585 0.15 0.066 0.51 0.09 0.072 -0.006 585 0.53 0.263 0.51 0.09 0.072 0.190
600 0.15 0.067 0.51 0.09 0.074 -0.007 600 0.52 0.264 0.51 0.09 0.074 0.190
615 0.15 0.067 0.51 0.09 0.076 -0.009 615 0.51 0.266 0.51 0.09 0.076 0.190
630 0.14 0.067 0.51 0.09 0.078 -0.010 630 0.50 0.267 0.51 0.09 0.078 0.189
645 0.14 0.068 0.51 0.09 0.080 -0.012 645 0.49 0.269 0.51 0.09 0.080 0.189
660 0.14 0.068 0.51 0.09 0.082 -0.013 660 0.48 0.270 0.51 0.09 0.082 0.188
675 0.14 0.069 0.51 0.09 0.083 -0.015 675 0.47 0.271 0.51 0.09 0.083 0.188
690 0.13 0.069 0.51 0.09 0.085 -0.016 690 0.46 0.273 0.51 0.09 0.085 0.187
705 0.13 0.069 0.51 0.09 0.087 -0.018 705 0.46 0.274 0.51 0.09 0.087 0.187
720 0.13 0.070 0.51 0.09 0.089 -0.019 720 0.45 0.275 0.51 0.09 0.089 0.186
735 0.13 0.070 0.51 0.09 0.091 -0.021 735 0.44 0.276 0.51 0.09 0.091 0.186
750 0.12 0.070 0.51 0.09 0.093 -0.022 750 0.43 0.278 0.51 0.09 0.093 0.185
765 0.12 0.070 0.50 0.09 0.094 -0.024 765 0.43 0.279 0.50 0.09 0.094 0.185
780 0.12 0.071 0.50 0.09 0.096 -0.025 780 0.42 0.280 0.50 0.09 0.096 0.184
795 0.12 0.071 0.50 0.09 0.098 -0.027 795 0.42 0.281 0.50 0.09 0.098 0.183
810 0.12 0.071 0.50 0.09 0.100 -0.029 810 0.41 0.282 0.50 0.09 0.100 0.183
825 0.12 0.072 0.50 0.09 0.102 -0.030 825 0.40 0.284 0.50 0.09 0.102 0.182
840 0.11 0.072 0.50 0.09 0.104 -0.032 840 0.40 0.285 0.50 0.09 0.104 0.181
855 0.11 0.072 0.50 0.09 0.105 -0.033 855 0.39 0.286 0.50 0.09 0.105 0.180
870 0.11 0.072 0.50 0.09 0.107 -0.035 870 0.39 0.287 0.50 0.09 0.107 0.180
885 0.11 0.073 0.50 0.09 0.109 -0.036 885 0.38 0.288 0.50 0.09 0.109 0.179
900 0.11 0.073 0.50 0.09 0.111 -0.038 900 0.38 0.289 0.50 0.09 0.111 0.178
Mod. FAA Minor Storage Volume (cubic ft.) = 1,298 Mod. FAA Major Storage Volume (cubic ft.) = 8,351
Mod. FAA Minor Storage Volume (acre-ft.) = 0.0298 Mod. FAA Major Storage Volume (acre-ft.) = 0.1917
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
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
Q100=2-yr Hist., C100*1.25, Vmajor*1.20
15298UD-Detention_v2.35Disturbedarea.xls, Modified FAA 5/1/2017, 8:19 AM
.
When the Runoff Coefficient in above table is < 0, use 0.
When compositing the Runoff Coefficient for different soil types, use the table values above regardless if they are < 0.
Type C and D NRCS Hydrologic Soil Groups Type A NRCS Hydrologic Soils Group
Values of Runoff Coefficient CCD Values of Runoff Coefficient CA
Storm Return Period
Values of Correction Factors K CD &
K A
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Runoff Coefficient
Watershed Impervious Ratio
Runoff Coefficient vs. Imperviousness
NRCS Hydrologic Soils C & D
100-yr
25-yr
10-yr
5-yr
2-yr
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Runoff Coefficient
Watershed Impervious Ratio
Runoff Coefficient vs. Imperviousness
NRCS Hydrologic Soil A
100-yr
25-yr
10-yr
5-yr
2-yr
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