HomeMy WebLinkAboutCHRISTIAN BROTHERS AUTOMOTIVE - FDP - FDP170034 - 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
FINAL DRAINAGE REPORT
October 25, 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........................................................................................ 4
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: 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 drainage 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 disturb approximately
0.790 acres of the western lot area. The remaining 0.357 acres is covered by a
35- foot wide Platte River Power Authority easement 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, City of Fort
Collins 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
referenced and a copy 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.
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, and emergency vehicle easements with the most
efficient layout. Runoff from impervious surfaces is conveyed to a rain garden
above the detention pond 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-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.
Page | 3
B. Directly Connected Impervious Area (DCIA) and Four Step Process
Compliance
1. Employ Runoff Reduction Practices: This site uses a rain garden to treat sediment and
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 rain garden
in addition to a WQCV. The release rate of the WQCV is 40 hours.
3. Stabilize Drainage ways: 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 existing 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.
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 | 4
3. Detention pond sizing, outlet structure configuration, and discharge rates were
calculated using 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. The stage storage volume of the pond
was calculated using the UDFCD spreadsheet UD-Detention. 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.
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. The site is not in a floodplain or floodway.
G. Modifications of Criteria
1. There is no modification of criteria requested.
H. Modifications of Criteria
2. There is no modification of criteria requested.
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.
Page | 5
3. Input and Output results of the Historic Condition and Developed Condition
Fort Collins Rational Method Spreadsheet analysis are in Appendix B. Input and
Output results of the Detention Volume (Mass Balance), WQCV and Stage
Storage Table are in Appendix C.
4. The proposed drainage pattern will generally follow 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.
Of the 0.79 acres impacted by this project, 0.67 acres of the project will drain to
the rain garden and or detention pond. Areas of landscaping adjacent to
Academy Court and Prospect Road will follow historic drainage patterns in
existing swales to on-site catch basins or towards the street. These undetained
flows will remain at historic rates.
The LID requirements are met by designing a rain garden above the detention
pond, to provide water quality benefits prior to entering the detention area. The
rain garden is sized to treat the impervious area of the parking and drive aisles
and the west half of the building. The east half of the building will drain across
grass slopes into the detention pond which will provide additional water quality
control for frequent, low intensity storms.
The total impervious area of the project is 19,012 S.F. A minimum of 75% or
14,259 S.F. of the impervious area is required to flow to the rain garden. The
project will direct 16,354 S.F. of impervious area runoff, or 86% of runoff from
impervious areas to the rain garden.
The rain garden is sized based on 16,354 S.F. of impervious area from the west
half of the building and the parking and paved areas. The required flat area is
326 S.F., the provided flat area is 465 S.F. The required volume is 543 C.F., the
provided volume is 683 C.F. The depth of the rain garden is 12-inches.
Calculations for the rain garden are included in Appendix C.
2. Detention storage & outlet design: The calculated 100-yr detention volume plus
Water Quality Capture Volume (WQCV) is 0.222 acre-ft using the City of Fort
Collins Rational Method spreadsheet. The outlet will consist of a single stage
structure, to pond the WQCV, then release excess runoff at the 2-year historic
runoff rate up to the 100-yr plus WQCV elevation. WQCV of 0.025 acre-feet is
provided in addition to the rain garden volume benefits.
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 east side of the
pond.
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.
3. Compliance w/ City floodplain regulations. This site is not in a floodplain and
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. Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted
December-2011 and February-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
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
0 10 20 30 40 50 60 70 80 90 100 110 120
Rainfall Intensity (inches/hour)
Storm Duration (minutes)
100-Year Storm
10-Year Storm
2-Year Storm
Rational Method Runoff Coefficients for Composite Analysis
Table RO-11 of the Fort Collins Amendments to the UDFCD Criteria Manual
Character or Surface Runoff Coefficient
Streets, Parking Lots, Drives:
Asphalt 0.95
Concrete 0.95
Gravel 0.5
Roofs 0.95
Recycled Asphalt 0.8
Lawns, Sandy Soil, Flat < 2% 0.1
Lawns, Sandy Soil, Avg 2-7% 0.15
Lawns, Sandy Soil, Steep >7% 0.2
Lawns, Heavy Soil, Flat < 2% 0.2
Lawns, Heavy Soil, Avg 2-7% 0.25
Steep >7% 0.35
Equation RO-8 of the Fort Collins Amendments to the UDFCD Criteria Manual
C=Composite Runoff Coefficient
Ci=Runoff Coefficient for Specific Area (Ai)
Ai=Area of Surface with Runoff Coefficient of Ci, acres or square feet
n=number of different surfaces to be considered
At=Total Area over which C is applicable, acres or square feet
Rational Method Runoff Coefficients for Composite Analysis - Adjustment for Infrequent Storms
Table RO-12 of the Fort Collins Amendments to the UDFCD Criteria Manual
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
Example Calculation Table
Basin or Sub-Basin Total Area (acres)
Roof Area
(acres)
Paved Area
(acres)
Sidewalk Area
(acres)
Gravel Area
(acres)
Landscape Area
(acres)
Composite Runoff
Coefficient, C (2
to 10-yr)
Composite Runoff
Coefficient, C (11
to 25-yr)
Composite Runoff
Coefficient, C (26
to 50-yr)
Composite Runoff
Coefficient, C (
51 to 100-yr)
Historic 0.79 0.00 0.00 0.00 0.00 0.79 0.25 0.28 0.30 0.31
Developed 0.79 0.12 0.31 0.00 0.00 0.36 0.63 0.70 0.76 0.79
Basin 1 0.37 0.06 0.31 0.01 0.94 1.00 1.00 1.00
Basin 2 0.30 0.06 0.24 0.39 0.43 0.47 0.49
Basin Information Surface Type Runoff Coefficients
Example Calculation Table
Basin or Sub-Basin
Total Area
(acres) C (2-yr) C (100-yr) Length (ft) Slope (%) Ti
(2-yr) Ti
(100-yr) Length (ft) Slope (%) Ground Cover
Velocity
(ft/sec)
(manual input) Tt
Total Tc
(2-yr) Total Tc
(100-yr)
Tc
Maximum**
for Urbanized
Basins =
(Length/180)+10 Final Tc
(2-yr)* Final Tc
(100-yr) *
Historic 0.79 0.25 0.31 86.00 2.29 11.19 9.34 190 2.38 PL 1.1 2.88 14.07 12.21 11.53 11.53 11.53
Developed 0.79 0.63 0.79 35.00 2.00 4.10 0.88 254 0.65 PA 1.5 2.82 6.93 3.70 11.61 6.19 5.00
Total
Time of Concentration - Initial Overland Flow - Ti
C = Runoff Coefficient
Cf = Frequency Adjustment Factor
L = Length of Overland Flow (feet) (500' maximum)
S = Slope (%) (not in ft/ft)
Time of Concentration - Channelized Flow - Tt Slope (%)
Ground Cover
Type K Velocity (fps)
Ground Cover
Type K Velocity (fps)
Ground Cover
Type K Velocity (fps) Ground Cover Type
K Velocity (fps)
Ground Cover
Type K Velocity (fps)
Ground Cover
Type K Velocity (fps)
0.5 PA 1.4 1.78 GW 1.11 0.91 BG 0.7 0.35 PL 0.5 0.22 TC 0.33 0.15 HG 0.18 0.11
1 PA 1.4 2.51 GW 1.11 1.29 BG 0.7 0.50 PL 0.5 0.32 TC 0.33 0.21 HG 0.18 0.15
2 PA 1.4 3.55 GW 1.11 1.82 BG 0.7 0.71 PL 0.5 0.45 TC 0.33 0.30 HG 0.18 0.21
3 PA 1.4 4.35 GW 1.11 2.23 BG 0.7 0.87 PL 0.5 0.55 TC 0.33 0.37 HG 0.18 0.26
4 PA 1.4 5.02 GW 1.11 2.58 BG 0.7 1.00 PL 0.5 0.63 TC 0.33 0.43 HG 0.18 0.30
5 PA 1.4 5.62 GW 1.11 2.88 BG 0.7 1.12 PL 0.5 0.71 TC 0.33 0.48 HG 0.18 0.34
6 PA 1.4 6.15 GW 1.11 3.16 BG 0.7 1.23 PL 0.5 0.77 TC 0.33 0.52 HG 0.18 0.37
7 PA 1.4 6.65 GW 1.11 3.41 BG 0.7 1.33 PL 0.5 0.84 TC 0.33 0.57 HG 0.18 0.40
8 PA 1.4 7.10 GW 1.11 3.64 BG 0.7 1.42 PL 0.5 0.89 TC 0.33 0.60 HG 0.18 0.43
9 PA 1.4 7.54 GW 1.11 3.86 BG 0.7 1.50 PL 0.5 0.95 TC 0.33 0.64 HG 0.18 0.45
10 PA 1.4 7.94 GW 1.11 4.07 BG 0.7 1.58 PL 0.5 1.00 TC 0.33 0.68 HG 0.18 0.48
20 PA 1.4 11.23 GW 1.11 5.76 BG 0.7 2.24 PL 0.5 1.41 TC 0.33 0.96 HG 0.18 0.68
30 PA 1.4 13.76 GW 1.11 7.06 BG 0.7 2.75 PL 0.5 1.73 TC 0.33 1.17 HG 0.18 0.83
40 PA 1.4 15.89 GW 1.11 8.15 BG 0.7 3.17 PL 0.5 2.00 TC 0.33 1.35 HG 0.18 0.96
50 PA 1.4 17.76 GW 1.11 9.11 BG 0.7 3.54 PL 0.5 2.24 TC 0.33 1.51 HG 0.18 1.07
60 PA 1.4 19.46 GW 1.11 9.98 BG 0.7 3.88 PL 0.5 2.45 TC 0.33 1.66 HG 0.18 1.17
Land Surface Types
HG Forest with Heavy Ground Litter & Meadow 0.18
TC Fallow or Minimum Tillage Cultivation 0.33
PL Short Grass Pasture & Lawns 0.5
BG Nearly Bare Ground 0.7
Example Calculation Table
Basin or Sub-
Basin
Total Area
(acres) C (2-yr) C (100-yr) Tc
(2-yr) Tc
(100-yr) I (2-yr) I (100-yr) Q (2-yr) Q (100-yr)
Historic 0.79 0.25 0.31 11.53 11.53 2.12 7.37 0.42 1.82
Developed 0.79 0.63 0.79 6.19 5.00 2.88 9.96 1.44 6.22
Total
Basin Information Runoff Coefficients - C Time of Concentration - Tc
(min) Rainfall Intensity - I (in/hr) Peak Discharge - Q (cfs)
APPENDIX C
HYDRAULIC COMPUTATIONS
Detention Volume - Mass Balance Method -100-yr (Major Storm)
Input
1.00
1.00
0.42 cfs
0.79 acres
Results
0.170
0.170
Rainfall Duration
(min)
Rainfall Intensity
(in/hr)
Qin
(cfs) Volumein
(ft
3
) Qout
(cfs) Volumeout
(ft
3
)
Volume detained
(acre-feet)
5 9.96 7.87 2360.52 0.42 125.61 0.051
10 7.74 6.11 3668.76 0.42 251.22 0.078
15 6.52 5.15 4635.72 0.42 376.83 0.098
20 5.61 4.43 5318.28 0.42 502.44 0.111
25 4.97 3.92 5887.08 0.42 628.05 0.121
30 4.52 3.57 6427.44 0.42 753.66 0.130
35 4.08 3.22 6768.72 0.42 879.27 0.135
40 3.74 2.95 7081.56 0.42 1004.88 0.140
45 3.45 2.73 7365.96 0.42 1130.49 0.143
50 3.23 2.55 7650.36 0.42 1256.10 0.147
55 3.03 2.40 7906.32 0.42 1381.71 0.150
60 2.86 2.26 8133.84 0.42 1507.32 0.152
65 2.71 2.14 8361.36 0.42 1632.93 0.154
70 2.59 2.04 8588.88 0.42 1758.54 0.157
75 2.48 1.96 8816.40 0.42 1884.15 0.159
80 2.38 1.88 9015.48 0.42 2009.76 0.161
85 2.29 1.81 9214.56 0.42 2135.37 0.163
90 2.21 1.74 9413.64 0.42 2260.98 0.164
95 2.13 1.68 9584.28 0.42 2386.59 0.165
100 2.06 1.63 9783.36 0.42 2512.20 0.167
105 2.00 1.58 9954.00 0.42 2637.81 0.168
110 1.94 1.53 10124.64 0.42 2763.42 0.169
115 1.88 1.49 10266.84 0.42 2889.03 0.169
120 1.835 1.45 10437.48 0.42 3014.64 0.170
125 1.78 1.40 10527.18 0.42 3140.25 0.170
130 1.72 1.36 10607.30 0.42 3265.86 0.169
135 1.67 1.32 10661.19 0.42 3391.47 0.167
140 1.61 1.27 10688.85 0.42 3517.08 0.165
145 1.56 1.23 10690.29 0.42 3642.69 0.162
150 1.50 1.19 10665.49 0.42 3768.30 0.158
155 1.44 1.14 10614.47 0.42 3893.91 0.154
160 1.39 1.10 10537.22 0.42 4019.52 0.150
165 1.33 1.05 10433.74 0.42 4145.13 0.144
170 1.28 1.01 10304.03 0.42 4270.74 0.139
175 1.22 0.97 10148.10 0.42 4396.35 0.132
180 1.17 0.92 9965.93 0.42 4521.96 0.125
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 90
WQCV = 0.40 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 0.79 acres
V = 0.026 acre-feet
Drain Time Coefficients
Extended Detention Basin
Outlet Structure Orifice Sizing
1. 100-yr Orifice (using orifice equation)
a. Use Orifice Equation to solve for orifice diamter
Q = Co
A√2gh
Where:
Q = flow rate or allowable discharge, cfs
Co
= orifice coefficient, typically 0.61
A = cross-sectional area, ft
2
A0
= 88V
(0.95/H^0.085)
g = gravitational constant, 32.2 ft/sec
2
TD
S
0.09
H
(2.6/S^0.3)
h = water surface elevation minus elevation of centroid of orifice, ft
Q = 0.42 cfs
Cd = 0.61 dimensionless
h = 4.66 ft
A = 0.040 ft
2
orifice diameter = 2.70 inches
2. WQCV Perforated Orifice
a. Determine the required area per row of orifices
a = WQCV
0.013DWQ
2
+ 0.22DWQ
-0.10
Where:
Ao
= Area per row of orifices spaced on 4" centers, in
2
WQCV = Water Quality Capture Volume or "Volume", acre-ft
DWQ
= Depth of volume, ft
V = 0.026 acre-ft
DWQ
= 1.63 ft
a = 0.107 in
2
per row or from Figure EDB-3
b. Determine diameter of circular perforations
A0
= 0.107 in
2
per row
Diameter = 0.370 inches
c. Determine number of columns
Number of Columns = 1 from Table 6a-1
d. Round Orifice Diameter to nearest 1/16 inch
Area per Perforation = 0.1074 in
2
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 38 7 0.001 0.000
4925.50 4.00 30.90 74.17 1,146.0 371 109 0.009 0.003
4926.00 4.00 35.82 85.97 1,539.9 1,052 465 0.024 0.011
WQCV@4926.47 4926.50 4.00 40.74 97.78 1,991.8 1,851 1,191 0.042 0.027 0.026
4927.00 4.00 45.66 109.59 2,501.9 2,570 2,296 0.059 0.053
4927.50 4.00 50.58 121.39 3,070.0 3,212 3,741 0.074 0.086
4928.00 4.00 55.50 133.20 3,696.2 3,798 5,494 0.087 0.126
100-yr @4928.47 4928.50 4.00 60.42 145.00 4,380.5 4,454 7,557 0.102 0.173 0.170
WQCV+100-yr @4928.70 4929.00 4.00 65.34 156.81 5,122.8 5,378 10,015 0.123 0.230 0.196
4929.50 4.00 70.26 168.62 5,923.2 6,496 12,983 0.149 0.298
4930.00 4.00 75.18 180.42 6,781.7 7,404 16,458 0.170 0.378
4930.25 4.00 77.64 186.33 7,232.7 7,898 18,371 0.181 0.422
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #N/A #N/A
4.00 #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-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 8/22/2017, 2:35 PM
Project:
Basin ID:
Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert.
Circular Opening: Diameter in Inches Dia. = 2.70 inches
OR
Rectangular Opening: Width in Feet W = 3.00 ft.
Length (Height for Vertical) L or H = 3.00 ft.
Percentage of Open Area After Trash Rack Reduction % open = 50 100 %
Orifice Coefficient Co
= 0.67 0.67
Weir Coefficient Cw
= 3.00
Orifice Elevation (Bottom for Vertical) Eo
= 4926.50 4,924.20 ft.
Calculation of Collection Capacity:
Net Opening Area (after Trash Rack Reduction) Ao
= 4.50 0.04 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 = 4924.43 ft.
Center Elevation of Vertical Orifice Opening, Cen = 4924.31 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)
4924.90 0.00 0.00 0.00 0.00 0.00 0.16 0.00 0.00
4925.00 0.00 0.00 0.00 0.00 0.00 0.18 0.00 0.00
4925.50 0.01 0.00 0.00 0.00 0.00 0.23 0.00 0.01
4926.00 0.01 0.00 0.00 0.00 0.00 0.28 0.00 0.01
4926.50 0.01 0.00 0.00 0.00 0.00 0.32 0.00 0.01
4927.00 0.02 9.55 17.11 0.00 0.00 0.35 0.00 0.35
4927.50 0.02 27.00 24.20 0.00 0.00 0.38 0.00 0.38
4928.00 0.02 49.60 29.63 0.00 0.00 0.41 0.00 0.41
4928.50 0.03 76.37 34.22 0.00 0.00 0.44 0.00 0.44
4929.00 0.03 106.73 38.26 0.00 0.00 0.46 0.00 0.46
4929.50 0.03 140.30 41.91 0.00 0.00 0.49 0.00 0.49
4930.00 0.04 176.79 45.27 0.00 0.00 0.51 0.00 0.51
4930.25 0.04 196.07 46.85 0.00 0.00 0.52 0.00 0.52
0.04 #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
0.04 #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
0.04 #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
0.04 #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
0.05 #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
Project:
Basin ID:
Christian Brothers Automotive 1500 Academy Court, Fort Collins, CO
STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL)
4923.75
4924.75
4925.75
4926.75
4927.75
4928.75
4929.75
4930.75
0 0.1 0.2 0.3 0.4 0.5 0.6
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE OUTLET STRUCTURE
15298UD-Detention_v2.35Disturbedarea.xls, Outlet 8/22/2017, 3:15 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
= 4924.20 ft. elev.
Outlet Elevation at Culvert Invert Oelev
= 4923.60 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 1.60 3.21 0.00 0.00 Regression Eqn.
4925.00 4922.50 2.00 3.39 0.00 0.00 Regression Eqn.
4925.50 4922.50 4.20 4.26 0.01 0.01 Regression Eqn.
4926.00 4922.50 6.10 5.56 0.01 0.01 Regression Eqn.
4926.50 4922.50 7.50 6.68 0.01 0.01 Regression Eqn.
4927.00 4922.50 8.70 7.62 0.35 0.35 Regression Eqn.
4927.50 4922.50 9.70 8.45 0.38 0.38 Regression Eqn.
4928.00 4922.50 10.70 9.21 0.41 0.41 Orifice Eqn.
4928.50 4922.50 11.50 9.93 0.44 0.44 Orifice Eqn.
4929.00 4922.50 12.30 10.58 0.46 0.46 Orifice Eqn.
4929.50 4922.50 13.00 11.19 0.49 0.49 Orifice Eqn.
4930.00 4922.50 13.70 11.77 0.51 0.51 Orifice Eqn.
4930.25 4922.50 14.00 12.06 0.52 0.52 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 0.10 0.20 0.30 0.40 0.50 0.60
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE FINAL OUTLET PIPE CULVERT
15298UD-Detention_v2.35Disturbedarea.xls, Culvert 8/22/2017, 3:16 PM
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 0.01
4926.00 0.00 0.00 0.00 0.01
4926.50 0.00 0.00 0.00 0.01
4927.00 0.00 0.00 0.00 0.35
4927.50 0.00 0.00 0.00 0.38
4928.00 0.00 0.00 0.00 0.41
4928.50 0.00 0.00 0.00 0.44
4929.00 0.00 0.00 0.00 0.46
4929.50 10.61 2.12 12.73 13.22
4930.00 30.00 12.00 42.00 42.51
4930.25 41.93 20.96 62.88 63.40
#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
4924.9
4925.9
4926.9
4927.9
4928.9
4929.9
4930.9
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 8/22/2017, 3:17 PM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 100.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 1.000
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.40 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 16,354 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 545 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 327 sq ft
D) Actual Flat Surface Area AActual = 465 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 900 sq ft
F) Rain Garden Total Volume VT= 683 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y = ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft
iii) Orifice Diameter, 3/8" Minimum DO = N/A in
Design Procedure Form: Rain Garden (RG)
Todd Rand, PE
Baseline Engineering Corporation
August 18, 2017
Christian Brothers Automotive
1500 Academy Court, Fort Collins, CO
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.06.xlsm, RG 8/18/2017, 10:59 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
Todd Rand, PE
Baseline Engineering Corporation
August 18, 2017
Christian Brothers Automotive
1500 Academy Court, Fort Collins, CO
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.06.xlsm, RG 8/18/2017, 10:59 AM
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
14
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
PROPOSED DRAINAGE PLAN
5,140 SF
AUTOMOTIVE REPAIR FACILITY
FFE=4932.64'
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 8/22/2017, 3:17 PM
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 8/22/2017, 3:16 PM
#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
15298UD-Detention_v2.35Disturbedarea.xls, Outlet 8/22/2017, 3:15 PM
#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 8/22/2017, 2:35 PM
Diameter per Perforation = 0.370 inches
Actual Perforation Diameter = 3/8 inches user input (round to nearest 1/16th inch)
Actual Area per Perforation = 0.1104 in
2
Actual Area per Row = 0.1104 in
2
per row
Minimum Steel Plate Thickness = 1/4 inches from Figure 5
0.0625 1/16
0.1250 1/8
0.1875 3/16
0.2500 1/4
0.3125 5/16
0.3750 3/8
0.4375 7/16
0.5000 1/2
0.5625 9/16
0.6250 5/8
0.6875 11/16
0.7500 3/4
0.8125 13/16
0.8750 7/8
0.9375 15/16
1.0000 1
e. Trach Rack Opening Width
Max Diameter of Perforations = 0.3750 inches
DWQ
= 1.86 ft
Width of Trash Rack per Column of Holes = 3 inches user input from Table 6a-1
Total Trash Rack Opening Width = 3 inches
Total Trash Rack Height = 24.32 inches
Trash Rack Design Specs = use Table 6a-2
Diameter Conversion from decimal to architectural
Micropools are typically not
allowed in Fort Collins.
Perforated orifice plate
must be configured such
that bottom orifice is at the
very bottom of the plate
and is a half perforation,
like shown.
Pond Bottom
185 1.11 0.88 9757.54 0.42 4647.57 0.117
190 1.06 0.84 9522.92 0.42 4773.18 0.109
195 1.00 0.79 9262.07 0.42 4898.79 0.100
200 0.95 0.75 8974.99 0.42 5024.40 0.091
205 0.89 0.70 8661.69 0.42 5150.01 0.081
210 0.84 0.66 8322.15 0.42 5275.62 0.070
215 0.78 0.62 7956.39 0.42 5401.23 0.059
220 0.73 0.57 7564.40 0.42 5526.84 0.047
225 0.67 0.53 7146.18 0.42 5652.45 0.034
230 0.61 0.49 6701.74 0.42 5778.06 0.021
235 0.56 0.44 6231.06 0.42 5903.67 0.008
240 0.50 0.40 5734.16 0.42 6029.28 -0.007
City of Fort Collins Criteria (120%)
Runoff Coefficient, C =
Frequency Factor, Cf
=
2-yr Release, Qout
=
Area =
Detention Volume Requirement (acre-feet)
GW Grassed Waterway 1.11
PA Paved Area (Sheet Flow) & Shallow Gutter Flow 1.4
Total Time of Concentration (Tc
) = Initial Overland Flow (Ti
) + Channelized Flow (Tt
)
Tc
= Ti
+ Tt
**Tc Maximum (check for Urbanized Basins)
(L/180) + 10
*Tc Minimum
5 minute minimum
Basin Information Runoff Coefficients Time of Concentration - Initial Overland Flow - Ti
(minutes) Time of Concentration - Channelized Flow - Tt
(minutes) Time of Concentration - Total - Tc
(minutes)
0.10
1.00
10.00
100.00
0.1 1 10 100
Series1
Series2
Series3
Series4
Series5
Series6