HomeMy WebLinkAboutDrainage Reports - 06/04/2021April 14, 2021
DRAINAGE LETTER AND LID REPORT
HOMESTEAD AT CLARENDON HILLS
Fort Collins, Colorado
Prepared for:
Kenneth R. Mitchell
Mosaic Real Estate LLC
1021 Nightingale Drive
Fort Collins, Colorado. 80525
Prepared by:
301 North Mason Street, Suite 100
Fort Collins, Colorado 80524
Phone: 970.221.4158
www.northernengineering.com
Project Number: 1013-008
City of Fort Collins Approved Plans
Approved by:
Date:
Dan Mogen
06/04/2021
Drainage Letter and LID Report Homestead at Clarendon Hills
Date: April 14, 2021
Project: Homestead at Clarendon Hills Project No. 1013-008
Final Development Plan (FDP)
Fort Collins, Colorado
Attn: City of Fort Collins Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
To whom it may concern:
Homestead at
Clarendon Hills The site is located in southwest Fort Collins bounded to the north by Front Range
Community College, to the east by existing Clarendon Hills Subdivision, to the south by Clarendon
Hills Drive and Langdale Drive, and to the west by South Shields Street. The project is part of the
Drainage Report for Clarendon Hills by Stuart and Associates written in 1986. The proposed
development consists of 8 low-density single-family lots and a detention area. The project site also
contains an existing irrigation ditch along the north property line.
The project was included in the drainage report for Clarendon Hills Subdivision. Therefore, this letter
intends to show conformance with the approved drainage design, including general drainage patterns
and imperviousness. This letter also documents how the project meets new Low Impact Development
requirements implemented City of Fort Collins since the approval of the original project.
Original Drainage Patterns
The original Clarendon Hill drainage design divided the subdivision into 3 basins. The current project
site is split by two of these basins - Drainage Basin A draining to the north, and Drainage Basin B
draining to the south. Drainage Basin B flows into Clarendon Hills Drive and Langdale Drive and
travels via gutter and pan flow south along Clarendon Hills Drive. The flow is then collected by inlets
at Clarendon Hills Drive and Hinsdale Drive and conveyed to a series of existing detention ponds.
Drainage Basin A generally flows to the northeast to an existing irrigation ditch on the property. A
small undisturbed area north of the irrigation ditch will flow into the Front Range Community College
drainage system. From there, it flows through existing drainage ways east to Mail Creek, and
eventually to Fossil Creek. An Existing Drainage Exhibit and excerpts from the original report are
provided in the appendices for reference.
Page | 3
Proposed Drainage Patterns
The Homestead at Clarendon Hills project was divided into seven proposed drainage basins that
essentially follow the established drainage patterns, as well as the drainage patterns approved with
the Drainage Report for Clarendon Hills.
Basin A encompasses the rear of the lots and open space between the rear lot lines and the existing
irrigation ditch. The only proposed improvements with Basin A are landscaping in the rear of the lots.
Flows from the basin will drain north into the irrigation ditch. Basin A is consistent with Basin A from
the Drainage Report for Clarendon Hills.
Basin B will roughly match the existing area draining south to the existing Clarendon Hills ponds.
Proposed improvements will include single-family homes, the front and side of the lots, driveways,
walks, and detention area. Basin B is further subdivided into Basins B1, B2, B3, and B4. Basins B1 and
B3 consists of the open space at the west and east ends that will discharge into the Clarendon Hills and
Langdon Drives curb and gutter. Basins B2 consists of Lots 1 through 8 building envelopes, driveways
and detention pond. The project was graded to allow the building envelopes to drain to south, and
small swales and curb and gutter in the shared driveway will convey drainage towards the detention
pond. Basin B4 consists of the landscaping along the front of the pond that is incapable of draining
into the detention pond. The release rate from the detention pond is reduced to accommodate the
undetained releases from Basins B1, B3, and B4. An exhibit calculating the release rate is included in
the appendices.
The percent impervious for the lots was developed by assuming a typical building footprint of 3,250
square feet. The building footprint was placed along the rear building envelope to maximize the
length of the driveway. This resulted in 49% imperviousness on a 7,982 sq. ft. lot. The area of the
driveway was adjusted on the other lots to maintain a 49% imperviousness on the other lots. Along
with the shared driveway, this resulted in a percent imperviousness of 51% in Basin B3. An exhibit is
included in the appendices.
Additionally, Basin OS1 and OS2 are on the east and the north sides of the site to quantify flows to the
Front Range Community College campus. Basin OS1 consists of the side and rear of Lot 8 and
adjacent open space. Basin OS2 is a small sliver of open space on the north side of the irrigation ditch
that drains directly to the Front Range Community College campus.
Development of Existing Runoff Coefficient
The drainage for Clarendon Hills Subdivision was originally analyzed in the Drainage Report:
Clarendon Hills: Fort Collins, Colorado prepared by Stuart and Associates in 1986 as part of the approval
process for Clarendon Hills 1st Filing. Homestead for Clarendon Hills is in the northwest corner of the
original drainage master plan for Clarendon Hills 1st Filing. In the approved original drainage report
for Clarendon Hills (1st Filing), the project site was planned as office and multi-family with a
developed runoff coefficient of C=0.50.
According to the approved drainage report for Clarendon Hills 4th Filing, prepared by Land
Development Services and dated April 9, 1991, a church site of 8.27 acres in the middle of the
Clarendon Hills 4th Filing was assumed to be an offsite undeveloped drainage basin with a developed
Page | 4
runoff coefficient of C=0.25. According to the approved drainage report for Clarendon Hills 6th Filing,
prepared by Land Development Services and dated January 8, 1992, the original developer of
Clarendon Hills swapped the northwest corner of Clarendon Hills (including Homestead for
Clarendon Hills) for the church site in Clarendon Hills 4th Filing. The old church site was then
developed as Clarendon Hills 6th Filing with runoff coefficients from 0.28 to 0.70.
Because of the subsequent drainage studies and land swaps, we assumed an existing runoff coefficient
of C=0.25 for Homestead at Clarendon Hills. A runoff coefficient of 0.25 is consistent with the
following design considerations:
The Fort Collins Stormwater Criteria Manual for lawns with clayey soil and an average slope of
2% to 7% requires a runoff coefficient of C = 0.25. The existing slopes throughout the site is
between 2% to 7% with clayey soil.
The drainage report for Clarendon Hills 4th Filing assumed a runoff coefficient C=0.25 for the
church site, and the church site was subsequently part of a land swap for the northwest corner
of the Clarendon Hills Subdivision.
Detention
Per the Clarendon Hills 1st
that required 10.46 acre-feet to detain the 100-year developed storm and release at a 2-year historic
Assuming a historic runoff coefficient of 0.25, detention from Basin B was provided as long as
the overall flow at Design Point B does not exceed 1.9 cfs. Because of the increased impervious area
within Basin B, detention is required within Basin B2 to reduce the post-developed flow rates at
Design Point B to equal or less than 1.9 cfs. Since Basins B1, B3, and B4 will be released into the
surrounding curb and gutter undetained, the detention pond in Basin B2 is designed to release the
100-year event at 1.5 cfs. A release rate of 1.5 cfs is required to maintain a 100-year flow rate of 1.9 cfs
at Design Point B. (See the included flowrate calculations included in the appendices.)
Detention Spillway
The detention pond is designed to overflow at the west driveway entrance on Clarendon Hills Drive.
In the even the outlet orifice is blocked, stormwater will first overflow through a weir into the west
rain garden. Then, it will overflow through a curb cut at the northwest end of the rain garden.
Finally, stormwater will overflow through the curb and gutter at a high point located at the back of
sidewalk at the west entrance. Hydraulic calculations are included in the appendices.
Inlets
By limiting the 100-year flowrate at Design Point B, the flowrate at the existing inlets will match or
decrease from the projected flowrates in the previously approved Clarendon Hills drainage reports.
This results in matching or decreasing runoff to the existing inlets that were designed and approved
with the earlier project, so no additional inlet calculations have been provided as a part of this report.
Water Quality/LID Conformance
water quality plus 50% site treated with LID (including pavers) equals 100% of site-treated (requirements met),
Page | 5
(page 14). This project proposes to treat 90.5% of the new impervious areas
through two rain gardens as LID treatment. However, due to grading constraints along the east side
of the project and requirements to provide a maintenance access for the ditch company, a gravel
pedestrian path (9.5% of new impervious area) will not be treated by either the rain gardens or the
detention pond. An exhibit showing the area of LID treatment is included in the appendices.
Although exact impervious area is unavailable at this preliminary stage, the building envelopes will
drain towards the rain gardens and the detention pond. The high point along each lot line is set at the
rear of the building envelopes to maximize as much of the lot draining towards the south. Space
limitations on the detention pond and rain gardens, natural buffer offsets from the ditch, and fire
accessibility requirements restrict the drainage towards the front. Even with the grading restrictions,
the proposed flowrate into the Mail Creek Basin is 2.2 cfs less than the existing flowrate.
Erosion and Sediment Control
During construction, the Contractor will follow the appropriate and applicable City of Fort Collins
standards for erosion and sediment control. Since more than 10,000 sf will be disturbed as a part of
this project, a comprehensive Stormwater Management Plan will be prepared for this project at final
design. Post construction water quality and erosion control will be achieved by a fully established and
stabilized site. All areas disturbed during construction will receive permanent hardscape, landscape,
or building structure.
Floodplains
There are no regulatory floodplains associated with the project.
Conclusions
The proposed grading concept matches the original drainage patterns. The site matches the designed
imperviousness draining to the existing Clarendon Hills curb and gutter. Onsite detention will be
provided for the increased imperviousness of the area draining to towards the existing Clarendon
Hills ponds, and onsite detention will be required to maintain historic flow rates within Clarendon
Hills. Stormwater quality has been provided and meets the city requirements for Low Impact
Development treatment. Therefore, it is my professional opinion that Homestead at Clarendon Hills
satisfies all applicable stormwater criteria and will effectively limit potential damage associated with
its stormwater runoff.
Please do not hesitate to contact me if you have questions or require additional information.
Sincerely,
Frederick S. Wegert, PE
Project Engineer
Page | 6
Compliance Statement
I hereby attest this report for the final drainage design for Homestead at Clarendon Hills was prepared
by me or under my direct supervision, in accordance with the provisions of the Fort Collins
Stormwater Criteria Manual. I understand that the City of Fort Collins does not and ill not assume
liability for drainage facilities designed by others.
4/14/202
ATTACHMENT 1
HYDROLOGIC CALCULATIONS
TYPICAL LOT IMPERVIOUSNESS EXHIBIT
FEMA Firmette
FORT COLLINS STORMWATER CRITERIA MANUAL Hydrology Standards (Ch. 5)
3.0 Rational Method
3.4 Intensity-Duration-Frequency Curves for Rational Method
Page 8
Table 3.4-1. IDF Table for Rational Method
Duration
(min)
Intensity
2-year
(in/hr)
Intensity
10-year
(in/hr)
Intensity
100-year
(in/hr)
Duration
(min)
Intensity
2-year
(in/hr)
Intensity
10-year
(in/hr)
Intensity
100-year
(in/hr)
5 2.85 4.87 9.95 39 1.09 1.86 3.8
6 2.67 4.56 9.31 40 1.07 1.83 3.74
7 2.52 4.31 8.80 41 1.05 1.80 3.68
8 2.40 4.10 8.38 42 1.04 1.77 3.62
9 2.30 3.93 8.03 43 1.02 1.74 3.56
10 2.21 3.78 7.72 44 1.01 1.72 3.51
11 2.13 3.63 7.42 45 0.99 1.69 3.46
12 2.05 3.50 7.16 46 0.98 1.67 3.41
13 1.98 3.39 6.92 47 0.96 1.64 3.36
14 1.92 3.29 6.71 48 0.95 1.62 3.31
15 1.87 3.19 6.52 49 0.94 1.6 3.27
16 1.81 3.08 6.30 50 0.92 1.58 3.23
17 1.75 2.99 6.10 51 0.91 1.56 3.18
18 1.70 2.90 5.92 52 0.9 1.54 3.14
19 1.65 2.82 5.75 53 0.89 1.52 3.10
20 1.61 2.74 5.60 54 0.88 1.50 3.07
21 1.56 2.67 5.46 55 0.87 1.48 3.03
22 1.53 2.61 5.32 56 0.86 1.47 2.99
23 1.49 2.55 5.20 57 0.85 1.45 2.96
24 1.46 2.49 5.09 58 0.84 1.43 2.92
25 1.43 2.44 4.98 59 0.83 1.42 2.89
26 1.4 2.39 4.87 60 0.82 1.4 2.86
27 1.37 2.34 4.78 65 0.78 1.32 2.71
28 1.34 2.29 4.69 70 0.73 1.25 2.59
29 1.32 2.25 4.60 75 0.70 1.19 2.48
30 1.30 2.21 4.52 80 0.66 1.14 2.38
31 1.27 2.16 4.42 85 0.64 1.09 2.29
32 1.24 2.12 4.33 90 0.61 1.05 2.21
33 1.22 2.08 4.24 95 0.58 1.01 2.13
34 1.19 2.04 4.16 100 0.56 0.97 2.06
35 1.17 2.00 4.08 105 0.54 0.94 2.00
36 1.15 1.96 4.01 110 0.52 0.91 1.94
37 1.16 1.93 3.93 115 0.51 0.88 1.88
38 1.11 1.89 3.87 120 0.49 0.86 1.84
FORT COLLINS STORMWATER CRITERIA MANUAL Hydrology Standards (Ch. 5)
3.0 Rational Method
3.4 Intensity-Duration-Frequency Curves for Rational Method
Page 9
Figure 3.4-1. Rainfall IDF Curve – Fort Collins
Tc2 Tc10 Tc100 C2 C10 C100
I2
(in/hr)
I10
(in/hr)
I100
(in/hr)
Q2
(cfs)
Q10
(cfs)
Q100
(cfs)
ex a EX A 2.382 14.25 14.25 17.21 0.25 0.25 0.31 1.92 3.29 6.10 1.1 2.0 4.5
ex b EX B 0.684 7.41 7.41 7.01 0.25 0.25 0.31 2.52 4.31 8.80 0.4 0.7 1.9
ex os1 EX OS1 0.147 11.08 11.08 10.32 0.25 0.25 0.31 2.13 3.63 7.72 0.1 0.1 0.4
ex os2 EX OS2 0.064 5.42 5.42 5.02 0.25 0.25 0.31 2.85 4.87 9.95 0.0 0.1 0.2
ex a North 2.594 14.06 14.06 16.80 0.25 0.25
0.31 1.92 3.29 6.20 1.25 2.13 5.03
Combined Basins
Velocity (Swale Flow), V = 15·S ½
Rational Equation: Q = CiA (Equation 6-1 per MHFD)
Design
Point Basin Area
(acres)
Tc (Min)Runoff C Intensity Flow
Velocity (Gutter Flow), V = 20·S ½
EXISTING DIRECT RUNOFF COMPUTATIONS (MHFD)
Overland Flow, Time of Concentration:
Project:Homestead at Clarendon
Gutter/Swale Flow, Time of Concentration:Calculations By:F. Wegert
Tt = L / 60V (Equation 6-4 per MHFD)Date:December 18, 2020
Tc = Ti + Tt (Equation 6-2 per MHFD)
Intensity, I from Fig. 3.4.1 Fort Collins Stormwater Manual
(Equation 6-4 per MHFD)}
(Equation 3.3-2 per Fort Collins
Stormwater Manual)
Page 3 of 3
Tc2 Tc10 Tc100 C2 C10 C100
I2
(in/hr)
I10
(in/hr)
I100
(in/hr)
Q2
(cfs)
Q10
(cfs)
Q100
(cfs)
a A 1.368 14.25 14.25 17.32 0.24 0.24 0.30 1.92 3.29 6.10 0.6 1.1 2.5
b B1 0.041 7.80 7.80 7.27 0.29 0.29 0.36 2.46 4.21 8.80 0.0 0.0 0.1
b B2 1.630 10.47 10.47 7.99 0.60 0.60 0.75 2.21 3.78 8.59 2.2 3.7 10.6
b B3 0.013 11.37 11.37 10.86 0.20 0.20 0.25 2.13 3.63 7.57 0.0 0.0 0.0
b B4 0.070 5.00 5.00 5.00 0.25 0.25 0.31 2.85 4.87 9.95 0.0 0.1 0.2
os1 OS1 0.092 6.12 6.12 5.16 0.46 0.46 0.57 2.67 4.56 9.95 0.1 0.2 0.5
os2 OS2 0.064 5.00 5.00 5.00 0.25 0.25
0.31 2.85 4.87 9.95 0.0 0.1 0.2
a North 1.525 14.25 14.25 17.21 0.25 0.25
0.31 1.92 3.29 6.10 0.7 1.3 2.9
b South 1.753 9.67 9.67 7.55 0.58 0.58
0.72 2.26 3.86 8.59 2.3 3.9 10.9
Velocity (Gutter Flow), V = 20·S ½
DEVELOPED DIRECT RUNOFF COMPUTATIONS (MHFD)
Overland Flow, Time of Concentration:
Project:Homestead at Clarendon
Gutter/Swale Flow, Time of Concentration:Calculations By:F. Wegert
Tt = L / 60V (Equation 6-4 per MHFD)Date:December 18, 2020
Tc = Ti + Tt (Equation 6-2 per MHFD)
Intensity, I from Fig. 3.4.1 Fort Collins Stormwater Manual
Combined Basins
Velocity (Swale Flow), V = 15·S ½
Rational Equation: Q = CiA (Equation 6-1 per MHFD)
Design
Point Basin Area
(acres)
Tc (Min)Runoff C Intensity Flow
(Equation 6-4 per MHFD)}
(Equation 3.3-2 per Fort Collins
Stormwater Manual)
Page 3 of 3
105°5'59.00"W
105°5'21.55"W
ATTACHMENT 2
HYDRAULIC CALCULATIONS
Area Inlet Performance Curve:
Rain Garden Overflow
Governing Equations:
At low flow depths, the inlet will act like a weir governed by the following equation:
* where P = 3.1416*Dia.of grate
* where H corresponds to the depth of water above the flowline
At higher flow depths, the inlet will act like an orifice governed by the following equation:
* where A equals the open area of the inlet grate
* where H corresponds to the depth of water above the centroid of the cross-sectional area (A)
The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown.
However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation
will cross at a certain flow depth. The two curves can be found below:
If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir.
Input Parameters:
Type of Grate: Nyloplast 24" Dome
Diameter of Grate (ft): 2
Open Area of Grate (ft2):1.88
Rim Elevation (ft): 5089.60
Reduction Factor: 50%
Depth vs. Flow:
Depth Above Inlet (ft)
Elevation
(ft)
Shallow
Weir Flow
(cfs)
Orifice
Flow
(cfs)
Actual
Flow
(cfs)
0.00 5089.60 0.00 0.00 0.00
0.10 5089.70 0.30 1.60 0.30
0.20 5089.80 0.84 2.27 0.84
0.30 5089.90 1.55 2.77 1.55
0.40 5090.00 2.38 3.20 2.38 10-Year
0.50 5090.10 3.33 3.58 3.33
0.60 5090.20 4.38 3.92 3.92
0.70 5090.30 5.52 4.24 4.24
0.80 5090.40 6.74 4.53 4.53
0.90 5090.50 8.05 4.81 4.81
1.00 5090.60 9.42 5.07 5.07 100-Year
10-Year Design Flow =1.80 cfs100-Year Design Flow = 5.12 cfs
5.10.3 HPQ
5.0)2(67.0 gHAQ
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Di
s
c
h
a
r
g
e
(
c
f
s
)
Stage (ft)
Stage - Discharge Curves
Weir Flow
Orifice Flow
Area Inlet Performance Curve:
Detention Pond Overflow
Governing Equations:
At low flow depths, the inlet will act like a weir governed by the following equation:
* where P = 2(L + W)
* where H corresponds to the depth of water above the flowline
At higher flow depths, the inlet will act like an orifice governed by the following equation:
* where A equals the open area of the inlet grate
* where H corresponds to the depth of water above the centroid of the cross-sectional area (A)
The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown.
However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation
will cross at a certain flow depth. The two curves can be found below:
If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir.
Input Parameters:
Type of Grate: FABRICATED
Length of Grate (ft): 3.00
Width of Grate (ft): 3.00
Open Area of Grate (ft2):7.65
Grate Elevation (ft): 5089.60
Allowable Capacity: 0.80
Depth vs. Flow:
Depth Above Inlet (ft)
Elevation
(ft)
Shallow
Weir Flow
(cfs)
Orifice
Flow
(cfs)
Actual
Flow
(cfs)
0.00 5089.60 0.00 0.00 0.00
0.10 5089.70 0.91 10.40 0.91
0.20 5089.80 2.58 14.71 2.58
0.30 5089.90 4.73 18.01 4.73
0.40 5090.00 7.29 20.80 7.29
0.52 5090.12 10.80 23.72 10.80
Q100
0.60 5090.20 13.39 25.48 13.39
0.70 5090.30 16.87 27.52 16.87
0.80 5090.40 20.61 29.42 20.61
0.90 5090.50 24.59 31.20 24.59
1.00 5090.60 28.80 32.89 28.80
100-Year Flow = 10.6 cfs
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Di
s
c
h
a
r
g
e
(
c
f
s
)
Stage (ft)
Stage - Discharge Curves
Weir Flow
Orifice Flow
5.10.3 HPQ
5.0)2(67.0 gHAQ
ATTACHMENT 3
DETENTION POND CALCULATIONS
STATE DRAIN TIME CALCULATIONS
WATER QUALITY CALCULATIONS
LID CALCULATIONS AND EXHIBIT
Project Number:
Project Name:
Project Location:
Date:
Basin Notes
Historic Basin EX A 4.6 cfs
Historic Basin EX OS1 0.4 cfs
Historic Basin EX OS2 0.2 cfs
Total Q100 to the North 5.2 cfs
Proposed Basin A 2.5 cfs
Proposed Basin OS1 0.5 cfs
Proposed Basin OS2 0.2 cfs
Total Q100 to the North 3.2 cfs
Change in Q100 to the North 2.0 cfs Results in a decrease for the 100-year storm.
Basin Notes
Historic Basin EX B 1.9 cfs
Total Q100 to the South 1.9 cfs
Proposed Basin B1 0.1 cfs
Proposed Basin B3 0.0 cfs
Proposed Basin B4 0.2 cfs
Detention Pond Release Rate 1.5 cfs
Pond release rate determined by subtracting Basin B1, B3, and
B4 from Basin EX B.
Total Q100 to the South 1.9 cfs
Change in Q100 to the South 0.0 cfs No change for the 100-year storm.
Q100
Historic vs. Developed Flowrates to the North
Historic vs. Developed Flowrates to the South
HISTORIC VS. DEVELOPED FLOWRATES
1013-008
Homestead at Clarendon
Fort Collins, Colorado
Q100
December 18, 2020
Pond No :
B2
100-yr
0.75
12.74 min Storage 7373 ft3
1.63 acres Water Quality 0 ft3
Max Release Rate =1.50 cfs 0.17 ac-ft
Time (min)
Ft Collins
100-yr
Intensity
(in/hr)
Inflow
Volume
(ft3)
Outflow
Adjustment
Factor
Qav
(cfs)
Outflow Volume
(ft3)
Storage
Volume
(ft3)
5 9.950 3649 1.00 1.50 450 3199
10 7.720 5663 1.00 1.50 900 4763
15 6.520 7174 1.00 1.50 1350 5824
20 5.600 8215 1.00 1.50 1800 6415
25 4.980 9132 1.00 1.50 2250 6882
30 4.520 9946 1.00 1.50 2700 7246
35 4.080 10474 1.00 1.50 3150 7324
40 3.740 10973 1.00 1.50 3600 7373
45 3.460 11421 1.00 1.50 4050 7371
50 3.230 11846 1.00 1.50 4500 7346
55 3.030 12224 1.00 1.50 4950 7274
60 2.860 12587 1.00 1.50 5400 7187
65 2.720 12968 1.00 1.50 5850 7118
70 2.590 13298 1.00 1.50 6300 6998
75 2.480 13643 1.00 1.50 6750 6893
80 2.380 13966 1.00 1.50 7200 6766
85 2.290 14278 1.00 1.50 7650 6628
90 2.210 14589 1.00 1.50 8100 6489
95 2.130 14842 1.00 1.50 8550 6292
100 2.060 15110 1.00 1.50 9000 6110
105 2.000 15404 1.00 1.50 9450 5954
110 1.940 15653 1.00 1.50 9900 5753
115 1.890 15943 1.00 1.50 10350 5593
120 1.840 16196 1.00 1.50 10800 5396
*Note: Using the method described in Urban Storm Drainage Criteria Manual Volume 2.
DETENTION POND CALCULATION; MODIFIED FAA METHOD w/ Ft Collins IDF
Input Variables Results
Required Detention Volume
Fort Collins, Colorado
1013-008
Homestead at Clarendon
Project Number :
Project Name :
Detention Pond
A =
Tc =
Project Location :
Design Point
C =
Design Storm
Page 1 of 1
1013-008_Pond_FAA_Fort Collins A Lots.xls
Project:
Date:
Outlet Elevation:5086.57 0.17 ac. ft.
Grate Elevation:5089.6 0.19 ac. ft.
Crest of Pond Elev.:5090.6 5089.41
Freeboard.:1.2 ft
Maximum
Elevation
Minimum
Elevation cu. ft. acre ft cu. ft. acre ft
5086.6 N/A 0.0 0 0.0 0.00 0.0 0.00
5087.0 5086.6 567.8 0.4 122.1 0.00 122.1 0.00
5087.5 5087.0 2,375.7 0.5 735.9 0.02 858.0 0.02
5088.0 5087.5 3,379.2 0.5 1,438.7 0.03 2,296.7 0.05
5088.5 5088.0 3,602.6 0.5 1,745.5 0.04 4,042.1 0.09
5089.0 5088.5 3,740.2 0.5 1,835.7 0.04 5,877.8 0.13
5089.5 5089.0 3,809.3 0.5 1,887.4 0.04 7,765.2 0.18
5090.0 5089.5 3,860.6 0.5 1,917.5 0.04 9,682.7 0.22
5090.6 5090.0 3,920.8 0.6 2,334.4 0.05 12,017.1 0.28
Volume at Grate:
Project Number:
Project Location:
Calculations By:
Pond No.:
Detention Pond Stage Storage Curve
Contour Contour
Surface Area
(ft2)
Depth
Incremental Volume Cummalitive Volume
Pond Stage Storage Curve
1013-008
Fort Collins, Colorado
F. Wegert
B2
Elev at Design Volume:
Homestead at Clarendon
12/18/2020
Pond Outlet and Volume Data
Design Volume:
12/17/2020 6:00 PM P:\1013-008\Drainage\Detention\
1013-008_Stage-Storage A Lots.xlsx\Pond
Stormwater Facility Name:
Facility Location & Jurisdiction:
User Input: Watershed Characteristics User Defined User Defined User Defined User Defined
Selected BMP Type = RG Stage [ft] Area [ft^2] Stage [ft]Discharge [cfs]
Watershed Area = 1.63 acres 0.00 0 0.00 0.00
Watershed Length =500 ft 0.40 568 0.18 0.37
Watershed Length to Centroid = 100 ft
0.90 2,376 0.43 0.58
Watershed Slope =0.018 ft/ft 1.40 3,379 0.68 0.73
Watershed Imperviousness = 51.0%percent 1.90 3,603 0.93 0.85
Percentage Hydrologic Soil Group A = 0.0%percent 2.40 3,740 1.18 0.96
Percentage Hydrologic Soil Group B = 0.0%percent 2.90 3,809 1.43 1.05
Percentage Hydrologic Soil Groups C/D = 100.0%percent 3.40 3,861 1.68 1.14
Target WQCV Drain Time = 12.0 hours 4.00 3,921 1.93 1.22
2.18 1.30
User Input 2.43 1.37
2.68 1.44
2.84 1.48
2.93 1.51
3.18 1.57
3.43 1.63
3.68 1.69
4.00 1.76
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif
Create a new stormwater facility, and attach the PDF of this
worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period =WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth =N/A 0.82 1.14 1.40 2.27 2.86 in
CUHP Runoff Volume =0.023 0.048 0.078 0.109 0.228 0.312 acre-ft
Inflow Hydrograph Volume =N/A 0.048 0.078 0.109 0.228 0.312 acre-ft
Time to Drain 97% of Inflow Volume =0.4 1.0 1.3 1.8 2.8 3.3 hours
Time to Drain 99% of Inflow Volume =0.4 1.1 1.4 1.8 2.8 3.4 hours
Maximum Ponding Depth =0.96 0.53 0.83 1.07 2.12 2.88 ft
Maximum Ponded Area =0.06 0.02 0.05 0.06 0.08 0.09 acres
Maximum Volume Stored =0.023 0.005 0.016 0.029 0.111 0.176 acre-ft
Once CUHP has been run and the Stage-Area-Discharge
information has been provided, click 'Process Data' to
interpolate the Stage-Area-Volume-Discharge data and
generate summary results in the table below. Once this is
complete, click 'Print to PDF'.
Stormwater Detention and Infiltration Design Data Sheet
Homestead at Clarendon
Fort Collins, Colorado
Location for 1-hr Rainfall Depths (use dropdown):
After providing required inputs above including 1-hour
rainfall depths, click 'Run CUHP' to generate runoff
hydrographs using the embedded Colorado Urban
Hydrograph Procedure.
SDI_Design_Data_v2.00.xlsm, Design Data 12/18/2020, 8:52 AM
Booleans for Message Booleans for CUHP
Watershed L:W 1 CUHP Inputs Complete
Watershed Lc:L 1 CUHP Results Calculated
Watershed Slope FALSE Time Interval
RunOnce 1
CountA 1
Draintime Coeff 0.8
User Precip 1
Equal SA Inputs 1
Equal SD Inputs 1
Stormwater Detention and Infiltration Design Data Sheet
0
1
2
3
4
5
6
0.1 1 10
FL
O
W
[
c
f
s
]
TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.5
1
1.5
2
2.5
3
3.5
0.1 1 10 100
PO
N
D
I
N
G
D
E
P
T
H
[
f
t
]
DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
SDI_Design_Data_v2.00.xlsm, Design Data 12/18/2020, 8:52 AM
Project Number :
Project Name :
Project Location :
Pond No :Calc. By:F. Wegert
Orifice Dia (in):5 9/16
Orifice Area (sf):0.1688
Orifice invert (ft):5086.57
Orifice Coefficient:0.65
Elevation Stage (ft)Velocity (ft/s)Flow Rate (cfs)Comments
5086.57 0.00 0.00 0.00
5086.75 0.18 2.21 0.37
5087.00 0.43 3.42 0.58
5087.25 0.68 4.30 0.73
5087.50 0.93 5.03 0.85
5087.75 1.18 5.66 0.96
5088.00 1.43 6.23 1.05
5088.25 1.68 6.76 1.14
5088.50 1.93 7.24 1.22
5088.75 2.18 7.70 1.30
5089.00 2.43 8.13 1.37
5089.25 2.68 8.54 1.44
5089.41 2.84 8.79 1.48 <-100 Year Elev.
5089.50 2.93 8.92 1.51
5089.75 3.18 9.30 1.57
5090.00 3.43 9.66 1.63
5090.25 3.68 10.00 1.69
5090.50 3.93 10.34 1.74
5090.75 4.18 10.66 1.80
5091.00 4.43 10.97 1.85
5091.25 4.68 11.28 1.90
5091.50 4.93 11.58 1.95
5091.75 5.18 11.87 2.00
ORIFICE RATING CURVE
Orifice Rating Curve
1013-008
Homestead at Clarendon
Fort Collins, Colorado
Pond B2
Orifice Design Data
Project Number :
Project Name :
Project Location :
Pond No :Calc. By:
Q=3.3LH 1.5
Length (L)=10.00 FT
Crest Elevation =5089.70 FT
Depth Above Crest
(ft)
Elevation
(ft)
Flow
(cfs)
0.00 5089.70 0.00
0.10 5089.80 1.04
0.20 5089.90 2.95
0.30 5090.00 5.42
0.40 5090.10 8.35
0.47 5090.17 10.63
Q100
0.50 5090.20 11.67
0.60 5090.30 15.34
0.70 5090.40 19.33
0.80 5090.50 23.61
0.90 5090.60 28.18 Crest of Pond
Q100 = 10.6 CFS
Input Parameters:
Depth vs. Flow:
B2
SHARP-CRESTED WEIR
This equation can be used to derive the stage-discharge relationship for a sharp crested weir where the depth of flow
is small compared to the length of weir. Reference 1) Hydrologic Analysis and Design, Richard H McCuen, Prentice
Hall, 1989. Pg.549.
* where Q is flow rate in CFS
* where L is the crest length of the weir (FT)
* where H is the height of flow over the crest (FT)
Governing Equations:
1013.008
Homestead at Clarendon
Fort Collins, Colorado
F. Wegert
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =51.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.510
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 34,627 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =482 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 = 0.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =353 sq ft
D) Actual Flat Surface Area AActual =495 sq ft
E) Area at Design Depth (Top Surface Area)ATop =571 sq ft
F) Rain Garden Total Volume VT=533 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 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
Frederick S. Wegert
Northern Engineering
December 17, 2020
Homestead at Clarendon - East Rain Garden
Fort Collins, Colorado
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
1013-008_UD-BMP_v3.07 Rain Garden East.xlsm, RG 12/17/2020, 5:17 PM
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)
Frederick S. Wegert
Northern Engineering
December 17, 2020
Homestead at Clarendon - East Rain Garden
Fort Collins, Colorado
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
1013-008_UD-BMP_v3.07 Rain Garden East.xlsm, RG 12/17/2020, 5:17 PM
Project:
Date:
Bottom Elevation:5088.6 578 ft
3
Overflow Elevation:5089.7 603 ft
3
Crest of Pond Elev.:5090.5 5089.7
Freeboard.:0.8 ft 1 ft
Maximum
Elevation
Minimum
Elevation cu. ft. acre ft cu. ft. acre ft
5088.6 N/A 495.2 0 0.0 0.00 0.0 0.00
5089.0 5088.6 542.6 0.4 207.6 0.00 207.6 0.00
5089.5 5089.0 570.8 0.5 278.4 0.01 485.9 0.01
5090.0 5089.5 598.2 0.5 292.3 0.01 778.2 0.02
5090.5 5090.0 625.7 0.5 306.0 0.01 1,084.1 0.02
Water Depth:
Volume at Overflow:
Project Number:
Project Location:
Calculations By:
Pond No.:
Rain Garden Stage Storage Curve
Contour Contour
Surface Area
(ft2)
Depth
Incremental Volume Cummalitive Volume
Pond Stage Storage Curve
1013-008
Fort Collins, Colorado
F. Wegert
East Rain Garden
Elev at Design Volume:
Homestead at Clarendon
12/18/2020
Pond Outlet and Volume Data
Design Volume1:
Notes:
1) The MHFD spreadsheet UD-BMP is a password protected black box that prevents the user from
multiplying the water quality volume by 120% per Fort Collins Stormwater Manual. Therefore, the Design
Volume on this spreadsheet is 482 cu. ft. * 1.2. The 482 cu. ft. is the water quality volume from the UD-
BMP.
12/17/2020 5:30 PM P:\1013-008\Drainage\LID\
1013-008_Stage-Storage East.xlsx\Pond
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =51.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.510
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 31,852 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =444 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 = 0.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =325 sq ft
D) Actual Flat Surface Area AActual =430 sq ft
E) Area at Design Depth (Top Surface Area)ATop =570 sq ft
F) Rain Garden Total Volume VT=500 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =cu ft
iii) Orifice Diameter, 3/8" Minimum DO = in
Design Procedure Form: Rain Garden (RG)
Frederick S. Wegert
Northern Engineering
December 17, 2020
Homestead at Clarendon - West Rain Garden
Fort Collins, Colorado
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
1013-008_UD-BMP_v3.07 Rain Garden West.xlsm, RG 12/17/2020, 5:32 PM
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)
Frederick S. Wegert
Northern Engineering
December 17, 2020
Homestead at Clarendon - West Rain Garden
Fort Collins, Colorado
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
1013-008_UD-BMP_v3.07 Rain Garden West.xlsm, RG 12/17/2020, 5:32 PM
Project:
Date:
Bottom Elevation:5088.6 533 ft
3
Overflow Elevation:5089.7 572 ft
3
Crest of Pond Elev.:5090.0 5089.6
Freeboard.:0.4 ft 1 ft
Maximum
Elevation
Minimum
Elevation cu. ft. acre ft cu. ft. acre ft
5088.6 N/A 430.0 0 0.0 0.00 0.0 0.00
5089.0 5088.6 493.3 0.4 184.7 0.00 184.7 0.00
5089.5 5089.0 570.0 0.5 265.8 0.01 450.5 0.01
5090.0 5089.5 647.2 0.5 304.3 0.01 754.8 0.02
Design Volume1:
Volume at Overflow:
Project Number:
Project Location:
Calculations By:
Pond No.:
Water Depth:
West Rain Garden Stage Storage Curve
Contour Contour
Surface Area
(ft2)
Depth
Incremental Volume Cummalitive Volume
Pond Stage Storage Curve
1013-008
Fort Collins, Colorado
F. Wegert
West Rain Garden
Elev at Design Volume:
Homestead at Clarendon
12/18/2020
Pond Outlet and Volume Data
Notes:
1) The MHFD spreadsheet UD-BMP is a password protected black box that prevents the user from
multiplying the water quality volume by 120% per Fort Collins Stormwater Manual. Therefore, the Design
Volume on this spreadsheet is 444 cu. ft. * 1.2. The 444 cu. ft. is the water quality volume from the UD-
BMP.
12/17/2020 5:40 PM P:\1013-008\Drainage\LID\
1013-008_Stage-Storage West.xlsx\Pond
Project:Homestead at Clarendon Calc. By:
Location:Fort Collins, Colorado Date:
39,434 sf
50%
19,717 sf
100%
39,434 sf
35,681 sf
90.5%
578 cf
603 cf
533 cf
572 cf
1111 cf
1175 cf
35,681 sf
90.5%
7,373 cf
7,373 cf
0.17 ac.-ft.
8,149 cf
0.19 ac.-ft.
LID & Water Quality Summary
F. Wegert
12/18/20
Project Summary
LID Summary
Total New Impervious Area
Target LID Treatment Percentage
Minimum Area to be Treated by LID measures
Target Water Quality Treatment Percentage
Detention
Detention Treatment Area
Minimum Area to be Treated by Water Quality measures
Rain Gardens
Rain Garden Treatment Area
East Rain Garden Volume (Required)
East Rain Garden Volume (Design)
West Rain Garden Volume (Required)
Percent Total Project Area Treated
West Rain Garden Volume (Design)
Total Rain Garden Volume (Required)
Total Rain Garden Volume (Design)
Water Quality Summary
Percent Total Project Area Treated
Storage Volume (Required)
Total Detention Volume (Required)
Total Detention Volume (Design)
Project: Calc. By:
Location: Date:
Surface
Area (SF)% Imperv.Imperv.
Area (SF)
Surface
Area (SF)% Imperv.Imperv.
Area (SF)
Rooftop 0 100%0 Rooftop 25,025 90%22,523
Concrete 0 100%0 Concrete 0 100%0
Asphalt 0 100%0 Asphalt 13,158 100%13,158
Gravel 0 40%0 Gravel 9,384 40%3,754
Landscaping 142,798 0%0 Landscaping 95,231 0%0
Total 142,798 0 Total 142,798 39,434
39,434
Surface
Area (SF)% Imperv.Imperv.
Area (SF)
Surface
Area (SF)% Imperv.Imperv.
Area (SF)
Rooftop 25,025 90%22,523 Rooftop 25,025 90%22,523
Concrete 0 100%0 Concrete 0 100%0
Asphalt 13,158 100%13,158 Asphalt 13,158 100%13,158
Gravel 0 40%0 Gravel 0 40%0
Landscaping 0 0%0 Landscaping 0 0%0
35,681 35,681
Additional Impervious Area (SF)
Existing Developed
Onsite Impervious Area
Onsite Impervious Areas
Homestead at Clarendon
Fort Collins, Colorado
F. Wegert
12/18/20
Extended Detention Rain Gardens
Total Total
Developed Imperv. Area with LID TreatmentDeveloped Imperv. Area with WQ Treatment
ATTACHMENT 4
PREVIOUS REPORT EXCERPTS
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Nov-02-2018 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
ATTACHMENT 5
USDA NRCS SOILS REPORT
ATTACHMENT 6
DRAINAGE EXHIBITS