HomeMy WebLinkAboutWILLOX FARM - PDP220008 - SUBMITTAL DOCUMENTS - ROUND 4 - DRAINAGE REPORT
PRELIMINARY DRAINAGE REPORT AND EROSION CONTROL REPORT
WILLOX FARM
FORT COLLINS, COLORADO
FEBRUARY 21, 2023
NORTHERNENGINEERING.COM
970.221.4158
FORT COLLINS
GREELEY
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NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY COVER LETTER
February 21, 2023
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
RE: PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR
WILLOX FARM
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report for your review.
This report accompanies the combined Project Development Plan (PDP) submittal for the proposed Willox Farm.
This report has been prepared in accordance with the Fort Collins Stormwater Criteria Manual (FCSCM) and
serves to document the stormwater impacts associated with the proposed Willox Farm. We understand review
by the City of Fort Collins is to assure general compliance with standardized criteria contained in the FCSCM.
If you have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
CARLOS ORTIZ GARCIA AUSTIN SNOW, PE
Project Engineer Project Engineer
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY TABLE OF CONTENTS
TABLE OF CONTENTS
GENERAL LOCATION AND DESCRIPTION .......................................................... 1
DRAIN BASINS AND SUB-BASINS ..................................................................... 4
DRAINAGE DESIGN CRITERIA .......................................................................... 5
DRAINAGE FACILITY DESIGN ........................................................................... 6
CONCLUSIONS .............................................................................................. 9
REFERENCES .............................................................................................. 10
TABLES AND FIGURES
FIGURE 1 – VICINITY MAP .................................................................................................1
FIGURE 2 – AERIAL PHOTOGRAPH ...................................................................................2
FIGURE 3 – PROPOSED SITE PLAN ...................................................................................3
FIGURE 4 – AREA FLOODPLAIN MAPPING ........................................................................4
APPENDICES
APPENDIX A – HYDROLOGIC COMPUTATIONS
APPENDIX B – DETENTION POND COMPUTATION
APPENDIX C –
C.1 - STORM SEWERS (WILL BE SIZED AT FINAL)
C.2. - INLETS & WEIRS(WILL BE SIZED AT FINAL)
C.3. - SWALES & RIPRAP (RIPRAP WILL BE SIZED AT FINAL)
APPENDIX D – EROSION CONTROL REPORT
APPENDIX E – PRELIMINARY LID DESIGN INFORMATION
APPENDIX F – PREVIOUS STUDIES AND USDA SOILS REPORT
MAP POCKET
DR1 – HISTORIC DRAINAGE EXHIBIT
DR2 & DR3 – DEVELOPED DRAINAGE EXHIBIT
This basin will generally drain via overland flow to the property adjacent to the west ost
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GENERAL LOCATION AND DESCRIPTION
A. LOCATION
Vicinity Map
The Willox Farm site is located in the Norteast ¼ of the Northwest ¼ of Section 2, Township 7
North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State
of Colorado.
The project site (refer to Figure 1) is bordered to the north by Willox Ln., to the south by Soft
Gold Park, to the east by Hickory Village and to the west by Garden Sweet and Private property.
B. DESCRIPTION OF PROPERTY
The Willox Farm site is comprised of roughly ±19.01 acres.
The site currently exists as an undeveloped parcel with native ground cover. The existing
ground slopes with a mild grade (i.e., 0.4 – 0.6±%) through the interior to the southeast across
flat grades. The drainage continues through the South property boundary to the Soft Gold
Park.
Figure 1 – Vicinity Map
This basin will generally drain via overland flow to the property adjacent to the west ost
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A subsurface exploration report was completed by Earth Engineering Consultants, LLC. on May
6, 2021 (EEC Project No. 1212027). At the time this report was written, the site was
undeveloped with established vegetation. According to Earth Engineering Consultants, the site
consists of Clayey sand, silty, clayey sand and/or sandy lean clay subsoils which were
encountered beneath the surficial topsoil/vegetative layer extended to depths of
approximately 3 to 5 feet below existing site grades. Silty sand with gravel and interbedded
cobbles at increased depths, was encountered beneath the upper slightly cohesive zone and
extended to the bedrock formation. Siltstone/sandstone/claystone bedrock was encountered
at depths of approximately 16 to 18 feet below existing site grades.
According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey website:
(http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists of Caruso Clay
Loam (Hydrologic Soil Group D)and Table Mountain Loam (Hydrologic Soil Group B). The
Figure 2 – Aerial Photograph
This basin will generally drain via overland flow to the property adjacent to the west ost
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calculations assume a Hydrologic Soil Group of D. Hydrologic Soil Group D has a very slow rate
of water absorption and infiltration
There are no major drainaway on the site. However the Larimer - Weld Canal is located
approximately 995’ north while the Cache La Poudre River is located approximately 2,220 feet
south.
The proposed project site plan will consist of approximately 66 single Family residential lots.
Figure 3 – Proposed Site Plan
This basin will generally drain via overland flow to the property adjacent to the west ost
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Other proposed improvements include: asphalt drive ways, sidewalks and landscape areas.
Figure 3 shows the proposed site plan.
C. FLOODPLAIN
The subject property is not located in a FEMA regulatory floodplain (see Figure 4).
DRAIN BASINS AND SUB-BASINS
A. MAJOR BASIN DESCRIPTION
Willox Farm is located in the Cache la Poudre River Basin, it is a major tributary to the South
Platte River. It is located in Larimer and Weld Counties, with a small portion of the drainage
basin extending into southern Wyoming. Passing through Fort Collins, the Poudre River
corridor provides for stormwater drainage from various contributing city drainage basins.
Floodplain restrictions have limited the amount of building in the floodplain, resulting in lower
development density. This lower density, combined with sensitivities to the natural
environment, has resulted in a high concentration of parks and open space along the river
corridors.
B. SUB-BASIN DESCRIPTION
The subject property historically drains overland through the interior to the southeast across
flat grades. Runoff from the site has historically overflow to the southeast property boundary
and then to the Soft Gold Park.
Figure 4 – Area Floodplain Mapping
This basin will generally drain via overland flow to the property adjacent to the west ost
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A more detailed description of the project drainage patterns is provided in Section IV-B.
DRAINAGE DESIGN CRITERIA
A. REGULATIONS
There are no optional provisions outside of the FCSCM proposed with the proposed
project. The Willox Farm project will be detaining the difference between the historic 2-year event
and proposed 100-year event.
B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS
In order to bring Willox Farm into compliance with current land use code and stormwater
criteria, 50% of all newly added impervious area will be treated by LID techniques, specifically
a rain garden. The contributing area to the rain garden will also be treated for water quality by
the rain garden. The detention pond will provide the remaining necessary water quality
treatment.
C. HYDROLOGICAL CRITERIA
The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-
1 of the FCSCM, serve as the source for all hydrologic computations associated with the
proposed development. Tabulated data contained in Table 3.4-1 was utilized for Rational
Method runoff calculations.
The Rational Method was employed to compute localized stormwater runoff utilizing
coefficients contained in Tables 3.2-1 and 3.2-2 of the FCSCM.
Two separate design storms were utilized to address distinct drainage scenarios. The first
event analyzed is the "Minor" or "Initial" storm, which has a two-year recurrence interval. The
second event considered is the "Major" storm, which has a 100-year recurrence interval.
No other assumptions or calculation methods were used for this development that are not
referenced by the current City of Fort Collins criteria.
D. HYDRAULIC CRITERIA
As previously noted, the subject property maintains historical drainage patterns.
All drainage facilities proposed with the project are designed in accordance with the criteria
outlined in the FCSCM and/or Mile High Flood Control District’s Urban Storm Drainage Criteria
Manual.
As discussed above, the subject property is not located in the 100-year floodplain. The
proposed project does not propose to modify any natural drainageways.
E. MODIFICATIONS OF CRITERIA
The proposed development is not requesting any modifications to criteria at this time.
F. STORM MANAGEMENT STRATEGY
The overall stormwater management strategy employed with the Willox Farm utilizes the "Four
Step Process" to minimize adverse impacts of urbanization on receiving waters. The following
describes how the proposed development has incorporated each step.
Step 1 – Employ Runoff Reduction Practices. The first consideration taken in trying to reduce the
stormwater impacts of this development is the site selection itself and the selection of developable
areas on the site.
This basin will generally drain via overland flow to the property adjacent to the west ost
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The Willox Farm aims to reduce runoff peaks, volumes, and pollutant loads from frequently
occurring storm events (i.e., water quality (i.e., 80th percentile) and two-year storm events). Site
constraints limit the possible Low Impact Development (LID) techniques; however, a rain garden
has been provided as LID technique for storm quality management.
Step 2 – Implement Best Management Practices (BMPs) that provide a Water Quality Capture
Volume (WQCV) with slow release. The efforts taken in Step 1 will help to minimize excess runoff
from frequently occurring storm events; however, development still generates additional
stormwater runoff beyond historical conditions. The primary water quality treatment and volume
control will occur in the detention pond.
Step 3 – Stabilize Drainageways. There are no major drainageways within the subject property.
While this step may not seem applicable to proposed development, the project indirectly helps
achieve stabilized drainageways, nonetheless. By providing water quality treatment, where none
previously existed, sediment with erosion potential is removed from downstream drainageway
systems.
Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to
industrial and commercial developments.
DRAINAGE FACILITY DESIGN
A. GENERAL CONCEPT
The main objectives of the project drainage design are to maintain existing drainage patterns
and ensure no adverse impacts to any adjacent properties.
The site does not receive offsite surface runoff.
Onsite detention and water quality treatment for the Willox Farm project will be provided by
the rain garden and the remainder within the detention pond.
Irrigation flows owned by the City of Fort Collins will be passed through the pond and
conveyed south to the drainage swale on the west side of Soft Gold Park, until such time as the
City’s Parks department constructs a pipeline on the west side of the project site to convey
these flows to the City owned irrigation pond in Soft Gold Park.
LID treatment will be provided using a rain garden on the southeast side of the project,
meeting the requirement that at least 50% of the new/improved impervious areas be treated.
B. SPECIFIC DETAILS
The detention volume required for the site is 2.04 ac-ft. This volume was calculated using the
FAA Method..
City Code requires LID treatment for all projects. This project proposes meeting the
requirement using a rain garden as an LID technique. The rain garden will capture the majority
of the water quality volume (WQCV) for the entire site, providing a total volume of 7,849 cu.ft.
This configuration will treat at least 50% of the new impervious area.
The Willox Farm site has been broken into onsite sub-basins for design purposes. Anticipated
drainage patterns for proposed drainage basins are described below.
This basin will generally drain via overland flow to the property adjacent to the west ost
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Basin A1
Basin A1 is approximately 0.31 acres, and consists of the frontside of lots along with a portion
of Saint Therese Street. The basin will generally sheet flow into curb and gutter in the
respective street, and will discharge into Basin E3.
Basin A2
Basin A2 is approximately 0.28 acres, and consists of open space with a portion of Saint
Therese Street. The basin will generally sheet flow into curb and gutter in the respective street,
and will discharge into Basin E3.
Basin A3
Basin A3 is approximately 1.98 acres, and consists of the frontside of lots along with a portion
of Saint Joesph Street. The basin will generally sheet flow into curb and gutter in the respective
street, and will discharge into proposed Rain Garden.
Basins A4
Basin A4 is approximately 1.21 acres, and consists of lots along with a portion of Saint Joesph
Street. The basin will generally sheet flow into curb and gutter in the respective street, and will
discharge into Basin A8.
Basins A5
Basin A5 is approximately 0.40 acres, and consists of open space. The basins will generally
sheet flow into a swale. The swale will convey flows into Basin A6.
Basin A6 & A7
Basin A6 is approximately 0.14 acres, and Basin A7 is approximately 0.12 acres, and consists of
open space with a portion of Moller Street. The basin will generally sheet flow into curb and
gutter in the respective street, and will discharge into Basin A8.
Basins A8
Basin A8 is approximately 0.73 acres, and consists of lots along with a portion of Saint Joesph
Street. The basin will generally sheet flow into curb and gutter in the respective street, and will
discharge into proposed Rain Garden.
Basins B1
Basin B1 is approximately 1.19 acres, and consists of lots along with a portion of Saint Therese
Street. The basin will generally sheet flow into curb and gutter in the respective street, and will
discharge into Basin B3.
Basin B2
Basin B2 is approximately 0.51 acres, and consists of the backside of lots, and open space. The
basin will generally sheet flow into a swale. The swale will convey flows into Basin B3.
Basin B3
Basin B3 is approximately 0.86 acres, and consists of the frontside of lots along with a portion
of Saint Therese Street. The basin will generally sheet flow into curb and gutter in the
respective street and will discharge into proposed Rain Garden.
Basin B4
Basin B4 is approximately 1.22 acres, and consists of the frontside of lots, open space along
with a portion of Saint Therese Street and Saint Francis Street. The basin will generally sheet
This basin will generally drain via overland flow to the property adjacent to the west ost
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FORT COLLINS | GREELEY 8 | 10
flow into curb and gutter in the respective streets, and will discharge into proposed Rain
Garden.
Basins C1 & C2
Basin C1 is approximately 1.76 acres, and Basin C2 is approximately 0.86 acres, and consists of
the backside of lots and open space. Runoff from basin C1 will sheet flow into a swale and will
convey flow to Basin C2 via a siphon, and Basin C2 will sheet flow into a swale and will convey
flows to the detention pond.
Basin C3
Basin C3 is approximately 2.34 acres, and consists of the backside of lots and open space. The
basin will generally sheet flow into the detention pond.
Basins C4
Basin C4 is approximately 0.61 acres, and consists of open space. The basin will generally sheet
flow into a swale. The swale will convey flows into Basin C5.
Basin C5
Basin C5 is approximately 1.45 acres, and consists of the backside of lots, and open space. The
basin will generally sheet flow into a swale. The swale will convey flows into proposed Rain
Garden.
Basins C6
Basin C6 is approximately 0.69 acres, and consists of open space. The basin will generally sheet
flow into prposed Rain Garden.
Basin D1 & D2
Basin D1 is approximately 0.90 acres, and Basin D2 is approximately 0.09 acres, and consists of
of the frontside of lots, open space along with a portion of Saint Therese Street and Moller
Street. The basin will generally sheet flow into curb and gutter in the respective streets, and
will discharge into into Bain C2.
Basins E1
Basins E1 is approximately 0.64 acres, and consists of south portion of Willow LN . ROW. The
basin will generally sheet flow into existing swale. The swale will convey flows to the east into
Basin C1.
Basin E2
Basin E2 is approximately 0.11 acres, , and consists of south portion of Willow LN . ROW. Runoff
will sheet flow into curb and gutter in the respective street, and will discharge into Basin E3.
Basin E3
Basin E3 is approximately 0.22 acres, and consists of south portion of Willow LN . ROW. Runoff
will sheet flow into curb and gutter in the respective street, and will discharge into Basin C4.
Basin E4
Basin E4 is approximately 0.34 acres, and consists of open space. The basin will generally sheet
flow to the south. Runoff from the basin will not be routed to the detention pond.
This basin will generally drain via overland flow to the property adjacent to the west ost
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Basin F1 & F2
Basin F1 is approximately 0.10 acres, and Basin F2 is approximately 0.59 acres, and consists of
open space. The basin will generally sheet flow to the east. Runoff from the basins will not be
routed to the detention pond.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report.
CONCLUSIONS
A. COMPLIANCE WITH STANDARDS
The drainage design proposed with the Willox Farm project complies with the City of Fort
Collins Stormwater Criteria Manual.
There are no FEMA regulatory floodplains associated with the Willox Farm development.
The drainage design proposed with this project complies with the Cache la Poudre River Basin
requirements.
This basin will generally drain via overland flow to the property adjacent to the west ost
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FORT COLLINS | GREELEY 10 | 10
REFERENCES
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and Reenacted,
Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service,
United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District,
Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX A
HYDROLOGIC COMPUTATIONS
Runoff Coefficient 1
Percent
Impervious1 Project:
Location:
0.95 100%Calc. By:
0.95 90%Date:
0.50 40%
0.55 50%
0.20 2%
0.20 2%
Basin ID Basin Area
(sq.ft.)
Basin Area
(acres)
Asphalt, Concrete
(acres)Rooftop (acres) Gravel (acres)
Residential: Low
Density (acres)
Undeveloped:
Greenbelts,
Agriculture (acres)
Lawns, Clayey Soil, Flat
Slope < 2% (acres)
Percent
Impervious
C2*Cf
Cf = 1.00
C5*Cf
Cf = 1.00
C10*Cf
Cf = 1.00
C100*Cf
Cf = 1.25
1 828,148 19.01 0.00 0.00 0.00 0.00 19.01 0.00 2% 0.20 0.20 0.20 0.25
Historic Basins:
Lawns and Landscaping:
2) Composite Runoff Coefficient adjusted per Table 3.2-3 of the Fort Collins
Stormwater Manual (FCSM).
Lawns, Clayey Soil, Flat Slope < 2%
USDA SOIL TYPE: D
Undeveloped: Greenbelts, Agriculture Composite Runoff Coefficient 2
1) Runoff coefficients per Tables 3.2-1 & 3.2 of the FCSM. Percent impervious per Tables 4.1-2 & 4.1-3 of the FCSM.
HISTORIC RUNOFF COEFFICIENT CALCULATIONS
Asphalt, Concrete
Rooftop
Gravel
Residential: Low Density
Streets, Parking Lots, Roofs, Alleys, and Drives:
Character of Surface:Willox Farm
Fort Collins
C. Ortiz
August 26, 2022
Notes:
Page 1 of 3
Where:
Length
(ft)
Elev
Up Elev Down Slope
(%)
Ti
2-Yr
(min)
Ti
10-Yr
(min)
Ti
100-Yr
(min)
Length
(ft)
Elev
Up
Elev
Down
Slope
(%)Surface n
Flow
Area3
(sq.ft.)
WP3 (ft)R (ft)V
(ft/s)
Tt
(min)
Tc
2-Yr
(min)
Tc
100-Yr
(min)
1 1 377 89.80 88.58 0.32%47.55 47.55 44.91 1,053 88.58 84.91 0.35% Swale (8:1)0.04 8.00 16.12 0.50 1.58 11.14 17.94 17.94
Historic Basins:
HISTORIC TIME OF CONCENTRATION COMPUTATIONS
Maximum Tc:Overland Flow, Time of Concentration:
Channelized Flow, Velocity:Channelized Flow, Time of Concentration:
Willox Farm
Fort Collins
C. Ortiz
August 26, 2022
Design
Point Basin ID
Overland Flow Channelized Flow Time of
Notes
S = Longitudinal Slope, feet/feet
R = Hydraulic Radius (feet)
n = Roughness Coefficient
V = Velocity (ft/sec)WP = Wetted Perimeter (ft)
(Equation 3.3-2 per Fort Collins Stormwater Manual)=1.87 1.1 − ∗
=1.49 ∗
/∗(Equation 5-4 per Fort Collins Stormwater Manual)
=180 + 10
(Equation 3.3-5 per Fort Collins
Stormwater Manual)
=∗ 60
(Equation 5-5 per Fort Collins
1) Add 4900 to all elevations.
2) Per Fort Collins Stormwater Manual,
minimum Tc = 5 min.
3) Assume a water depth of 6" and a
typical curb and gutter per Larimer
County Urban Street Standard Detail 701
for curb and gutter channelized flow.
Assume a water depth of 1', fixed side
Page 2 of 3
Tc2 Tc10 Tc100 C2 C10 C100 I2 I10 I100 Q2 Q10 Q100
Historic Basins:
1 1 19.01 17.9 17.9 17.9 0.2 0.2 0.3 1.7 2.9 6.0 6.6 11.2 28.6
Rational Equation: Q = CiA (Equation 6-1 per MHFD)
Area
(acres)
Runoff CTc (Min)
HISTORIC DIRECT RUNOFF COMPUTATIONS
Intensity (in/hr)Flow (cfs)
Willox Farm
C. Ortiz
August 26, 2022Date:
Fort Collins
Project:
Location:
Calc. By:
Design
Point Basin
Intensity, I, from Fig. 3.4.1 Fort Collins Stormwater Manual.
Page 3 of 3
Runoff Coefficient1
Percent
Impervious1 Project:
Location:
0.95 100%Calc. By:
0.95 90%Date:
0.50 40%
0.55 50%
0.20 2%
0.20 2%
Basin ID Basin Area
(sq.ft.)
Basin Area
(acres)
Asphalt, Concrete
(acres)Rooftop (acres) Gravel (acres)
Residential: Low
Density (acres)
Undeveloped:
Greenbelts,
Agriculture (acres)
Lawns, Clayey Soil, Flat
Slope < 2% (acres)
Percent
Impervious
C2*Cf
Cf = 1.00
C5*Cf
Cf = 1.00
C10*Cf
Cf = 1.00
C100*Cf
Cf = 1.25
A1 13,675 0.31 0.14 0.03 0.00 0.00 0.00 0.15 53%0.60 0.60 0.60 0.75
A2 12,238 0.28 0.13 0.00 0.00 0.00 0.00 0.16 46%0.54 0.54 0.54 0.67
A3 86,187 1.98 0.34 0.34 0.00 0.00 0.00 1.30 34%0.46 0.46 0.46 0.57
A4 52,676 1.21 0.34 0.16 0.00 0.00 0.00 0.71 41%0.51 0.51 0.51 0.64
A5 17,407 0.40 0.15 0.03 0.00 0.00 0.00 0.23 44%0.53 0.53 0.53 0.66
A6 5,983 0.14 0.11 0.00 0.00 0.00 0.00 0.03 81%0.81 0.81 0.81 1.00
A7 5,420 0.12 0.21 0.00 0.00 0.00 0.00 -0.09 169%1.48 1.48 1.48 1.00
A8 31,657 0.73 0.25 0.13 0.00 0.00 0.00 0.35 52%0.59 0.59 0.59 0.74
B1 51,676 1.19 0.29 0.25 0.00 0.00 0.00 0.65 44%0.54 0.54 0.54 0.68
B2 22,333 0.51 0.00 0.08 0.00 0.00 0.00 0.43 16%0.32 0.32 0.32 0.40
B3 37,526 0.86 0.23 0.10 0.00 0.00 0.00 0.53 38%0.49 0.49 0.49 0.61
B4 53,108 1.22 0.28 0.16 0.00 0.00 0.00 0.77 37%0.48 0.48 0.48 0.59
C1 76,871 1.76 0.00 0.17 0.00 0.00 0.00 1.60 10%0.27 0.27 0.27 0.34
C2 37,302 0.86 0.00 0.11 0.00 0.00 0.00 0.75 13%0.30 0.30 0.30 0.37
C3 101,939 2.34 0.02 0.13 0.00 0.00 0.00 2.19 8%0.25 0.25 0.25 0.31
C4 26,536 0.61 0.05 0.00 0.00 0.00 0.00 0.56 10%0.26 0.26 0.26 0.33
C5 62,959 1.45 0.18 0.25 0.00 0.00 0.00 1.02 29%0.42 0.42 0.42 0.52
C6 29,935 0.69 0.08 0.00 0.00 0.00 0.00 0.61 13%0.29 0.29 0.29 0.36
D1 39,142 0.90 0.36 0.11 0.00 0.00 0.00 0.43 52%0.59 0.59 0.59 0.74
D2 4,070 0.09 0.06 0.00 0.00 0.00 0.00 0.03 68%0.70 0.70 0.70 0.88
E1 28,022 0.64 0.25 0.00 0.00 0.00 0.00 0.39 40%0.49 0.49 0.49 0.62
E2 4,756 0.11 0.10 0.00 0.00 0.00 0.00 0.01 91%0.88 0.88 0.88 1.00
E3 9,706 0.22 0.20 0.00 0.00 0.00 0.00 0.02 90%0.87 0.87 0.87 1.00
E4 14,676 0.34 0.00 0.00 0.00 0.00 0.00 0.34 2%0.20 0.20 0.20 0.25
F1 4,418 0.10 0.00 0.00 0.00 0.00 0.00 0.10 2% 0.20 0.20 0.20 0.25
F2 25,901 0.59 0.00 0.00 0.00 0.00 0.00 0.59 2% 0.20 0.20 0.20 0.25
A1-A8 + B1-B4 +C1-C6+D1-
D2 ; (WQ1)801,417 18.40 3.5671 2.0453 0.00 0.00 0.00 12.79 31% 0.43 0.43 0.43 0.54
A3-A8; East Side (Concrete
Culvert)199,330 4.58 1.40 0.66 0.00 0.00 0.00 2.52 45% 0.54 0.54 0.54 0.67
B1-B4; West Side
(Concrete Culvert)164,644 3.78 0.81 0.59 0.00 0.00 0.00 2.38 37% 0.48 0.48 0.48 0.60
A1-A8 + B1-B4+C4-C6+E1-
E2 ; (Rain Garden)523,776 12.02 3.08 1.53 0.00 0.00 0.00 7.42 38% 0.49 0.49 0.49 0.61
DEVELOPED RUNOFF COEFFICIENT CALCULATIONS
Asphalt, Concrete
Rooftop
Gravel
Residential: Low Density
Streets, Parking Lots, Roofs, Alleys, and Drives:
Character of Surface:Willox Farm
Fort Collins
C. Ortiz
January 3, 2023
Lawns and Landscaping:
Combined Basins A,B & C
2) Composite Runoff Coefficient adjusted per Table 3.2-3 of the Fort
Collins Stormwater Manual (FCSM).
Lawns, Clayey Soil, Flat Slope < 2%
USDA SOIL TYPE: D
Undeveloped: Greenbelts, Agriculture Composite Runoff Coefficient2
1) Runoff coefficients per Tables 3.2-1 & 3.2 of the FCSM. Percent impervious per Tables 4.1-2 & 4.1-3 of the FCSM.
Developed Basins:
Notes:
1) Basins A1 to A8 + B1 to B4+ C4 ot C6 are draining towards Rain Gardens (LID).
2) Basins A1-A8 + B1-B4 +C1-C6+D1-D2 + E2-E3 are draining towards the detention pond.
3) Basin E4-E5+F1-F2 is not detained.
Where: WP = Wetted Perimeter (ft)
Length
(ft)
Elev
Up Elev Down Slope
(%)
Ti
2-Yr
(min)
Ti
100-Yr
(min)
Length
(ft)
Elev
Up
Elev
Down
Slope
(%)Surface n
Flow
Area3
(sq.ft.)
WP3 (ft)R (ft)V
(ft/s)
Tt
(min)
Tc
2-Yr
(min)
Tc
100-Yr
(min)
a1 A1 63 95.19 93.60 2.52%5.45 3.82 263 93.60 91.58 0.77% Gutter 0.02 3.61 19.18 0.19 2.86 1.53 6.98 5.35
a2 A2 15 93.64 93.33 2.02%3.26 2.49 168 93.33 91.58 1.04% Gutter 0.02 3.61 19.18 0.19 3.33 0.84 5.00 5.00
a3 A3 117 95.26 92.17 2.63%9.43 7.76 941 92.17 86.22 0.63% Gutter 0.02 3.61 19.18 0.19 2.60 6.04 15.47 13.80
a4 A4 15 93.86 93.53 2.26%3.21 2.51 652 93.53 89.00 0.69% Gutter 0.02 3.61 19.18 0.19 2.72 4.00 7.20 6.51
a5 A5 17 94.56 92.78 10.51%2.01 1.55 368 92.78 89.30 0.94% Swale (6:1)0.04 6.00 12.17 0.49 2.58 2.38 5.00 5.00
a6 A6 34 93.45 91.99 4.26%1.99 0.68 200 91.99 89.00 1.50% Gutter 0.02 3.61 19.18 0.19 4.00 0.83 5.00 5.00
a7 A7 16 92.63 92.02 3.73%-1.84 0.49 175 92.02 89.00 1.72% Gutter 0.02 3.61 19.18 0.19 4.28 0.68 5.00 5.00
a8 A8 141 92.01 88.35 2.59%8.19 5.79 256 88.35 86.22 0.83% Gutter 0.02 3.61 19.18 0.19 2.98 1.43 9.62 7.22
b1 B1 132 95.15 93.21 1.47%10.58 8.02 356 93.21 90.90 0.65% Gutter 0.02 3.61 19.18 0.19 2.63 2.25 12.71 10.28
b2 B2 63 92.66 90.13 3.99%7.33 6.58 228 90.13 87.85 1.00% Swale (6:1)0.04 6.00 12.17 0.49 2.66 1.43 8.76 8.01
b3 B3 14 92.30 92.02 2.05%3.34 2.68 668 92.02 86.22 0.87% Gutter 0.02 3.61 19.18 0.19 3.04 3.66 7.00 6.34
b4 B4 65 92.51 90.80 2.64%6.79 5.50 582 90.80 86.22 0.79% Gutter 0.02 3.61 19.18 0.19 2.90 3.35 10.14 8.85
c1 C1 31 92.87 89.21 11.81%3.79 3.48 631 89.21 85.80 0.54% Swale (6:1)0.04 6.00 12.17 0.49 1.95 5.38 9.17 8.86
c2 C2 80 92.24 85.14 8.87%6.51 5.91 384 85.14 83.05 0.54% Swale (6:1)0.04 6.00 12.17 0.49 1.96 3.26 9.77 9.18
c3 C3 146 88.42 83.87 3.13%13.14 12.19 342 83.87 82.50 0.40% Swale (8:1)0.04 8.00 16.12 0.50 1.69 3.37 12.71 12.71
c4 C4 115 95.26 91.32 3.43%11.11 10.23 400 91.32 89.73 0.40% Swale (8:1)0.04 8.00 16.12 0.50 1.68 3.96 12.86 12.86
c5 C5 23 91.13 89.73 6.14%3.32 2.81 816 89.73 86.46 0.40% Swale (6:1)0.04 6.00 12.17 0.49 1.68 8.09 11.41 10.90
c6 C6 33 89.45 87.20 6.90%4.56 4.15 70 87.20 85.20 2.85% Swale (8:1)0.04 8.00 16.12 0.50 4.50 0.26 5.00 5.00
d1 D1 63 95.19 93.57 2.58%5.47 3.86 521 93.57 87.16 1.23% Gutter 0.02 3.61 19.18 0.19 3.62 2.40 7.87 6.26
d2 D2 34 91.28 90.05 3.57%2.85 1.59 125 90.05 87.16 2.32% Gutter 0.02 3.61 19.18 0.19 4.97 0.42 5.00 5.00
e1 E1 61 98.81 91.00 12.77%3.80 3.03 604 91.00 89.99 0.17% Swale (6:1)0.04 6.00 12.17 0.49 1.09 9.28 13.08 12.31
e2 E2 24 93.04 92.41 2.67%1.44 0.65 165 92.41 91.58 0.50% Gutter 0.02 3.61 19.18 0.19 2.31 1.19 5.00 5.00
e3 E3 31 92.47 91.58 2.85%1.68 0.74 130 91.58 91.10 0.37% Gutter 0.02 3.61 19.18 0.19 1.98 1.09 5.00 5.00
e4 E4 184 88.73 87.51 0.66%26.20 24.75 50 87.51 87.31 0.40% Swale (8:1)0.04 8.00 16.12 0.50 1.69 0.49 11.30 11.30
f1 F1 5 91.60 90.00 32.26%1.18 1.11 10 90.00 89.81 1.91% Swale (8:1)0.04 8.00 16.12 0.50 3.69 0.04 5.00 5.00
f2 F2 4 89.35 88.27
25.06%1.19 1.13 5 88.27 86.94
24.91% Gutter 0.02 3.61 19.18 0.19 16.29 0.01 5.00 5.00
A1-A8 + B1-B4 +C1-C6+D1-
D2 ; (WQ1)15 93.64 93.33 2.02%3.88 3.26 1,514 93.33 86.46 0.45% Swale (6:1)
0.04 6.00 12.17 0.49 1.79 14.10 17.99 17.37
A3-A8; East Side (Concrete
Culvert)117 95.26 92.17 2.63%8.25 6.28 941 92.17 86.22 0.63% Gutter
0.02 3.61 19.18 0.19 2.60 6.04 14.29 12.32
B1-B4; West Side (Concrete
Culvert)132 95.15 93.21 1.47%11.77 9.52 937 93.21 86.22 0.75% Gutter
0.02 3.61 19.18 0.19 2.82 5.54 15.94 15.06
A1-A8 + B1-B4+C4-C6+E1-
E2 ; (Rain Garden)15 93.64 93.33 2.02%3.55 2.84 1,514 93.33 86.46 0.45% Swale (6:1)
0.04 6.00 12.17 0.49 1.79 14.10 17.65 16.94
S = Longitudinal Slope, feet/feet
R = Hydraulic Radius (feet)
n = Roughness Coefficient
V = Velocity (ft/sec)Notes
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Maximum Tc:Overland Flow, Time of Concentration:
Channelized Flow, Velocity:Channelized Flow, Time of Concentration:
Willox Farm
Fort Collins
C. Ortiz
January 3, 2023
Overland Flow Channelized Flow Time of
Concentration
Developed Basins:
Combined Basins
Design
Point Basin ID
(Equation 3.3-2 per Fort Collins Stormwater Manual)
1.87 1.1 ∗
1.49 ∗
/∗(Equation 5-4 per Fort Collins Stormwater Manual)
180 10 (Equation 3.3-5 per Fort Collins
Stormwater Manual)
∗ 60
(Equation 5-5 per Fort Collins
Stormwater Manual)
1)Add 4900 to all elevations.
2) Per Fort Collins Stormwater Manual, minimum Tc = 5 min.
3) Assume a water depth of 6" and a typical curb and gutter
per Larimer County Urban Street Standard Detail 701 for
curb and gutter channelized flow. Assume a water depth of
1', fixed side slopes, and a triangular swale section for grass
channelized flow. Assume a water depth of 1', 4:1 side
slopes, and a 2' wide valley pan for channelized flow in a
valley pan.
Tc2Tc10Tc100C2C10C100I2I10I100Q2Q10Q100Developed Basins:a1 A1 0.317.0 7.0 5.3 0.6 0.60.72.6 4.4 10.0 0.5 0.8 2.3a2 A2 0.28 5.0 5.0 5.0 0.5 0.5 0.7 2.9 4.9 10.0 0.4 0.7 1.9a3 A3 1.98 15.5 15.5 13.8 0.5 0.5 0.6 1.9 3.2 6.8 1.7 2.9 7.7a4 A4 1.21 7.2 7.2 6.5 0.5 0.5 0.6 2.5 4.3 9.1 1.6 2.7 7.0a5 A5 0.40 5.0 5.0 5.0 0.5 0.5 0.7 2.9 4.9 10.0 0.6 1.0 2.6a6 A6 0.14 5.0 5.0 5.0 0.8 0.8 1.0 2.9 4.9 10.0 0.3 0.5 1.4a7 A7 0.12 5.0 5.0 5.0 1.5 1.5 1.0 2.9 4.9 10.0 0.5 0.9 1.2b1 B1 1.19 12.7 12.7 10.3 0.5 0.5 0.7 2.0 3.4 7.7 1.3 2.2 6.2b2 B2 0.51 8.8 8.8 8.0 0.3 0.3 0.4 2.4 4.0 8.4 0.4 0.7 1.7b3 B3 0.86 7.0 7.0 6.3 0.5 0.5 0.6 2.5 4.3 9.3 1.1 1.8 4.9b4 B4 1.22 10.1 10.1 8.8 0.5 0.5 0.6 2.2 3.8 8.2 1.3 2.2 5.9c1 C1 1.76 9.2 9.2 8.9 0.3 0.3 0.3 2.3 3.9 8.2 1.1 1.9 4.9c2 C2 0.86 9.8 9.8 9.2 0.3 0.3 0.4 2.3 3.9 8.0 0.6 1.0 2.5c3 C3 2.34 12.7 12.7 12.7 0.2 0.2 0.3 2.0 3.4 7.0 1.2 2.0 5.1c4 C4 0.61 12.9 12.9 12.9 0.3 0.3 0.3 2.0 3.4 7.0 0.3 0.6 1.4c5 C5 1.45 11.4 11.4 10.9 0.4 0.4 0.5 2.1 3.6 7.6 1.3 2.2 5.7c6 C6 0.69 5.0 5.0 5.0 0.3 0.3 0.4 2.9 4.9 10.0 0.6 1.0 2.5d1 D1 0.90 7.9 7.9 6.3 0.6 0.6 0.7 2.5 4.2 9.3 1.3 2.2 6.2d2 D2 0.09 5.0 5.0 5.0 0.7 0.7 0.9 2.9 4.9 10.0 0.2 0.3 0.8e1 E1 0.64 13.1 13.1 12.3 0.5 0.5 0.6 2.0 3.4 7.2 0.6 1.1 2.8e2 E2 0.11 5.0 5.0 5.0 0.9 0.9 1.0 2.9 4.9 10.0 0.3 0.5 1.1e3 E3 0.22 5.0 5.0 5.0 0.9 0.9 1.0 2.9 4.9 10.0 0.6 0.9 2.2e4 E4 0.34 11.3 11.3 11.3 0.2 0.2 0.3 2.1 3.6 7.4 0.1 0.2 0.6f1 F1 0.10 5.0 5.0 5.0 0.2 0.2 0.3 2.9 4.9 10.0 0.1 0.1 0.3f2 F2 0.59 5.0 5.0 5.0 0.2 0.2 0.3 2.9 4.9 10.0 0.3 0.6 1.5A1-A8 + B1-B4 +C1-C6+D1-D2 ; (WQ1)18.4018.018.0 17.4 0.4 0.4 0.5 1.7 2.9 6.1 13.6 23.2 60.2A3-A8; East Side (Concrete Culvert)4.5814.314.3 12.3 0.5 0.5 0.7 1.9 3.3 7.2 4.7 8.1 22.0B1-B4; West Side (Concrete Culvert)3.7815.915.9 15.1 0.5 0.5 0.6 1.8 3.1 6.5 3.3 5.7 14.7A1-A8 + B1-B4+C4-C6+E1- E2 ; (Rain Garden)12.0217.617.6 16.9 0.5 0.5 0.6 1.7 2.9 6.2 10.1 17.2 45.4DEVELOPED DIRECT RUNOFF COMPUTATIONSIntensity (in/hr)Flow (cfs)Willox FarmC. OrtizJanuary 3, 2023DesignPointBasinIntensity, I, from Fig. 3.4.1 Fort Collins Stormwater Manual.Rational Equation: Q = CiA (Equation 6-1 per MHFD)Area(acres)Runoff CTc (Min)Date:Fort CollinsCombined BasinsProject:Location:Calc. By:
This basin will generally drain via overland flow to the property adjacent to the west ost
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX B
DETENTION POND COMPUTATION
COG
Pond No :1
C3
100-yr
0.54 WQCV 4538 ft3
Area (A)=18.40 acres Detention 84112 ft3
Max Release Rate =6.60 cfs Total 2.0351 ac-ft
Time Time 100-yr
Intensity Q100
Inflow
(Runoff)
Volume
Outflow
(Release)
Volume
Storage
Detention
Volume
(mins)(secs)(in/hr)(cfs)(ft3)(ft3)(ft3)
5 300 9.950 98.86 29659 1980.0 27679.0
10 600 7.720 76.71 46024 3960.0 42063.6
15 900 6.520 64.78 58304 5940.0 52364.4
20 1200 5.600 55.64 66770 7920.0 58849.9
25 1500 4.980 49.48 74222 9900.0 64321.9
30 1800 4.520 44.91 80839 11880.0 68959.3
35 2100 4.080 40.54 85132 13860.0 71271.6
40 2400 3.740 37.16 89186 15840.0 73345.5
45 2700 3.460 34.38 92822 17820.0 75002.1
50 3000 3.230 32.09 96280 19800.0 76479.8
55 3300 3.030 30.11 99350 21780.0 77570.1
60 3600 2.860 28.42 102301 23760.0 78541.1
65 3900 2.720 27.03 105401 25740.0 79661.1
70 4200 2.590 25.73 108084 27720.0 80363.8
75 4500 2.480 24.64 110886 29700.0 81185.8
80 4800 2.380 23.65 113509 31680.0 81828.9
85 5100 2.290 22.75 116043 33660.0 82382.5
90 5400 2.210 21.96 118576 35640.0 82936.2
95 5700 2.130 21.16 120633 37620.0 83013.0
100 6000 2.060 20.47 122809 39600.0 83209.0
105 6300 2.000 19.87 125194 41580.0 83613.6
110 6600 1.940 19.28 127221 43560.0 83660.5
115 6900 1.890 18.78 129575 45540.0 84035.4
120 7200 1.840 18.28 131632 47520.0 84112.1
DETENTION POND CALCULATION; FAA METHOD
Project Number :987-012
Date :December 20, 2022
Project Location :Fort Collins, CO.
Developed "C" =
Calculations By:
Input Variables Results
Design Point
Design Storm Required Detention Volume
Project Title Date:
Project Number Calcs By:
City
Basins
1
WQCV = Watershed inches of Runoff (inches)31%
a = Runoff Volume Reduction (constant)
i = Total imperviousness Ratio (i = Iwq/100)0.155 in
A =18.40 ac
V = 0.28 ac-ft
V = 1.2 x Water Quality Design Volume (ac-ft)
WQCV = Water Quality Capture Volume (inches)
A = Watershed Area (acres)
Provided (LID) Rain Gardens =
Volume to be provided in the Pond =
0.10 Ac-ft
7849 cu. ft.
4538 cu. ft.
Willox Farm December 20, 2022
207-030 C. Ortiz
Fort Collins
12387 cu. ft.
Drain Time
a =
i =
WQCV =
Figure EDB-2 - Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event
1, 2, 3, 4, and 6 DETENTION POND Dp1
0.169
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
00.10.20.30.40.50.60.70.80.91WQCV (watershed inches)Total Imperviousness Ratio (i = Iwq/100)
Water Quality Capture Volume
6 hr
12 hr
24 hr
40 hr
()iii78.019.10.91aWQCV 23 +−=
()iii78.019.10.91aWQCV 23 +−=
AV*12
WQCV
=
40 hr
Project:Willox Farm
Date:1/3/2023
ACTUAL STORAGE :
(A) (B) (C) (D)
Elevation Depth Area Volume Σ Volume Σ Volume
(Sf.) (Cf.) (Cf.) (Ac.-ft.)Total Volume = 88,648.26 2.04 Ac.
Elev. (A1) = 4,985.00
Outlet Elevation:4,982.50 1.00 Σ Volume (D1) = 69,936.17
0.50 1,627.00 1,627.00 0.04 Partial volume (C2) = 31,634.20
4,983.00 6,507.00 Depth, partial volume = 0.50
0.50 6,731.88 8,358.88 0.19
4,983.50 20,420.51 High water level (HWL) = 4985.30
0.50 13,585.79 21,944.66 0.50 Freeboard = 0.70
4,984.00 33,922.63 Top of Bank Elevation = 4,986.00
0.50 20,327.53 42,272.20 0.97
4,984.50 47,387.50
0.50 27,663.97 69,936.17 1.61
Detention Req'd:4,985.00 63,268.39
0.50 31,634.20 101,570.36 2.33
4,985.50 63,268.39
Pond No.:Pond 1
Detention Pond Stage Storage
Project Number:987-012
Project Location:Fort Collins, Colorado
Calculations By:C. Ortiz
This basin will generally drain via overland flow to the property adjacent to the west ost
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX C
C.1 – STORM SEWERS
C.2 - INLETS & WEIRS
C,3 – SWALES & RIPRAP
(WILL BE SIZED AT FINAL)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A1 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 6.00, 8.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.40
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 8.90
Highlighted
Depth (ft) = 0.78
Q (cfs) = 8.900
Area (sqft) = 5.82
Velocity (ft/s) = 1.53
Wetted Perim (ft) = 13.03
Crit Depth, Yc (ft) = 0.51
Top Width (ft) = 12.92
EGL (ft) = 0.82
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A2 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 8.00, 6.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.40
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 14.60
Highlighted
Depth (ft) = 0.96
Q (cfs) = 14.60
Area (sqft) = 8.37
Velocity (ft/s) = 1.74
Wetted Perim (ft) = 15.58
Crit Depth, Yc (ft) = 0.65
Top Width (ft) = 15.44
EGL (ft) = 1.01
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A3 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 5.00, 4.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.50
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 7.74
Highlighted
Depth (ft) = 0.78
Q (cfs) = 7.740
Area (sqft) = 4.30
Velocity (ft/s) = 1.80
Wetted Perim (ft) = 9.19
Crit Depth, Yc (ft) = 0.54
Top Width (ft) = 9.02
EGL (ft) = 0.83
0 2 4 6 8 10 12 14 16 18 20
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A4 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 7.00, 5.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.50
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 17.20
Highlighted
Depth (ft) = 1.03
Q (cfs) = 17.20
Area (sqft) = 8.43
Velocity (ft/s) = 2.04
Wetted Perim (ft) = 14.54
Crit Depth, Yc (ft) = 0.73
Top Width (ft) = 14.36
EGL (ft) = 1.09
0 2 4 6 8 10 12 14 16 18 20 22 24
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A5 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 9.00, 17.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.50
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 2.60
Highlighted
Depth (ft) = 0.37
Q (cfs) = 2.600
Area (sqft) = 2.52
Velocity (ft/s) = 1.03
Wetted Perim (ft) = 11.65
Crit Depth, Yc (ft) = 0.24
Top Width (ft) = 11.62
EGL (ft) = 0.39
0 5 10 15 20 25 30 35 40 45 50 55
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Feb 21 2023
Swale A6 (100-yr)
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 9.00, 8.00
Total Depth (ft) = 1.50
Invert Elev (ft) = 1.00
Slope (%) = 0.50
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 1.70
Highlighted
Depth (ft) = 0.34
Q (cfs) = 1.700
Area (sqft) = 1.66
Velocity (ft/s) = 1.02
Wetted Perim (ft) = 7.82
Crit Depth, Yc (ft) = 0.21
Top Width (ft) = 7.78
EGL (ft) = 0.36
0 5 10 15 20 25 30 35 40
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
This basin will generally drain via overland flow to the property adjacent to the west ost
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX D
EROSION CONTROL REPORT
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY EROSION CONTROL REPORT
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included with the
final construction drawings. It should be noted; however, any such Erosion and Sediment Control Plan serves
only as a general guide to the Contractor. Staging and/or phasing of the BMPs depicted, and additional or
different BMPs from those included may be necessary during construction, or as required by the authorities
having jurisdiction.
It shall be the responsibility of the Contractor to ensure erosion control measures are properly maintained and
followed. The Erosion and Sediment Control Plan is intended to be a living document, constantly adapting to
site conditions and needs. The Contractor shall update the location of BMPs as they are installed, removed, or
modified in conjunction with construction activities. It is imperative to reflect the current site conditions
appropriately always.
The Erosion and Sediment Control Plan shall address both temporary measures to be implemented during
construction, as well as permanent erosion control protection. Best Management Practices from the Volume 3,
Chapter 7 – Construction BMPs will be utilized. Measures may include, but are not limited to, silt fencing and/or
wattles along the disturbed perimeter, gutter protection in the adjacent roadways, and inlet protection at
existing and proposed storm inlets. Vehicle tracking control pads, spill containment and clean-up procedures,
designated concrete washout areas, dumpsters, and job site restrooms shall also be provided by the Contractor.
Grading and Erosion Control Notes can be found on Sheet CS2 of the Utility Plans. The Final Utility Plans will also
contain a full-size Erosion Control Plan as well as a separate sheet dedicated to Erosion Control Details. In
addition to this report and the referenced plan sheets, the Contractor shall be aware of, and adhere to, the
applicable requirements outlined in any existing Development Agreement(s) of record, as well as the
Development Agreement, to be recorded prior to issuance of the Development Construction Permit. Also, the
Site Contractor for this project may be required to secure a Stormwater Construction General Permit from the
Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division – Stormwater
Program, before commencing any earth disturbing activities. Prior to securing said permit, the Site Contractor
shall develop a comprehensive Storm Water Management Plan (SWMP) pursuant to CDPHE requirements and
guidelines. The SWMP will further describe and document the ongoing activities, inspections, and maintenance
of construction BMPs.
NNORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX E
PRELIMINARY LID DESIGN INFORMATION
TSSTTTTEEEWILLOX LNSOFT GOLD PARKSOUTH RAIN GARDENREQUIRED VOLUME: 6,093.0 CU. FT.MINIMUM FLAT AREA: 3,981.0 SFPROVIDED VOLUME: 7,849 CU. FT.PROVIDED FLAT AREA: 7,044.0 SFIMPERVIOUS AREA TREATED: 200,441 SFWILLOX FARMSHEET NO:P:\987-012\DWG\DRNG\987-012_LID.DWG301 N. Howes Street, Suite 100Fort Collins, Colorado 80521ENGINEERNGIEHTRONRNPHONE: 970.221.4158www.northernengineering.comDRAWING REFERENCE:LID TREATMENT EXHIBITC. Ortiz 1"=150'AUGUST 2022LID-1DRAWN BY:SCALE:ISSUED:NOTES1.FOR LID RAIN GARDEN CALCULATIONS PLEASE REFER TO THEPRELIMINARY DRAINAGE REPORT, DATED AUG 31, 2022.2.REFER TO UTILITY PLANS FOR WILLOX FARM FOR ADDITIONALGRADING AND UTILITY INFORMATION.3.REFER TO LANDSCAPE PLANS FOR ADDITIONAL INFORMATION ONHARDSCAPES.LEGENDPROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETUNTREATED AREATREATMENT AREANORTH( IN FEET )01 INCH = 150 FEET150150Willox Farm On-Site LID TreatmentProject SummaryTotal Impervious Area242,255sfTarget Treatment Percentage50%Minimum Area to be Treated by LIDmeasures121,127sfTreated Impervious Areas by TreatmentMethodRain Garden200,441sfTotal Treated Impervious Areas200,441sfPercent Total Project Area Treated82.7%
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1.Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =38.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.380
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV =0.14 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area)Area =523,776 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =6,093 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 =884.0 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 =3981 sq ft
D) Actual Flat Surface Area AActual =7044 sq ft
E) Area at Design Depth (Top Surface Area)ATop =8654 sq ft
F) Rain Garden Total Volume VT=7,849 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 =35.0 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =6,093 cu ft
iii) Orifice Diameter, 3/8" Minimum DO =1 in
Design Procedure Form: Rain Garden (RG)
C. Ortiz
Northern Engineering
December 21, 2022
Willox Farm
South Rain Garden (Basin 3)
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
987-012_RG_UD-BMP_v3.06.xlsm, RG 12/21/2022, 10:51 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)
C. Ortiz
Northern Engineering
December 21, 2022
Willox Farm
South Rain Garden (Basin 3)
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
987-012_RG_UD-BMP_v3.06.xlsm, RG 12/21/2022, 10:51 AM
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
APPENDIX F
PREVIOUS STUDIES AND USDA SOILS REPORT
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Area, ColoradoNatural
Resources
Conservation
Service
March 9, 2022
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado......................................................................13
22—Caruso clay loam, 0 to 1 percent slope...............................................13
105—Table Mountain loam, 0 to 1 percent slopes......................................14
References............................................................................................................16
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
449515044952004495250449530044953504495400449545044955004495550449515044952004495250449530044953504495400449545044955004495550492450 492500 492550 492600 492650 492700 492750
492450 492500 492550 492600 492650 492700 492750
40° 36' 39'' N 105° 5' 21'' W40° 36' 39'' N105° 5' 7'' W40° 36' 24'' N
105° 5' 21'' W40° 36' 24'' N
105° 5' 7'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 100 200 400 600
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,200 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
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 16, Sep 2, 2021
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
22 Caruso clay loam, 0 to 1
percent slope
14.2 78.9%
105 Table Mountain loam, 0 to 1
percent slopes
3.8 21.1%
Totals for Area of Interest 17.9 100.0%
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
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
Custom Soil Resource Report
11
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
12
Larimer County Area, Colorado
22—Caruso clay loam, 0 to 1 percent slope
Map Unit Setting
National map unit symbol: jpvt
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Caruso and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Caruso
Setting
Landform:Flood-plain steps, stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium
Typical profile
H1 - 0 to 35 inches: clay loam
H2 - 35 to 44 inches: fine sandy loam
H3 - 44 to 60 inches: gravelly sand
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:About 24 to 48 inches
Frequency of flooding:NoneOccasional
Frequency of ponding:None
Calcium carbonate, maximum content:5 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.4 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: D
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Loveland
Percent of map unit:9 percent
Custom Soil Resource Report
13
Landform:Terraces
Ecological site:R067BY036CO - Overflow
Hydric soil rating: Yes
Fluvaquents
Percent of map unit:6 percent
Landform:Terraces
Hydric soil rating: Yes
105—Table Mountain loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: jpty
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
Table mountain and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Table Mountain
Setting
Landform:Stream terraces, flood plains
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
H1 - 0 to 36 inches: loam
H2 - 36 to 60 inches: clay loam
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Sodium adsorption ratio, maximum:5.0
Available water supply, 0 to 60 inches: High (about 9.8 inches)
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Interpretive groups
Land capability classification (irrigated): 1
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: B
Ecological site: R049XY036CO - Overflow
Hydric soil rating: No
Minor Components
Caruso
Percent of map unit:7 percent
Hydric soil rating: No
Fluvaquentic haplustolls
Percent of map unit:4 percent
Landform:Terraces
Hydric soil rating: Yes
Paoli
Percent of map unit:4 percent
Hydric soil rating: No
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References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
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
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NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Willox Farm
FORT COLLINS | GREELEY APPENDIX
MAP POCKET
EXHIBITS AS LISTED ON TABLE OF CONTENTS
WWWWWWWTWSSWTELECSSTMSWWWMWWTSMMWMHYDMMMMFOFOFOFOWWWWWXXXXXXXGGGGGOHUOHUOHUOHUFOFOFOFOWWXXWWWWWWWWWWWWWWFOFOXGGFOFOWWGGGGGGXXXXXXXXXXXXXXXXXXXXXFOFOFOOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUW
WWWWWWGOHUOHUFOFOFOFOFOFOFOFOOHUXGXXXWWWWWWWWWWXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXFOFOFOFOFOFOFOFOFOGGGGGGGGGFOFOFOFOFOFOFOFOFOEEEEEEEWWWWX X X OHUOHU
OHU OHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUXXXXXXPROPERTYBOUNDARY19.01 ac.1PROPERTYBOUNDARYPROPERTYBOUNDARYPROPERTYBOUNDARY1HICKORY VILLAGESUBDIVISIONWILLOW LNKEYMAPTC.O.WEST WILLOX LANESOFTGOLD PARKHICKORY STREETSheetWILLOX FARM These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.NOT FOR CO
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of 33NORTH( IN FEET )01 INCH = 60 FEET6060120180DR1HISTORIC DRAINAGE EXHIBIT34 PROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETADESIGN POINTFLOW ARROWDRAINAGE BASIN LABELDRAINAGE BASIN BOUNDARYPROPOSED SWALE SECTION11NOTES:ALEGEND:1.REFER TO THE PRELIMINARY DRAINAGE REPORT, DATED MAY 24, 2022 BYNORTHERN ENGINEERING FOR ADDITIONAL INFORMATION.C2C100Q2(cfs)Q100(cfs)DR1CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOUDIG, GRADE, OR EXCAVATE FOR THE MARKING OFUNDERGROUND MEMBER UTILITIES.CALL UTILITY NOTIFICATION CENTER OFCOLORADOKnow what'sbelow.before you dig.CallR
TWWWWWSSWTELECSSMWWTSMMWMXXXXOHUOHUXXXXXXXXXXXXXXXXOHUOHUOHUOHUOHUOHUOHUOHUOHUXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXEEEEEEEEEEEOHUOHU
OHU
OHU
OHU OHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUOHUa1a4a6c1e4d1e2e3A3A3A1A1SAINT THERESE STREET SAINT JOESPH STREETMOLLER STREETa2WILLOX LNa5ACKELSON CONNIE A.KAFKA, AMYPEREZ DANIEL A.PROPOSEDSWALEPROPOSEDSWALEPROPOSEDSWALEPROPOSEDSWALEPROPERTYBOUNDARYPROPERTYBOUNDARYPROPERTYBOUNDARYPROPOSEDSIDEWALK CHASEe1b11.76 ac.C10.31 ac.A10.61 ac.C41.21 ac.A41.98 ac.A30.90 ac.D11.19 ac.B10.34 ac.E40.11 ac.E20.22 ac.E30.28 ac.A20.40 ac.A50.14 ac.A60.10 ac.F1c4f1PROPOSEDCULVERT FROM DITCHPROPOSEDSWALEA5A5KEYMAPTC.O.WEST WILLOX LANESOFTGOLD PARKHICKORY STREETSheetWILLOX FARM
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of 36DR2DEVELOPED DRAINAGE EXHIBIT35 NORTH( IN FEET )1 inch = ft.Feet0404040801201.REFER TO THE "PRELIMINARY DRAINAGE REPORT, DATED FEB 21, 2023" BYNORTHERN ENGINEERING DATED FOR ADDITIONAL INFORMATION.2.THE WILLOX FARM PROJECT WILL BE DETAINING THE DIFFERENCE BETWEEN THEHISTORIC 2-YEAR EVENT AND THE DEVELOPED 100-YEAR EVENT.3.LID MEASURES IS PROVIDED VIA RAIN GARDEN.4.ALL PROPOSED STORM SEWER ARE TO BE PRIVATELY OWNED AND MAINTAINED.SWALE SECTIONSPROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETADESIGN POINTFLOW ARROWDRAINAGE BASIN LABELDRAINAGE BASIN BOUNDARYPROPOSED SWALE SECTION11NOTES:ALEGEND:MATCH LINE - SEE SHEET DR3DR2DR3CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOUDIG, GRADE, OR EXCAVATE FOR THE MARKING OFUNDERGROUND MEMBER UTILITIES.CALL UTILITY NOTIFICATION CENTER OFCOLORADOKnow what'sbelow.before you dig.CallRC2C100Q2(cfs)Q100(cfs)SWALE SUMMARY TABLESWALE IDMIN DMIN TWS1 (n:1)BWS2 (n:1)QA1 - A10.7819.926.02.08.08.90A2 - A20.9622.448.02.06.014.60A3 - A30.7813.525.02.04.07.70A4 - A41.0320.367.02.05.017.20A5 - A50.3724.629.02.017.02.60A6 - A60.3416.289.02.08.01.70
WWTWXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX X X X XXX
XXXXXXXXXXXc5a4a6a8b2a3b3c3c2c1e4d2d1A2A2A4A4A3A3SAINT THERESE STREET
SAINT JOESPH STREET MOLLER STREETSAINT FRANCIS STREETa5a7b4PITT, JEANGBP LLCPEREZ DANIEL A.PEREZ DANIEL A.SOFT GOLD PARKPROPOSEDSWALEPROPOSEDSWALEPOND 1100-YR DETENTION VOLUME = 2.04 AC-FT100-YR WSEL=4985.50PROPOSED RAINGARDENPROPOSEDSIDEWALKCHASEPROPERTYBOUNDARYPROPERTYBOUNDARYPROPERTYBOUNDARYPROPOSED POND OUTLET STRUCTUREPROPOSED PONDOUTLET PIPEb1c60.09 ac.D21.22 ac.B40.86 ac.C22.34 ac.C30.51 ac.B20.86 ac.B30.14 ac.A60.12 ac.A70.73 ac.A81.45 ac.C50.69 ac.C60.59 ac.F2f2A5A5A6A6PROPOSEDSWALEKEYMAPTC.O.WEST WILLOX LANESOFTGOLD PARKHICKORY STREETSheetWILLOX FARM
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of 36DR3DEVELOPED DRAINAGE EXHIBIT36 NORTH( IN FEET )1 inch = ft.Feet0404040801201.REFER TO THE "PRELIMINARY DRAINAGE REPORT, DATED FEB 21, 2023" BYNORTHERN ENGINEERING FOR ADDITIONAL INFORMATION.2.THE WILLOX FARM PROJECT WILL BE DETAINING THE DIFFERENCE BETWEEN THEHISTORIC 2-YEAR EVENT AND THE DEVELOPED 100-YEAR EVENT.3.LID MEASURES IS PROVIDED VIA RAIN GARDEN.4.ALL PROPOSED STORM SEWER ARE TO BE PRIVATELY OWNED AND MAINTAINED.PROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETADESIGN POINTFLOW ARROWDRAINAGE BASIN LABELDRAINAGE BASIN BOUNDARYPROPOSED SWALE SECTION11NOTES:ALEGEND:MATCH LINE - SEE SHEET DR2SWALE SECTIONSDR3DR2CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOUDIG, GRADE, OR EXCAVATE FOR THE MARKING OFUNDERGROUND MEMBER UTILITIES.CALL UTILITY NOTIFICATION CENTER OFCOLORADOKnow what'sbelow.before you dig.CallRC2C100Q2(cfs)Q100(cfs)SWALE SUMMARY TABLESWALE IDMIN DMIN TWS1 (n:1)BWS2 (n:1)QA1 - A10.7819.926.02.08.08.90A2 - A20.9622.448.02.06.014.60A3 - A30.7813.525.02.04.07.70A4 - A41.0320.367.02.05.017.20A5 - A50.3724.629.02.017.02.60A6 - A60.3416.289.02.08.01.70