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PRELIMINARY UTILITY DEMAND REPORT
STRAUSS LAKES ODP
CITY OF FORT COLLINS
COUNTY OF LARIMER
STATE OF COLORADO
PREPARED FOR:
Cottonwood Land and Farms, LLC
PO Box 229
Boulder, CO 80306
PREPARED BY:
Civil Resources, LLC
8308 Colorado Blvd.
Suite 200
Firestone, Colorado 80504
PREPARED: SEPTEMBER, 2025
Strauss Lakes PUD – Utility Demand Memo September, 2025
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TABLE OF CONTENTS
Page
1.0 INTRODUCTION .............................................................................................................................................. 1
2.0 GENERAL LOCATION AND DESCRIPTION ................................................................................................... 1
2.1 Location .................................................................................................................................................... 1
2.2 Proposed Land Uses ................................................................................................................................ 2
3.0 EXISTING INFRASTRUCTURE ....................................................................................................................... 2
3.1 Water Distribution System ........................................................................................................................ 2
3.2 Wastewater Collection System ................................................................................................................. 2
4.0 DEMAND DESIGN CRITERIA .......................................................................................................................... 2
4.1 Reference Materials ................................................................................................................................. 2
5.0 ESTIMATED DEMANDS .................................................................................................................................. 2
5.1 Domestic Water and Fire Service ............................................................................................................. 2
5.2 Wastewater Demand ................................................................................................................................ 3
6.0 PROPOSED IMPROVEMENTS........................................................................................................................ 4
List of Tables
Table 1 Assumed Land Uses
Table 2 Estimated Domestic Water Demand
Table 3 Summary of Estimated Wastewater Demand (including infiltration)
List of Figures
Figure 1 Project Location – Vicinity Map
Exhibits 8 and 9 Sanitary And Water System Concepts (appendix)
List of Appendices
Appendix A Domestic Water Demand Calculations
Appendix B Wastewater Demand and Lift Station Calculations
Strauss Lakes ODP – Utility Demand Memo September, 2025
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1.0 INTRODUCTION
The purpose of this report is to accompany an annexation and ODP overlay application of approximately 165 acres of
land to the City of Fort Collins, known as Strauss Lakes. The ODP establishes overall land use by zoning
classification, but does not propose specific layouts or design. This report presents an estimate of the overall
domestic water and sanitary sewer demand for the project. Detailed utility analysis will accompany future PDP
applications.
This Preliminary Utility Demand Report Supplement has been developed to address the following items:
• Estimated domestic water demand
• Estimated wastewater generation
2.0 GENERAL LOCATION AND DESCRIPTION
2.1 Location
The Strauss Lakes project is located northeast of the intersection of Ziegler Road and East Horsetooth Road, and is
situated in Section 28, Township 7 North, Range 68 West of the 6th Principal Meridian, County of Larimer, State of
Colorado. The project area includes parcel 8728000003, located within the City of Fort Collins, and parcel
8728000009, located in unincorporated Larimer County. The Site is bounded by Ziegler Road to the west, East
Horsetooth Road to the south, and the Boxelder Ditch to the northeast.
Figure 1 – Vicinity Map
Strauss Lakes ODP – Utility Demand Memo September, 2025
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2.2 Proposed Land Uses
The PUD includes a mix of affordable apartments, work force housing, various styles of attached and detached
single-family housing, and retail and commercial units. A specific mix of units is not as part of the ODP, but the table
below summarizes the mix assumed for utility demands:
Table 1 - Assumed Land Use Mix
3.0 EXISTING INFRASTRUCTURE
3.1 Water Distribution System
There is an existing 24-inch diameter water main in Ziegler Road, north of Horsetooth, and two 8-inch mains stubs
terminating at or just east of Zeigler Road at the intersections with Percheron Drive and William Neal Parkway. New
mains will be extended from the existing stubs through the main portion of the Site. A new tap will be made off the
existing 24-inch main to serve the southwestern portion of the development, situated at the NE corner of Zeigler
Road and Horsetooth Road.
3.2 Wastewater Collection System
There is an existing 24-inch diameter sewer main in Ziegler Road, north of Horsetooth. This is the only available point
of connection to the existing sewer system for this project. Zeigler Road is higher than most of the Site area;
therefore, a sewer lift station will be required to serve this project.
4.0 DEMAND DESIGN CRITERIA
4.1 Reference Materials
The following documents were referenced in preparation of this report:
• Fort Collins Utilities Water and Wastewater Design Criteria Manual
• City of Fort Collins GIS utility mapping
• City of Westminster Standards and Specifications, Chapters 3 and 4 (for estimated demand rates)
• 2021 International Fire Code
5.0 ESTIMATED DEMANDS
5.1 Domestic Water and Fire Service
Proposed land uses for the evaluation of domestic water demand were obtained from the anticipated maximum
density achieved at full build-out of the project. The City of Ft. Collins Design Manual does not include generalized
demand rates for planning purposes, therefore the estimated demand from each use was multiplied by a unit demand
rate taken from the City of Westminster Standards and Specifications (Westminster Standards) to estimate the
average daily flow. A peak day factor of 2.5 and peak hour factor of 4.0 was used to determine the peak domestic
ESTIMATED DENSITY
DU/AC
A COMMERCIAL LMN 4.9 N/A N/A N/A N/A ALLOWED USES
B RESIDENTIAL LMN 70.6 619 8.8 SF 2.5-3 STORIES** N/A
C AFFORDABLE RESIDENTIAL MMN 7.6 144 18.9 MF 4 STORIES N/A
D RESIDENTIAL LMN 6.4 47 7.3 SF 2.5-3 STORIES** N/A
E COMMON AREAS LMN 69.4 N/A N/A N/A N/A N/A
TOTAL 158.9
USE MAX BLDG. HEIGHT
LAND USE STATISTICS
PLANNING AREA ZONE DISTRICT TYPE GROSS ACREAGE ESTIMATED UNITS HOUSING TYPE BUSINESS TYPE
Strauss Lakes ODP – Utility Demand Memo September, 2025
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demands. Irrigation of public and commercial areas will be by ditch water, and is therefore not included in domestic
demand estimates.
The proposed IBC building construction types and maximum building size for uses within the property are not
established as part of the PUD. The 2021 International Fire Code states that the maximum fire flow, regardless of
square footage or building construction type, is 8,000 gpm. Using the maximum flow provides flexibility to
accommodate a variety of construction types and building sizes within the development. It is anticipated that large
buildings will be sprinklered, and as such a 50% reduction of fire flows will be allowed; therefore, the assumed fire
flow for this project is 4,000 gpm.
Refer to Appendix A for additional excerpts from the Westminster Standards and calculations for this project. The
various residential typologies depicted in the PUD were applied based on anticipated densities (DU/AC) to
correspond with the Westminster Standards. The estimated demands are included in Table 2:
Table 2: Estimated Domestic Water Demand
Gallons per Minute
(GPM)
Million Gallons per Day
(MGD)
Average Day 122 0.175
Maximum Day 304 0.438
Maximum Hour 486 0.700
Fire Service 4,000 -
Design Flow Rate
(Max Day + Fire Flow)
4,304 -
5.2 Wastewater Demand
Proposed land uses for evaluation of wastewater demand were obtained from the anticipated maximum density
achieved at full build-out of the project. The City of Ft. Collins Design Manual does not include generalized demand
rates for planning purposes, therefore the estimated demand from each use was multiplied by a unit demand rate
taken from the Westminster Standards to develop an estimated average daily flow. A peak day factor of 3.6 was
used to estimate the maximum daily flow.
Strauss Lakes ODP – Utility Demand Memo September, 2025
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Figure 2 – Westminster Standards
The Site is underlain by a high groundwater table. Basements will not be feasible for much of the project area.
Infiltration was estimated to be 1,000 gpm/acre for the Site and undeveloped parcels within the tributary area. No
peak factor was applied to infiltration values. Table 3 summarizes the estimated wastewater demands. Refer to
Appendix B for additional excerpts from the Westminster Standards and calculations for this project. The various
residential typologies depicted in the ODP were applied based on anticipated densities (DU/AC) to correspond with
the Westminster Standards. The used in the commercial area are unknown; therefore the generation rate was
assumed to be the average of Restaurant, Service and Retail.
Table 3: Summary of Estimated Wastewater Demand (including infiltration)
(CFS) (MGD)
Average Day 0.16 0.105
Maximum Day 0.52 0.339
6.0 PROPOSED IMPROVEMENTS
The ODP does not require a detailed utility plan: however, a conceptual layout of water distribution and sanitary
sewer collection piping has been prepared to develop preliminary cost estimates for the project. These layouts are
included in the Appendix. Detailed designs and hydraulic analysis of all infrastructure will be prepared as part of
future PDP and Plat applications.
Land Use Category Unit Demand Units Demand Demand Notes
(GPD/unit) (GPD) (MGD)
Commercial AC 1430 5 7,150 0.007
Multifamily Affordable UNIT 129.6 144 18,662 0.019 1.8 occupants per unit, 72 gpd per occupant
Townhomes UNIT 178 447 79,566 0.080 2.0 occupants per unit, 90 gpd per occupant
Detached Homes UNIT 258 270 69,687 0.070 2.9 occupants per unit, 89 gpd per occupant
GPM GPD MGD Peak Factor
Total Average Daily Demand 122 175,065 0.175
Maximum Day 304 437,664 0.438 2.5
Maximum Hour 486 700,262 0.700 4.0
Fire Flow (GPM) 4000 5,760,000 5.760 Max fire flow per IFC with 50% sprinkler reduction
Design Point (Max Day + Fire Flow) 4304 6,197,664 6.198
Domestic Water Demand
Strauss Lakes ODP
water sewer demand 11-2024.xlsx
9/22/2025
Land Use Category Unit Demand Units Demand Demand Notes
(/unit) (GPD) (MGD)
Commercial General AC 1.01 5.00 7,296 0.007 Average of Restaurant, Service and Retail
Aaffordable (R36) UNIT 0.07 144 14,515 0.015
Townhomes (R18) UNIT 0.07 447 45,058 0.045
Detached Homes (R8) UNIT 0.07 270 27,216 0.027
Infiltration/Inflow AC 800 14 11,200 0.011 Excludes open space areas not sewered
GPM CFS GPD MGD
Total Average Daily Demand 73.1 0.16 105,285 0.105
Maximum Day 235.2 0.52 338,705 0.339 peak factor 3.6, no peak on infiltration
Sewer Demand
Strauss Lakes ODP
water sewer demand 11-2024.xlsx
9/22/2025
February 2023 3-4
corresponding node locations, distribution of fire flows among
hydrants, and maximum pipe velocities. Data should be
presented in table format. Reference shall be made to modeling
data in the appendix and a figure of the pipe and node network
provided.
f) Conclusions – a description of the results and how they follow
the CITY criteria shall be provided. Any deviations from the CITY
criteria shall be described and applicable variances requested.
f) Appendices - Printed data output from the modeling results
shall be provided in the appendix and shall correspond with a
figure of the pipe and node network. The appendix shall also
include hydrant flow test results, hand calculations and any
other pertinent data. A large size figure (24” x 36”) illustrating the
existing and proposed utility improvements shall be provided
and shall conform to the CITY’s latest master plan. The drawing
shall include pressure zone boundaries, building finished floor
elevations, elevation contours and locations of proposed and
existing utility easements and right-of-way.
In situations where a previous utility study was conducted and is still
applicable, a utility conformance letter may be submitted in place of
the Utility Study, at the discretion and with written authorization of the
CITY ENGINEER.
3.13.0 DESIGN DEMAND
The domestic demands for a particular development vary depending on the type of
development, land use density, irrigation demand and building fire sprinkler flow
requirements. However, the demand used to design a water system is largely a
function of the required fire flow for a particular development.
There are two general categories of development for which domestic flow rates are
determined: residential and commercial/industrial. Domestic demands for these
developments are determined from Tables 3.13.A, 3.13.B and 3.13.C below and then
peaking factors are applied to develop the Maximum Day Demand and Peak Hour
Demand as follows:
Maximum Day Demand = 2.5 x Average Day Demand
Peak Hour Demand = 4.0 x Average Day Demand
Domestic demands for a development shall be combined with peak irrigation
demand, building fire sprinkler demand and the project fire flow. The peak irrigation
demand shall be determined by the irrigation designer and the fire sprinkler
demand shall be determined by the fire sprinkler Engineer. The fire flow for a project
is determined from the International Fire Code (Edition currently approved by the
CITY Building Department) and requires the approval of the CITY Fire Marshal.
Factors such as building area and construction type are required to determine the
fire flow for a structure.
The design of the water distribution system shall be based on the higher of the two
demand scenarios:
February 2023 3-5
Maximum Day Demand + project fire flow + building fire sprinkler flow + peak
irrigation flow, or
Peak Hour Demand + peak irrigation flow.
The CITY shall be consulted for design criteria with regard to non-standard
developments, design of municipal infrastructure such as transmission mains, pump
stations, etc. and for developments with unusually high demands. The CITY
ENGINEER shall have final input in these instances.
Residential Average Day Demand shall be based on density, and zoning as
determined by the Preliminary Development Plan and Official Development Plan for
the project and the proposed number of units. This estimate is to be used solely for
the purposes of planning and design infrastructure. The CITY PWU’s Water
Resources Division shall be contacted to determine tap size and fees.
Table 3.13.A – Residential Average Day Demand Data.
Zoning Type of
Development
Units per Acre People per
Unit
Gallons per
person per
day
R-1 to R-5 Single Family
Detached Up to 5 2.90 89
R-8 to R-18
and
District Center
Single Family
Attached Up to 18 2.00 90
R-36 Attached,
Multi-family Up to 36 1.80 72
Commercial and industrial Average Day Demands will vary widely depending on the
type of development. The following criteria in Table 3.13.B is based on historic
information from the CITY’s water records and can be used to estimate the water
usage for the various developments listed for the purposes of infrastructure design.
The CITY PWU’s Water Resources Division shall be contacted to determine tap size
and fees.
Table 3.13.B – Commercial/Industrial Average Day Demand Data
Type of Development Unit
Indoor Design
Demand
(gallons/unit-
day)
Auto Service and Repair sf 0.12
Car Wash bay 528
Childcare sf 0.32
Church sf 0.18
Grocery Store sf 0.22
Gas Station with Car Wash sf 8
Gas Station without Car Wash sf 1.32
February 2023 3-6
Hospital sf 0.32
Hotel/Motel room 130
Medical Office sf 0.2
General Offices sf 0.04
Restaurant sf 1.1
Retail/Shopping Center sf 0.16
School sf 0.06
Warehouse/Industrial sf 0.04
For commercial and industrial planning purpose, where specific densities and
building uses are not yet known, average day demands can be calculated on an
acreage basis as specified in Table 3.13.C.
Table 3.13.C – Commercial/Industrial Average Day Demand Data (Based on
Acreage)
Type of Development Gallons per Acre-Day
Retail Commercial 1430
Office 1430
Office – High density 2480
Mixed-Use 4100
Industrial 1430
School/Church 1260
If the developer has specific information for their proposal that is different from the
above, and the developer wishes to design using the different information, the
developer must contact PWU to discuss and obtain approval.
3.14.00 HYDRAULIC DESIGN
A computer generated hydraulic analysis of the proposed infrastructure, or “model”,
shall be developed using standard industry software such as WaterCAD or CITY
approved equal. In order for the model to properly correlate with the CITY’s
distribution system, a hydrant flow test needs to be performed on nearby hydrants
and static and residual pressures obtained as a function of flow rate. This data shall
be used in the model to develop a water source curve, represented by a reservoir and
pump, and this will allow modeled pressures to vary over a range of imposed
demands. The water source curve functions as a boundary condition in the model
where proposed piping interfaces with the existing distribution system at this
boundary.
For purposes of hydraulic modeling, Hagen Williams C coefficient shall be 130 for
PVC pipe, lined ductile iron pipe, and lined steel pipe. For any other condition,
coordination with the PWU is required.
The objective during hydrant flow testing is to obtain a flow rate similar to the
design demand required for the proposed development. The hydrants to be tested
shall be determined by the PWU and data obtained during this test shall be valid for
up to one-year, unless otherwise approved in writing by the PWU. Distribution
system factors may require that a fire flow be increased for a particular area of the
March 2022 4-5
(D) Appendices and Figures - Printed data output from any pipe flow
analysis shall be provided in the Appendix and shall correspond with a
figure of the pipe network. The Appendix shall also include hand
calculations and any other pertinent data. A large size figure (24” x 36”)
illustrating the existing and proposed utility improvements may be
required and should include building finished floor elevations,
elevation contours and locations of proposed and existing utility
easements and right-of-way as necessary.
4.13.00 DESIGN FLOW
Projected flows used to design the sanitary sewer system for a particular
development vary depending on the type of development and land use. Six general
categories of development for which typical average flow rates are given below
include residential, restaurants, service, retail, office, hotel and industrial uses. For
non-residential and non-hotel uses, apply the factor to the total area of the lot. Once
the specific type of development is determined, peak design flows are calculated by
multiplying the average flow with the peaking factor and then adding infiltration
and inflow.
Typical Average Flow Uses:
Restaurants 1.24 Gallons/Minute/Acre*
Service 0.99 Gallons/Minute/Acre*
Retail 0.81 Gallons/Minute/Acre*
Office 0.40 Gallons/Minute/Acre*
Industrial 0.22 Gallons/Minute/Acre*
Hotel 5.16 Gallons/Minute/100 rooms*
R-36 residential zoning 0.07 Gallons/Minute/Unit*
R-18 residential zoning 0.07 Gallons/Minute/Unit*
R-8 residential zoning 0.09 Gallons/Minute/Unit*
R-3.5 residential zoning 0.10 Gallons/Minute/Unit*
Peaking Factor 3.6 × [Average Flow (mgd)]-0.12, maximum value of 4**
Infiltration and Inflow 1000 Gallons/Acre/Day ***
Some development projects may not be considered “typical” as they may be infill
type projects and capacities of the downstream sewer may be limited. In these
cases, design flows must be calculated using historic flow data available from the
CITY for various use types projected and available capacities in the downstream
sewers may need to be modeled as described in section 4.12.02 (B) g. Refer to the
“Orchard Town Center Sanitary Sewer System Analysis”, February, 2013 by J&T.
Flow rates in pipelines downstream of lift stations shall take into account the
maximum pumping rate generated by the pump station plus peak daily flow plus
Infiltration and Inflow.
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DETENTION PONDDETENTION POND
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EXISTING WATER IN PERCHERON DR
EXISTING WATER IN WILLIAM NEAL PARKWAY
CONNECT TO EXISTING
DETENTION
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DETENTION
POND
REVISIONS
NO.DESCRIPTION DATE
DATE:
SHEET:
DESIGNED BY:
DRAWN BY:
CHECKED BY:
JOB NO.:
DWG NAME:37200101WAT_EXHIB
JAB
CMH
CMH 11/18/2024
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372.001.01
7 OF 9
WATER
EXHIBIT
8308 COLORADO BLVD
SUITE 200
FIRESTONE, CO 80530
303.833.1416
WWW.CIVILRESOURCES.COM
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BOULDER, CO 80306
PO BOX 229
ATTN: BILL MCDOWELL
COTTONWOOD LAND
AND FARMS, LLC
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PROPERTY LINE
WATER LINE
ASPHALT
CONCRETE
LEGEND
PROPOSED
BORE
NOTE:
WATER MAINS IN STREETS DEPICTED IN APPROXIMATE LOCATIONS ONLY.
ADDITIONAL PUBLIC MAINS WILL BE REQUIRED WITHIN INDIVIDUAL
DEVELOPMENT BLOCKS, BASED ON SITE PLAN AND HYDRANT COVERAGE TO
BE DETERMINED AS PART OF FUTURE SITE SPECIFIC DEVELOPMENT PLANS.
LIFT STATION
CITY OF FT COLLINS
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EXISTING SANITARY SEWER IN ZIEGLER RD
FORCE MAIN FROM LIFT STATION
REVISIONS
NO.DESCRIPTION DATE
DATE:
SHEET:
DESIGNED BY:
DRAWN BY:
CHECKED BY:
JOB NO.:
DWG NAME:37200101SAN_EXHIB
JAB
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372.001.01
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SANITARY
SEWER
EXHIBIT
8308 COLORADO BLVD
SUITE 200
FIRESTONE, CO 80530
303.833.1416
WWW.CIVILRESOURCES.COM
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BOULDER, CO 80306
PO BOX 229
ATTN: BILL MCDOWELL
COTTONWOOD LAND
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PROPERTY LINE
SANITARY SEWER
ASPHALT
CONCRETE
LEGEND
PROPOSED
FORCE MAIN
BORE
NOTE:
SEWER MAINS IN STREETS DEPICTED IN APPROXIMATE LOCATIONS ONLY.
ADDITIONAL PUBLIC MAINS WILL BE REQUIRED WITHIN INDIVIDUAL
DEVELOPMENT BLOCKS, BASED ON FUTURE SITE SPECIFIC DEVELOPMENT
PLANS.