HomeMy WebLinkAboutPOWERHOUSE 2 - PDP220006 - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORT
PRELIMINARY DRAINAGE REPORT AND EROSION CONTROL REPORT
POWERHOUSE 2
FORT COLLINS, COLORADO
AUGUST 17, 2022
NORTHERNENGINEERING.COM
970.221.4158
FORT COLLINS
GREELEY
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FORT COLLINS | GREELEY COVER LETTER
August 17, 2022
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
RE: PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR
POWERHOUSE 2
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 Powerhouse
2 development.
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 Powerhouse 2 development. 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
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FORT COLLINS | GREELEY TABLE OF CONTENTS
TABLE OF CONTENTS
GENERAL LOCATION AND DESCRIPTION .......................................................... 1
DRAIN BASINS AND SUB-BASINS ..................................................................... 5
DRAINAGE DESIGN CRITERIA .......................................................................... 6
DRAINAGE FACILITY DESIGN .......................................................................... 7
CONCLUSIONS ........................................................................................... 11
REFERENCES .............................................................................................. 11
TABLES AND FIGURES
FIGURE 1 – VICINITY MAP .................................................................................................1
FIGURE 2 – AERIAL PHOTOGRAPH ...................................................................................2
FIGURE 3 – PROPOSED SITE PLAN ...................................................................................3
FIGURE 4 – AREA FLOODPLAIN MAPPING ........................................................................3
FIGURE 5 – FOUNDATION DETAIL ....................................................................................4
APPENDICES
APPENDIX A – HYDROLOGIC COMPUTATIONS
APPENDIX B – DETENTION POND COMPUTATION
APPENDIX C – INLETS & WEIRS (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
DR-A – EXISTING VS. PROPOSED IMPERVIOUS AREA – BASIN A
DR1 – POWER HOUSE II DRAINAGE EXHIBIT; (NORTHERN ENGINEERING)
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GENERAL LOCATION AND DESCRIPTION
A. LOCATION
Vicinity Map
The Powerhouse 2 site is located in the Southwest Quarter of Section 1, 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 the Lake Canal, to the south by
East Vine Drive to the east by Jerome Street, and to the west by N. College Avenue.
B. DESCRIPTION OF PROPERTY
The Powerhouse 2 site is comprised of roughly ±4.97 acres.
The site is currently occupied by three buildings as well as concrete sidewalks, open areas,
gravel parking areas, and ±48,482 square feet of asphalt. The existing imperviousness of the
site is 54%. An exhibit for existing versus proposed imperviousness is provided in the Map
Pocket section. The existing ground slopes with a mild to moderate grade (i.e., 0.5 – 2.0±%)
Figure 1 – Vicinity Map
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through the interior to the south across flat grades into East Vine Drive. The drainage continues
through the Poudre River Whitewater Park and on to the Cache La Poudre River.
A soils report (Project No. FC10223-125) was completed by CTL Thompson, Inc. on March 14,
2022. The report contains the results of a complete geotechnical subsurface exploration as well
as pertinent geotechnical recommendations.
There are two major drainageways close to the site. The Lake Canal is located on the north side
of the site and the Cache la Poudre River is located approximately 550 feet south of the site.
The proposed project site consists of one building. Other proposed improvements include
concrete and permeable paver drive aisle, gravel parking, walkways, a courtyard, landscape,
and open space areas. The proposed imperviousness of the site is 56%. An existing and
proposed imperviousness exhibit is provided in the Map Pocket section. Figure 3 shows the
proposed site plan.
Figure 2 – Aerial Photograph
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C. FLOODPLAIN
The Powerhouse 2 project is located within a FEMA Special Flood Hazard Area of the Cache la
Poudre River (Poudre River). Most of this area is designated as With Base Flood Elevation (BFE)
or Depth in Zone AE on FIRM Panel 08069C0997G, effective June 17, 2008. The floodplain from
the Whitewater Park Letter of Map Revision (LOMR) Case No. 20-08-0643P, effective June 25,
2021, will supersedes the current FEMA RiskMap. Most of the property falls inside the regulated
100-year floodplain. Chapter 10 of the City of Fort Collins Municipal Code regulates critical
facilities within this Flood Hazard Zone. It should be noted FEMA, as part of RiskMap, is
Figure 4 – Area Floodplain Mapping
Figure 3 – Proposed Site Plan
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currently remapping the Poudre River. Anderson Consulting Engineers (ACE) will provide the
updated Floodplain modeling, mapping, and report for the site when completed.
Anderson Consulting Engineers is in the process of preparing a variance request to the Fort
Collins Water Commission to allow construction of the Powerhouse 2 Building, which is
considered to be a critical facility, within the currently effective 1% annual chance of
occurrence (100-year) floodplain. Once constructed, the building will be elevated above, and
mapped out of, both the 100-year and 0.2% annual chance (500-year) floodplains. The as-built
condition will be documented in a LOMR to be submitted to the City and FEMA for review and
adoption. However, since the building (as a critical facility) is planned to be constructed prior
to the LOMR being approved by FEMA, a variance is required by City Code. The variance request
also seeks to allow the City to issue a Certificate of Occupancy (CO) for the building once the
City has reviewed and approved the LOMR application, but prior to final adoption by FEMA. It is
currently anticipated that this variance request will come before the Water Commission in
September 2022.
It is assumed a portion of the project site will continue to be located within the updated 100-
year floodplain. To ensure the proposed buildings have adequate flood protection, the finished
floors and all ductwork, heating, ventilation, electrical systems, etc., will be elevated 24-inches
above the effective Base Flood Elevation (BFE). This elevation is known as the Regulatory Flood
Protection Elevation (RFPE). The RFPE = BFE + 24 inches. The solar panels and the electric
vehicle charging components in the parking lot shall be installed above the RFPE or have
floodproofing as required by Chapter 10 of the City of Fort Collins Municipal Code. A minimum
of 24-inches of freeboard will be provided from base (100-year) flood elevation (BFE). This
freeboard level will be applied to either the design of finished floor elevations or the minimum
level of floodproofing measures
The vertical datum utilized for site survey work is the City of Fort Collins Benchmark # 1-00
(Elevation=4968.74); NAVD 88.
Furniture or site components not elevated above the floodplain or contained within a utility
wall shall be securely anchored with a system of 4" lag bolts epoxied into ground base concrete
or stone with straps and/or chains secured to elements to prevent flotation. Anchoring details
will be supplied at the time of the floodplain use permit.
Figure 5 – Foundation Detail
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A floodplain use permit will be required for the building structure and each site construction
element in the floodplain. The floodplain use permit for the building will be approved at the
time of the building permit application.
A floodplain use permit and no rise certification is required prior to performing any work within
the floodplain (i.e., curb cut removal, landscaping).
A post-construction elevation certificate including components like transformer, yards, EV.
charging stations, solar panel components, elevator, HVAC equipment, emergency vehicle
access gate, other electrical and mechanical systems, etc. must be approved before a
certificate of occupancy will be issued.
All elevators installed below the RFPE in the project will comply with FEMA NFIP technical
bulletin on June 4, 2019, and the 2021 IBC.
An Emergency Response and Preparedness Plan (ERPP) will be required by the City of Fort
Collins prior to a floodplain or building permit being issued.
Outdoor classrooms and informal outdoor gathering space will be used for site tours and
outdoor learning. These spaces will be constructed using large boulders and crusher-fine
surfacing.
DRAIN BASINS AND SUB-BASINS
A. MAJOR BASIN DESCRIPTION
Powerhouse 2 is located in the Cache la Poudre River Basin, a major tributary to the South
Platte River. The river 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 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 spaces along the river
corridors.
B. SUB-BASIN DESCRIPTION
The subject property historically drains overland through the interior to the south across flat
grades. Runoff from the site has historically been routed to an existing pond/wetland on the
south side of Vine Drive.
The project site was a part of a previous drainage study in this area, "Drainage, Water Quality
and Erosion Control Report for the Poudre River Whitewater Park Project" by Anderson
Consulting Engineers, Inc., dated June 6, 2017. Within the drainage study, Powerhouse 2 is
associated with Basin 9, with a contributing area of 4.68 acres and an assumed fully-developed
imperviousness of 85%.
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DRAINAGE DESIGN CRITERIA
A. REGULATIONS
There are no optional provisions outside of the FCSCM proposed with the proposed project.
B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS
In June 2017, Anderson Consulting Engineers, Inc. (ACE), per the direction of the City of Fort
Collins Stormwater staff, provided a Stormwater Management Model (SWMM) model for a fully-
developed condition scenario to evaluate the size of the proposed project infrastructure for the
Poudre River Whitewater Park project. The objective of this modeling was to generate a
conceptual drainage plan for future improvements. In the final modeling, Subbasins 8, 9, 10,
and 11 are related to the site. ACE considered conceptual detention ponds for the privately
owned properties located north of East Vine Drive (Subbasins 9 and 11) to detain and release
fully-developed 100-year flows at a 2-year historical rate. For the Powerhouse 2 project, the
corresponding basin is Subbasin 9 of the drainage study. An excerpt from the "Drainage, Water
Quality and Erosion Control Report for the Poudre River Whitewater Park Project" drainage
report is included in Appendix F.
In order to bring Powerhouse 2 into compliance with the current land use code and stormwater
criteria, 75% of all newly added impervious areas will be treated by Low Impact Development
(LID) techniques. The remaining water quality will be provided in the proposed detention
pond.
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 is 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 the Urban Drainage and Flood Control District (UDFCD) Urban
Storm Drainage Criteria Manual.
As discussed above, the subject property is located in a 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 the criteria at this time.
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F. STORM MANAGEMENT STRATEGY
The overall stormwater management strategy employed with the Powerhouse 2 development
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.
The Powerhouse 2 development 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 LID techniques; however, rain gardens have been
provided for this site as LID techniques 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, the 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. As stated in Section I.A.3, the Lake Canal is located on the north
side of the site; however, no changes are proposed to Lake Canal with this project. While this step
may not seem applicable to the Powerhouse 2 development, the proposed project indirectly helps
stabilize drainageways. Once again, site selection has a positive effect on stream stabilization.
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.
A total combined release rate of 16.77 cubic feet per second (cfs) has been determined for the
proposed detention facility. This release rate has been grandfathered and agreed to by City
staff. The methodology accounts for existing impervious areas on the site, which will be
allowed to be released at the 100-year historical rate. There is a combined 1.32 acres of existing
impervious area within the development site, which drains to East Vine Drive. The 100-year
discharge from this impervious area is 13.11 cfs. There is a combined 3.66 acres of existing
pervious area within the development site, which also drains to East Vine Drive. A 2-year
discharge of 3.66 cfs has been calculated from this pervious area. The sum of "grandfathered"
existing impervious areas discharging into East Vine Drive combined with 2-year existing
pervious areas is 16.77 cfs, which is considered the allowable peak release rate for the site. We
have subtracted the 100-year undetained discharge computed from Basins 5, 7, 8, 10, 11, and
12 (2.73 cfs total) for an allowable release rate of 16.77-2.73=14.04 cfs. However, the detention
pond calculations are limited to a release rate of 8.5 cfs due to the capacity of the proposed 15"
outlet pipe.
The Conceptual Design from Anderson Consulting Engineers, Inc. included an 18" RCP outlet
pipe. Upon checking the conceptual design, it was discovered that the pipe did not have
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enough cover on the north flowline of Vine Drive; therefore, the pipe diameter has been
changed to a 15" pipe with a lower release rate of 8.5 cfs. We have used this value when sizing
our detention pond.
Onsite detention and water quality treatment for the Powerhouse 2 project will be provided
within the detention pond and rain gardens.
A temporary piezometer was installed approximately 25’ north of the proposed detention
pond. On July 29, 2022, the groundwater reading was at 5 feet below existing grade, which is
approximately 1’ below the proposed detention pond bottom. While it is desired to have more
separation between the pond bottom and groundwater, the pond bottom has been elevated as
much as possible and the outfall pipe is already as shallow as it can go. Undulations have been
added to the pond bottom, so most areas of the pond have more separation than the 1’
minimum.
LID treatment requirements will be met using rain gardens on the north and south sides of the
project, thereby meeting the requirement of at least 75% of all newly added impervious areas.
As mentioned above, Anderson Consulting Engineers, Inc. included East Vine Drive and the
Powerhouse 2 site in their drainage study for the Poudre River Whitewater Project. Their Site
Map can be found in Appendix F. That study dictated that flows from Vine, Jerome, and the
parcel at the northeast corner of the Jerome/Vine intersection be conveyed along Vine to an
inlet that would then convey flows south using the proposed 18 RCP and on to the downstream
detention and water quality features. Our proposed drainage design follows this approach but
uses a 15" pipe, as noted above.
B. SPECIFIC DETAILS
The detention volume required for the site is 0.34 acre-feet. This volume was calculated using
the FAA Method.
City Code requires LID treatment for all projects. This project proposes meeting the
requirement by using rain gardens as a LID technique. The rain gardens will capture the
majority of the water quality volume (WQCV) for the entire site, providing a total volume of
3,045 cubic feet. This configuration will treat at least 75% of the new impervious area. The
project is also including permeable pavers and gravel parking areas throughout the project.
While these don't count towards the official LID calculation, they achieve similar outcomes and
further enhance stormwater treatment on the site.
The Powerhouse 2 site has been broken into onsite sub-basins for design purposes. Anticipated
drainage patterns for proposed drainage basins are described below.
Basin 1
Basin 1, approximately 2.23 acres, consists of building, asphalt, sidewalk, paver, gravel, open
areas, and solar panel rooftops in the parking area. Runoff from the basin will sheet flow north
into a swale along the north property line. The swale will discharge into the rain garden and
then to Basin 6.
Basin 2
Basin 2, approximately 0.74 acres, consists of asphalt, sidewalk, gravel, open areas, and solar
panel rooftops in the parking lot. Runoff from the basin will sheet flow to a proposed curb
opening located on the southeast side of the parking area and then to Basin 6.
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Basin 3
Basin 3, approximately 0.72 acres, consists of a building, sidewalk, and open areas. Runoff from
the basin will convey flows via sheet flow and roof leaders to a rain garden located on the
south and then to Basin 6.
Basins 4
Basin 4, approximately 0.11 acres, consists of asphalt, sidewalk, and landscape areas. Runoff
from the basin will convey flows via sheet flow to a proposed Type R Inlet and then to Basin 6.
Basins 5 & 7
Basin 5, approximately 0.14 acres, and Basin 7, approximately 0.04 acres, consists of sidewalk
and landscape areas. Runoff from the basins will convey flows via sheetflow to a proposed area
inlet located on East Vine Drive, then routed to the Whitewater Park detention pond.
Basin 6
Basin 6, approximately 0.41 acres, consists of open space. This basin is the onsite detention
pond.
Basin 8 and Co1
Basin 8, approximately 0.11 acres, and Basin Co1, approximately 0.42 acres, consists of asphalt,
sidewalks, and landscape. Runoff from the basins will drain via sheet flow to the curb and
gutter along North College Avenue, then into an existing inlet in sump. The runoff will follow
existing drainage patterns.
Basin 9
Basin 9, approximately 0.14 acres, is an offsite basin and consists of open space. Runoff from
the basin will be conveyed through the north rain garden and then through Basin 6 without
being detained.
Basins 10 and 11
Basin 10, approximately 0.03 acres, and Basin 11, approximately 0.05 acres, consist of open
space. Runoff from the basins will drain via sheet flow north to Lake Canal. The areas are
outside the limits of disturbance and will continue to drain to the ditch as they currently do.
Basin 12
Basin 12, approximately 0.14 acres, consists of sidewalks and landscape. Runoff from the basin
will drain via sheet flow east to Jerome Street and follow existing drainage patterns to a
proposed area inlet located on East Vine Drive. Runoff from the basin will be routed to the
Whitewater Park detention pond.
Basins W8 & W10
Basin W8, approximately 0.63 acres, and Basin 10, approximately 1.50 acres, are part of the
"Drainage, Water Quality and Erosion Control Report for the Poudre River Whitewater Park
Project" Drainage Study. Runoff from the basins will follow the assumed fully-developed
conceptual design path from the drainage study. The runoff will be routed to a proposed area
inlet on East Vine Drive and then to the Whitewater Park detention pond.
Basin W11
Basin W11, approximately 0.89 acres, is part of the "Drainage, Water Quality and Erosion
Control Report for the Poudre River Whitewater Park Project" Drainage Study. Runoff from the
basin will follow the assumed fully-developed conceptual design path from the drainage study
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and will be routed via storm drain to Whitewater Park detention pond in the future when the
parcel is developed.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report.
C. LID SUMMARY
Powerhouse 2 is providing a rain garden to treat a portion of the north area of the site that will
see the highest runoff rate and contains portions of the building, concrete drive aisles,
sidewalk, permeable pavers, gravel parking, landscape areas, and solar panel rooftops in a
portion of the parking lot (Basin 1).
Powerhouse 2 is providing a rain garden to treat a portion of the southwest area of the site,
which contains a portion of the building, sidewalks, and open areas (Basin 3).
Powerhouse 2 On-Site LID Treatment
Project Summary
Total Impervious Area 114,856 sf
Target Treatment Percentage 75%
Minimum area to be Treated by LID measures 86,142 sf
Treated Impervious Areas by Treatment Method
Rain Garden 91,420 sf
Total Treated Impervious Areas 91,420 sf
Percent Total Project Area Treated 79.6%
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CONCLUSIONS
A. COMPLIANCE WITH STANDARDS
The drainage design proposed with the Powerhouse 2 project complies with the City of Fort
Collins Stormwater Criteria Manual.
The drainage design proposed for this project complies with the "Drainage, Water Quality and
Erosion Control Report for the Poudre River Whitewater Park Project" Drainage Study.
The drainage design proposed with this project complies with the Cache la Poudre River Basin
requirements.
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.
6. Drainage, Water Quality and Erosion Control Report for the Poudre River Whitewater Park Project
dated June 6, 2017, by Anderson Consulting Engineers, Inc.
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FORT COLLINS | GREELEY APPENDIX
APPENDIX A
HYDROLOGIC COMPUTATIONS
Runoff Coefficient1
Percent
Impervious1 Project:
Location:
0.95 100%Calc. By:
0.95 90%Date:
0.50 40%
0.50 40%
0.20 2%
0.20 2%
Basin ID Basin Area
(sq.ft.)
Basin Area
(acres)
Asphalt, Concrete
(acres)Rooftop (acres) Gravel (acres) Pavers (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
Imp. Areas lot 2 & 3 30,613 0.70 0.60 0.10 0.00 0.00 0.00 0.00 99% 0.95 0.95 0.95 1.00
Perv. Areas lot 2 & 3 20,004 0.46 0.00 0.00 0.32 0.00 0.00 0.14 28% 0.41 0.41 0.41 0.51
Imp. Areas lot 4 26,797 0.62 0.51 0.11 0.00 0.00 0.00 0.00 98% 0.95 0.95 0.95 1.00
Perv. Areas lot 4 139,212 3.20 0.00 0.00 3.08 0.00 0.00 0.11 39% 0.49 0.49 0.49 0.61
H1 216,626 4.97 1.11 0.20 3.40 0.00 0.00 0.25 54% 0.60 0.60 0.60 0.76
1 (North Rain Garden) 97,274 2.23 0.81 0.34 0.13 0.15 0.00 0.80 56% 0.63 0.63 0.63 0.78
2 32,182 0.74 0.41 0.00 0.32 0.00 0.00 0.02 72%0.74 0.74 0.74 0.93
3 (South Rain Garden) 31,334 0.72 0.11 0.55 0.00 0.00 0.00 0.05 85% 0.90 0.90 0.90 1.00
4 4,748 0.11 0.10 0.00 0.00 0.00 0.00 0.00 96% 0.92 0.92 0.92 1.00
6 17,909 0.41 0.00 0.00 0.00 0.00 0.00 0.41 2% 0.20 0.20 0.20 0.25
5 5,988 0.14 0.03 0.00 0.00 0.00 0.00 0.10 27% 0.39 0.39 0.39 0.49
7 1,768 0.04 0.01 0.00 0.00 0.00 0.00 0.03 35% 0.45 0.45 0.45 0.56
8 4,818 0.11 0.03 0.00 0.00 0.00 0.00 0.08 31% 0.42 0.42 0.42 0.52
9 5,990 0.14 0.00 0.00 0.00 0.00 0.00 0.14 2% 0.20 0.20 0.20 0.25
10 1,258 0.03 0.00 0.00 0.00 0.00 0.00 0.03 2% 0.20 0.20 0.20 0.25
11 2,385 0.05 0.00 0.00 0.00 0.00 0.00 0.05 2% 0.20 0.20 0.20 0.25
12 6,264 0.14 0.07 0.00 0.00 0.00 0.00 0.07 52% 0.58 0.58 0.58 0.73
Co1 18,884 0.43 0.29 0.00 0.00 0.00 0.00 0.15 67% 0.70 0.70 0.70 0.87
W8 27,443 0.63 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park" 90%
W10 65,340 1.50 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park" 90%
W11 38,768 0.89 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park" 85%
2, 4, 6 to Extended Detention
Basin WQ 54,840 1.26 0.51 0.00 0.32 0.00 0.00 0.43 51% 0.58 0.58 0.58 0.72
1, 2, 3, 4 and 6 to Detention
Pond 183,448 4.21 1.44 0.90 0.45 0.15 0.00 1.28 60% 0.66 0.66 0.66 0.82
Basins Not Detained
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: C
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.
Historic Basins:
Developed Basins:
DEVELOPED RUNOFF COEFFICIENT CALCULATIONS
Asphalt, Concrete
Rooftop
Gravel
Pavers
Streets, Parking Lots, Roofs, Alleys, and Drives:
Character of Surface:Powerhouse II
Fort Collins
C. Ortiz
June 29, 2022
Notes:
1) Basins 1 and 3 are draining towards Rain Gardens (LID).
2) Extended Detention Basin WQ, consist of basins draining into detention pond that is not treated by LID. (2, 4, 6)
3) Basin 10 and 11 Drain to Lake Canal.
4) Basin 5 and 7 Drain to Vine Drive.
5) Basin 12 Drain to Jerome St.
6) Basin 8 and Co1 Drain to College Ave.
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)
imp. areas lot 2 & 3 Imp. Areas lot 2 & 3 119 65.00 64.17 0.70%3.45 3.45 2.30 327 64.17 61.50 0.82% Swale (8:1)0.04 8.00 16.12 0.50 2.41 2.26 5.71 5.00
perv. areas lot 2 & 3 Perv. Areas lot 2 & 3 119 65.00 64.17 0.70%15.89 15.89 13.54 327 64.17 61.50 0.82% Swale (8:1)0.04 8.00 16.12 0.50 2.41 2.26 12.48 12.48
imp. areas lot 4 Imp. Areas lot 4 119 63.75 61.60 1.81%2.51 2.51 1.67 181 61.60 60.41 0.66% Swale (8:1)0.04 8.00 16.12 0.50 2.16 1.39 5.00 5.00
perv. areas lot 4 Perv. Areas lot 4 119 63.75 61.60
1.81%10.23 10.23 8.18 181 61.60 60.41
0.66% Swale (8:1)0.04 8.00 16.12 0.50 2.16 1.39 11.62 9.57
1 (north rain garden) 1 (North Rain Garden)92 67.51 64.37 3.41%5.66 5.66 3.80 283 64.37 60.48 1.38% Swale (4:1)0.04 4.00 8.25 0.48 3.08 1.53 7.19 5.33
2 2 75 62.52 61.32 1.60%4.97 4.97 2.41 228 61.32 60.18 0.50% Gutter 0.02 3.61 19.18 0.19 2.31 1.64 6.61 5.00
3 (south rain garden) 3 (South Rain Garden)59 68.80 68.67 0.22%4.88 4.88 2.39 12 68.67 68.63 0.33% Gutter 0.04 3.61 19.18 0.19 0.81 0.25 5.13 5.00
4 4 38 68.48 62.60 15.39%0.84 0.84 0.46 117 62.60 60.58 1.73% Gutter 0.02 3.61 19.18 0.19 4.29 0.45 5.00 5.00
6 6 49 62.04 58.09
8.00%5.92 5.92 5.59 208 58.09 56.99
0.53% Swale (8:1)0.04 8.00 16.12 0.50 1.94 1.79 7.70 7.37
5 5 42 68.68 67.08 3.82%5.50 5.50 4.74 24 67.08 66.23 3.49% Gutter 0.02 3.61 19.18 0.19 6.09 0.07 5.57 5.00
7 7 27 62.36 61.21 4.27%3.89 3.89 3.22 28 61.21 60.35 3.11% Swale (8:1)0.02 8.00 16.12 0.50 10.98 0.04 5.00 5.00
8 8 21 68.77 67.69 5.12%3.39 3.39 2.87 25 67.69 67.05 2.60% Swale (8:1)0.04 8.00 16.12 0.50 4.31 0.10 5.00 5.00
9 9 53 67.99 65.10 5.46%6.95 6.95 6.57 49 65.10 64.37 1.49% Swale (6:1)0.04 6.00 12.17 0.49 3.24 0.25 7.21 6.82
10 10 5 65.85 63.45 52.86%0.96 0.96 0.90 4 63.45 61.20 55.01% Swale (8:1)0.04 8.00 16.12 0.50 19.79 0.00 5.00 5.00
11 11 6 63.42 63.29 2.19%3.16 3.16 2.98 8 63.29 63.11 2.16% Swale (8:1)0.04 8.00 16.12 0.50 3.93 0.04 5.00 5.00
12 12 27 63.56 62.85 2.65%3.62 3.62 2.60 34 62.85 62.50 1.03% Swale (8:1)0.04 8.00 16.12 0.50 2.71 0.21 5.00 5.00
co1 Co1 34 67.54 66.78 2.23%3.37 3.37 1.91 179 66.78 65.93 0.47% Gutter 0.02 3.61 19.18 0.19 2.25 1.33 5.00 5.00
w8 W8 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park"
w10 W10 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park"
w11 W11 Information taken from "Drainage, Water Quality and Erosion Control Report for Poudre River Whitewater Park"
2, 4, 6 to Extended
Detention Basin WQ 49 62.04 58.09 8.00% 3.42 3.42 2.47 208 58.09 56.99 0.53% Swale (8:1) 0.04 8.00 16.12 0.50 1.94 1.79 5.21 5.00
1, 2, 3, 4 and 6 to
Detention Pond 49 62.04 58.09 8.00% 2.91 2.91 1.83 208 58.09 56.99 0.53% Swale (6:1) 0.04 6.00 12.17 0.49 1.93 1.80 5.00 5.00
Design
Point Basin ID
Overland Flow Channelized Flow Time of
Historic Basins:
Developed Basins:
Basins Not Detain
Combined Basins
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Maximum Tc:Overland Flow, Time of Concentration:
Channelized Flow, Velocity:Channelized Flow, Time of Concentration:
Powerhouse II
Fort Collins
C. Ortiz
June 29, 2022
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
Tc2 Tc10 Tc100 C2 C10 C100 I2 I10 I100 Q2 Q10 Q100
Historic Basins:
imp. areas lot 2 & 3 Imp. Areas lot 2 & 3 0.70 5.7 5.7 5.0 1.0 1.0 1.0 2.8 4.7 10.0 1.8 3.1 7.0
perv. areas lot 2 & 3 Perv. Areas lot 2 & 3 0.46 12.5 12.5 12.5 0.4 0.4 0.5 2.1 3.5 7.2 0.4 0.7 1.7
imp. areas lot 4 Imp. Areas lot 4 0.62 5.0 5.0 5.0 0.9 0.9 1.0 2.9 4.9 10.0 1.7 2.8 6.1
perv. areas lot 4 Perv. Areas lot 4 3.20 11.6 11.6 9.6 0.5 0.5 0.6 2.1 3.6 7.9 3.3 5.6 15.4
Developed Basins:
1 (north rain garden) 1 (North Rain Garden) 2.23 7.2 7.2 5.3 0.6 0.6 0.8 2.5 4.3 10.0 3.5 6.0 17.4
2 2 0.74 6.6 6.6 5.0 0.7 0.7 0.9 2.6 4.4 10.0 1.4 2.4 6.8
3 (south rain garden) 3 (South Rain Garden) 0.72 5.1 5.1 5.0 0.9 0.9 1.0 2.9 4.9 10.0 1.8 3.1 7.2
4 4 0.11 5.0 5.0 5.0 0.9 0.9 1.0 2.9 4.9 10.0 0.3 0.5 1.1
6 6 0.41 7.7 7.7 7.4 0.2 0.2 0.3 2.5 4.2 8.8 0.2 0.3 0.9
5 5 0.14 5.6 5.6 5.0 0.4 0.4 0.5 2.8 4.7 10.0 0.1 0.3 0.7
7 7 0.04 5.0 5.0 5.0 0.4 0.4 0.6 2.9 4.9 10.0 0.1 0.1 0.2
8 8 0.11 5.0 5.0 5.0 0.4 0.4 0.5 2.9 4.9 10.0 0.13 0.23 0.58
9 9 0.14 7.2 7.2 6.8 0.2 0.2 0.3 2.5 4.3 9.1 0.07 0.12 0.31
10 10 0.03 5.0 5.0 5.0 0.2 0.2 0.3 2.9 4.9 10.0 0.02 0.03 0.07
11 11 0.05 5.0 5.0 5.0 0.2 0.2 0.3 2.9 4.9 10.0 0.03 0.05 0.14
12 12 0.14 5.0 5.0 5.0 0.6 0.6 0.7 2.9 4.9 10.0 0.24 0.41 1.04
co1 Co1 0.43 5.0 5.0 5.0 0.7 0.7 0.9 2.9 4.9 10.0 0.86 1.47 3.76
w8 W8
1.5 3.0 6.9
w10 W10
2.8 5.6 13.2
w11 W11
1.8 3.5 8.1
2, 4, 6 to Extended
Detention Basin WQ 1.26 5.2 5.2 5.0 0.6 0.6 0.7 2.9 4.9 10.0 2.1 3.6 9.1
1, 2, 3, 4 and 6 to
Detention Pond 4.21 5.0 5.0 5.0 0.7 0.7 0.8 2.9 4.9 10.0 7.9 13.5 34.5
DEVELOPED DIRECT RUNOFF COMPUTATIONS
Intensity (in/hr)Flow (cfs)
Powerhouse II
C. Ortiz
June 29, 2022
Design
Point Basin
Intensity, 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 Collins
Project:
Location:
Calc. By:
Basins Not Detain
Combined Basins
Information taken from "Drainage, Water Quality and Erosion
Control Report for Poudre River Whitewater Park"
Information taken from "Drainage, Water Quality and Erosion
Control Report for Poudre River Whitewater Park"
Information taken from "Drainage, Water Quality and Erosion
Control Report for Poudre River Whitewater Park"
This basin will generally drain via overland flow to the property adjacent to the west ost
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FORT COLLINS | GREELEY APPENDIX
APPENDIX B
DETENTION POND COMPUTATION
COG
Pond No :1
6
100-yr
0.82 WQCV 1108 ft3
Area (A)=4.21 acres Detention 13038 ft3
Max Release Rate =8.50 cfs Total 0.32 ac-ft
Time Time
100-yr
Intensity Q100
Inflow
(Runoff)
Volume
Outflow
(Release)
Volume
Storage
Detention
Volume
(mins) (secs) (in/hr) (cfs)
(ft3) (ft
3) (ft
3)
5 300 9.950 34.35 10305 2550.0 7754.8
10 600 7.720 26.65 15991 5100.0 10890.6
15 900 6.520 22.51 20258 7650.0 12607.5
20 1200 5.600 19.33 23199 10200.0 12998.8
25 1500 4.980 17.19 25788 12750.0 13037.9
30 1800 4.520 15.60 28087 15300.0 12787.1
35 2100 4.080 14.08 29578 17850.0 11728.4
40 2400 3.740 12.91 30987 20400.0 10586.9
45 2700 3.460 11.94 32250 22950.0 9300.5
50 3000 3.230 11.15 33452 25500.0 7951.8
55 3300 3.030 10.46 34519 28050.0 6468.5
60 3600 2.860 9.87 35544 30600.0 4943.9
65 3900 2.720 9.39 36621 33150.0 3470.9
70 4200 2.590 8.94 37553 35700.0 1853.0
75 4500 2.480 8.56 38527 38250.0 276.6
80 4800 2.380 8.22 39438 40800.0 -1362.1
85 5100 2.290 7.91 40318 43350.0 -3031.8
90 5400 2.210 7.63 41199 45900.0 -4701.4
95 5700 2.130 7.35 41913 48450.0 -6536.8
100 6000 2.060 7.11 42669 51000.0 -8330.8
105 6300 2.000 6.90 43498 53550.0 -10052.3
110 6600 1.940 6.70 44202 56100.0 -11898.0
115 6900 1.890 6.52 45020 58650.0 -13629.9
120 7200 1.840 6.35 45735 61200.0 -15465.3
DETENTION POND CALCULATION; FAA METHOD
Project Number : 207-030
Date : June 22, 2022
Project Location : Fort Collins, CO.
Developed "C" =
Calculations By:
Input Variables Results
Design Point
Design Storm Required Detention Volume
1
Project:
Date:8/11/2022
WQCV ELEVATION :
(A) (B) (C) (D)Total Volume Detention = 1,306.79 0.03 Ac.
Elevation Depth Area Volume Σ Volume Σ Volume Elev. (A1) = 4,957.50
(Sf.) (Cf.) (Cf.) (Ac.-ft.)Σ Volume (D1) = 469.61
Partial volume (C2) = 1,462.22
Outlet Elevation:4,957.00 26.39 Depth, partial volume = 0.50
0.50 469.61 469.61 0.01
>>>>>>>>> 4,957.50 1,852.03 High water level (HWL) = 4957.79
0.50 1,462.22 1,931.83 0.04
4,958.00 3,996.85 Water Depth = 0.79 Ft.
0.50 2,627.94 4,559.76 0.10
4,958.50 6,514.90
0.50 3,855.37 8,415.14 0.19
4,959.00 8,906.59
ACTUAL STORAGE :
(A) (B) (C) (D)Total Volume Detention = 13,939.09 0.32 Ac.
Elevation Depth Area Volume Σ Volume Σ Volume Elev. (A1) = 4,959.50
(Sf.) (Cf.) (Cf.) (Ac.-ft.)Σ Volume (D1) = 13,043.45
Partial volume (C2) = 4,976.99
Outlet Elevation:4,957.00 26.39 Depth, partial volume = 0.50
0.50 469.61 469.61 0.01
4,957.50 1,852.03 High water level (HWL) = 4959.59
0.50 1,462.22 1,931.83 0.04 Free board = 0.41
4,958.00 3,996.85 Top pond bank elevation = 4960.00
0.50 2,627.94 4,559.76 0.10
4,958.50 6,514.90 Water Depth = 2.59 Ft.
0.50 3,855.37 8,415.14 0.19
4,959.00 8,906.59
Detention Req'd 0.50 4,628.32 13,043.45 0.30
>>>>>>>>> 4,959.50 9,606.68
0.50 4,976.99 18,020.45 0.41
4,960.00 10,301.29
Pond No.:1
Detention Pond Stage Storage Curve
Pond Stage Storage Curve
Project Number:207-030
Project Location:Fort Collins, Colorado
Calculations By:C. Ortiz
Powerhouse II
207-030 - D-pond_Capacity, Det. Pond-1, 8/11/2022, 5:00 PM
Project Title Date:
Project Number Calcs By:
City
Basins
1
WQCV = Watershed inches of Runoff (inches)60%
a = Runoff Volume Reduction (constant)
i = Total imperviousness Ratio (i = Iwq/100)0.236 in
A =4.21 ac
V = 0.10 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 =
0.03 Ac-ft
3223 cu. ft.
1108 cu. ft.
Powerhouse II June 22, 2022
207-030 C. Ortiz
Fort Collins
4331 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
0.231
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
Stormwater Facility Name:
Facility Location & Jurisdiction:
User (Input) Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope =0.005 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length-to-Width Ratio = 2.72 L:W 0.00 26 0.00 0.00
Watershed Area = 4.21 acres 0.50 1,929 0.50 3.20
Watershed Imperviousness = 60.0% percent 1.00 4,966 1.00 4.53
Percentage Hydrologic Soil Group A = 0.0% percent 1.50 7,401 1.50 5.99
Percentage Hydrologic Soil Group B = 0.0% percent 2.00 8,450 2.00 7.51
Percentage Hydrologic Soil Groups C/D = 100.0% percent 2.50 9,540 2.50 8.77
3.00 10,806 3.00 9.86
User Input: Detention Basin Characteristics
WQCV Design Drain Time = 40.00 hours
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif,
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period =WQCV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year
Two-Hour Rainfall Depth =0.53 0.98 1.36 1.71 2.31 2.91 3.67 in
Calculated Runoff Volume =0.082 0.198 0.321 0.436 0.650 0.850 1.125 acre-ft
OPTIONAL Override Runoff Volume =acre-ft
Inflow Hydrograph Volume =0.081 0.198 0.320 0.436 0.650 0.849 1.125 acre-ft
Time to Drain 97% of Inflow Volume =1 1 1 1 2 2 2 hours
Time to Drain 99% of Inflow Volume =1 1 1 1 2 2 2 hours
Maximum Ponding Depth =0.22 0.50 0.87 1.19 1.68 2.13 2.72 ft
Maximum Ponded Area =0.020 0.044 0.095 0.135 0.179 0.200 0.232 acres
Maximum Volume Stored =0.002 0.011 0.037 0.074 0.153 0.237 0.366 acre-ft
Stormwater Detention and Infiltration Design Data Sheet
Powerhouse II
Fort Collins, Colorado
Workbook Protected Worksheet Protected
6573312, Design Data 6/27/2022, 5:20 PM
Doing_Clear_Formatting =Yes
CountA=1
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Stormwater Detention and Infiltration Design Data Sheet
Area
Discharge
0
2
4
6
8
10
12
14
16
18
20
0.1 1 10FLOW [cfs]TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
25YR IN
25YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.5
1
1.5
2
2.5
3
0.1 1 10 100PONDING DEPTH [ft]DRAIN TIME [hr]
100YR
50YR
25YR
10YR
5YR
2YR
WQCV
6573312, Design Data 6/27/2022, 5:20 PM
This basin will generally drain via overland flow to the property adjacent to the west ost
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FORT COLLINS | GREELEY APPENDIX
APPENDIX C
INLETS & WEIRS
(WILL BE SIZED AT FINAL)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Wednesday, Jun 22 2022
Swale Section 1 -1
Triangular
Side Slopes (z:1) = 3.70, 10.80
Total Depth (ft) = 1.40
Invert Elev (ft) = 1.00
Slope (%) = 1.25
N-Value = 0.035
Calculations
Compute by: Known Q
Known Q (cfs) = 11.20
Highlighted
Depth (ft) = 0.79
Q (cfs) = 11.20
Area (sqft) = 4.52
Velocity (ft/s) = 2.48
Wetted Perim (ft) = 11.60
Crit Depth, Yc (ft) = 0.69
Top Width (ft) = 11.45
EGL (ft) = 0.89
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)
This basin will generally drain via overland flow to the property adjacent to the west ost
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Powerhouse II
FORT COLLINS | GREELEY APPENDIX
APPENDIX D
EROSION CONTROL REPORT
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Powerhouse II
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.
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FORT COLLINS | GREELEY APPENDIX
APPENDIX E
PRELIMINARY LID DESIGN INFORMATION
VAULTCABLETVAULTF.O.F.O.CONTROLIRRCONTROLIRR
GASOHU OHULIDMH/ / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / /GASEAST VINE DRIVENORTH COLLEGE AVENUE
JEROME STREET UGEUDUDUDUDSFWIRTFTFSOUTH RAIN GARDENSREQUIRED VOLUME: 756 CU. FT.MINIMUM FLAT AREA: 533 SFPROVIDED VOLUME: 1,281 CU. FT.PROVIDED FLAT AREA: 1,538 SFTREATMENT AREA: 28,639 SFNORTH RAIN GARDENREQUIRED VOLUME: 1,449 CU. FT.MINIMUM FLAT AREA: 1,089 SFPROVIDED VOLUME: 1,942 CU. FT.PROVIDED FLAT AREA: 2,234 SFTREATMENT AREA: 63.000 SFJEROME STREET LLC,216 E OAK STJEROME STREET STATION LLC,742 N COLLEGE AVELMC VENTURES LLC,742 N COLLEGE AVECITY OF FORT COLLINS405 N COLLEGE AVEMORAK KAREN LLC622 N COLLEGE AVECITY OF FORT COLLINS,740 N COLLEGE AVEPOWERHOUSE IISHEET NO:P:\207-030\DWG\DRNG\207-030_LID.DWG
DRAWING REFERENCE:LID TREATMENT EXHIBITC. Ortiz 1" = 80'AUGUST 2022LID-1DRAWN BY:SCALE:ISSUED:NOTES1.FOR LID RAIN GARDENS CALCULATIONS PLEASE REFER TO THEPRELIMINARY DRAINAGE REPORT, DATED AUGUST 17, 2022.2.REFER TO UTILITY PLANS FOR POWERHOUSE II FOR ADDITIONALGRADING AND UTILITY INFORMATION.3.REFER TO LANDSCAPE PLANS FOR ADDITIONAL INFORMATION ONHARDSCAPES.4.REFER TO DRAINAGE EXHIBIT SHEET DR1 OF UTILITY PLANS FORSOIL AMENDMENT NOTESLEGENDPROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETLID TREATMENT AREANORTH( IN FEET )01 INCH = 80 FEET8080EXTENDED DETENTIONTREATMENT AREAUNTREATED AREAPowerhouse 2 On-Site LID TreatmentProject SummaryTotal Impervious Area 114,856sfTarget Treatment Percentage75%Minimum Area to be Treated by LIDmeasures 86,142sfTreated Impervious Areas by TreatmentMethodRain Garden91,420sfTotal Treated Impervious Areas91,420sfPercent Total Project Area Treated79.6%
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =56.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.560
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.18 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 97,274 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,449 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 =1,998.0 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 =8 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 5.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =1089 sq ft
D) Actual Flat Surface Area AActual =2234 sq ft
E) Area at Design Depth (Top Surface Area)ATop =3591 sq ft
F) Rain Garden Total Volume VT=1,942 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 =N/A ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =N/A cu ft
iii) Orifice Diameter, 3/8" Minimum DO =N/A in
Design Procedure Form: Rain Garden (RG)
C. Ortiz
Northern Engineering
June 22, 2022
Powerhouse II
North Rain Garden (Basin 1)
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
207-030_RG-North_UD-BMP_v3.06, RG 6/22/2022, 11:11 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
June 22, 2022
Powerhouse II
North Rain Garden (Basin 1)
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
207-030_RG-North_UD-BMP_v3.06, RG 6/22/2022, 11:11 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =85.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.850
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.29 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 31,334 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =756 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 =10 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 =533 sq ft
D) Actual Flat Surface Area AActual =1538 sq ft
E) Area at Design Depth (Top Surface Area)ATop =1538 sq ft
F) Rain Garden Total Volume VT=1,281 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 =N/A ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =N/A cu ft
iii) Orifice Diameter, 3/8" Minimum DO =N/A in
Design Procedure Form: Rain Garden (RG)
C. Ortiz
Northern Engineering
June 22, 2022
Powerhouse II
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
207-030_RG-South_UD-BMP_v3.06, RG 6/22/2022, 11:34 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
June 22, 2022
Powerhouse II
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
207-030_RG-South_UD-BMP_v3.06, RG 6/22/2022, 11:34 AM
NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Powerhouse II
FORT COLLINS | GREELEY APPENDIX
APPENDIX F
PREVIOUS STUDIES AND USDA SOILS
REPORT
DRAINAGE, WATER QUALITY AND
EROSION CONTROL REPORT
FOR THE
POUDRE RIVER WHITEWATER PARK PROJECT
PREPARED FOR:
City of Fort Collins
Park Planning & Development
215 North Mason Street
Fort Collins, CO 80524
PREPARED BY:
Anderson Consulting Engineers, Inc.
375 East Horsetooth Road, Building 5
Fort Collins, CO 80525
(ACE Project No. COFC18.1)
June 6, 2017
COFC18.1 Drainage Report (June 6 2017).docx 3 Anderson Consulting Engineers, Inc.
Figure 2.1 Site Map for the Poudre River Whitewater Project.
Cache
L
a
P
o
u
d
r
e
Ri
ver
Vine Dr
Linden StreetCherry St College AveProject Area
Union Pacific RailroadB urlington N orthern R ailroadJerome St0 500 1,000250
Feet
COFC18.1 Drainage Report (June 6 2017).docx 14 Anderson Consulting Engineers, Inc.
• Poudre River Pedestrian Bridge: As part of the City’s masterplan for the Poudre River Trail
system, the trail will eventually be relocated to the northern side of the river between Linden
Street and the BNSF Railroad when improvements to the Linde Street Bridge are
implemented. In order to reconnect Poudre River trail users with the current trail as it passes
underneath College Avenue, and to provide a pedestrian connection across the river for
residents and businesses in northern Fort Collins, a new pedestrian bridge will be installed
across the Poudre River as part of the project. The bridge will be 185-feet long and 15-feet
wide. As identified on the Floodplain Plan provided as part of the Utility Plan drawings, the
low chord elevation of the bridge (4964.0 NAVD88) will be located approximately 0.5-feet
above the proposed/post-project base flood elevation of 4963.5. The bridge will also span
the proposed/post-project floodway limits and a minimum 8-foot clearance will be provided
between the low chord and proposed trails beneath the bridge. Since the bridge will be
located above the base flood elevation, it will be designed as a non-breakaway bridge and will
be incorporated into the hydraulic modeling conducted for the CLOMR/LOMR as part of this
project.
5.2 Fully Developed Project Conditions
Based on coordination with City stormwater staff, it was decided that a fully developed condition
scenario would be developed to evaluate the sizing of proposed project infrastructure to accommodate
fully developed conditions, as well as generate a conceptual drainage plan for future improvements. A
figure depicting the fully developed project condition conveyance elements is provided as Sheet 2 in
Appendix C. Tabular results from the fully developed project condition EPA SWMM model are also
provided in Appendix C. Electronic copies of the fully developed project conditions EPA SWMM models
are provided as digital data on the disk included with this report. A description of the fully developed
proposed project condition is provided below:
• Fully Developed Basins and Conceptual Detention Ponds: Subbasins 9, 11, 13, and 14 were
assumed to be fully developed with increased impervious areas. Per the direction of City
Stormwater staff, conceptual detention ponds were assumed for the three privately owned
properties located north of Vine Drive (Subbasins 9, 11, and 14) to detain and release fully
developed 100-year flows to a 2-year historic rate. It is noted that the conceptual detention
ponds were simulated with a two-point rating curve. Conceptual detention for Subbasin 13
was not assumed per the development agreement between the City and the developer for
this property. Fully developed flows from this basin will be conveyed underneath Vine Drive
and into the water quality pond via the existing storm sewer system that was installed as part
of the Innosphere development (Subbasin 12).
COFC18.1 Drainage Report (June 6 2017).docx 15 Anderson Consulting Engineers, Inc.
• Conceptual Future Vine Drive Improvements: In order to meet stormwater criteria, a 5-foot
Type R inlet was conceptually assumed in the sump area on the n orth side of Vine Drive. Flow
collected by this inlet, along with the detained released from Subbasins 9 and 11 is
conceptually conveyed underneath Vine Drive in an 18-inch pipe. This pipe conceptually
connects to the inlet on the south side of the street and into the storm drainage system
proposed by the project. The installation of the inlet on the north side of the street will reduce
the frequency of road overtopping for events less than the 50-year.
Basin NameArea (ac) Width (ft)*OFL (ft) % Slope% Impervious (Proposed Conditions) % Impervious (Fully Developed)Description for Fully Developed ConditionB-1 2.78 1211 100 2.00 60 60Assumes 100% impervious for ponded areaB-2 3.34 1455 100 3.00 50 50 Assumes 100% impervious for ponded areaB-3 0.56 76 320 1.20 90 90B-4 0.35 152 100 0.50 90 90B-5 0.80 290 120 2.00 75 75B-6 0.33 287 50 2.00 75 75B-7 1.38 194 310 1.00 50 50 Assumes 100% impervious for ponded areaB-8 0.74 101 320 1.20 90 90B-9 4.68 371 550 1.00 45 85 Assumes property is fully developedB-10 1.50 163 400 0.90 90 90B-11 0.89 194 200 0.50 45 85 Assumes property is fully developedB-12 2.50 573 190 4.40 85 85B-13 2.77 710 170 1.00 25 85 Assumes property is fully developedB-142.514972200.502585Assumes property is fully developed*Width is calculated from area and Overland Flow Length (OFL)SWMM MODEL INPUT PARAMETERS
Basin Name Area (ac)
2-Year Peak
Runoff (cfs)
10-Year Peak
Runoff (cfs)
100-Year Peak
Runoff (cfs)
100-Year Peak
Unit
Runoff Rate
(cfs/acre)
B-1 2.78 4.8 10.5 25.6 9.2
B-2 3.34 4.8 11.1 29.3 8.8
B-3 0.56 1.2 2.3 5.2 9.3
B-4 0.35 0.8 1.6 3.4 9.8
B-5 0.80 1.7 3.4 7.7 9.6
B-6 0.33 0.7 1.5 3.3 9.8
B-7 1.38 1.8 3.6 9.2 6.6
B-8 0.74 1.5 3.0 6.9 9.3
B-9 4.68 7.5 15.7 38.3 8.2
B-10 1.50 2.8 5.6 13.2 8.8
B-11 0.89 1.8 3.5 8.1 9.1
B-12 2.50 5.9 11.5 24.6 9.9
B-13 2.77 6.2 11.9 26.6 9.6
B-14 2.51 4.9 9.8 22.7 9.0
FULLY DEVELOPED CONDITION BASIN RUNOFF RESULTS
SWMM
Element
2-Year Peak
Discharge (cfs)
10-Year Peak
Runoff (cfs)
100-Year Peak
Runoff (cfs)Description
D-6 1.8 3.5 8.1
P-17 0.8 0.9 1.1
N-7 0.8 0.9 1.1
P-16 0.8 0.9 1.1
D-5 7.5 15.7 38.3
P-15 3.1 3.9 5.0
N-6 1.5 3.0 7.3
S-3 0.0 0.0 4.2
N-14 2.8 5.6 16.6
S-4 0.0 0.0 7.3
P-14 2.8 5.6 6.7
N-13 5.3 7.0 9.4
P-13 5.3 7.0 9.4
P-7 1.5 3.0 3.0
N-5 2.7 5.3 7.0
P-6 2.7 5.1 5.7
S-2 0.0 0.0 1.0
N-4 6.0 8.6 12.6
P-5 6.0 8.6 10.2
N-3 8.7 13.7 22.5
S-1 7.7 12.3 20.1
N-2 7.7 12.3 20.1
P-4 7.5 11.6 18.5
D-1 10.7 20.8 40.1
P-3 6.8 12.3 23.2
D-4 4.9 9.8 22.7
P-12 1.2 1.4 1.8
N-12 1.2 1.4 1.8
P-11 1.2 1.4 1.8
N-11 1.7 1.7 1.9
P-10 1.3 2.1 2.1
N-10 6.2 11.9 26.6
S-6 5.5 11.4 26.0
N-9 12.0 23.7 50.9
P-9 12.0 20.1 50.9
N-8 12.0 20.1 50.9
P-8 11.8 20.1 50.9
D-3 14.2 24.4 63.3
S-5 2.8 12.9 44.0
D-2 6.5 19.4 76.0
P-2 4.1 8.1 11.4
N-1 9.6 19.3 32.4
P-1 9.6 19.3 32.4
O-1 9.6 19.3 32.4
FULLY DEVELOPED CONDITION DISCHARGE RESULTS
Western Flow PathEastern Flow PathOut-fall
COLLEGE AVENUE CACHE LA POUDRE RIVERBNSF RAILROADUNION PACIFIC RAILROAD JEROME STREETLINDEN STREET
R
E
DW
O
O
D
S
T
R
E
E
TVINE DRIVECOY DITCHCOY DITCHLAKE CANALLAKE CANALAnderson Consulting Engineers, Inc
Civil ▪ Water Resources ▪ Environmental
375 East Horsetooth Road, Building 5, Fort Collins, CO 80525
Phone (970) 226-0120 / Fax (970) 226-0121
www.acewater.com
CITY OF FORT COLLINS
POUDRE RIVER
WHITEWATER PARK
FULLY DEVELOPED
CONDITION
SUBBASIN AND
CONVEYANCE
ELEMENTS MAP2
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Area, Colorado
207-030 Powerhouse II
Natural
Resources
Conservation
Service
January 13, 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
73—Nunn clay loam, 0 to 1 percent slopes.................................................13
81—Paoli fine sandy loam, 0 to 1 percent slopes.......................................14
105—Table Mountain loam, 0 to 1 percent slopes......................................15
Soil Information for All Uses...............................................................................17
Soil Properties and Qualities..............................................................................17
Soil Qualities and Features.............................................................................17
Hydrologic Soil Group.................................................................................17
References............................................................................................................22
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
4493890449392044939504493980449401044940404494070449410044938904493920449395044939804494010449404044940704494100493480 493510 493540 493570 493600 493630 493660 493690 493720 493750 493780 493810
493480 493510 493540 493570 493600 493630 493660 493690 493720 493750 493780 493810
40° 35' 51'' N 105° 4' 37'' W40° 35' 51'' N105° 4' 23'' W40° 35' 44'' N
105° 4' 37'' W40° 35' 44'' N
105° 4' 23'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 20 40 80 120
Meters
Map Scale: 1:1,530 if printed on A landscape (11" x 8.5") 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
73 Nunn clay loam, 0 to 1 percent
slopes
3.0 30.5%
81 Paoli fine sandy loam, 0 to 1
percent slopes
0.9 8.8%
105 Table Mountain loam, 0 to 1
percent slopes
6.0 60.7%
Totals for Area of Interest 9.8 100.0%
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
Custom Soil Resource Report
11
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
12
Larimer County Area, Colorado
73—Nunn clay loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: 2tlng
Elevation: 4,100 to 5,700 feet
Mean annual precipitation: 14 to 15 inches
Mean annual air temperature: 48 to 52 degrees F
Frost-free period: 135 to 152 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Pleistocene aged alluvium and/or eolian deposits
Typical profile
Ap - 0 to 6 inches: clay loam
Bt1 - 6 to 10 inches: clay loam
Bt2 - 10 to 26 inches: clay loam
Btk - 26 to 31 inches: clay loam
Bk1 - 31 to 47 inches: loam
Bk2 - 47 to 80 inches: loam
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Medium
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:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:7 percent
Maximum salinity:Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum:0.5
Available water supply, 0 to 60 inches: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: R067BY042CO - Clayey Plains
Hydric soil rating: No
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Minor Components
Heldt
Percent of map unit:10 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY042CO - Clayey Plains
Hydric soil rating: No
Wages
Percent of map unit:5 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
81—Paoli fine sandy loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: jpxx
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
Paoli and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Paoli
Setting
Landform:Stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
H1 - 0 to 30 inches: fine sandy loam
H2 - 30 to 60 inches: fine sandy loam
Properties and qualities
Slope:0 to 1 percent
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14
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Very low
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00
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)
Available water supply, 0 to 60 inches: Moderate (about 8.7 inches)
Interpretive groups
Land capability classification (irrigated): 1
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: A
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Caruso
Percent of map unit:6 percent
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
Table mountain
Percent of map unit:6 percent
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
Fluvaquentic haplustolls
Percent of map unit:3 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.
Custom Soil Resource Report
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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)
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
Custom Soil Resource Report
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Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Hydrologic Soil Group
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
17
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Custom Soil Resource Report
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19
Custom Soil Resource Report
Map—Hydrologic Soil Group
4493890449392044939504493980449401044940404494070449410044938904493920449395044939804494010449404044940704494100493480 493510 493540 493570 493600 493630 493660 493690 493720 493750 493780 493810
493480 493510 493540 493570 493600 493630 493660 493690 493720 493750 493780 493810
40° 35' 51'' N 105° 4' 37'' W40° 35' 51'' N105° 4' 23'' W40° 35' 44'' N
105° 4' 37'' W40° 35' 44'' N
105° 4' 23'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 20 40 80 120
Meters
Map Scale: 1:1,530 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
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
20
Table—Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
73 Nunn clay loam, 0 to 1
percent slopes
C 3.0 30.5%
81 Paoli fine sandy loam, 0
to 1 percent slopes
A 0.9 8.8%
105 Table Mountain loam, 0
to 1 percent slopes
B 6.0 60.7%
Totals for Area of Interest 9.8 100.0%
Rating Options—Hydrologic Soil Group
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
21
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
22
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
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NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: Powerhouse II
FORT COLLINS | GREELEY APPENDIX
MAP POCKET
EXHIBITS AS LISTED ON TABLE OF
CONTENTS
EAST VINE DRIVENORTH COLLEGE AVENUE
LAKE CANALTVAULTF.O.VAULTF.O.F.O.CONTROLIRR CONTROLIRR
GAS/ / / / / / / // / / / / / / /GASLOT 1BRUSH MOBILEHOME P.U.D.(740 N. COLLEGE)LOT 3BRUSH MOBILEHOME P.U.D.(108 E. VINE)LOT 2BRUSH MOBILEHOME P.U.D.(704 N. COLLEGE)LOT 4(202 E. VINE)EAST VINE DRIVENORTH COLLEGE AVENUE
LAKE CANALTVAULTF.O
.VAULTF.O.F.O.CONTROLIRR CONTROLIRR
GAS/ / / / / / / // / / / / / / /GASLOT 1BRUSH MOBILEHOME P.U.D.(740 N. COLLEGE)TFTFLOT 3BRUSH MOBILEHOME P.U.D.(108 E. VINE)LOT 2BRUSH MOBILEHOME P.U.D.(704 N. COLLEGE)LOT 4(202 E. VINE)ROOFTOPCONCRETEASPHALTPAVERSSURFACEAREA (SF)% IMPERV.IMPERV.AREA (SF)8,9255,04843,18809010010040TOTALS201,281109,526TOTAL=EXISTINGP:\207-030\DWG\DRNG\207-030_DRNG-IMP.DWG
POWERHOUSE 2FORT COLLINS COLORADODESCRIPTIONEXISTING VS. PROPOSEDIMPERVIOUS AREA - BASIN ADRAWN BYC. ORTIZDATEJUNE 29th, 2022PROJECT207-030DR-ADRAWINGSCALE1"=100'GRAVEL133,1454053,258LANDSCAPE10,975008,0335,04843,1880TOTAL PERCENT IMPERVIOUS = 54%PROPOSEDROOFTOPCONCRETEPAVERSGRAVELSURFACEAREA (SF)% IMPERV.IMPERV.AREA (SF)TOTALS206,172114,855TOTAL=LANDSCAPEASPHALT39,028 35,93833,4146,44690%100%100%40%12,93440%5,17371,8460%035,12535,93833,4142,578TOTAL PERCENT IMPERVIOUS = 56%GRAVEL W/ SOLAR6,56740%2,627STORMWATER RATE FACTOR TABLEPremiseAddressSURFACEAREA (SF)% IMPERV.IMPER.AREA (SF)Lot 2704 N. COLLEGE37,7380 -Lot 3108 E. VINE12,88095 12,236Lot 4202 E. VINE 166,00660 99,604 216,62452 111,840
DVAULTCABLEDDDSTTVAULTF.O.VAULTF.O.F.O.DCONTROLIRRCONTROLIRR
GASXXOHU OHU OHUD
FESLIDMH/ / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / // / / / / / / /FESFESFESSTSTSTGASDTFTFGUGEUGEUDUDUDUDUDUDUDS11VINE DRIVECOLLEGE AVENUE
JEROME STREET JEROME STREET LLC,216 E OAK STJEROME STREET STATION LLC,742 N COLLEGE AVELMC VENTURES LLC,742 N COLLEGE AVECITY OF FORT COLLINS405 N COLLEGE AVEMORAK KAREN LLC622 N COLLEGE AVECITY OF FORT COLLINS,740 N COLLEGE AVEFORT COLLINS1432568101112co1w8w10w1179PROPERTYBOUNDARYPROPERTYBOUNDARYPROPOSED STORM LINESOUTH RAIN GARDENWQ1 - OUTLETSTRUCTUREPROPOSEDSTORM LINEEXISTINGSTORM LINEPROPOSEDSTORM LINEPROPOSEDSTORM LINEPROPOSEDSTORM LINEPROPOSEDSTORM LINEPROPOSEDSTORM LINEPROPOSED STORMINLET (TYP.)PROPOSED STORMINLET (TYP.)SOUTH RAIN GARDENNORTH RAIN GARDENDETENTION POND 1WQCV VOLUME = 0.03 AC-FTTOTAL VOLUME REQUIRED = 0.32 AC-FTMAXIMUM RELEASE RATE = 8.50 CFSOUTLET IN. EL. = 4957.00WQCV WATER SURFACE EL. = 4957.74100-YR. WATER SURFACE EL. = 4959.52FREEBOARD = 0.48 FTTOP OF BERM EL. = 4960.00EXISTINGINLET12.23 ac20.74 ac60.41 ac30.72 acW80.63 ac120.14 ac90.14 ac110.05 acCo10.42 ac80.11 ac100.03 ac40.11 ac50.14 ac70.04 acW101.50 acW110.89 acSOUTH RAIN GARDENEXISTINGSTORM LINEEXISTINGINLET100 YR FLOOD PLAIN(CURRENT EFFECTIVE)500 YR FLOOD PLAIN(CURRENT EFFECTIVE)100 YR FLOOD PLAIN(CURRENT EFFECTIVE)100 YR FLOOD PLAIN(CURRENT EFFECTIVE)500 YR FLOOD PLAIN(CURRENT EFFECTIVE)100 YR FLOOD PLAIN(CURRENT EFFECTIVE)500 YR FLOOD PLAIN(CURRENT EFFECTIVE)100 YR FLOOD PLAIN(CURRENT EFFECTIVE)500 YR FLOOD PLAIN(CURRENT EFFECTIVE)100 YR FLOOD PLAIN(CURRENT EFFECTIVE)SheetPOWERHOUSE 2
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of 16( IN FEET )1 inch = ft.Feet05050501001501.REFER TO THE PRELIMINARY DRAINAGE REPORT, DATED JUNE 29, 2022 FORADDITIONAL INFORMATION.2.PORTIONS OF THIS PROPERTY ARE LOCATED IN THE FEMA REGULATED, 100YEAR AND 500 YEAR POUDRE RIVER FLOODPLAIN. ANY DEVELOPMENT WITHINTHE FLOODPLAIN MUST COMPLY WITH THE SAFETY REGULATIONS OF CHAPTER10 OF CITY MUNICIPAL CODE.3.ANY CONSTRUCTION ACTIVITIES IN THE FLOOD FRINGE (E.G. STRUCTURES,SIDEWALK OR CURB & GUTTER INSTALLATION/REPLACEMENT, UTILITY WORK,LANDSCAPING, ETC.) MUST BE PRECEDED BY AN APPROVED FLOODPLAIN USEPERMIT, THE APPROPRIATE PERMIT APPLICATION FEES, AND APPROVED PLANS.4.CONSTRUCTION OF RESIDENTIAL AND/OR MIXED_USE STRUCTURES ISPROHIBITED IN THE POUDRE RIVER 100_YEAR FLOODPLAIN.5.OUTSIDE STORAGE OF EQUIPMENT OR FLOATABLE MATERIALS WHETHERPERMANENT OR TEMPORARY IS PROHIBITED IN THE 100_YEAR FLOODPLAIN.6.AT_RISK POPULATIONS, ESSENTIAL SERVICES, HAZARDOUS MATERIALS, ANDGOVERNMENT SERVICES CRITICAL FACILITIES ARE PROHIBITED IN THE 100_YEARFLOODPLAIN.7.THE APPLICANT ACKNOWLEDGES THAT THIS SITE DEVELOPMENT PLAN DOESNOT COMPLY WITH THE CURRENT REGULATORY FLOODPLAIN. PERMITS CANNOTBE ISSUED FOR RESIDENTIAL STRUCTURES IN THE REGULATORY FLOODPLAINUNTIL A LOMR IS APPROVED THROUGH FEMA. IT IS AT OUR OWN RISK THAT WECONTINUE THROUGH THE PLANNING PROCESSDR1DRAINAGE EXHIBIT15 NORTHSWALE SECTIONSSWALE SUMMARY TABLESWALE IDMIN DMIN TWS1 (n:1)S2 (n:1)Q1 - 10.7911.453.710.811.20PROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETADESIGN POINTFLOW ARROWDRAINAGE BASIN LABELDRAINAGE BASIN BOUNDARYPROPOSED SWALE SECTION11NOTES:ALEGEND:CALL 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)