HomeMy WebLinkAboutHANSEN FARM - PDP - PDP170036 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTSeptember 19, 2017
PRELIMINARY DRAINAGE AND
EROSION CONTROL REPORT FOR
HANSEN PROPERTY
Fort Collins, Colorado
Prepared for:
Jeff Mark
Lorson South Land Corp
212 N. Wahsatch Ave, Suite 301
Colorado Springs, CO 80903
Prepared by:
301 N. Howes, Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 911-015
This Drainage Report is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy is absolutely necessary, we recommend double-sided printing.
September 19, 2017
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report for
HANSEN PROPERTY
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report
for your review. This report accompanies the Project Development Plan submittal for the
proposed Hansen Property development.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed project. We
understand that review by the City is to assure general compliance with standardized criteria
contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Frederick S. Wegert, PE
Project Engineer
Hansen Property
Preliminary Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 3
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 4
A. Major Basin Description .................................................................................................................... 4
B. Sub-Basin Description ....................................................................................................................... 4
III. DRAINAGE DESIGN CRITERIA ................................................................................... 5
A. Regulations........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 5
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 6
F. Modifications of Criteria ................................................................................................................... 6
IV. DRAINAGE FACILITY DESIGN .................................................................................... 6
A. General Concept ............................................................................................................................... 6
B. Specific Details .................................................................................................................................. 7
V. CONCLUSIONS ........................................................................................................ 8
A. Compliance with Standards .............................................................................................................. 8
B. Drainage Concept .............................................................................................................................. 8
APPENDICES:
APPENDIX A – Hydrologic Computations
APPENDIX B - USDA Soils Information
APPENDIX C – SWMM Modeling; Detention Computations
APPENDIX D – LID Information; Water Quality Capture Volume Computations
APPENDIX E – Erosion Control Report
Hansen Property
Preliminary Drainage Report
LIST OF FIGURES:
Figure 1 -- Vicinity Map ....................................................................................................... 1
Figure 2 – Aerial Photograph ................................................................................................ 2
Figure 3– Proposed Site Plan ................................................................................................ 3
Figure 4 –Area Floodplain Mapping ....................................................................................... 4
MAP POCKET:
Proposed Drainage Exhibit
Hansen Property
Preliminary Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
Figure 1 -- Vicinity Map
2. The project site is located in the northeast quarter of Section 7, Township 6 North,
Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado.
3. The proposed development site is located northwest of the intersection of South
Timberline Road and Zephyr Road in Fort Collins, Colorado. The site is bounded to
the north by the Mail Creek Ditch, to the south and west by a lateral of the Mail Creek
Ditch, and the east by South Timberline Road.
4. The project site is in the City of Fort Collins Fossil Creek Master Drainage Basin. The
required onnsite detention is typically the runoff volume difference between the 100-
year developed inflow rate and the historic 2-year release rate. However, according to
the Overall Drainage Report for the Hansen Overall Development Plan, flows are
limited by the capacity of an existing 18” RCP storm drain just west of the
intersection of Timberline Road and Zephyr Road. Additionally the site must provide
water quality treatment. Water quality treatment methods are proposed for the site,
and are described in further detail below.
5. The area to the north, west, and southeast of the site is fully developed. The area to
the east is partially developed. The area to the immediate south is undeveloped, but
the Linden Park Subdivision is approximately 1,000 feet to the south. Zoning across
the site includes Low Density Mixed Use Neighborhood (LMN), Neighborhood
Commercial (NC), and Medium Density Mixed Use Neighborhood (MMN).
Hansen Property
Preliminary Drainage Report 2
6. Because of the Mail Creek Ditch, there are no offsite flows that impact the site.
B. Description of Property
1. The development area is roughly 69.8 net acres.
Figure 2 – Aerial Photograph
2. The subject property is currently composed of irrigated farmland, with ground cover
consisting of grass. Existing ground slopes are mild to moderate (i.e., 1 - 3±%)
through the interior of the property. General topography slopes from the exterior of
the property towards a depressed area in the center.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey website:
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx,
the site consists of Nunn clay loam and Caruso clay loam, which fall into Hydrologic
Soil Groups C and D, respectively.
4. The proposed project site plan is composed of the development of single-family
homes; multi-family apartment in the north-central of the site and towards the east;
and commercial buildings towards southeast. Associated site work, water, and sewer
lines will be constructed with the development. Onsite detention water quality
treatment is proposed and will consist of several features which are discussed in
Section IV, below.
Hansen Property
Preliminary Drainage Report 3
Figure 3– Proposed Site Plan
5. There are no known irrigation laterals crossing the site, but the Mail Creek Ditch
bounds the site to the north, and an irrigation lateral bounds the site to the south.
6. The proposed land use is single-family homes; multi-family apartment in the north-
central of the site and towards the east; and commercial buildings towards southeast
C. Floodplain
1. According to the Overall Drainage Report for the Hansen Overall Development Plan,
the project site is not encroached by any floodplains
2. A 50’ natural habitat buffer along the Mail Creek Ditch and the irrigation lateral to the
south exists on the site. All drainage improvements will be located outside this 50’
natural habitat buffer.
Hansen Property
Preliminary Drainage Report 4
Figure 4 –Area Floodplain Mapping
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site is in the City of Fort Collins Fossil Creek Master Basin. Detention
requirements for this basin are to detain the difference between the 100-year
developed inflow rate and the historic 2-year release rate, specified as 0.20 cfs/ac.
2. However, outflow from this property is limited by an existing 18” RCP storm drain just
west of the Timberline Road and Zephyr Road intersection. The existing 18” RCP
storm drain and Basins A and B of the Final Drainage Report for The Timbers PD
prepared by TST, Inc. was included in the attached SWMM model (see Appendix C).
According to the SWMM Model, the peak discharge from the proposed ponds for the
Hansen Property will occur 2 hours after the peak from The Timbers PD. Therefore,
the outflow from the Hansen Property is limited to 10 cfs by the capacity of the
existing 18” RCP storm drain and City of Fort Collins criteria.
B. Sub-Basin Description
1. The subject property historically drains towards the east side of the of the property at
a low point in Timberline Road.
2. A more detailed description of the project drainage patterns is provided below.
Hansen Property
Preliminary Drainage Report 5
III. DRAINAGE DESIGN CRITERIA
A. Regulations
There are no optional provisions outside of the FCSCM proposed with the proposed
project.
B. Four Step Process
The overall stormwater management strategy employed with the proposed project utilizes
the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters.
The following is a description of how the proposed development has incorporated each
step.
Step 1 – Employ Runoff Reduction Practices
Several techniques have been utilized with the proposed development to facilitate the
reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the
current use by implementing multiple Low Impact Development (LID) strategies including:
Conserving existing amenities in the site including the existing vegetated areas.
Providing vegetated open areas throughout the site to reduce the overall impervious
area and to minimize directly connected impervious areas (MDCIA).
Routing flows, to the extent feasible, through vegetated swales to increase time of
concentration, promote infiltration and provide initial water quality.
Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with
Slow Release
The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban
development of this intensity will still generate stormwater runoff that will require
additional BMPs and water quality. The majority of stormwater runoff from the site will
ultimately be intercepted and treated using detention and LID treatment methods prior to
exiting the site.
Step 3 – Stabilize Drainageways
There are no major drainageways within the subject property. While this step may not
seem applicable to proposed development, the project indirectly helps achieve stabilized
drainageways nonetheless. By providing water quality treatment, where none previously
existed, sediment with erosion potential is removed from downstream drainageway
systems. Furthermore, this project will pay one-time stormwater development fees, as
well as ongoing monthly stormwater utility fees, both of which help achieve City-wide
drainageway stability.
Step 4 – Implement Site Specific and Other Source Control BMPs.
The proposed project will improve upon site specific source controls compared to historic
conditions:
The proposed development will provide LID and water quality treatment; thus,
eliminating sources of potential pollution previously left exposed to weathering and
runoff processes.
C. Development Criteria Reference and Constraints
The subject property is surrounded by currently developed properties. Thus, several
constraints have been identified during the course of this analysis that will impact the
proposed drainage system including:
Hansen Property
Preliminary Drainage Report 6
Existing elevations along the property lines will generally be maintained.
As previously mentioned, overall drainage patterns of the existing site will be
maintained.
Elevations of existing downstream facilities that the subject property will release to
will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above, the subject property is not located in a City designated floodplain.
The proposed project does not propose to modify any natural drainageways.
F. Modifications of Criteria
1. The proposed development is not requesting any modifications to criteria at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of the project drainage design are to maintain existing drainage
patterns, and to ensure no adverse impacts to any adjacent properties.
2. LID treatment will be provided in pre-treatment areas upstream of detention ponds for
Basin 1. Multi-family and commercial areas within Basins 2, 3, and 4 will be
required to provide their own site-specific LID treatment prior to discharging into the
detention ponds. Thus, the “treatment train” philosophy will be followed, with
stormwater treatment occurring through a variety of in-series methods prior to
ultimate discharge into the Fossil Creek drainageway.
3. Drainage patterns anticipated for drainage basins shown in the Drainage Exhibit are
described below. Drainage basins have been defined for preliminary design purposes
Hansen Property
Preliminary Drainage Report 7
and are subject to change at Final design; however, general drainage patterns and
concepts are not expected to be significantly altered.
Basins 1A to 1M (Detention Pond 1)
Basins 1A to 1E and 1H to 1M consist of single-family homes, local streets, and
landscaped areas. Basins 1A, 1F and 1G consist of multi-family apartments, parking
lots, and landscaped areas. These basins will generally drain via overland flow and
street curb and gutter first into the proposed LID features as shown on the Drainage
Exhibit, and ultimately into Detention Pond 1.
Basin 2A to 2E (Detention Pond 2A)
Basins 2A, 2B, 2C, and 2D consist of single-family homes, local streets, and
landscaped areas. Basins 2C, 2B and 2E consist of multi-family apartments, parking
lots, and landscaped area. These basins will generally drain via overland flow and
street and parking lot curb and gutter into Detention Pond 2A. Surface runoff from the
rear of the single-family lots will flow across grassy open space prior to Detention
Pond 2A.
Basins 2F to 2J (Detention Pond 2B)
Basins 2F, 2G, and 2J consist of apartment complex areas, parking, and landscaped
areas. Basin 2H consists of a proposed neighborhood park. We anticipate some form
of LID pre-treatment and onsite detention for Basin 2, when this basin develops in the
future. These basins will generally drain via overland flow and street and parking lot
curb and gutter into Detention Pond 2B.
Basin 3 (Detention Pond 3)
Basin 3 is anticipated to be developed in the future in accordance to the
Neighborhood Commercial (NC) zoning requirements. We anticipate some form of LID
pre-treatment and onsite detention for Basin 3, when this basin develops in the future.
If the discharge from Detention Pond 3 increases the total discharge from Ponds 1,
2A, 2B, and 3 beyond 9.99 cfs, then the developer for Basin 3 would need to
demonstrate the additional flows do not exceed the capacity of the existing 18” RCP
at the intersection of Timberline Road and Zephyr Road.
Basin 4 (Detention Pond 4)
Basin 4 is anticipated to be developed in the future in accordance to the
Neighborhood Commercial (NC) zoning requirements. We anticipate some form of LID
pre-treatment and onsite detention for Basin 4, when this basin develops in the future.
The development of Basin 4 will be required to negotiate with neighboring property
owners for a drainage easement to discharge stormwater.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report.
B. Specific Details
1. Five detention ponds are proposed within the site and will detain up to the
100-year storm event and release at or below the allowable (for Fossil Creek
Basin) runoff rate of 0.20 cfs per acre. The ponds have been modeled utilizing
the computer program EPA SWMM 5.1. Please see SWMM modeling results
provided in Table 1, below, and SWMM modeling output provided in Appendix
C.
Hansen Property
Preliminary Drainage Report 8
2. LID pre-treatment involving rain gardens are currently proposed in this
preliminary design to treat storm runoff prior to discharging into proposed
detention ponds. The proposed design intends to provide a “treatment train”
of LID pre-treatment features prior to discharge into Detention Pond 1. We
anticipate the mutli-family and commercial sites zoned as MMF and NC will
be required to provide site-specific LID treatment. We intend to meet or
exceed the LID treatment requirement of 75% of new impervious area. Please
see the Drainage Exhibit for locations of proposed LID treatment features.
3. Please see preliminary LID information and Water Quality Capture Volume
(Extended Detention) computations provided in Appendix D.
Table 1 - SWMM Modeling Output and Detention Volume Summary
Pond ID
Pond Volume
(CF)
Pond Volume
(AC-FT)
Peak Release
(CFS)
1 342,553 7.86 1.45
2A 52,112 1.20 0.86
2B 70,232 1.61 6.58
3 35,174 0.81 1.10
4 34,498 0.79 0.59
4. Final design details, and construction documentation shall be provided to the
City of Fort Collins for review prior to Final Development Plan approval.
5. Stormwater facility Standard Operating Procedures (SOP) will be provided by
the City of Fort Collins in the Development Agreement.
V. CONCLUSIONS
A. Compliance with Standards
1. The drainage design proposed with the proposed project complies with the City of Fort
Collins’ Stormwater Criteria Manual.
2. The drainage design proposed with this project complies with requirements for Fossil
Creek Basin.
3. The drainage plan and stormwater management measures proposed with the
proposed development are compliant with all applicable State and Federal regulations
governing stormwater discharge.
B. Drainage Concept
1. The drainage design proposed with this project will effectively limit any potential
damage associated with its stormwater runoff by providing detention and water
quality mitigation features.
2. The drainage concept for the proposed development is consistent with requirements
for the Fossil Creek Basin.
Hansen Property
Preliminary Drainage Report 9
References
1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
2. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
4. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
5. Final Drainage Report for The Timbers PD, TST, Inc.; Fort Collins, Colorado, June 28, 2002.
6. Overall Drainage Report for Hansen Overall Development Plan, Northern Engineering; Fort
Collins, Colorado, August 29, 2017.
Hansen Property
Preliminary Erosion Control Report
APPENDIX A
HYDROLOGIC COMPUTATIONS
Hansen Development
Runoff
Coefficient
1
Percentage
Impervious
2
Project:
LMN Zoning 0.55 60% Calculations By:
MMN Zoning 0.65 70% Date:
NC Zoning 0.95 90%
Asphalt ………………… ................... .............................................................................. ....................... 0.95 100%
Concrete ………………. ................... .............................................................................. ....................... 0.95 90%
Gravel (packed) ………. ................... .............................................................................. ....................... 0.50 40%
Roofs………………….. ................... .............................................................................. ....................... 0.95 90%
Pavers…………………. ................... .............................................................................. ....................... 0.40 22%
Undeveloped
Open Lands, Transition ................... .............................................................................. ....................... 0.20 2%
Greenbelts, Agriculture ................... .............................................................................. ....................... 0.20 2% 2-year C
f
= 1.00 10-year C
f
= 1.00
USDA SOIL TYPE: C
Sub-Basin ID
Sub-Basin
Area
(sq. ft.)
Sub-Basin
Area
(ac.)
Area of
Asphalt
(ac.)
Area of
Roofs
(ac.)
Area of SF
Homes
3
(ac.)
Area of
Landscaping
2% to 7%
(ac)
Area of
MMN
(ac.)
Area of
NC
(ac.)
2-year
Composite
Runoff
Coefficient
10-year
Composite Runoff
Coefficient
100-year
Composite
Hansen Development
Project: Hansen
Calculations By:
Date:
Is Length
>500' ?
C*C
f
(2-yr
C
f
=1.00)
C*C
f
(10-yr
C
f
=1.00)
C*C
f
(100-yr
C
f
=1.25)
Length,
L
(ft)
Up Stream
Elevation
Down
Stream
Elevation
Slope,
S
(%)
T
i
2-yr
(min)
T
i
10-yr
(min)
T
i
100-yr
(min)
Length,
L
(ft)
Up Stream
Elevation
Down
Stream
Elevation
Slope,
S
(%)
Velocity,
V
Hansen Development
Project:
Calculations By:
Date:
h1 H1 65.01 58 58 57 0.20 0.20 0.25 0.84 1.43 2.98 10.92 0.17 18.59 48.35
h3 H3 1.71 19 19 18 0.24 0.24 0.30 1.65 2.82 6.01 0.68 0.40 1.17 3.10
h4 H4 3.08
26 26 25 0.20 0.20 0.25 1.40 2.39 4.98 0.86 0.28 1.47 3.83
September 19, 2017
Flow/Acre,
Q
2
(cfs/acre)
Intensity,
i
10
(in/hr)
C
10
Area, A
(acres)
Intensity,
i
2
(in/hr)
100-yr
T
c
(min)
F. Wegert
Hansen
HISTORIC RUNOFF COMPUTATIONS
C
100
Design
Point
Flow,
Q
100
(cfs)
Flow,
Q
2
(cfs)
10-yr
T
c
(min)
2-yr
T
c
(min)
C
2
Flow,
Q
10
(cfs)
Intensity,
i
Hansen Development
Runoff
Coefficient
1
Percentage
Impervious
2
Project:
LMN Zoning 0.55 60% Calculations By:
MMN Zoning 0.65 70% Date:
NC Zoning 0.95 90%
Asphalt ………………… ................... .............................................................................. ....................... 0.95 100%
Concrete ………………. ................... .............................................................................. ....................... 0.95 90%
Gravel (packed) ………. ................... .............................................................................. ....................... 0.50 40%
Roofs………………….. ................... .............................................................................. ....................... 0.95 90%
Pavers…………………. ................... .............................................................................. ....................... 0.40 22%
Lawns and Landscaping
Sandy Soil
Flat <2% ………….. ................... .............................................................................. ....................... 0.10 0%
Average 2% to 7% ................... .............................................................................. ....................... 0.15 0%
Steep >7% ………… ................... .............................................................................. ....................... 0.20 0%
Clayey Soil
Flat <2% ………….. ................... .............................................................................. ....................... 0.20 0%
Average 2% to 7% ................... .............................................................................. ....................... 0.25 0%
Steep >7% ………… ................... .............................................................................. ....................... 0.35 0% 2-year C
f
= 1.00 10-year C
f
= 1.00
USDA SOIL TYPE: C
Sub-Basin ID
Sub-Basin
Area
(sq. ft.)
Sub-Basin
Area
(ac.)
Area of
Asphalt
(ac.)
Area of
Roofs
(ac.)
Area of SF
Homes
3
(ac.)
Area of
Landscaping
2% to 7%
(ac)
Area of
MMN
(ac.)
Area of
NC
(ac.)
2-year
Composite
Runoff
Hansen Development
Runoff
Coefficient
1
Percentage
Impervious
2
Project:
LMN Zoning 0.55 60% Calculations By:
MMN Zoning 0.65 70% Date:
NC Zoning 0.95 90%
Asphalt ………………… ................... .............................................................................. ....................... 0.95 100%
Concrete ………………. ................... .............................................................................. ....................... 0.95 90%
Gravel (packed) ………. ................... .............................................................................. ....................... 0.50 40%
Roofs………………….. ................... .............................................................................. ....................... 0.95 90%
Pavers…………………. ................... .............................................................................. ....................... 0.40 22%
Lawns and Landscaping
Sandy Soil
Flat <2% ………….. ................... .............................................................................. ....................... 0.10 0%
Average 2% to 7% ................... .............................................................................. ....................... 0.15 0%
Steep >7% ………… ................... .............................................................................. ....................... 0.20 0%
Clayey Soil
Flat <2% ………….. ................... .............................................................................. ....................... 0.20 0%
Average 2% to 7% ................... .............................................................................. ....................... 0.25 0%
Steep >7% ………… ................... .............................................................................. ....................... 0.35 0% 2-year C
f
= 1.00 10-year C
f
= 1.00
USDA SOIL TYPE: C
Sub-Basin ID
Sub-Basin
Area
(sq. ft.)
Sub-Basin
Area
(ac.)
Area of
Asphalt
(ac.)
Area of
Roofs
(ac.)
Area of SF
Homes
3
(ac.)
Area of
Landscaping
2% to 7%
(ac)
Area of
MMN
(ac.)
Area of
NC
(ac.)
2-year
Composite
Runoff
Hansen Development
Project: Hansen
Calculations By:
Date:
Is Length
>500' ?
C*C
f
(2-yr
C
f
=1.00)
C*C
f
(10-yr
C
f
=1.00)
C*C
f
(100-yr
C
f
=1.25)
Length,
L
(ft)
Up Stream
Elevation
Down
Stream
Elevation
Slope,
S
(%)
T
i
2-yr
(min)
T
i
10-yr
(min)
T
i
100-yr
(min)
Length,
L
(ft)
Up Stream
Elevation
Down
Stream
Elevation
Slope,
S
(%)
Velocity,
V
Hansen Development
Project:
Calculations By:
Date:
1a 1A 10.99 14 14 13 0.45 0.45 0.57 1.95 3.34 7.04 9.71 16.63 43.82
1b 1B 0.44 10 10 8 0.54 0.54 0.68 2.21 3.78 8.38 0.53 0.91 2.53
1c 1C 1.56 9 9 7 0.79 0.79 0.99 2.30 3.93 9.06 2.84 4.86 14.00
1d 1D 1.06 11 11 8 0.61 0.61 0.76 2.17 3.71 8.59 1.39 2.38 6.90
1e 1E 8.14 25 25 23 0.58 0.58 0.72 1.43 2.44 5.26 6.71 11.45 30.84
1f 1F 2.27 14 14 13 0.57 0.57 0.71 1.92 3.29 7.04 2.48 4.26 11.39
1g 1G 2.35 12 12 9 0.81 0.81 1.00 2.09 3.57 8.21 3.95 6.75 19.26
1h 1H 9.81 25 25 22 0.56 0.56 0.70 1.45 2.47 5.32 7.99 13.63 36.78
1j 1J 1.04 5 5 5 0.70 0.70 0.88 2.85 4.87 9.95 2.09 3.57 9.13
1k 1K 0.75 9 9 7 0.55 0.55 0.69 2.35 4.02 9.06 0.97 1.66 4.67
1l 1L 2.85 6 6 5 0.65 0.65 0.82 2.67 4.56 9.95 4.97 8.49 23.15
1m 1M 3.21 14 14 11 0.65 0.65 0.81 1.95 3.34 7.57 4.08 6.98 19.78
2a 2A 2.85 12 12 11 0.37 0.37 0.47 2.09 3.57 7.57 2.23 3.81 10.11
2b 2B 1.32 9 9 7 0.75 0.75 0.93 2.30 3.93 9.06 2.27 3.87 11.15
2c 2C 1.38 21 21 15 0.59 0.59 0.74 1.59 2.71 6.52 1.29 2.20 6.62
2d 2D 0.54 6 6 5 0.83 0.83 1.00 2.76 4.72 9.95 1.24 2.11 5.34
2e 2E 0.80 11 11 6 0.72 0.72 0.90 2.17 3.71 9.31 1.25 2.13 6.70
2f 2F 4.65 12 12 7 0.69 0.69 0.86 2.05 3.50 8.80 6.59 11.25 35.35
2g 2G 2.54 14 14 9 0.68 0.68 0.85 1.95 3.34 8.03 3.37 5.78 17.37
2h 2H 3.92 20 20 19 0.32 0.32 0.40 1.61 2.74 5.84 2.04 3.47 9.23
2j 2J 0.87 11 11 6 0.79 0.79 0.98 2.17 3.71 9.31 1.49 2.54 7.98
3 3 3.35 5 5 5 0.95 0.95 1.00 2.85 4.87 9.95 9.08 15.52 33.37
4 4 3.10
7 7 5 0.95 0.95 1.00 2.60 4.44 9.95 7.63 13.04 30.80
F. Wegert
Hansen
PROPOSED RUNOFF COMPUTATIONS
C
100
Design
Point
Flow,
Q
100
(cfs)
Flow,
Q
2
(cfs)
10-yr
T
c
(min)
2-yr
T
c
(min)
C
2
Flow,
Q
10
(cfs)
Intensity,
i
100
Hansen Property
Preliminary Erosion Control Report
APPENDIX B
WATER WAWAUSDA SOILS REPORT
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Natural Area, Colorado
Resources
Conservation
Service
September 12, 2017
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface.................................................................................................................... 2
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...................................................................... 14
5—Aquepts, loamy......................................................................................14
22—Caruso clay loam, 0 to 1 percent slope............................................... 15
34—Fort Collins loam, 0 to 1 percent slopes.............................................. 16
35—Fort Collins loam, 0 to 3 percent slopes.............................................. 17
36—Fort Collins loam, 3 to 5 percent slopes.............................................. 19
37—Fort Collins loam, 5 to 9 percent slopes.............................................. 20
55—Kim loam, 5 to 9 percent slopes.......................................................... 21
63—Longmont clay, 0 to 3 percent slopes.................................................. 23
73—Nunn clay loam, 0 to 1 percent slopes.................................................24
74—Nunn clay loam, 1 to 3 percent slopes.................................................25
76—Nunn clay loam, wet, 1 to 3 percent slopes.........................................27
79—Otero sandy loam, 5 to 9 percent slopes.............................................28
Soil Information for All Uses...............................................................................30
Soil Properties and Qualities.............................................................................. 30
Soil Qualities and Features.............................................................................30
Hydrologic Soil Group................................................................................. 30
References............................................................................................................35
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
4483300 4483400 4483500 4483600 4483700 4483800 4483900 4484000 4484100 4484200 4484300 4484400 4484500
4483300 4483400 4483500 4483600 4483700 4483800 4483900 4484000 4484100 4484200 4484300 4484400 4484500
495900 496000 496100 496200 496300 496400 496500 496600 496700
495900 496000 496100 496200 496300 496400 496500 496600 496700
40° 30' 41'' N
105° 2' 58'' W
40° 30' 41'' N
105° 2' 16'' W
40° 29' 58'' N
105° 2' 58'' W
40° 29' 58'' N
105° 2' 16'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 50 100 200 300
Meters
Map Scale: 1:6,420 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
5 Aquepts, loamy 15.4 8.8%
22 Caruso clay loam, 0 to 1
percent slope
4.0 2.3%
34 Fort Collins loam, 0 to 1 percent
slopes
1.9 1.1%
35 Fort Collins loam, 0 to 3 percent
slopes
8.6 4.9%
36 Fort Collins loam, 3 to 5 percent
slopes
30.9 17.6%
37 Fort Collins loam, 5 to 9 percent
slopes
1.1 0.6%
55 Kim loam, 5 to 9 percent slopes 4.4 2.5%
63 Longmont clay, 0 to 3 percent
slopes
6.6 3.8%
73 Nunn clay loam, 0 to 1 percent
slopes
23.5 13.4%
74 Nunn clay loam, 1 to 3 percent
slopes
67.6 38.5%
76 Nunn clay loam, wet, 1 to 3
percent slopes
3.8 2.2%
79 Otero sandy loam, 5 to 9
percent slopes
7.7 4.4%
Totals for Area of Interest 175.6 100.0%
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.
Custom Soil Resource Report
11
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
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
Custom Soil Resource Report
12
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
13
Larimer County Area, Colorado
5—Aquepts, loamy
Map Unit Setting
National map unit symbol: jpws
Elevation: 4,500 to 6,700 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 39 to 50 degrees F
Frost-free period: 80 to 140 days
Farmland classification: Not prime farmland
Map Unit Composition
Aquepts and similar soils: 80 percent
Minor components: 20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Aquepts
Setting
Landform: Depressions, draws, stream terraces
Landform position (three-dimensional): Base slope, tread, dip
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Loamy alluvium
Typical profile
H1 - 0 to 60 inches: variable
Properties and qualities
Slope: 0 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Very poorly drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
very high (0.60 to 99.90 in/hr)
Depth to water table: About 6 to 18 inches
Frequency of flooding: Rare
Frequency of ponding: None
Interpretive groups
Land capability classification (irrigated): 5w
Land capability classification (nonirrigated): 3w
Hydrologic Soil Group: A/D
Hydric soil rating: Yes
Minor Components
Fort collins
Percent of map unit: 5 percent
Hydric soil rating: No
Nunn
Percent of map unit: 5 percent
Hydric soil rating: No
Custom Soil Resource Report
14
Stoneham
Percent of map unit: 5 percent
Hydric soil rating: No
Kim
Percent of map unit: 5 percent
Hydric soil rating: No
22—Caruso clay loam, 0 to 1 percent slope
Map Unit Setting
National map unit symbol: jpvt
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Caruso and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Caruso
Setting
Landform: Flood-plain steps, stream terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium
Typical profile
H1 - 0 to 35 inches: clay loam
H2 - 35 to 44 inches: fine sandy loam, sandy loam
H2 - 35 to 44 inches: sand, gravelly sand
H3 - 44 to 60 inches:
H3 - 44 to 60 inches:
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Somewhat poorly drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: About 24 to 48 inches
Frequency of flooding: Occasional
Frequency of ponding: None
Calcium carbonate, maximum in profile: 5 percent
Custom Soil Resource Report
15
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: High (about 9.8 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: D
Hydric soil rating: No
Minor Components
Loveland
Percent of map unit: 9 percent
Landform: Terraces
Hydric soil rating: Yes
Fluvaquents
Percent of map unit: 6 percent
Landform: Terraces
Hydric soil rating: Yes
34—Fort Collins loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: jpw7
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Terraces, fans
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 8 inches: loam
H2 - 8 to 18 inches: loam, clay loam
H2 - 8 to 18 inches: loam, silt loam, fine sandy loam
H3 - 18 to 60 inches:
Custom Soil Resource Report
16
H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Very high (about 26.0 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Stoneham
Percent of map unit: 6 percent
Hydric soil rating: No
Larim
Percent of map unit: 5 percent
Hydric soil rating: No
Ascalon
Percent of map unit: 4 percent
Hydric soil rating: No
35—Fort Collins loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlnc
Elevation: 4,020 to 6,730 feet
Mean annual precipitation: 14 to 16 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 143 to 154 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils: 85 percent
Custom Soil Resource Report
17
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Interfluves
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Pleistocene or older alluvium derived from igneous, metamorphic
and sedimentary rock and/or eolian deposits
Typical profile
Ap - 0 to 4 inches: loam
Bt1 - 4 to 9 inches: clay loam
Bt2 - 9 to 16 inches: clay loam
Bk1 - 16 to 29 inches: loam
Bk2 - 29 to 80 inches: loam
Properties and qualities
Slope: 0 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.20 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 12 percent
Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4c
Hydrologic Soil Group: C
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit: 10 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
Vona
Percent of map unit: 5 percent
Landform: Interfluves
Landform position (two-dimensional): Backslope, footslope
Landform position (three-dimensional): Side slope, base slope
Custom Soil Resource Report
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Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Sandy Plains (R067BY024CO)
Hydric soil rating: No
36—Fort Collins loam, 3 to 5 percent slopes
Map Unit Setting
National map unit symbol: jpw9
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Terraces, fans
Landform position (three-dimensional): Base slope, riser
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 9 inches: loam
H2 - 9 to 20 inches: loam, clay loam
H2 - 9 to 20 inches: loam, silt loam, fine sandy loam
H3 - 20 to 60 inches:
H3 - 20 to 60 inches:
H3 - 20 to 60 inches:
Properties and qualities
Slope: 3 to 5 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Custom Soil Resource Report
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Available water storage in profile: Very high (about 25.5 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Ascalon
Percent of map unit: 5 percent
Hydric soil rating: No
Kim
Percent of map unit: 3 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 2 percent
Hydric soil rating: No
37—Fort Collins loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jpwb
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Fort collins and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Terraces, fans
Landform position (three-dimensional): Base slope, riser
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 6 inches: loam
H2 - 6 to 18 inches: loam, clay loam
H2 - 6 to 18 inches: loam, silt loam, fine sandy loam
H3 - 18 to 60 inches:
Custom Soil Resource Report
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H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
Properties and qualities
Slope: 5 to 9 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Very high (about 26.4 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Larimer
Percent of map unit: 8 percent
Hydric soil rating: No
Kim
Percent of map unit: 4 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 3 percent
Hydric soil rating: No
55—Kim loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jpwz
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Farmland of local importance
Map Unit Composition
Kim and similar soils: 85 percent
Custom Soil Resource Report
21
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform: Fans
Landform position (three-dimensional): Base slope, side slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium
Typical profile
H1 - 0 to 7 inches: loam
H2 - 7 to 60 inches: loam, clay loam, sandy clay loam
H2 - 7 to 60 inches:
H2 - 7 to 60 inches:
Properties and qualities
Slope: 5 to 9 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 26.5 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Thedalund
Percent of map unit: 10 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 5 percent
Hydric soil rating: No
Custom Soil Resource Report
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63—Longmont clay, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpx8
Elevation: 4,800 to 5,800 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 and reclaimed of excess salts
and sodium
Map Unit Composition
Longmont and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Longmont
Setting
Landform: Flood plains, valleys
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Clayey alluvium derived from shale
Typical profile
H1 - 0 to 60 inches: clay
Properties and qualities
Slope: 0 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Poorly drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: About 24 to 30 inches
Frequency of flooding: Occasional
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Gypsum, maximum in profile: 5 percent
Salinity, maximum in profile: Slightly saline to strongly saline (4.0 to 16.0
mmhos/cm)
Sodium adsorption ratio, maximum in profile: 20.0
Available water storage in profile: Moderate (about 8.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: D
Ecological site: Salt Meadow (R067BY035CO)
Custom Soil Resource Report
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Hydric soil rating: No
Minor Components
Dacono
Percent of map unit: 5 percent
Hydric soil rating: No
Aquolls
Percent of map unit: 5 percent
Landform: Swales
Hydric soil rating: Yes
Heldt
Percent of map unit: 5 percent
Hydric soil rating: No
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
Custom Soil Resource Report
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Natural 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 in profile: 7 percent
Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
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: Clayey Plains (R067BY042CO)
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: Loamy Plains (R067BY002CO)
Hydric soil rating: No
74—Nunn clay loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlpl
Elevation: 3,900 to 5,840 feet
Mean annual precipitation: 13 to 17 inches
Mean annual air temperature: 50 to 54 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Custom Soil Resource Report
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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 9 inches: clay loam
Bt - 9 to 13 inches: clay loam
Btk - 13 to 25 inches: clay loam
Bk1 - 25 to 38 inches: clay loam
Bk2 - 38 to 80 inches: clay loam
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural 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 in profile: 7 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.1 to 2.0
mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.9 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
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: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Custom Soil Resource Report
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Satanta
Percent of map unit: 5 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
76—Nunn clay loam, wet, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpxq
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
Nunn, wet, and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn, Wet
Setting
Landform: Alluvial fans, stream terraces
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 10 inches: clay loam
H2 - 10 to 47 inches: clay loam, clay
H2 - 10 to 47 inches: clay loam, loam, gravelly sandy loam
H3 - 47 to 60 inches:
H3 - 47 to 60 inches:
H3 - 47 to 60 inches:
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Somewhat poorly drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.60 in/hr)
Depth to water table: About 24 to 36 inches
Frequency of flooding: Rare
Custom Soil Resource Report
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Frequency of ponding: None
Calcium carbonate, maximum in profile: 10 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Very high (about 19.8 inches)
Interpretive groups
Land capability classification (irrigated): 2w
Land capability classification (nonirrigated): 3s
Hydrologic Soil Group: C
Hydric soil rating: No
Minor Components
Heldt
Percent of map unit: 6 percent
Hydric soil rating: No
Dacono
Percent of map unit: 3 percent
Hydric soil rating: No
Mollic halaquepts
Percent of map unit: 1 percent
Landform: Swales
Hydric soil rating: Yes
79—Otero sandy loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jpxt
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: Not prime farmland
Map Unit Composition
Otero and similar soils: 80 percent
Minor components: 20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Otero
Setting
Landform: Fans
Landform position (three-dimensional): Base slope, side slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium and/or eolian deposits
Custom Soil Resource Report
28
Typical profile
H1 - 0 to 14 inches: sandy loam
H2 - 14 to 60 inches: sandy loam, fine sandy loam, loamy very fine sand
H2 - 14 to 60 inches:
H2 - 14 to 60 inches:
Properties and qualities
Slope: 5 to 9 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Somewhat excessively drained
Runoff class: 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 in profile: 5 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 15.4 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: A
Ecological site: Sandy Plains (R067BY024CO)
Hydric soil rating: No
Minor Components
Kim
Percent of map unit: 9 percent
Hydric soil rating: No
Nelson
Percent of map unit: 6 percent
Hydric soil rating: No
Tassel
Percent of map unit: 5 percent
Hydric soil rating: No
Custom Soil Resource Report
29
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.
30
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
31
32
Custom Soil Resource Report
Map—Hydrologic Soil Group
4483300 4483400 4483500 4483600 4483700 4483800 4483900 4484000 4484100 4484200 4484300 4484400 4484500
4483300 4483400 4483500 4483600 4483700 4483800 4483900 4484000 4484100 4484200 4484300 4484400 4484500
495900 496000 496100 496200 496300 496400 496500 496600 496700
495900 496000 496100 496200 496300 496400 496500 496600 496700
40° 30' 41'' N
105° 2' 58'' W
40° 30' 41'' N
105° 2' 16'' W
40° 29' 58'' N
105° 2' 58'' W
40° 29' 58'' N
105° 2' 16'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 50 100 200 300
Meters
Map Scale: 1:6,420 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil 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
Table—Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
5 Aquepts, loamy A/D 15.4 8.8%
22 Caruso clay loam, 0 to 1
percent slope
D 4.0 2.3%
34 Fort Collins loam, 0 to 1
percent slopes
B 1.9 1.1%
35 Fort Collins loam, 0 to 3
percent slopes
C 8.6 4.9%
36 Fort Collins loam, 3 to 5
percent slopes
B 30.9 17.6%
37 Fort Collins loam, 5 to 9
percent slopes
B 1.1 0.6%
55 Kim loam, 5 to 9 percent
slopes
B 4.4 2.5%
63 Longmont clay, 0 to 3
percent slopes
D 6.6 3.8%
73 Nunn clay loam, 0 to 1
percent slopes
C 23.5 13.4%
74 Nunn clay loam, 1 to 3
percent slopes
C 67.6 38.5%
76 Nunn clay loam, wet, 1 to
3 percent slopes
C 3.8 2.2%
79 Otero sandy loam, 5 to 9
percent slopes
A 7.7 4.4%
Totals for Area of Interest 175.6 100.0%
Rating Options—Hydrologic Soil Group
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
34
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
35
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
36
Hansen Property
Preliminary Erosion Control Report
APPENDIX C
SWMM Modeling; Detention Computations
Project: 911-015
Date: 9/19/2017
By: FSW
Pond ID
Pond Volume
(CF)
Pond Volume
(AC-FT)
Peak Release
(CFS)
1 82,920 1.90 0.79
2A 11,456 0.26 0.50
2B 16,998 0.39 2.79
3 11,186 0.26 0.44
4 11,110 0.26 0.24
Project: 911-015
Date: 9/19/2017
By: FSW
Pond ID
Pond Volume
(CF)
Pond Volume
(AC-FT)
Peak Release
(CFS)
1 342,553 7.86 1.45
2A 52,112 1.20 0.86
2B 70,232 1.61 6.58
3 35,174 0.81 1.10
4 34,498 0.79 0.59
SWMM Detention Summary (5-YR)
SWMM Detention Summary (100-YR)
Hansen PDP 100‐yr.rpt
EPA STORM WATER MANAGEMENT MODEL ‐ VERSION 5.1 (Build 5.1.012)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
*********************************************************
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
*********************************************************
****************
Analysis Options
****************
Flow Units ............... CFS
Process Models:
Rainfall/Runoff ........ YES
RDII ................... NO
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... YES
Ponding Allowed ........ NO
Water Quality .......... NO
Infiltration Method ...... HORTON
Flow Routing Method ...... KINWAVE
Starting Date ............ 03/15/2016 00:00:00
Ending Date .............. 03/20/2016 06:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:05:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 00:30:00
Routing Time Step ........ 15.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre‐feet inches
************************** ‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐
Page 1
Hansen PDP 100‐yr.rpt
Total Precipitation ...... 25.794 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 8.166 1.162
Surface Runoff ........... 17.375 2.472
Final Storage ............ 0.374 0.053
Continuity Error (%) ..... ‐0.467
************************** Volume Volume
Flow Routing Continuity acre‐feet 10^6 gal
************************** ‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 17.375 5.662
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 17.352 5.655
Flooding Loss ............ 0.000 0.000
Evaporation Loss ......... 0.000 0.000
Exfiltration Loss ........ 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 0.012 0.004
Continuity Error (%) ..... 0.062
********************************
Highest Flow Instability Indexes
********************************
All links are stable.
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 15.00 sec
Average Time Step : 15.00 sec
Maximum Time Step : 15.00 sec
Page 2
Hansen PDP 100‐yr.rpt
Percent in Steady State : 0.00
Average Iterations per Step : 1.01
Percent Not Converging : 0.00
***************************
Subcatchment Runoff Summary
***************************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Total Total Total Total Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10^6 gal CFS
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
SUB1A 3.67 0.00 0.00 1.75 1.90 0.57 35.18 0.517
SUB1B 3.67 0.00 0.00 1.25 2.41 0.03 2.58 0.657
SUB1C 3.67 0.00 0.00 0.59 3.03 0.13 9.89 0.825
SUB1D 3.67 0.00 0.00 1.13 2.51 0.07 5.86 0.685
SUB1E 3.67 0.00 0.00 1.60 2.04 0.45 25.61 0.555
SUB1F 3.67 0.00 0.00 1.46 2.18 0.13 8.54 0.593
SUB1G 3.67 0.00 0.00 0.54 3.08 0.20 13.80 0.838
SUB1H 3.67 0.00 0.00 1.58 2.06 0.55 32.98 0.561
SUB1J 3.67 0.00 0.00 0.82 2.81 0.08 6.58 0.767
SUB1L 3.67 0.00 0.00 1.03 2.60 0.20 15.63 0.710
SUB1M 3.67 0.00 0.00 1.07 2.56 0.22 16.90 0.699
SUB2A 3.67 0.00 0.00 2.15 1.51 0.12 5.62 0.411
SUB2B 3.67 0.00 0.00 0.63 2.99 0.11 9.13 0.816
SUB2C 3.67 0.00 0.00 1.00 2.64 0.10 7.99 0.719
SUB2D 3.67 0.00 0.00 0.32 3.29 0.05 4.43 0.898
SUB2E 3.67 0.00 0.00 0.48 3.14 0.07 7.13 0.856
SUB2F 3.67 0.00 0.00 0.55 3.08 0.39 35.87 0.839
SUB2G 3.67 0.00 0.00 0.56 3.07 0.21 20.15 0.835
SUB2H 3.67 0.00 0.00 2.30 1.36 0.14 5.61 0.371
SUB2J 3.67 0.00 0.00 0.49 3.13 0.07 5.93 0.852
SUB3 3.67 0.00 0.00 0.19 3.42 0.31 30.70 0.931
SUB4 3.67 0.00 0.00 0.20 3.41 0.29 26.21 0.930
SUB1K 3.67 0.00 0.00 1.23 2.43 0.05 4.45 0.662
Page 3
Hansen PDP 100‐yr.rpt
TimbersB 3.67 0.00 0.00 0.64 2.98 0.84 69.31 0.812
TimbersA 3.67 0.00 0.00 1.09 2.53 0.29 15.90 0.690
******************
Node Depth Summary
******************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Average Maximum Maximum Time of Max Reported
Depth Depth HGL Occurrence Max Depth
Node Type Feet Feet Feet days hr:min Feet
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
J1 JUNCTION 0.24 0.79 51.99 0 02:07 0.79
J2 JUNCTION 0.31 1.04 49.17 0 02:08 1.04
J4 JUNCTION 0.29 2.58 41.83 0 00:41 2.41
J3 JUNCTION 0.32 2.57 45.22 0 00:40 2.53
O1 OUTFALL 0.28 2.58 41.69 0 00:41 2.40
O2 OUTFALL 0.00 0.00 0.00 0 00:00 0.00
POND1 STORAGE 2.07 3.80 58.80 0 03:11 3.80
POND2B STORAGE 0.17 4.70 58.70 0 02:05 4.70
POND3 STORAGE 0.37 4.41 57.41 0 02:10 4.41
POND4 STORAGE 0.62 4.33 61.33 0 02:18 4.33
POND2A STORAGE 0.91 6.00 59.00 0 02:27 6.00
*******************
Node Inflow Summary
*******************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Maximum Maximum Lateral Total Flow
Lateral Total Time of Max Inflow Inflow Balance
Inflow Inflow Occurrence Volume Volume Error
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal Percent
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
J1 JUNCTION 0.00 9.93 0 02:07 0 4.24 0.000
Page 4
Hansen PDP 100‐yr.rpt
J2 JUNCTION 0.00 9.93 0 02:08 0 4.24 0.000
J4 JUNCTION 15.90 85.60 0 00:41 0.286 5.37 0.000
J3 JUNCTION 69.31 73.36 0 00:40 0.843 5.08 0.000
O1 OUTFALL 0.00 85.64 0 00:41 0 5.37 0.000
O2 OUTFALL 0.00 0.59 0 02:18 0 0.287 0.000
POND1 STORAGE 177.97 177.97 0 00:40 2.68 2.68 0.002
POND2B STORAGE 67.56 67.56 0 00:40 0.819 0.819 0.035
POND3 STORAGE 30.70 30.70 0 00:40 0.311 0.311 0.013
POND4 STORAGE 26.21 26.21 0 00:40 0.287 0.287 0.007
POND2A STORAGE 34.31 34.31 0 00:40 0.439 0.439 0.008
*********************
Node Flooding Summary
*********************
No nodes were flooded.
**********************
Storage Volume Summary
**********************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Average Avg Evap Exfil Maximum Max Time of Max Maximum
Volume Pcnt Pcnt Pcnt Volume Pcnt Occurrence Outflow
Storage Unit 1000 ft3 Full Loss Loss 1000 ft3 Full days hr:min CFS
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
POND1 121.664 20 0 0 342.553 57 0 03:11 1.45
POND2B 2.044 3 0 0 70.232 90 0 02:05 6.58
POND3 2.455 6 0 0 35.174 87 0 02:10 1.10
POND4 4.116 10 0 0 34.498 85 0 02:18 0.59
POND2A 5.004 6 0 0 52.112 63 0 02:27 0.86
***********************
Outfall Loading Summary
Page 5
Hansen PDP 100‐yr.rpt
***********************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Flow Avg Max Total
Freq Flow Flow Volume
Outfall Node Pcnt CFS CFS 10^6 gal
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
O1 99.86 1.58 85.64 5.367
O2 37.84 0.22 0.59 0.287
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
System 68.85 1.81 85.91 5.654
********************
Link Flow Summary
********************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Maximum Time of Max Maximum Max/ Max/
|Flow| Occurrence |Veloc| Full Full
Link Type CFS days hr:min ft/sec Flow Depth
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Hansen_Out CONDUIT 9.93 0 02:08 8.65 0.33 0.39
Timber_Out CONDUIT 85.64 0 00:41 9.07 0.63 0.57
ExPipe1 CONDUIT 9.93 0 02:10 6.02 0.53 0.52
ExPipe2 CONDUIT 70.23 0 00:41 8.69 0.71 0.62
OUT4 DUMMY 0.59 0 02:18
OUT1 DUMMY 1.45 0 03:11
OUT2 DUMMY 6.58 0 02:05
OUT3 DUMMY 1.10 0 02:10
OUT2A DUMMY 0.86 0 02:27
*************************
Conduit Surcharge Summary
*************************
Page 6
Hansen PDP 100‐yr.rpt
No conduits were surcharged.
Analysis begun on: Fri Sep 15 13:34:41 2017
Analysis ended on: Fri Sep 15 13:34:41 2017
Total elapsed time: < 1 sec
Page 7
Pond 1 5-Year
Pond 2A 5-Year
Pond 2B 5-Year
Pond 3 5-Year
Pond 4 5-Year
Pond 1 100-Year
Pond 2A 100-Year
Pond 2B 100-Year
Pond 3 100-Year
Pond 4 100-Year
Hansen Property
Preliminary Erosion Control Report
APPENDIX D
WATER QUALITY CALCULATIONS
Basin(s) LID Treatment
Totale Basin(s)
Area (Ac.)
Rain Garden Req'd Min.
Volume (Cu.-Ft.)
1A Grass Buffer 10.99
1B, 1C, 1D, & 1E NE Rain Garden 11.23 6,278
1F, 1G, 1H, 1J, & 1K NW Rain Garden 16.22 9,087
1L & 1M Grass Buffer 6.06
2A Grass Buffer 2.85
2B, 2C, 2D, 2J None 4.11
2E, 2F, 2G, 2H Site Specific 11.91
3 Site Specific 3.35
4 Site Specific 3.10
69.82
4.39 Acres
5.29 Acres
4.85 Acres
3.92 Acres
51.37 Acres
47.35 Acres
92.18%
Total Newly Developed Area less Site Specific
Areas
Neighborhood Park
Total Newly Developed Area Treated
Percent of Newly Developed Area Treated
Areas Requiring Site Specific LID Treatment
Multi-family lots (Tract D)
Multi-family lots (Tract E)
Local Commerical (Tract C)
75% On-Site Treatment by LID Summary Table
Total Site Area
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 45.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.450
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.15 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 488,026 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 6,278 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 12.00 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 = 4392 sq ft
D) Actual Flat Surface Area AActual = 5284 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 7366 sq ft
F) Rain Garden Total Volume VT= 6,325 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y = ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft
iii) Orifice Diameter, 3/8" Minimum DO = N/A in
Design Procedure Form: Rain Garden (RG)
D. Weber
Northern Engineering
August 28, 2017
Hansen
Northeast
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
Rain Garden Northeast.xlsm, RG 9/18/2017, 11:30 AM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 45.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.450
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.15 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 706,463 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 9,087 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 12.00 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 = 6358 sq ft
D) Actual Flat Surface Area AActual = 9371 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 10020 sq ft
F) Rain Garden Total Volume VT= 9,696 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y = ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft
iii) Orifice Diameter, 3/8" Minimum DO = N/A in
Design Procedure Form: Rain Garden (RG)
D. Weber
Northern Engineering
September 19, 2017
Hansen
Northwest
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
Rain Garden Northwest.xlsm, RG 9/18/2017, 11:30 AM
X
VAULT
F.O.
VAULT
F.O.
VAULT
F.O.
B M
X
X
X
PT
PT
PT
X
X
X
X
X
PT
PT
PT
X
X
B M
TH
TH
C
VAULT
F.O.
TH
TH
TH
X
PT
X
X
X
X
X
X
X
PT
PT
PT
PT
PT
M F.O.
MM
M F.O.
LID
LID EXHIBIT
OVERALL D. Weber
M. Ruebel
1"=150'
35
No. Revisions: By:
Date:
R
EVIEWED BY:
Hansen Property
Preliminary Erosion Control Report
APPENDIX E
EROSION CONTROL REPORT
Hansen Property
Preliminary 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, that 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 appropriately
reflect the current site conditions at all times.
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 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 the Utility Plans. The Final Plans will contain a full-
size Erosion Control sheet 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 the Development Agreement for the development. Also, the Site Contractor for this
project will 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, prior to
any earth disturbance activities. Prior to securing said permit, the Site Contractor shall develop a
comprehensive StormWater 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.
Hansen Property
Preliminary Erosion Control Report
MAP POCKET
DRAINAGE EXHIBITS
X
V.P.
TH
VAULT
F.O.
VAULT
F.O.
VAULT
F.O.
TH
V.P.
VAULT
F.O.
TH
V.P.
B M
X
X
X
PT
PT
PT
X
X
X
X
X
PT
PT
PT
M F.O.
2a
2c 2b
2g 2j
2h
2f
3
4
1a
1m
1l
1k 1b
3
3.35 AC.
4
3.10 AC.
2F
4.65 AC.
2J
0.87
2H
3.92 AC.
2G
2.54 AC.
2E
2B 0.80 AC.
1.32 AC.
2A
2.85 AC.
2C
1.38 AC.
1A
10.99 AC.
1M
3.21 AC.
1L
2.85 AC.
1J
1.04 AC.
2D
0.54 AC.
2d
2e
DETENTION POND 2B
100-YR VOL=1.61 ac
PEAK RELEASE=6.58 cfs
100-YR VOL=1.20 ac
PEAK RELEASE=0.86 cfs
DETENTION POND 3
100-YR VOL=0.81 ac
PEAK RELEASE=1.10 cfs
FUTURE
DETENTION POND 4
100-YR VOL=0.79 ac
PEAK RELEASE=0.59 cfs
DETENTION POND 1
100-YR VOL=7.86 ac
PEAK RELEASE=1.45 cfs
NORTHEAST
RAIN GARDEN
X
X
B M
TH
V.P.
C
TH
X
PT
X
X
X
X
X
X
X
PT
PT
PT
PT
PT
M F.O.
MM
1k 1b
1d
1e
1H
9.81 AC.
2A
1K
0.75 AC.
1G
2.35 AC.
1F
2.27 AC.
1B
0.44 AC.
1C
1.56 AC.
1D
1.06 AC.
1E
8.14
2j
2h
2g
2f
1c
DETENTION POND 2A
100-YR VOL=1.20 ac
NORTHWEST
RAIN GARDEN
DR1
DRAINAGE EXHIBIT
OVERALL D. Weber
M. Ruebel
1"=150'
35
No. Revisions:
By: Date:
REVIEWED BY:
D. Weber
DESIGNED BY:
DRAWN BY:
SCALE:
DATE:
09/19/17
PROJECT:
911-015
Sheet
of 35
HANSEN SUBDIVISION
These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.
NOT FOR CONSTRUCTION
REVIEW SET
09/19/17
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
E N G I N E E R I N G
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what's below.
Call before you dig.
R
City Engineer Date
Date
Date
Date
Date
Stormwater Utility
Parks & Recreation
Traffic Engineer Date
APPROVED:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
Water Utility
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
Environmental Planner
KEYMAP
NTS
WV
WV
WV
WV
B M
VAULT
ELEC
PT
TIMBERLINE RD
LEGEND:
5013
93
ST
PROPOSED EASEMENT
EXISTING RIGHT OF WAY
PROPOSED LOT LINE
PROPERTY BOUNDARY
PROPOSED CURB AND GUTTER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CONTOUR
PROPOSED STORM INLET
PROPOSED STORM SEWER
EXISTING STORM SEWER
PROPOSED RIGHT OF WAY
A
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
B2
1.45 ac
DESIGN POINT
FLOW ARROWS
1. EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE
UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST
INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT
GUARANTEE THE ACCURACY OF SUCH INFORMATION. EXISTING UTILITY
MAINS AND SERVICES MAY NOT BE STRAIGHT LINES OR AS INDICATED
ON THESE DRAWINGS. THE CONTRACTOR SHALL BE RESPONSIBLE TO
CALL ALL UTILITY COMPANIES (PUBLIC AND PRIVATE) PRIOR TO ANY
CONSTRUCTION TO VERIFY EXACT UTILITY LOCATIONS.
2. REFER TO THE "PRELIMINARY DRAINAGE AND EROSION CONTROL
REPORT FOR HANSEN PROPERTY" BY NORTHERN ENGINEERING, DATED
SEPTEMBER 12, 2017 FOR ADDITIONAL INFORMATION.
3. ALL PROJECT DATA IS ON THE CITY OF FORT COLLINS VERTICAL DATUM;
NAVD88. SEE COVER SHEET FOR BENCHMARK REFERENCES.
4. REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT
DIMENSIONS, UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER
SURVEY INFORMATION.
NOTES:
BASIN
DESIGNATION
BASIN
AREA (AC)
( IN FEET )
0
1 INCH = 150 FEET
150 150 300 450
NORTH
DRAINAGE SUMMARY TABLE
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C2 C100
2-yr
Tc
(min)
100-yr
Tc
(min)
Q2
(cfs)
Q100
(cfs)
1a 1A 10.99 0.45 0.57 13.6 12.6 9.71 43.82
1b 1B 0.44 0.54 0.68 10.4 8.4 0.53 2.53
1c 1C 1.56 0.79 0.99 9.5 7.0 2.84 14.00
1d 1D 1.06 0.61 0.76 10.6 7.8 1.39 6.90
1e 1E 8.14 0.58 0.72 25.4 22.8 6.71 30.84
1f 1F 2.27 0.57 0.71 14.4 12.7 2.48 11.39
1g 1G 2.35 0.81 1.00 12.0 8.9 3.95 19.26
1h 1H 9.81 0.56 0.70 24.8 22.2 7.99 36.78
1j 1J 1.04 0.70 0.88 5.0 5.0 2.09 9.13
1k 1K 0.75 0.55 0.69 8.8 6.8 0.97 4.67
1l 1L 2.85 0.65 0.82 6.1 5.2 4.97 23.15
1m 1M 3.21 0.65 0.81 13.7 10.7 4.08 19.78
2a 2A 2.85 0.37 0.47 11.8 10.8 2.23 10.11
2b 2B 1.32 0.75 0.93 9.1 6.5 2.27 11.15
2c 2C 1.38 0.59 0.74 20.8 15.4 1.29 6.62
2d 2D 0.54 0.83 1.00 5.7 5.0 1.24 5.34
2e 2E 0.80 0.72 0.90 10.9 6.3 1.25 6.70
2f 2F 4.65 0.69 0.86 12.0 7.5 6.59 35.35
2g 2G 2.54 0.68 0.85 13.9 9.1 3.37 17.37
2h 2H 3.92 0.32 0.40 20.4 18.8 2.04 9.23
2j 2J 0.87 0.79 0.98 10.5 6.2 1.49 7.98
3 3 3.35 0.95 1.00 5.0 5.0 9.08 33.37
4 4 3.10 0.95 1.00 6.7 5.3 7.63 30.80
75% On-Site Treatment by LID Summary Table
Basin(s) LID Treatment
Totale Basin(s)
Area (Ac.)
Rain Garden Req'd Min.
Volume (Cu.-Ft.)
1A Grass Buffer 10.99
1B, 1C, 1D, & 1E NE Rain Garden 11.23 6,278
1F, 1G, 1H, 1J, & 1K NW Rain Garden 16.22 9,087
1L & 1M Grass Buffer 6.06
2A Grass Buffer 2.85
2B, 2C, 2D, 2J None 4.11
2E, 2F, 2G, 2H Site Specific 11.91
3 Site Specific 3.35
4 Site Specific 3.10
Total Site Area 69.82
Areas Requiring Site Specific LID Treatment
Multi-family lots (Tract D) 4.39 Acres
Multi-family lots (Tract E) 5.29 Acres
Local Commerical (Tract C) 4.85 Acres
Neighborhood Park 3.92 Acres
Total Newly Developed Area less Site
Specific Areas 51.37 Acres
Total Newly Developed Area Treated 47.35 Acres
Percent of Newly Developed Area Treated 92.18%
D. Weber
DESIGNED BY:
DRAWN BY:
SCALE:
DATE:
09/19/17
PROJECT:
911-015
Sheet
of 35
HANSEN SUBDIVISION
These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.
NOT FOR CONSTRUCTION
REVIEW SET
09/19/17
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
E N G I N E E R I N G
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what's below.
Call before you dig.
R
City Engineer Date Date
Date
Date
Date
Stormwater Utility
Parks & Recreation
Traffic Engineer Date
APPROVED:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
Water Utility
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
Environmental Planner
KEYMAP
NTS
WV
WV
WV
B M
VAULT
PT
TIMBERLINE RD
1. EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE
UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST
INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT
GUARANTEE THE ACCURACY OF SUCH INFORMATION. EXISTING UTILITY
MAINS AND SERVICES MAY NOT BE STRAIGHT LINES OR AS INDICATED
ON THESE DRAWINGS. THE CONTRACTOR SHALL BE RESPONSIBLE TO
CALL ALL UTILITY COMPANIES (PUBLIC AND PRIVATE) PRIOR TO ANY
CONSTRUCTION TO VERIFY EXACT UTILITY LOCATIONS.
2. REFER TO THE "PRELIMINARY DRAINAGE AND EROSION CONTROL
REPORT FOR HANSEN PROPERTY" BY NORTHERN ENGINEERING, DATED
SEPTEMBER 12, 2017 FOR ADDITIONAL INFORMATION.
3. ALL PROJECT DATA IS ON THE CITY OF FORT COLLINS VERTICAL DATUM;
NAVD88. SEE COVER SHEET FOR BENCHMARK REFERENCES.
4. REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT
DIMENSIONS, UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER
SURVEY INFORMATION.
NOTES:
LEGEND:
5013
93
ST
PROPOSED EASEMENT
EXISTING RIGHT OF WAY
PROPOSED LOT LINE
PROPERTY BOUNDARY
PROPOSED CURB AND GUTTER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CONTOUR
PROPOSED STORM INLET
PROPOSED STORM SEWER
EXISTING STORM SEWER
PROPOSED RIGHT OF WAY
( IN FEET )
0
1 INCH = 150 FEET
150 150 300 450
NORTH
PROPOSED AREA OF LID TREATMENT
PROPOSED AREA OF SITE-SPECIFIC LID TREATMENT
75% On-Site Treatment by LID Summary Table
Basin(s) LID Treatment
Totale Basin(s)
Area (Ac.)
Rain Garden Req'd Min.
Volume (Cu.-Ft.)
1A Grass Buffer 10.99
1B, 1C, 1D, & 1E NE Rain Garden 11.23 6,278
1F, 1G, 1H, 1J, & 1K NW Rain Garden 16.22 9,087
1L & 1M Grass Buffer 6.06
2A Grass Buffer 2.85
2B, 2C, 2D, 2J None 4.11
2E, 2F, 2G, 2H Site Specific 11.91
3 Site Specific 3.35
4 Site Specific 3.10
Total Site Area 69.82
Areas Requiring Site Specific LID Treatment
Multi-family lots (Tract D) 4.39 Acres
Multi-family lots (Tract E) 5.29 Acres
Local Commerical (Tract C) 4.85 Acres
Neighborhood Park 3.92 Acres
Total Newly Developed Area less Site
Specific Areas 51.37 Acres
Total Newly Developed Area Treated 47.35 Acres
Percent of Newly Developed Area Treated 92.18%
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Mar 20, 2015—Oct
15, 2016
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
33
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Mar 20, 2015—Oct
15, 2016
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
(in/hr)
Sub-Basin(s)
Rational Method Equation:
Rainfall Intensity:
Rainfall Intensity taken from the Fort Collins Stormwater Criteria Manual (FCSCM), Tables RA-7 and RA-8
Intensity,
i
10
(in/hr)
C
10
Area, A
(acres)
Intensity,
i
2
(in/hr)
100-yr
T
c
(min)
September 19, 2017
Q C f C i A
9/18/2017 10:58 AM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Rational_Calcs.xlsx\Runoff
(ft/s)
T
t
(min)
2-yr
T
c
(min)
10-yr
T
c
(min)
100-yr
T
c
(min)
1a 1A No 0.45 0.45 0.57 64 64.89 62.14 4.30% 6.0 6.0 4.9 885 62.14 54.00 0.92% 1.92 7.7 13.6 13.6 12.6
1b 1B No 0.54 0.54 0.68 95 62.00 60.27 1.82% 8.3 8.3 6.3 172 60.27 59.50 0.45% 1.34 2.1 10.4 10.4 8.4
1c 1C No 0.79 0.79 0.99 65 65.00 63.87 1.74% 3.9 3.9 1.4 573 63.87 59.71 0.73% 1.70 5.6 9.5 9.5 7.0
1d 1D No 0.61 0.61 0.76 200 67.00 61.25 2.88% 9.1 9.1 6.3 171 61.25 59.71 0.90% 1.90 1.5 10.6 10.6 7.8
1e 1E No 0.58 0.58 0.72 186 75.65 70.47 2.78% 9.5 9.5 6.9 1575 70.47 59.71 0.68% 1.65 15.9 25.4 25.4 22.8
1f 1F No 0.57 0.57 0.71 85 71.43 68.81 3.08% 6.3 6.3 4.6 870 68.81 61.86 0.80% 1.79 8.1 14.4 14.4 12.7
1g 1G No 0.81 0.81 1.00 62 70.95 70.43 0.84% 4.6 4.6 1.6 850 70.43 62.61 0.92% 1.92 7.4 12.0 12.0 8.9
1h 1H No 0.56 0.56 0.70 186 75.65 70.47 2.78% 9.7 9.7 7.2 1412 70.47 61.86 0.61% 1.56 15.1 24.8 24.8 22.2
1j 1J No 0.70 0.70 0.88 47 71.38 64.00 15.70% 2.0 2.0 1.1 275 64.00 61.43 0.93% 1.93 2.4 5.0 5.0 5.0
1k 1K No 0.55 0.55 0.69 127 64.38 60.50 3.06% 8.0 8.0 5.9 100 60.50 59.50 1.00% 2.00 0.8 8.8 8.8 6.8
1l 1L No 0.65 0.65 0.82 47 71.38 64.00 15.70% 2.3 2.3 1.4 446 64.00 59.71 0.96% 1.96 3.8 6.1 6.1 5.2
1m 1M No 0.65 0.65 0.81 175 67.00 63.02 2.27% 8.5 8.5 5.4 510 63.02 59.71 0.65% 1.61 5.3 13.7 13.7 10.7
2a 2A No 0.37 0.37 0.47 73 67.00 64.50 3.42% 7.7 7.7 6.7 650 64.50 53.33 1.72% 2.62 4.1 11.8 11.8 10.8
2b 2B No 0.75 0.75 0.93 64 62.79 61.99 1.25% 4.9 4.9 2.3 380 61.99 59.84 0.57% 1.50 4.2 9.1 9.1 6.5
2c 2C No 0.59 0.59 0.74 267 62.11 60.57 0.58% 18.8 18.8 13.4 160 60.57 59.84 0.46% 1.35 2.0 20.8 20.8 15.4
2d 2D No 0.83 0.83 1.00 42 63.82 63.32 1.19% 3.0 3.0 1.1 314 63.32 60.25 0.98% 1.98 2.6 5.7 5.7 5.0
2e 2E No 0.72 0.72 0.90 125 61.30 60.60 0.56% 9.6 9.6 5.0 91 60.60 60.29 0.34% 1.17 1.3 10.9 10.9 6.3
2f 2F No 0.69 0.69 0.86 200 63.31 61.27 1.02% 10.8 10.8 6.2 260 61.27 53.74 2.90% 3.40 1.3 12.0 12.0 7.5
2g 2G No 0.68 0.68 0.85 150 62.27 61.43 0.56% 11.6 11.6 6.9 240 61.43 59.53 0.79% 1.78 2.2 13.9 13.9 9.1
2h 2H No 0.32 0.32 0.40 175 67.00 63.02 2.27% 14.6 14.6 13.1 537 63.02 59.75 0.61% 1.56 5.7 20.4 20.4 18.8
2j 2J No 0.79 0.79 0.98 192 65.97 62.71 1.70% 6.8 6.8 2.5 400 62.71 59.49 0.81% 1.79 3.7 10.5 10.5 6.2
3 3 No 0.95 0.95 1.00 200 67.00 63.00 2.00% 3.1 3.1 2.1 229 63.00 56.87 2.68% 3.27 1.2 5.0 5.0 5.0
4 4 No 0.95 0.95 1.00 200 67.00 65.00 1.00% 4.0 4.0 2.6 485 65.00 54.00 2.27% 3.01 2.7 6.7 6.7 5.3
PROPOSED TIME OF CONCENTRATION COMPUTATIONS
F. Wegert
September 19, 2017
Design
Point
Sub-Basin
Overland Flow Gutter Flow Time of Concentration
Velocity (Gutter Flow), V = 20·S
½
T
t
= L / 60V
T
c
= T
i
+ T
t
(Equation RO-2)
Velocity (Swale Flow), V = 15·S
½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Overland Flow, Time of Concentration:
Gutter/Swale Flow, Time of Concentration:
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
9/18/2017 10:58 AM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Rational_Calcs.xlsx\Tc
Coefficient
10-year
Composite Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
Streets, Parking Lots, Roofs, Alleys, and Drives:
CHARACTER OF SURFACE:
Composite Runoff Coefficient with Adjustment
PROPOSED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Hansen
F. Wegert
September 19, 2017
100-year C
f
= 1.25
2H 170,731 3.92 0.41 0.00 0.00 3.51 0.00 0.00 0.32 0.32 0.40 10%
2J 37,977 0.87 0.67 0.00 0.00 0.20 0.00 0.00 0.79 0.79 0.98 77%
3 146,081 3.35 0.00 0.00 0.00 3.35 0.00 3.35 0.95 0.95 1.00 90%
4 134,860 3.10 0.00 0.00 0.00 3.10 0.00 3.10 0.95 0.95 1.00 90%
3) Assume single-family residences are 3/4 roof & driveways (C = 0.95) and 1/4 lawn (C=0.25)
2) Runoff coefficients are taken from the Overall Drainage Report for Hansen Overall Development Plan prepared by Northern Engineering dated 8/29/2017.
1) Runoff coefficients are taken from the Fort Collins Stormwater Criteria Manaual, Table 3.2.1 and Table 3.2.2.
9/18/2017 10:57 AM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Rational_Calcs.xlsx\Composite C
Coefficient
10-year
Composite Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1A 478,569 10.99 0.00 0.00 2.24 6.10 2.64 0.00 0.45 0.45 0.57 31%
1B 19,318 0.44 0.00 0.00 0.25 0.19 0.00 0.00 0.54 0.54 0.68 38%
1C 68,034 1.56 0.50 0.00 0.95 0.12 0.00 0.00 0.79 0.79 0.99 73%
1D 45,994 1.06 0.14 0.00 0.53 0.38 0.00 0.00 0.61 0.61 0.76 47%
1E 354,435 8.14 0.88 0.00 3.88 3.37 0.00 0.00 0.58 0.58 0.72 43%
1F 98,941 2.27 0.63 0.41 0.00 1.23 0.00 0.00 0.57 0.57 0.71 44%
1G 102,255 2.35 1.11 0.76 0.00 0.48 0.00 0.00 0.81 0.81 1.00 76%
1H 427,495 9.81 1.51 0.40 3.31 4.59 0.00 0.00 0.56 0.56 0.70 42%
1J 45,456 1.04 0.44 0.00 0.32 0.29 0.00 0.00 0.70 0.70 0.88 62%
1K 32,513 0.75 0.00 0.00 0.43 0.32 0.00 0.00 0.55 0.55 0.69 39%
1L 123,997 2.85 0.49 0.00 1.54 0.82 0.00 0.00 0.65 0.65 0.82 54%
1M 140,014 3.21 0.55 0.00 1.71 0.95 0.00 0.00 0.65 0.65 0.81 53%
2A 124,266 2.85 0.00 0.00 0.68 2.18 0.00 0.00 0.37 0.37 0.47 16%
2B 57,471 1.32 0.40 0.00 0.53 0.15 0.24 0.00 0.75 0.75 0.93 70%
2C 60,105 1.38 0.30 0.00 0.00 0.44 0.65 0.00 0.59 0.59 0.74 54%
2D 23,382 0.54 0.45 0.00 0.00 0.09 0.00 0.00 0.83 0.83 1.00 84%
2E 34,779 0.80 0.27 0.00 0.00 0.06 0.47 0.00 0.72 0.72 0.90 75%
2F 202,678 4.65 0.83 0.00 0.00 0.15 3.67 0.00 0.69 0.69 0.86 73%
2G 110,582 2.54 0.42 0.00 0.00 0.12 2.00 0.00 0.68 0.68 0.85 72%
Streets, Parking Lots, Roofs, Alleys, and Drives:
CHARACTER OF SURFACE:
Composite Runoff Coefficient with Adjustment
PROPOSED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Hansen
F. Wegert
September 19, 2017
100-year C
f
= 1.25
9/18/2017 10:57 AM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Rational_Calcs.xlsx\Composite C
100
(in/hr)
Sub-Basin(s)
Rational Method Equation:
Rainfall Intensity:
Rainfall Intensity taken from the Fort Collins Stormwater Criteria Manual (FCSCM), Tables RA-7 and RA-8
Q C f C i A
9/18/2017 1:27 PM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Hist_Rational_Calcs.xlsx\Runoff
(ft/s)
T
t
(min)
2-yr
T
c
(min)
10-yr
T
c
(min)
100-yr
T
c
(min)
h1 H1 No 0.20 0.20 0.25 275 4975.00 4972.00 1.09% 27.1 27.1 25.6 2560 4972.00 4960.00 0.47% 1.37 31.2 58.3 58.3 56.8
h3 H3 No 0.24 0.24 0.30 200 67.00 63.00 2.00% 18.0 18.0 16.7 229 63.00 56.87 2.68% 3.27 1.2 19.2 19.2 17.9
h4 H4 No 0.20 0.20 0.25 200 67.00 65.00 1.00% 23.8 23.8 22.5 485 65.00 54.00 2.27% 3.01 2.7 26.5 26.5 25.2
HISTORIC TIME OF CONCENTRATION COMPUTATIONS
F. Wegert
September 19, 2017
Design
Point
Sub-Basin
Overland Flow Gutter Flow Time of Concentration
Velocity (Gutter Flow), V = 20·S
½
T
t
= L / 60V
T
c
= T
i
+ T
t
(Equation RO-2)
Velocity (Swale Flow), V = 15·S
½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Overland Flow, Time of Concentration:
Gutter/Swale Flow, Time of Concentration:
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
9/18/2017 1:27 PM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Hist_Rational_Calcs.xlsx\Tc
Runoff
Coefficient
Composite
% Imperv.
H1 2,832,002 65.01 0.00 0.00 0.00 65.01 0.00 0.00 0.20 0.20 0.25 2%
H3 74,352 1.71 0.00 0.10 0.00 1.61 0.00 0.00 0.24 0.24 0.30 7%
H4 134,123 3.08 0.00 0.00 0.00 3.08 0.00 0.00 0.20 0.20 0.25 2%
3) Assume single-family residences are 3/4 roof & driveways (C = 0.95) and 1/4 lawn (C=0.25)
Streets, Parking Lots, Roofs, Alleys, and Drives:
CHARACTER OF SURFACE:
Composite Runoff Coefficient with Adjustment
HISTORIC COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Hansen
F. Wegert
September 19, 2017
2) Runoff coefficients are taken from the Overall Drainage Report for Hansen Overall Development Plan prepared by Northern Engineering dated 8/29/2017.
1) Runoff coefficients are taken from the Fort Collins Stormwater Criteria Manaual, Table 3.2.1 and Table 3.2.2.
100-year C
f
= 1.25
9/18/2017 1:28 PM D:\Projects\911-015\Drainage\Hydrology\911-015_PDP_Hist_Rational_Calcs.xlsx\Composite C