HomeMy WebLinkAboutCOUNTRY CLUB RESERVE - FDP180030 - SUBMITTAL DOCUMENTS - ROUND 5 - DRAINAGE REPORTSeptember 2, 2020
FINAL DRAINAGE AND
EROSION CONTROL REPORT FOR
COUNTRY CLUB RESERVE
Fort Collins, Colorado
Prepared for:
Crystal Cove Development
8020 S. County Road 5, Unit 200
Fort Collins, CO 80528
Prepared by:
301 N. Howes, Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 1324-001
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 2, 2020
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Final Drainage and Erosion Control Report for
COUNTRY CLUB RESERVE
Dear Staff:
Northern Engineering is pleased to submit this Final Drainage and Erosion Control Report for your
review. This report accompanies the Final Plan submittal for the proposed Country Club Reserve
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.
Aaron Cvar, PhD, PE Blaine Mathisen, EI
Senior Project Engineer Project Engineer
Country Club Reserve
Final Drainage and Erosion Control Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 5
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 5
A. Major Basin Description .................................................................................................................... 5
B. Sub-Basin Description ....................................................................................................................... 5
III. DRAINAGE DESIGN CRITERIA ................................................................................... 6
A. Regulations........................................................................................................................................ 6
B. Four Step Process .............................................................................................................................. 6
C. Development Criteria Reference and Constraints ............................................................................ 6
D. Hydrological Criteria ......................................................................................................................... 7
E. Hydraulic Criteria .............................................................................................................................. 7
F. Modifications of Criteria ................................................................................................................... 7
IV. DRAINAGE FACILITY DESIGN .................................................................................... 8
A. General Concept ............................................................................................................................... 8
B. Specific Details .................................................................................................................................. 9
V. CONCLUSIONS ...................................................................................................... 11
A. Compliance with Standards ............................................................................................................ 11
B. Drainage Concept ............................................................................................................................ 11
APPENDICES:
APPENDIX A – Hydrologic Computations, Offsite Drainage Exhibit and Computations
APPENDIX B - USDA Soils Information
APPENDIX C – SWMM Modeling; Detention Computations and Emergency Overflow Exhibits
APPENDIX D – Water Quality and LID Computations and Information
APPENDIX E – Street Capacity Calculations
APPENDIX F – Inlet Calculations
APPENDIX G – Storm Line Calculations
APPENDIX H – Riprap Calculations
APPENDIX I – Erosion Control Report
Country Club Reserve
Final Drainage and Erosion Control Report
LIST OF FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 4
Figure 3 – Existing Floodplains ............................................................................................. 5
MAP POCKET:
Proposed Drainage Exhibit
Country Club Reserve
Final Drainage and Erosion Control Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the northeast quarter of Section 30, Township 8 North,
Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado.
3. The project site is located just southwest of the intersection of Turnberry Road and
East Douglas Road.
4. With the No. Eight Ditch being the historic outfall for the site, a significant amount of
discussion and coordination has occurred with the ditch company to allow developed
flows to be released into the ditch. A historic 2-year discharge rate of 6.21 cfs has
been determined in this study; however, based on dialogue with the ditch company
we will release into the ditch at or below a rate of 1.0 cfs.
5. The proposed site design will include both LID and Extended Detention water quality
treatment prior to stormwater discharge from the site. Water quality treatment
methods are described in further detail below.
6. Existing residential developments, Serramonte Highlands, and Cherrywood Acres
exist to the south and west of the site, respectively; farmland exist to the east of the
site.
7. Offsite flows enter the site from the west and south. Offsite runoff peak flow rates
Country Club Reserve
Final Drainage and Erosion Control Report 2
have been calculated, and offsite basins are depicted in the Historic Drainage Exhibit
provided in Appendix A.
B. Description of Property
1. The overall property is 80.4 acres, of which roughly 62.4 acres will be developed.
Figure 1 – Aerial Photograph
2. The subject property is currently composed of undeveloped land. Existing ground
slopes are mild to moderate (i.e., 1 - 6±%) through the interior of the property.
Historic drainage on the site is generally split in two directions, with the north 1/3 of
the site (Basin H1) draining to the northeast and the southern 2/3 of the site (Basin
H2) draining to the southeast. There is an existing culvert near the middle of Historic
Basin H1 and another existing culvert at the northeast corner of Basin H1 that collect
runoff from the basin and direct flows to an existing ditch on the north side of Douglas
Road and then east to a culvert under Turnberry Road at the northwest corner of the
intersection of Turnberry and East Douglas Roads. Flows are directed east by the
culvert under Turnberry Road into the No. Eight Ditch, located just east of Turnberry
Road. Historic Basin H2 drains to an existing culvert located near the southeast
corner of Basin H2; flows are conveyed east under Turnberry Road and continue to
the No. Eight Ditch in this culvert. Please see the Historic Drainage Exhibit in
Appendix A for additional information.
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 primarily consists of Fort Collins Loam, which falls into Hydrologic Soil Group
B and C, and Longmont Clay, which falls into Hydrologic Soil Group D.
SITE
Country Club Reserve
Final Drainage and Erosion Control Report 3
4. Historically, runoff from several offsite basins has been received by the property.
These offsite flows have collected in localized areas on the project site and in large
events have eventually overtopped Turnberry Road. There is one existing 24” CMP
pipe at the southeast corner of the site that has historically discharged a portion of the
site to the No. Eight Ditch. Historic flows have not overtopped Douglas Road, but
rather, have been conveyed under this road via an existing culvert. This issue has
been discussed with City of Fort Collins Stormwater staff and a modeling approach
has been agreed upon which incorporates three onsite historic attenuation areas
identified as H1a, H2a, and H2b. There are also one other very negligible attenuation
area in the northeast corner, design point H1b, which will be removed but historic
runoff to this area will be accounted for in the proposed pond and routed through a
rain garden as well. Please see the Historic Drainage Exhibit in Appendix A for
additional information.
5. Attenuation area H2b has historically been routed to No. Eight Ditch via a 24” CMP
pipe near the southeast corner. With the development of Country Club Reserve this
runoff will now be routed through the proposed detention Pond 1.
6. We have analyzed the historic attenuation areas in detail and have provided
attenuation rating curves and historic SWMM input and output in Appendix A. Table
1, provided below, summarizes historic attenuation within the project site and peak
100-year discharge rates.
7. In the proposed condition, offsite flows will continue to enter the onsite stormwater
system. Proposed grading will modify or remove historic attenuation areas and direct
all offsite flows into proposed detention Pond 1. Flows will no longer being conveyed
to the north side of Douglas Road, via the culvert. Due to the large size of the
proposed pond, both onsite developed flows and offsite flows will be attenuated by
the proposed storm system, resulting in an overall reduction of flow from the site and
the complete removal of emergency overtopping of Turnberry Road in the 100-yr
event. Please see Table 1 below for a summary of proposed discharge rates.
8. Table 1 provides a summary of the historic and proposed stormwater attenuation for
the project site. As noted above, three historic attenuation areas were included in the
historic SWMM modeling, and each of those areas had a corresponding release rate in
the 100-yr event. This release was historically conveyed by culverts, with excess
flows conveyed on the surface. In the proposed condition, the central historic
attenuation area will be removed (H2a) while the northern attenuation area (H1a) will
be redirected to the proposed detention pond. As a result, neither of these areas will
have pipe or surface flows associated with them in the proposed condition. The third
historic attenuation area (H2b), located in the southeast corner of the site, will also be
routed to the proposed detention pond. This proposed facility is much larger than the
existing attenuation areas, and as a result, proposed flows from this area will be
reduced significantly from the historic condition. In particular, total flows from the
southeast will decrease from 80.56 cfs to 9.60 cfs, with all flows being conveyed via
the new outlet to the No. Eight Ditch and no-emergency overtopping occurring in a
100-yr event. The new outlet to the No. Eight Ditch is currently shown above the
invert of the Ditch at the direction of the ditch company and this is currently shown
on the utility plans. The engineer of record for the utility plans may make further
adjustments to the outlet invert at the direction of the Ditch Company to avoid long-
term scour concerns.
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Final Drainage and Erosion Control Report 4
TABLE 1 – HISTORIC VS PROPOSED CONDITIONS SWMM MODELING SUMMARY
Historic
Release
Point
Historic
100-Yr.
Attenuation
Vol.
(Ac-Ft)
Historic
Culvert
Flow (cfs)
Historic
Surface
Flow (cfs)
Total
Historic
Flow (cfs)
Proposed
100-Yr.
Attenuation
Vol.
(Ac-Ft)
Proposed
Culvert
Flow (cfs)
Proposed
Surface
Flow (cfs)
Total
Proposed
Flow (cfs)
H1a
(North)
4.55
1.43
0
1.45
N/A
N/A
N/A
0
H2a
(Central)
0.26
0
35.07
35.07
N/A
N/A
N/A
0
H2b (East)
7.32
8.03
72.53
80.56
14.81
Country Club Reserve
Final Drainage and Erosion Control Report 5
C. Floodplain
1. The project site is not encroached by any FEMA jurisdictional flood zone and is not in
any City designated flood zone.
Figure 3 –Area Floodplain Mapping
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site lies within the Boxelder/Cooper Slough Master Drainage Basin. Onsite
detention is required for the runoff volume difference between the 100-year developed
inflow rate and the historic 2-year rate. The historic outfall for the site is the No.
Eight Ditch, which is located adjacent to the site along the east side of Turnberry
Road. The No. Eight Ditch will serve as the primary outfall for the proposed site.
Onsite LID treatment, water quality treatment and detention will be provided prior to
discharge into the ditch.
B. Sub-Basin Description
1. Historic drainage patterns direct flows in the north 1/3 of the site generally from
southwest to northeast while the south 2/3 have generally flowed from northwest to
southeast and have historically been conveyed into collection points along the west
side of Turnberry Road, which are piped east under the roadway and into the No.
Eight Ditch.
2. A more detailed description of the project drainage patterns is provided below.
SITE
Country Club Reserve
Final Drainage and Erosion Control Report 6
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 majority of stormwater runoff from the site will ultimately be intercepted and treated
using detention and LID treatment methods prior to exiting the site. Rain gardens will be
utilized as the BMP control measure. No additional source control BMPs are proposed for
the project site.
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:
Existing elevations along the property lines will generally be maintained.
Country Club Reserve
Final Drainage and Erosion Control Report 7
As previously mentioned, overall drainage patterns of the existing site will be
maintained. With the exception for the southeast corner where historic runoff will
be getting routed through the proposed detention pond instead.
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 generally maintains historic drainage
patterns. However, with the proposed addition of Pond 1, the inadvertent detention
that has historically occurred within the site will be enhanced. The proposed site now
receives and detains more historic runoff volume compared to historic conditions, as
discussed in Section I.B, above.
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 any City or FEMA 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.
Country Club Reserve
Final Drainage and Erosion Control Report 8
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 the form of Rain Gardens upstream of each
detention pond, as discussed further below. Design of these Rain Gardens conforms
to porous landscape detention (PLD) criteria.
3. Drainage patterns anticipated for drainage basins shown in the Drainage Exhibit are
described below.
Basins 1a, 1b
Basins 1a and 1b are comprised of areas along the northwest and southwest portions
of the property that will generally not be developed (a small portion of Basin 1a
consists of residential back of lots) or be significantly altered by grading. These
portions of the property will be received by the proposed drainage system, conveyed
into on-site detention ponds, but will not receive LID treatment. The portion of Basin
1a that consist of residential back of lot will be detained.
Basins 2 through 4
Basins 2 through 4 consist of single-family residential development and will generally
drain via sheet flow into a street curb and gutter, which will convey runoff into
proposed storm sewer systems and swales. Ultimately, storm systems will direct up
to 100-year developed flows into proposed onsite Pond 2.
Basins 5a, 5b, 9a, 9b
Basins 5a, 5b, 9a and 9b consist of single-family residential development and open
space/detention area. These basins will generally drain via sheet flow into a street
curb and gutter, which will convey runoff into proposed storm sewer systems and
swales. Ultimately, storm systems will direct up to 100-year developed flows into
proposed onsite Pond 1.
Basins 6, 7, 8
Basins 6, 7, and 8 consist of single-family residential development and will generally
drain via sheet flow into a street curb and gutter, which will convey runoff into
proposed storm sewer systems and swales. Ultimately, storm systems will direct up
to 100-year developed flows into proposed onsite Pond 1.
Basin 10
Basin 10 is comprised, for the most part, of an area along the southeast portion of the
property that will not be significantly developed, but will be altered by grading. Runoff
from this basin will be directed by sheet flow to the southeast corner of the site, where
drainage has historically collected (Basin H2b). From there the runoff will be conveyed
to Pond 1 via storm drain. Please see Section I.B, above, for discussion of how
historic attenuation has occurred in this area and how proposed Pond 1 will increase
attenuation and reduce peak discharge.
Basin OS1a, OS1b, and OS2
Basins OS1a, OS1b and OS2 consist primarily of adjacent Right of Way. Basin OS1a
will be captured in a proposed storm system on East Douglas Road, and runoff will be
directed into proposed onsite Pond 1. Runoff from these basins will be received by the
Country Club Reserve
Final Drainage and Erosion Control Report 9
proposed drainage system, conveyed into on-site detention ponds, but will not receive
LID treatment. However, due to the size of Pond 1 (necessary for provision of fill
material for site grading) these offsite basins will be detained in Pond 1. The 100-YR
Blocked Outlet Scenario SWMM model provided in Appendix C routes flows from
Basins OS1a, OS1b, and OS2 through Pond 1. In this model, a blocked Pond 1
outlet is assumed.
Basin OS3, OS4 and OS5,
Basins OS3, OS4, and OS5 consist primarily of adjacent areas to the west and south
that sheet flow onto the site. Runoff from these basins will be received by the
proposed drainage system, conveyed into on-site detention ponds, but will not receive
LID treatment. However, due to the size of Pond 1 (necessary for provision of fill
material for site grading) these offsite basins will be detained in Pond 1. The 100-YR
Blocked Outlet Scenario SWMM model provided in Appendix C routes flows from
Basins OS3, OS4, and OS5 through Pond 1.
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. Two detention basins are proposed within the project site, and will detain up
to the 100-year storm event. Pond 2 routes through Pond 1, which will
release at or below the agreed to discharge rate of 1.0 cfs (based on
discussions with Ditch Company). Detention pond performance has been
modeled in the computer program EPA-SWMM.
2. Per the Stormwater Detention and Infiltration Design Data Sheets provided in
Appendix D, we have ensured drain times meet State criteria.
3. Emergency overflow from Pond 1 has been analyzed in more detail, with the
formulation of a blocked outlet scenario run in the computer program EPA-
SWMM. Based on this model we have determined during a clogged condition
Pond 1 has the volume to adequately retain all offsite and onsite flows within
its foot print. Therefore, there will not be any overtopping into Turnberry Road
during a 100-year clogged outfall event.
4. During the typical100-year event Pond 1 will be discharging 9.60 cfs into the
into the No. Eight Ditch via a proposed new outfall pipe. The 9.60 cfs at this
location is a significant reduction from the current/historic 100-year overflow,
as shown in the Historic SWMM analysis discussed above in Section I.B. This
flow will be fully conveyed in the into the No. Eight Ditch via the proposed
new outfall pipe.
5. 100-year overflow from Raingardens 1 through 3 will be directed across large
vegetated areas, which will act as a means of spreading 100-year overflow. At
each point of overflow we have added erosion fabric at a minimum which will
act to stabilize overflow areas, and allow for revegetation of disturbed soil to
occur. There is also riprap rundowns as well as concrete weirs that will more
than adequately maintain stabilization. 100-year overflow areas are noted on
the Drainage Exhibit. Please see overflow calculations provided in Appendix
D.
6. A subdrain system is proposed for the development site, which will drain via
the outfall pipe for proposed Pond 1. Per the groundwater study for the
Country Club Reserve
Final Drainage and Erosion Control Report 10
subdrain system an estimated peak discharge from the subdrain system is
0.022 cfs (10 gallons per minute). The allowable release rate from Pond 1 is
1.0 cfs. We are proposing a release rate of 0.88 cfs and are adding the
0.022 cfs subdrain flow to this release for a total of 0.902 cfs. There is no
way to model the impacts of the subdrain in SWMM and thus are just added
to the overall discharge. Thus, we will be releasing slightly under the
allowable release rate into the No. Eight Ditch. Additionally, Pond 1 is
bypassing offsite flow from Basin OS4. Therefore, the ultimate peak discharge
is 9.67 cfs.
Table 2, below, summarizes results of final SWMM modeling. Please see
SWMM modeling output provided in Appendix C.
TABLE 2 – SWMM SUMMARY TABLE
7. This development site is somewhat unique in that there is a significant portion of the
overall property that will be merely regraded or left as untouched open space. For the
purpose of calculating required LID treatment volume and water quality capture
volume, we have determined a “Total Newly Developed Area” acreage of 33.43 acres
as noted in the LID Exhibit provided in Appendix D. This area is based on residential
lots, streets, and open space areas being developed within the site. Areas within the
property boundary that are merely being regraded, but will experience no additional
imperviousness are not included in this area.
8. Rain Gardens (designed as porous landscape detention (PLD) holding cells) are
proposed as the primary LID treatment method for the site. The PLD’s will provide
standard 12-hour porous landscape detention (PLD) treatment. PLD basins will be
incorporated in the upper stages of Ponds1, 2, and 3. The site will provide in excess
of the onsite LID treatment requirement 75% of newly developed areas. Please see
LID computations and an LID Exhibit provided in Appendix D.
9. Water quality capture volume will be incorporated in the lower stage of Pond
1, providing 40-hour extended detention for 50% of the “Total Newly
Developed Area” as discussed above. Please see Water Quality computations
provided in Appendix D.
10. The area utilized for Pond 2 is a seasonal wetland, as identified by the City of
Fort Collins, and a Wetland Buffer Zone will be incorporated in the proposed
design of the pond area. As noted previously, Pond 2 will have pre-treatment
in the form of Porous Landscape Detention (PLD), and therefore all developed
runoff will be treated prior to discharge into the wetland area. Detention is
proposed in the upper stage of the wetland water surface. The grading of
Pond 2 has been designed to maintain a permanent pool elevation of the
wetland at 5079.0. This permanent pool elevation has been determined
based on the invert elevation of the historic outfall for the wetland area which
is an existing CMP culvert under East Douglas Road. The invert elevation of
this pipe matches fairly consistently with the wetland boundary as identified in
the environmental study for the property, further increasing confidence that the
Pond ID
100-Yr.
Detention
Vol. (Ac-Ft)
Water Quality
Capture Volume
(Ac-Ft)
Water Quality
Capture Volume
WSEL (Ft)
Total
Req'd Vol.
(Ac-Ft)
100-Yr.
WSEL (Ft)
Peak
Country Club Reserve
Final Drainage and Erosion Control Report 11
permanent pool elevation of 5079.0 is the correct elevation to utilize.
11. Stormwater facility Standard Operating Procedures (SOP) will be provided 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 the
Boxelder/Cooper Slough Master Drainage 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 Boxelder/Cooper Slough Master Drainage Basin.
Country Club Reserve
Final Drainage and Erosion Control Report 12
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.
APPENDIX A
Hydrologic Computations, Offsite Drainage Exhibit and Computations
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 1324-001
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC
Asphalt ……....……………...……….....…...……………….………………………………….. 0.95 100% Date:
Concrete …….......……………….….……….………………..….…………………………………0.95 90%
Gravel ……….…………………….….…………………………..……………………………….. 0.50 40%
Roofs …….…….………………..……………….…………………………………………….. 0.95 90%
Pavers…………………………...………………..…………………………………………….. 0.40 22%
Lawns and Landscaping
Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0%
Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf
= 1.00 100-year Cf = 1.25
Basin ID
Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Lawn, Rain
Garden, or
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1a 387876 8.90 0.00 0.11 0.37 0.00 8.43 0.29 0.29 0.36 4.8%
1b 125967 2.89 0.00 0.00 0.00 0.00 2.89 0.25 0.25 0.31 0.0%
2 128938 2.96 0.60 0.34 0.41 0.00 1.61 0.57 0.57 0.71 43.2%
3a 13068 0.30 0.27 0.01 0.00 0.00 0.02 0.90 0.90 1.00 93.0%
3b 219689 5.04 1.00 0.63 1.10 0.00 2.31 0.63 0.63 0.79 50.8%
4 299842 6.88 0.00 0.17 0.55 0.00 6.17 0.32 0.32 0.40 9.4%
5a 29480 0.68 0.21 0.11 0.14 0.00 0.21 0.73 0.73 0.91 64.7%
5b 119579 2.75 0.54 0.35 0.55 0.00 1.30 0.62 0.62 0.77 49.2%
6 324634 7.45 0.00 0.18 0.60 0.00 6.68 0.32 0.32 0.40 9.4%
Overland Flow, Time of Concentration:
Project: 1324-001
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = T
i + Tt
(Equation RO-2)
Velocity (Gutter Flow), V = 20·S
½
Velocity (Swale Flow), V = 15·S
½
Overland Flow Gutter Flow Swale Flow
Is Length
>500' ?
C5 Length,
L
(ft)
Slope,
S
(%)
Ti
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Tc
(min)
Check
Tc
(min)
Final
Tc
(min)
1a 1a Yes 0.25 500 2.40% 26.0 0 0.00% N/A N/A 263 2.40% 2.32 1.9 27.9 23.5 23.5
1b 1b Yes 0.25 500 3.10% 23.9 0 0.00% N/A N/A 420 3.10% 2.64 2.7 26.5 25.3 25.3
2 2 No 0.25 110 2.00% 13.0 1132 2.30% 3.03 6.2 0 0.00% N/A N/A 19.2 17.7 17.7
3a 3a No 0.25 122 2.00% 13.7 392 3.10% 3.52 1.9 0 0.00% N/A N/A 15.5 5.5 5.5
3b 3b No 0.25 17 2.00% 5.1 580 2.60% 3.22 3.0 0 0.00% N/A N/A 8.1 12.9 8.1
4 4 No 0.25 178 2.00% 16.5 0 0.00% N/A N/A 0 0.00% N/A N/A 16.5 18.1 16.5
Rational Method Equation: Project: 1324-001
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1a 1a 8.90 24 0.29 0.29 0.36 1.48 2.52 5.15 3.78 6.45 16.47
1b 1b 2.89 25 0.25 0.25 0.31 1.43 2.44 4.98 1.03 1.76 4.50
2 2 2.96 18 0.57 0.57 0.71 1.73 2.95 6.01 2.91 4.97 12.68
3a 3a 0.30 6 0.90 0.90 1.00 2.76 4.72 9.63 0.75 1.28 2.89
3b 3b 5.04 8 0.63 0.63 0.79 2.40 4.10 8.38 7.62 13.02 33.28
4 4 6.88 17 0.32 0.32 0.40 1.78 3.04 6.20 3.96 6.74 17.22
5a 5a 0.68 10 0.73 0.73 0.91 2.26 3.86 7.88 1.11 1.90 4.86
5b 5b 2.75 13 0.62 0.62 0.77 1.98 3.39 6.92 3.36 5.75 14.66
6 6 7.45 25 0.32 0.32 0.40 1.45 2.47 5.04 3.48 5.93 15.14
7 7 12.33 19 0.58 0.58 0.73 1.68 2.86 5.84 12.02 20.53 52.36
8 8 9.45 23 0.30 0.30 0.37 1.51 2.58 5.26 4.26 7.28 18.56
9a 9a 2.47 22 0.33 0.33 0.42 1.53 2.61 5.32 1.26 2.15 5.49
9b 9b 8.42 19 0.26 0.26 0.33 1.65 2.82 5.75 3.68 6.29 16.03
10 10 2.63 21 0.25 0.25 0.31 1.56 2.67 5.46 1.03 1.76 4.49
OS1a OS1a 1.91 23 0.67 0.67 0.84 1.51 2.58 5.26 1.93 3.30 8.42
OS1b OS1b 2.41 25 0.68 0.68 0.86 1.45 2.47 5.04 2.38 4.06 10.36
OS2 OS2 0.26 9 0.73 0.73 0.91 2.30 3.93 8.03 0.43 0.74 1.88
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Area, A
(acres)
Intensity,
i2
(in/hr)
DEVELOPED RUNOFF COMPUTATIONS
C100
Design
Point
Flow,
Q100
(cfs)
Flow,
Q2
(cfs)
Tc
(min)
C2
Flow,
Q10
(cfs)
Intensity,
i100
(in/hr)
Basin(s)
ATC
September 1, 2019
Q C f C i A
H2a
OS3
OS4
OS3
OS4
H2b
H1a H1b
OS5
OS5
H2b
H2a
H1a H1b
12" CMP
ST
14" CMP
24" CMP
12" CMP
HISTORIC
PONDING
AREA H1a
HISTORIC
PONDING
AREA H2a
HISTORIC
PONDING
AREA H2b
APPROX. EXTENTS OF
HISTORIC 100-YR
OVERTOPPING
ST
HISTORIC DRAINAGE EXHIBIT
ENGINEER ING 1324-001
N O R T H E RN
08.25.19
D:\PROJECTS\1324-001\DWG\DRNG\1324-001-HISTOFFSITE.DWG
( IN FEET )
1 inch = ft.
300 0 300 Feet
300
NORTH
Project: 1324-001
By: ATC
Date: 9/3/19
Pond ID
Historic 100-Yr. Attenuation Vol.
(Ac-Ft)
Peak Release/Overflow
(cfs)
H1a 4.55 1.43
H2a 0.26 35.07
H2b 7.32 80.56
HISTORIC CONDITIONS SWMM MODELING SUMMARY TABLE
Pond Stage-Storage Curve
Pond: Historic Attenuation-H1a
Project: 1324-001
By: ATC
Date: 8/27/19
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
5077.60 77634.00 0.00 0.00
5078.370 87652.00 63532.52 1.46
5079.000 92542.51 120230.06 2.76
5080.000 141176.77 236121.01 5.42
5081.000 170880.99 391757.93 8.99
Pond Stage-Storage Curve
Pond: Historic Attenuation-H2a
Project: 1324-001
By: ATC
Date: 8/27/19
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
5073.000 2662.64 0.00 0.00
5074.000 4550.04 3560.89 0.08
5075.000 11912.43 11494.51 0.26
Pond Stage-Storage Curve
Pond: Historic Attenuation-H2b
Project: 1324-001
By: ATC
Date: 8/27/19
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
5065.000 21393.00 0.00 0.00
5066.000 57548.85 37972 0.87
5066.540 68761.00 71997 1.65
5067.000 101536.55 110882 2.55
5068.000 149900.73 235693 5.41
5068.500 163297.55 313890.40 7.21
ORIFICE RATING CURVE
Historic Attenuation H1a
Existing 12-inch Dia. CMP
PROJECT: 1324-001
DATE: 8/26/19
BY: ATC
ORIFICE RATING (ASSUME 50% BLOCKAGE)
Orifice Dia (in) 12
Orifice Area (sf) 0.7854
Orifice invert (ft) 5078.37
Orifice Coefficient 0.65
Outlet
Stage release
(FT) (CFS)
5078.37 0.00
5079.00 0.74
5079.50 1.63
5080.00 2.18
5080.50 2.62
5081.00 2.99
5081.50 3.32
ORIFICE RATING CURVE
Historic Attenuation H2b
Existing 24-inch Dia. CMP
PROJECT: 1324-001
DATE: 8/26/19
BY: ATC
ORIFICE RATING (ASSUME 50% BLOCKAGE)
Orifice Dia (in) 24
Orifice Area (sf) 3.1416
Orifice invert (ft) 5066.54
Orifice Coefficient 0.65
Outlet
Stage release
(FT) (CFS)
5066.54 0.00
5067.00 1.80
5067.50 3.62
5068.00 5.56
5068.50 8.03
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 ............ 01/01/2000 00:00:00
Ending Date .............. 01/06/2000 01:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 40.122 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 20.047 1.833
Surface Runoff ........... 20.057 1.834
SWMM 5 Page 1
Final Storage ............ 0.093 0.008
Continuity Error (%) ..... -0.186
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 20.057 6.536
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 16.437 5.356
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 ...... 3.592 1.170
Continuity Error (%) ..... 0.142
********************************
Highest Flow Instability Indexes
********************************
All links are stable.
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 29.00 sec
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
Percent Not Converging : 0.00
***************************
Subcatchment Runoff Summary
***************************
SWMM 5 Page 2
--------------------------------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------------------------------
H1a 3.67 0.00 0.00 1.92 1.75 0.79 24.21 0.476
OS4 3.67 0.00 0.00 1.66 2.00 2.13 99.04 0.545
H2b 3.67 0.00 0.00 2.11 1.56 1.23 31.65 0.426
H2a 3.67 0.00 0.00 1.98 1.69 1.27 37.46 0.461
H1b 3.67 0.00 0.00 1.75 1.92 0.36 13.41 0.523
OS5 3.67 0.00 0.00 0.60 3.04 0.09 9.81 0.827
OS3 3.67 0.00 0.00 1.38 2.28 0.66 38.37 0.622
******************
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
---------------------------------------------------------------------------------
Outfall2 OUTFALL 0.00 0.00 100.00 0 00:00 0.00
Outfall1 OUTFALL 0.00 0.00 100.00 0 00:00 0.00
P_H1a STORAGE 1.04 1.88 103.88 0 02:54 1.88
P_H2b STORAGE 1.67 3.47 105.47 0 01:37 3.46
P_H2a STORAGE 1.50 1.99 105.99 0 00:52 1.97
*******************
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
-------------------------------------------------------------------------------------------------
SWMM 5 Page 3
Outfall2 OUTFALL 0.00 81.95 0 01:37 0 4.35 0.000
Outfall1 OUTFALL 0.00 1.43 0 02:54 0 1 0.000
P_H1a STORAGE 70.41 70.41 0 00:40 1.55 1.55 0.004
P_H2b STORAGE 139.14 156.20 0 00:41 3.72 4.93 0.117
P_H2a STORAGE 37.46 37.46 0 00:50 1.27 1.27 0.271
*********************
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
--------------------------------------------------------------------------------------------------
P_H1a 98.424 4 0 0 198.495 9 0 02:53 1.43
P_H2b 90.871 4 0 0 320.367 13 0 01:37 81.95
P_H2a 6.816 2 0 0 11.758 3 0 00:52 36.97
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg Max Total
Freq Flow Flow Volume
Outfall Node Pcnt CFS CFS 10^6 gal
-----------------------------------------------------------
Outfall2 47.49 2.81 81.95 4.352
Outfall1 99.26 0.31 1.43 1.003
-----------------------------------------------------------
System 73.38 3.12 82.89 5.356
SWMM 5 Page 4
********************
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
-----------------------------------------------------------------------------
Out_H1a DUMMY 1.43 0 02:54
Out_H2b DUMMY 81.95 0 01:37
Out_H2a DUMMY 36.97 0 00:52
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Thu Sep 05 15:18:44 2019
Analysis ended on: Thu Sep 05 15:18:44 2019
Total elapsed time: < 1 sec
SWMM 5 Page 5
Link Out_H1a Flow (CFS)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
SWMM 5 Page 1
Node P_H1a Volume (ft3)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
200000.0
180000.0
160000.0
140000.0
120000.0
100000.0
80000.0
60000.0
40000.0
20000.0
0.0
SWMM 5 Page 1
Link Out_H2a Flow (CFS)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
SWMM 5 Page 1
Node P_H2a Volume (ft3)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
12000.0
10000.0
8000.0
6000.0
4000.0
2000.0
0.0
SWMM 5 Page 1
Link Out_H2b Flow (CFS)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
90.0
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
SWMM 5 Page 1
Node P_H2b Volume (ft3)
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
350000.0
300000.0
250000.0
200000.0
150000.0
100000.0
50000.0
0.0
SWMM 5 Page 1
APPENDIX B
USDA Soils Information
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 22, 2016
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 (http://
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 alternative means
2
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..................................................................................................................7
Soil Map................................................................................................................8
Legend..................................................................................................................9
Map Unit Legend................................................................................................10
Map Unit Descriptions........................................................................................10
Larimer County Area, Colorado......................................................................12
35—Fort Collins loam, 0 to 3 percent slopes..............................................12
36—Fort Collins loam, 3 to 5 percent slopes..............................................13
37—Fort Collins loam, 5 to 9 percent slopes..............................................14
48—Heldt clay loam, 0 to 3 percent slopes.................................................16
63—Longmont clay, 0 to 3 percent slopes..................................................17
95—Satanta loam, 1 to 3 percent slopes....................................................18
103—Stoneham loam, 5 to 9 percent slopes..............................................19
Soil Information for All Uses...............................................................................22
Soil Properties and Qualities..............................................................................22
Soil Qualities and Features.............................................................................22
Hydrologic Soil Group (BOMA)...................................................................22
References............................................................................................................27
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
scientists classified and named the soils in the survey area, they compared the
5
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
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
6
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.
7
8
Custom Soil Resource Report
Soil Map
4498300 4498400 4498500 4498600 4498700 4498800
4498300 4498400 4498500 4498600 4498700 4498800
495900 496000 496100 496200 496300 496400 496500 496600 496700 496800
495900 496000 496100 496200 496300 496400 496500 496600 496700 496800
40° 38' 25'' N
105° 2' 57'' W
40° 38' 25'' N
105° 2' 15'' W
40° 38' 4'' N
105° 2' 57'' W
40° 38' 4'' N
105° 2' 15'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 200 400 800 1200
Feet
0 50 100 200 300
Meters
Map Scale: 1:4,470 if printed on A landscape (11" x 8.5") sheet.
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: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
35 Fort Collins loam, 0 to 3 percent
slopes
28.2 36.0%
36 Fort Collins loam, 3 to 5 percent
slopes
18.8 23.9%
37 Fort Collins loam, 5 to 9 percent
slopes
9.1 11.6%
48 Heldt clay loam, 0 to 3 percent
slopes
2.3 3.0%
63 Longmont clay, 0 to 3 percent
slopes
13.9 17.7%
95 Satanta loam, 1 to 3 percent
slopes
1.6 2.0%
103 Stoneham loam, 5 to 9 percent
slopes
4.5 5.7%
Totals for Area of Interest 78.4 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the soils
or miscellaneous areas in the survey area. The map unit descriptions, along with the
maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the landscape,
however, the soils are natural phenomena, and they have the characteristic variability
of all natural phenomena. Thus, the range of some observed properties may extend
beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic
class rarely, if ever, can be mapped without including areas of other taxonomic
classes. Consequently, every map unit is made up of the soils or miscellaneous areas
for which it is named and some minor components that belong to taxonomic classes
other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They generally
are in small areas and could not be mapped separately because of the scale used.
Some small areas of strongly contrasting soils or miscellaneous areas are identified
by a special symbol on the maps. If included in the database for a given area, the
contrasting minor components are identified in the map unit descriptions along with
Custom Soil Resource Report
10
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 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
11
Larimer County Area, Colorado
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
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
Custom Soil Resource Report
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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
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:
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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)
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
Custom Soil Resource Report
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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:
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
Custom Soil Resource Report
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48—Heldt clay loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpwq
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
Heldt and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Heldt
Setting
Landform: Fans, valley sides
Landform position (three-dimensional): Base slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Clayey alluvium derived from shale
Typical profile
H1 - 0 to 4 inches: clay loam
H2 - 4 to 60 inches: silty clay, clay loam, clay
H2 - 4 to 60 inches:
H2 - 4 to 60 inches:
Properties and qualities
Slope: 0 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well 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: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 10 percent
Gypsum, maximum in profile: 5 percent
Salinity, maximum in profile: Nonsaline to moderately saline (0.0 to 8.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 10.0
Available water storage in profile: Very high (about 27.6 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Custom Soil Resource Report
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Hydric soil rating: No
Minor Components
Renohill
Percent of map unit: 5 percent
Hydric soil rating: No
Ulm
Percent of map unit: 5 percent
Hydric soil rating: No
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: Valleys, flood plains
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
Custom Soil Resource Report
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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)
Hydric soil rating: No
Minor Components
Heldt
Percent of map unit: 5 percent
Hydric soil rating: No
Dacono
Percent of map unit: 5 percent
Hydric soil rating: No
Aquolls
Percent of map unit: 5 percent
Landform: Swales
Hydric soil rating: Yes
95—Satanta loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpyd
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
Satanta and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta
Setting
Landform: Terraces
Landform position (three-dimensional): Side slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium and/or eolian deposits
Custom Soil Resource Report
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Typical profile
H1 - 0 to 10 inches: loam
H2 - 10 to 18 inches: loam, clay loam, sandy clay loam
H2 - 10 to 18 inches: loam, clay loam, fine sandy loam
H2 - 10 to 18 inches:
H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
Properties and qualities
Slope: 1 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
(0.60 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: 10 percent
Available water storage in profile: Very high (about 27.1 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
Minor Components
Fort collins
Percent of map unit: 5 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 5 percent
Hydric soil rating: No
Altvan
Percent of map unit: 5 percent
Hydric soil rating: No
103—Stoneham loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jptw
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
Custom Soil Resource Report
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Map Unit Composition
Stoneham and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Stoneham
Setting
Landform: Benches, terraces
Landform position (three-dimensional): Side slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium and/or eolian deposits
Typical profile
H1 - 0 to 3 inches: loam
H2 - 3 to 9 inches: clay loam, sandy clay loam, loam
H2 - 3 to 9 inches: loam, clay loam, sandy clay loam
H2 - 3 to 9 inches:
H3 - 9 to 60 inches:
H3 - 9 to 60 inches:
H3 - 9 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 27.7 inches)
Interpretive groups
Land capability classification (irrigated): 6e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Kim
Percent of map unit: 8 percent
Hydric soil rating: No
Larimer
Percent of map unit: 5 percent
Hydric soil rating: No
Fort collins
Percent of map unit: 2 percent
Hydric soil rating: No
Custom Soil Resource Report
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Custom Soil Resource Report
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Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and qualities
displayed as thematic maps with a summary table for the soil map units in the selected
area of interest. A single value or rating for each map unit is generated by aggregating
the interpretive ratings of individual map unit components. This aggregation process
is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly measured,
but are inferred from observations of dynamic conditions and from soil properties.
Example soil qualities include natural drainage, and frost action. Soil features are
attributes that are not directly part of the soil. Example soil features include slope and
depth to restrictive layer. These features can greatly impact the use and management
of the soil.
Hydrologic Soil Group (BOMA)
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.
22
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or soils
of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential,
soils that have a high water table, soils that have a claypan or clay layer at or near the
surface, and soils that are shallow over nearly impervious material. These soils have
a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for
drained areas and the second is for undrained areas. Only the soils that in their natural
condition are in group D are assigned to dual classes.
Custom Soil Resource Report
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24
Custom Soil Resource Report
Map—Hydrologic Soil Group (BOMA)
4498300 4498400 4498500 4498600 4498700 4498800
4498300 4498400 4498500 4498600 4498700 4498800
495900 496000 496100 496200 496300 496400 496500 496600 496700 496800
495900 496000 496100 496200 496300 496400 496500 496600 496700 496800
40° 38' 25'' N
105° 2' 57'' W
40° 38' 25'' N
105° 2' 15'' W
40° 38' 4'' N
105° 2' 57'' W
40° 38' 4'' N
105° 2' 15'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 200 400 800 1200
Feet
0 50 100 200 300
Meters
Map Scale: 1:4,470 if printed on A landscape (11" x 8.5") sheet.
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: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Table—Hydrologic Soil Group (BOMA)
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
35 Fort Collins loam, 0 to 3
percent slopes
C 28.2 36.0%
36 Fort Collins loam, 3 to 5
percent slopes
B 18.8 23.9%
37 Fort Collins loam, 5 to 9
percent slopes
B 9.1 11.6%
48 Heldt clay loam, 0 to 3
percent slopes
C 2.3 3.0%
63 Longmont clay, 0 to 3
percent slopes
D 13.9 17.7%
95 Satanta loam, 1 to 3
percent slopes
B 1.6 2.0%
103 Stoneham loam, 5 to 9
percent slopes
B 4.5 5.7%
Totals for Area of Interest 78.4 100.0%
Rating Options—Hydrologic Soil Group (BOMA)
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
26
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
27
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
28
APPENDIX C
SWMM Modeling; Detention Computations and Emergency
Overflow/Blocked Outlet Scenario Modeling
Project: 1324-001
By: ATC
Date: 6/8/20
Pond ID
100-Yr.
Detention Vol.
(Ac-Ft)
Water Quality
Capture Volume (Ac-
Ft)
Water Quality
Capture Volume
WSEL (Ft)
Total Req'd
Vol. (Ac-Ft)
100-Yr.
WSEL (Ft)
Peak
Release
(cfs)
Pond 1 8.76 0.32 5059.80 9.08 5063.40 0.88
Pond 2 1.70 N/A N/A 1.70 5079.90 3.20
POND SUMMARY TABLE
Pond Stage-Storage Curve
Pond: 1
Project: 1324-001
By: ATC
Date: 6/8/20
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
5058.200 48.710 0.000 0.000
5058.400 597.680 54.470 0.001
5058.600 1759.870 280.010 0.006
5058.800 3578.830 803.230 0.018
5059.000 6287.630 1777.240 0.041
5059.200 10115.310 3402.440 0.078
5059.400 15145.990 5911.710 0.136
5059.600 21289.630 9537.880 0.219
5059.800 28228.330 14473.390 0.332
5060.000 35737.180 20855.200 0.479
5060.200 43678.970 28783.540 0.661
5060.4 51889.26 38328.59 0.880
5060.6 60392.5 49546.02 1.137
5060.8 69270.25 62502.15 1.435
5061 78660.26 77285.26 1.774
5061.2 88591.94 94000.64 2.158
5061.4 99088.93 112758.93 2.589
5061.6 110130.68 133671.18 3.069
5061.8 121550.39 156829.9 3.600
5062 131569.59 182135.28 4.181
5062.2 140567.24 209344.01 4.806
5062.4 149442.81 238340.48 5.472
5062.6 158099.32 269090.64 6.177
5062.8 165183.42 301416.32 6.920
5063 171162.65 335049.16 7.692
5063.2 176199.99 369784.2 8.489
5063.4 179963.31 405399.87 9.307
5063.6 183768.39 441772.38 10.142
5063.8 187611.22 478909.68 10.994
5064 191537.24 516823.84 11.865
5064.2 195630.81 555539.93 12.753
5064.4 199900.88 595092.33 13.661
5064.6 204357.26 635517.32 14.589
5064.8 209011.82 676853.36 15.538
5065 213876.56 719141.26 16.509
5065.2 218953.49 762423.28 17.503
5065.4 224220.43 806739.63 18.520
5065.6 229676.88 852128.26 19.562
5065.8 235133.33 897516.89 20.604
Pond Stage-Storage Curve
Pond: 2
Project: 1324-001
By: ATC
Date: 6/8/20
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
5,078.200 21504.78 0.00 0.00
5,078.400 23374.76 4482.17 0.10
5,078.500 25407.34 6918.13 0.16
5,078.600 27616.68 9565.91 0.22
5,078.600 30018.13 9565.91 0.22
5,078.800 32628.40 15822.49 0.36
5,079.200 34,447.64 29222.64 0.67
5,079.400 70,812.82 39522.33 0.91
5,079.600 76,556.18 54240.77 1.25
5,079.800 82,173.55 70094.56 1.61
5,080.000 86,215.46 86915.00 2.00
5,080.200 90,062.64 104523.79 2.40
5,080.400 93,938.76 122904.17 2.82
5080.600 113200.39 143567.48 3.30
5080.850 113501.80 171876.91 3.95
ORIFICE RATING CURVE
Pond 1
100-yr Orifice
PROJECT: 1324-001
DATE: 6/8/20
BY: ATC
ORIFICE RATING
Orifice Dia (in) 3 3/4
Orifice Area (sf) 0.0747
Orifice invert (ft) 5058.2
Orifice Coefficient 0.65
Outlet
Stage release
(FT) (CFS)
5058.20 0.00
5058.40 0.08
5058.60 0.19
5058.80 0.26
5059.00 0.31
5059.20 0.36
5059.40 0.40
5059.60 0.43
5059.80 0.47
5060.00 0.50
5060.20 0.53
5060.40 0.56
5060.60 0.58
5060.80 0.61
5061.00 0.63
5061.20 0.66
5061.40 0.68
5061.60 0.70
5061.80 0.72
5062.00 0.74
5062.20 0.76
5062.40 0.78
5062.60 0.80
5062.80 0.82
5063.00 0.84
5063.20 0.86
5063.40 0.87
5063.60 0.89
5063.80 0.91
5064.00 0.93
5064.20 0.94
5064.40 0.96
5064.60 0.97
5064.80 0.99
5065.00 1.00
5065.20 1.02
5065.40 1.03
5065.60 1.05
ORIFICE RATING CURVE
Pond 2
100-yr Orifice
PROJECT: 1324-001
DATE: 6/8/20
BY: ATC
ORIFICE RATING
Orifice Dia (in) 8 3/4
Orifice Area (sf) 0.4224
Orifice invert (ft) 5077.4
Orifice Coefficient 0.65
Outlet
Stage release
(FT) (CFS)
5077.40 0.000
5077.65 0.000
5077.90 0.000
5078.15 0.000
5078.40 1.753
5078.65 2.071
5078.90 2.345
5079.15 2.591
5079.40 2.816
5079.65 3.024
5079.90 3.218
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.014)
--------------------------------------------------------------
*********************************************************
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 ............ 01/01/2000 00:00:00
Ending Date .............. 01/06/2000 01:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
SWMM 5 Page 1
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 14.548 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 4.905 1.237
Surface Runoff ........... 9.575 2.415
Final Storage ............ 0.123 0.031
Continuity Error (%) ..... -0.375
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 9.575 3.120
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 8.481 2.764
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 ...... 1.093 0.356
Continuity Error (%) ..... 0.007
********************************
Highest Flow Instability Indexes
********************************
All links are stable.
SWMM 5 Page 2
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 29.00 sec
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
Percent Not Converging : 0.00
***************************
Subcatchment Runoff Summary
***************************
------------------------------------------------------------------------------------------------------------------------------
Total Total Total Total Imperv Perv Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Runoff Runoff Coeff
Subcatchment in in in in in in in 10^6 gal CFS
------------------------------------------------------------------------------------------------------------------------------
SW-2 3.67 0.00 0.00 1.48 0.84 1.33 2.17 0.72 38.83 0.592
SW-1 3.67 0.00 0.00 1.15 1.21 1.29 2.50 2.40 160.83 0.681
******************
Node Depth Summary
******************
---------------------------------------------------------------------------------
Average Maximum Maximum Time of Max Reported
Depth Depth HGL Occurrence Max Depth
SWMM 5 Page 3
Node Type Feet Feet Feet days hr:min Feet
---------------------------------------------------------------------------------
outfall OUTFALL 0.00 0.00 96.00 0 00:00 0.00
Pond_2 STORAGE 0.13 1.97 103.97 0 02:21 1.97
Pond_1 STORAGE 3.86 4.97 105.97 0 11:45 4.97
*******************
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
-------------------------------------------------------------------------------------------------
outfall OUTFALL 0.00 0.88 0 11:45 0 2.76 0.000
Pond_2 STORAGE 38.83 38.83 0 00:40 0.72 0.72 0.031
Pond_1 STORAGE 160.83 162.39 0 00:40 2.4 3.12 0.000
*********************
Node Flooding Summary
*********************
No nodes were flooded.
**********************
Storage Volume Summary
**********************
SWMM 5 Page 4
--------------------------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------------------------
Pond_2 3.512 0 0 0 74.134 3 0 02:21 3.26
Pond_1 223.154 14 0 0 376.908 24 0 11:45 0.88
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg Max Total
Freq Flow Flow Volume
Outfall Node Pcnt CFS CFS 10^6 gal
-----------------------------------------------------------
outfall 99.86 0.85 0.88 2.763
-----------------------------------------------------------
System 99.86 0.85 0.88 2.763
********************
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
-----------------------------------------------------------------------------
Out_2 DUMMY 3.26 0 02:21
SWMM 5 Page 5
Out_1 DUMMY 0.88 0 11:45
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Mon Jun 8 13:48:24 2020
Analysis ended on: Mon Jun 8 13:48:24 2020
Total elapsed time: < 1 sec
SWMM 5 Page 6
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
1.0
0.8
0.6
0.4
0.2
0.0
Link Out_1 Flow (CFS)
SWMM 5 Page 1
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
400000.0
350000.0
300000.0
250000.0
200000.0
150000.0
100000.0
50000.0
0.0
Node Pond_1 Volume (ft3)
SWMM 5 Page 1
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Link Out_2 Flow (CFS)
SWMM 5 Page 1
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
80000.0
70000.0
60000.0
50000.0
40000.0
30000.0
20000.0
10000.0
0.0
Node Pond_2 Volume (ft3)
SWMM 5 Page 1
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.014)
--------------------------------------------------------------
*********************************************************
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 ............ 01/01/2000 00:00:00
Ending Date .............. 01/06/2000 01:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
SWMM 5 Page 1
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 40.040 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 17.747 1.626
Surface Runoff ........... 22.179 2.032
Final Storage ............ 0.219 0.020
Continuity Error (%) ..... -0.261
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 22.179 7.227
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 10.752 3.504
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 ...... 11.426 3.723
Continuity Error (%) ..... 0.003
********************************
Highest Flow Instability Indexes
********************************
All links are stable.
SWMM 5 Page 2
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 29.00 sec
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
Percent Not Converging : 0.00
***************************
Subcatchment Runoff Summary
***************************
------------------------------------------------------------------------------------------------------------------------------
Total Total Total Total Imperv Perv Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Runoff Runoff Coeff
Subcatchment in in in in in in in 10^6 gal CFS
------------------------------------------------------------------------------------------------------------------------------
SW-2 3.67 0.00 0.00 1.48 0.84 1.33 2.17 0.72 38.83 0.592
SW-1 3.67 0.00 0.00 1.15 1.21 1.29 2.50 2.40 160.83 0.681
SW-Onsite-Undev 3.67 0.00 0.00 1.86 0.07 1.74 1.81 1.40 47.14 0.493
SW-Offsite 3.67 0.00 0.00 1.84 0.72 1.10 1.82 2.71 126.48 0.495
******************
Node Depth Summary
******************
---------------------------------------------------------------------------------
SWMM 5 Page 3
Average Maximum Maximum Time of Max Reported
Depth Depth HGL Occurrence Max Depth
Node Type Feet Feet Feet days hr:min Feet
---------------------------------------------------------------------------------
outfall OUTFALL 0.00 0.00 96.00 0 00:00 0.00
Pond_2 STORAGE 0.13 1.97 103.97 0 02:21 1.97
Pond_1 STORAGE 6.59 7.45 108.45 0 03:04 7.45
*******************
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
-------------------------------------------------------------------------------------------------
outfall OUTFALL 0.00 9.67 0 03:04 0 3.5 0.000
Pond_2 STORAGE 38.83 38.83 0 00:40 0.72 0.72 0.031
Pond_1 STORAGE 328.57 330.13 0 00:40 6.51 7.23 -0.000
*********************
Node Flooding Summary
*********************
No nodes were flooded.
**********************
Storage Volume Summary
SWMM 5 Page 4
**********************
--------------------------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------------------------
Pond_2 3.512 0 0 0 74.134 3 0 02:21 3.26
Pond_1 687.418 45 0 0 869.809 56 0 03:04 9.67
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg Max Total
Freq Flow Flow Volume
Outfall Node Pcnt CFS CFS 10^6 gal
-----------------------------------------------------------
outfall 99.86 1.08 9.67 3.504
-----------------------------------------------------------
System 99.86 1.08 9.67 3.504
********************
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
SWMM 5 Page 5
-----------------------------------------------------------------------------
Out_2 DUMMY 3.26 0 02:21
Out_1 DUMMY 9.67 0 03:04
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Mon Jun 8 13:53:38 2020
Analysis ended on: Mon Jun 8 13:53:38 2020
Total elapsed time: < 1 sec
SWMM 5 Page 6
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Flow (CFS)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
Link Out_1 Flow (CFS)
SWMM 5 Page 1
Elapsed Time (hours)
0 20 40 60 80 100 120 140
Volume (ft3)
900000.0
800000.0
700000.0
600000.0
500000.0
400000.0
300000.0
200000.0
100000.0
0.0
Node Pond_1 Volume (ft3)
SWMM 5 Page 1
APPENDIX D
Water Quality, LID Computations and Information, State Drain Time
Computations
B M
V.P.
V.P.
A.R.V.
GAS
GAS
V.P. V.P.
X
X
X
/ / / / / / / /
X
X
V.P.
X X
X
X
X X
X
X
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
M
X
X
F
E
S
M
M
F
E
S
F
E
S
MM
TELE
F.O.
TELE
F
E
S
F
E
S
F
E
S
MM
/ / / / / / / /
/ / / / / / / /
MGAS
F
E
S
F
E
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 59.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.590
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.19 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 349,351 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 5,423.2 cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 4122 sq ft
D) Actual Flat Surface Area AActual = 5204 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 6740 sq ft
F) Rain Garden Total Volume VT= 5,723 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)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Rain Garden #1
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
RainGarden1 - UD.xlsm, RG 10/16/2019, 1:45 PM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Rain Garden #1
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
RainGarden1 - UD.xlsm, RG 10/16/2019, 1:45 PM
Trapezoidal Weir Performance Curve:
Raingarden #1 100-year Overflow Weir
Project: 1324-001
Date: 06.09.2020
By: BPM
Governing Equation:
The trapezoidal weir is a broad-crested weir governed by the following equation:
* where Q = discharge (cfs)
* where C w = weir coefficient
* where L = crest length (ft)
* where H = head on weir (ft)
* where b = 1.5
For 4:1 side slopes, θ = 151.9276° so that tan (θ/2) = 4
Input Parameters:
Length of Crest (ft): 20
Weir Coefficient: 2.60
Depth vs. Flow:
Depth Above Crest (ft)
0.00
0.10
0.15
0.20
0.27
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Q100= 7.7
Emergency Overflow Weir Discharge (cfs)
0.0
1.7
4.8
9.0
7.7
60.3
3.0
14.0
19.9
26.5
33.9
42.0
50.8
b
Q C w L H H
= +
RG 1 Stage Storage.txt
Project:
Basin Description:
Contour Contour Depth Incremental Cumulative Incremental Cumulative
Elevation Area (ft) Volume Volume Volume Volume
(sq. ft) Avg. End Avg. End Conic Conic
(cu. ft) (cu. ft) (cu. ft) (cu. ft)
5,069.300 5,204.85 N/A N/A 0.00 N/A 0.00
5,069.400 5,361.73 0.100 528.33 528.33 528.31 528.31
5,069.500 5,519.55 0.100 544.06 1072.39 544.05 1072.36
5,069.600 5,678.31 0.100 559.89 1632.29 559.87 1632.23
5,069.700 5,838.01 0.100 575.82 2208.10 575.80 2208.03
5,069.800 5,998.65 0.100 591.83 2799.94 591.81 2799.84
5,069.900 6,160.22 0.100 607.94 3407.88 607.93 3407.77
5,070.000 6,322.74 0.100 624.15 4032.03 624.13 4031.90
5,070.100 6,486.20 0.100 640.45 4672.47 640.43 4672.33
5,070.200 6,650.60 0.100 656.84 5329.31 656.82 5329.15
5,070.300 12,507.54 0.100 957.91 6287.22 942.62 6271.77
Page 1
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 41.5 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.415
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 = 676,922 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 8,294.2 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 = 7 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 = 5618 sq ft
D) Actual Flat Surface Area AActual = 14668 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 16420 sq ft
F) Rain Garden Total Volume VT= 9,067 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)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Raingarden #2
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
RainGarden2 - UD.xlsm, RG 10/16/2019, 1:43 PM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Raingarden #2
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
RainGarden2 - UD.xlsm, RG 10/16/2019, 1:43 PM
Trapezoidal Weir Performance Curve:
Raingarden #2 100-year Overflow Weir
Project: 1324-001
Date: 06.09.2020
By: BPM
Governing Equation:
The trapezoidal weir is a broad-crested weir governed by the following equation:
* where Q = discharge (cfs)
* where C w = weir coefficient
* where L = crest length (ft)
* where H = head on weir (ft)
* where b = 1.5
For 4:1 side slopes, θ = 151.9276° so that tan (θ/2) = 4
Input Parameters:
Length of Crest (ft): 115
Weir Coefficient: 2.60
Depth vs. Flow:
Depth Above Crest (ft)
0.00
0.10
0.20
0.30
0.37
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Q100= 67.9
Emergency Overflow Weir Discharge (cfs)
0.0
9.5
26.9
49.5
307.3
67.2
76.5
107.2
141.3
178.5
218.7
261.7
b
Q C w L H H
= +
2
0 . 8 tan θ
RG 2 Stage Storage.txt
Project:
Basin Description:
Contour Contour Depth Incremental Cumulative Incremental Cumulative
Elevation Area (ft) Volume Volume Volume Volume
(sq. ft) Avg. End Avg. End Conic Conic
(cu. ft) (cu. ft) (cu. ft) (cu. ft)
5,070.000 14,668.09 N/A N/A 0.00 N/A 0.00
5,070.200 15,246.32 0.200 2991.44 2991.44 2991.25 2991.25
5,070.400 15,970.04 0.200 3121.64 6113.08 3121.36 6112.61
5,070.600 16,827.66 0.200 3279.77 9392.85 3279.40 9392.01
5,070.800 17,816.94 0.200 3464.46 12857.31 3463.99 12856.00
Page 1
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 51.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.510
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 275,299 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 3,835.7 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 = 4 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 = 2808 sq ft
D) Actual Flat Surface Area AActual = 11205 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 12133 sq ft
F) Rain Garden Total Volume VT= 3,890 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)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Raingarden #3
UD-BMP (Version 3.06, November 2016)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
RainGarden3 - UD.xlsm, RG 10/16/2019, 1:48 PM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
BPM
Northern Engineering
October 16, 2019
Country Club Reserve
Raingarden #3
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
RainGarden3 - UD.xlsm, RG 10/16/2019, 1:48 PM
Trapezoidal Weir Performance Curve:
Raingarden #3 100-year Overflow Weir
Project: 1324-001
Date: 06.09.2020
By: BPM
Governing Equation:
The trapezoidal weir is a broad-crested weir governed by the following equation:
* where Q = discharge (cfs)
* where C w = weir coefficient
* where L = crest length (ft)
* where H = head on weir (ft)
* where b = 1.5
For 4:1 side slopes, θ = 151.9276° so that tan (θ/2) = 4
Input Parameters:
Length of Crest (ft): 152
Weir Coefficient: 2.60
Depth vs. Flow:
Depth Above Crest (ft)
0.00
0.10
0.20
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Q100= 36.2
287.5
343.8
403.5
65.3
100.8
141.2
186.0
Emergency Overflow Weir Discharge (cfs)
0.0
12.5
35.5
36.3
234.9
b
Q C w L H H
= +
2
0 . 8 tan θ
RG 3 Stage Storage.txt
Project:
Basin Description:
Contour Contour Depth Incremental Cumulative Incremental Cumulative
Elevation Area (ft) Volume Volume Volume Volume
(sq. ft) Avg. End Avg. End Conic Conic
(cu. ft) (cu. ft) (cu. ft) (cu. ft)
5,081.200 11,205.41 N/A N/A 0.00 N/A 0.00
5,081.400 11,791.76 0.200 2299.72 2299.72 2299.47 2299.47
5,081.600 12,452.86 0.200 2424.46 4724.18 2424.16 4723.63
5,081.800 13,211.26 0.200 2566.41 7290.59 2566.04 7289.67
5,082.000 14,105.78 0.200 2731.70 10022.30 2731.22 10020.89
Page 1
WATER QUALITY POND DESIGN CALCULATIONS
Pond 1 - Lower Stage
Project: 1324-001
By: ATC
Date: 5/29/19
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 16.720 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 45.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.4500 <-- CALCULATED
WQCV (watershed inches) = 0.193 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.323 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 2.000 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in2) = 0.891 <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = 1 1/8 <-- INPUT from Figure 5
n = 5 <-- INPUT from Figure 5
t (in) = 1/4 <-- INPUT from Figure 5
number of rows = 1 <-- CALCULATED from WQ Depth and row spacing
Stormwater Facility Name:
Facility Location & Jurisdiction:
User Input: Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope = 0.010 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length = 3468 ft 0.00 0 0.00 0.00
Watershed Area = 35.38 acres 2.00 43,678 2.00 0.53
Watershed Imperviousness = 33.6% percent 4.00 140,567 4.00 0.76
Percentage Hydrologic Soil Group A = percent 6.00 195,630 6.00 0.94
Percentage Hydrologic Soil Group B = 63.0% percent 7.40 229,676 7.40 1.05
Percentage Hydrologic Soil Groups C/D = 37.0% percent
User Input 17
WQCV Treatment Method = 40.00 hours
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period = WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth = 0.53 0.86 1.14 1.43 2.38 2.89 in
Calculated Runoff Volume = 0.478 0.703 1.100 1.711 4.346 5.923 acre-ft
OPTIONAL Override Runoff Volume = acre-ft
Inflow Hydrograph Volume = 0.478 0.702 1.100 1.710 4.346 5.922 acre-ft
Time to Drain 97% of Inflow Volume = 27.2 32.8 40.8 51.6 93.4 115.9 hours
Time to Drain 99% of Inflow Volume = 29.7 35.7 44.3 56.0 100.4 124.1 hours
Maximum Ponding Depth = 1.27 1.56 1.98 2.45 3.64 4.14 ft
Maximum Ponded Area = 0.64 0.78 0.99 1.49 2.82 3.31 acres
Maximum Volume Stored = 0.403 0.609 0.978 1.555 4.129 5.691 acre-ft
Location for 1-hr Rainfall Depths (use dropdown):
Workbook Protected Worksheet Protected
Stormwater Detention and Infiltration Design Data Sheet
Country Club Reserve-POND 1
Fort Collins, CO
SDI_Design_Data_v1.08_Pond1.xlsm, Design Data 6/9/2020, 9:09 AM
WQCV_Trigger = 1
RunOnce= 1
CountA= 1
Draintime Coeff= 1.0
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Area
Discharge
Stormwater Detention and Infiltration Design Data Sheet
0
10
20
30
40
50
60
0.1 1 10
FLOW [cfs]
TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0.1 1 10 100
PONDING DEPTH [ft]
DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
SDI_Design_Data_v1.08_Pond1.xlsm, Design Data 6/9/2020, 9:09 AM
Stormwater Facility Name:
Facility Location & Jurisdiction:
User Input: Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope = 0.010 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length = 1168 ft 0.00 0 0.00 0.00
Watershed Area = 12.20 acres 1.00 34,447 1.00 1.75
Watershed Imperviousness = 23.4% percent 2.00 90,062 2.00 2.81
Percentage Hydrologic Soil Group A = percent 2.50 113,501 2.50 3.21
Percentage Hydrologic Soil Group B = 40.0% percent
Percentage Hydrologic Soil Groups C/D = 60.0% percent
User Input 17
WQCV Treatment Method = 40.00 hours
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period = WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth = 0.53 0.86 1.14 1.43 2.38 2.89 in
Calculated Runoff Volume = 0.131 0.162 0.280 0.472 1.376 1.922 acre-ft
OPTIONAL Override Runoff Volume = acre-ft
Inflow Hydrograph Volume = 0.131 0.161 0.279 0.471 1.375 1.922 acre-ft
Time to Drain 97% of Inflow Volume = 3.5 3.7 4.6 5.7 9.9 12.0 hours
Time to Drain 99% of Inflow Volume = 3.7 4.0 5.0 6.2 10.6 12.9 hours
Maximum Ponding Depth = 0.40 0.46 0.64 0.87 1.57 1.85 ft
Maximum Ponded Area = 0.32 0.36 0.50 0.69 1.51 1.87 acres
Maximum Volume Stored = 0.063 0.082 0.161 0.299 1.046 1.527 acre-ft
Location for 1-hr Rainfall Depths (use dropdown):
Workbook Protected Worksheet Protected
Stormwater Detention and Infiltration Design Data Sheet
Country Club Reserve-POND 2
Fort Collins, CO
SDI_Design_Data_v1.08_Pond3.xlsm, Design Data 6/9/2020, 9:15 AM
WQCV_Trigger = 1
RunOnce= 1
CountA= 1
Draintime Coeff= 1.0
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Area
Discharge
Stormwater Detention and Infiltration Design Data Sheet
0
5
10
15
20
25
30
0.1 1 10
FLOW [cfs]
TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0.1 1 10 100
PONDING DEPTH [ft]
DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
SDI_Design_Data_v1.08_Pond3.xlsm, Design Data 6/9/2020, 9:15 AM
APPENDIX E
Street Capacity Calculations
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 6.3 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.012
Height of Curb at Gutter Flow Line HCURB = 4.70 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 1.17 ft
Street Transverse Slope SX = 0.023 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.008 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 15.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 4.7 10.7 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 8.2 106.0 cfs
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
1324-001
Local Residential Street Capacity - DP 3
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
DP3.xlsm, Q-Allow 12/10/2018, 3:59 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 6.3 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.012
Height of Curb at Gutter Flow Line HCURB = 4.70 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 1.17 ft
Street Transverse Slope SX = 0.023 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.031 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 15.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 4.7 10.7 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 16.1 122.6 cfs
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
1324-001
Local Residential Street Capacity - DP 5a
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
DP5a.xlsm, Q-Allow 12/10/2018, 4:00 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 6.3 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.012
Height of Curb at Gutter Flow Line HCURB = 4.70 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 1.17 ft
Street Transverse Slope SX = 0.023 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.011 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 15.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 4.7 10.7 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 9.6 124.3 cfs
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
1324-001
Local Residential Street Capacity - DP 5b
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
DP5b.xlsm, Q-Allow 12/10/2018, 4:04 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 6.3 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.012
Height of Curb at Gutter Flow Line HCURB = 4.70 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 1.17 ft
Street Transverse Slope SX = 0.023 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.023 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 15.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 4.7 10.7 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 13.8 134.1 cfs
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
1324-001
Local Residential Street Capacity - DP 7
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
DP7.xlsm, Q-Allow 12/10/2018, 4:02 PM
APPENDIX F
Inlet Calculations
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 5.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.200 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.020
Height of Curb at Gutter Flow Line HCURB = 6.00 inches
Distance from Curb Face to Street Crown TCROWN = 20.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.250 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.050 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 10.0 10.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.0 6.0 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 7.6 7.6 cfs
Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Version 4.05 Released March 2017
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Country Club Reserve
Inlets D1, D2, and D3
Inlets D1-D3.xlsm, Inlets D1, D2, and D3 12/11/2018, 2:37 PM
Design Information (Input) MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a') aLOCAL = 3.0 3.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening) No = 2 2
Length of a Single Unit Inlet (Grate or Curb Opening) Lo = 5.00 5.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width) Wo = N/A N/A ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5) Cf-G = N/A N/A
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) Cf-C = 0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity' MINOR MAJOR
Total Inlet Interception Capacity Q = 1.6 1.6 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet) Qb = 0.0 0.0 cfs
Capture Percentage = Qa/Qo = C% = 100 100 %
CDOT Type R Curb Opening
INLET ON A CONTINUOUS GRADE
Version 4.05 Released March 2017
CDOT Type R Curb Opening
Inlets D1-D3.xlsm, Inlets D1, D2, and D3 12/11/2018, 2:37 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 5.6 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.200 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.020
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 1.41 ft
Street Transverse Slope SX = 0.250 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.050 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.012
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 6.0 6.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 4.8 4.8 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 6.6 6.6 cfs
Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Version 4.05 Released March 2017
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Country Club Reserve
Inlets D5 and D6
Inlets D1-D3.xlsm, Inlets D5 and D6 12/11/2018, 4:30 PM
Design Information (Input) MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a') aLOCAL = 4.3 4.3 inches
Total Number of Units in the Inlet (Grate or Curb Opening) No = 1 1
Length of a Single Unit Inlet (Grate or Curb Opening) Lo = 5.00 5.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width) Wo = N/A N/A ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5) Cf-G = N/A N/A
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) Cf-C = 0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity' MINOR MAJOR
Total Inlet Interception Capacity Q = 0.5 0.5 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet) Qb = 0.0 0.0 cfs
Capture Percentage = Qa/Qo = C% = 100 100 %
CDOT Type R Curb Opening
INLET ON A CONTINUOUS GRADE
Version 4.05 Released March 2017
CDOT Type R Curb Opening
Inlets D1-D3.xlsm, Inlets D5 and D6 12/11/2018, 4:30 PM
Area Inlet Performance Curve:
Project: 1324-001
Inlet ID: Inlet A2 (CDOT Type C Inlet)
Governing Equations:
At low flow depths, the inlet will act like a weir governed by the following equation:
* where P = 2(L + W)
* where H corresponds to the depth of water above the flowline
At higher flow depths, the inlet will act like an orifice governed by the following equation:
* where A equals the open area of the inlet grate
* where H corresponds to the depth of water above the centroid of the cross-sectional area (A)
The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown.
However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation
will cross at a certain flow depth. The two curves can be found below:
If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir.
Input Parameters:
Type of Grate: CDOT Type C
Length of Grate (ft): 3.417
Width of Grate (ft): 2.917
Open Area of Grate (ft2): 8.47
Flowline Elevation (ft): 100.000
Allowable Capacity: 50%
Depth vs. Flow:
Depth Above Inlet (ft)
Elevation
(ft)
Shallow
Weir Flow
(cfs)
Orifice
Flow
(cfs)
Actual
Flow
(cfs)
0.00 100.00 0.00 0.00 0.00
0.10 100.10 0.60 7.20 0.60
0.20 100.20 1.70 10.18 1.70
0.30 100.30 3.12 12.47 3.12
0.40 100.40 4.81 14.40 4.81
0.50 100.50 6.72 16.09 6.72
0.60 100.60 8.83 17.63 8.83 Capacity of
0.70 100.70 11.13 19.04 11.13 Existng
0.80 100.80 13.60 20.36 13.60 24-inch CMP
0.90 100.90 16.22 21.59 16.22
1.00 101.00 19.00 22.76 19.00
Inlet designed to match capacity of existing open-ended 24-inch CMP
Q 3 . 0 P H 1 . 5
Q 0 . 67 A ( 2 gH ) 0 . 5
0.00
5.00
10.00
15.00
20.00
25.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Discharge (cfs)
Stage (ft)
Stage - Discharge Curves
Weir Flow
Orifice Flow
Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Jun 8 2020
Design Point 3b
Rectangular Weir
Crest = Sharp
Bottom Length (ft) = 2.00
Total Depth (ft) = 1.25
Calculations
Weir Coeff. Cw = 3.33
Compute by: Known Q
Known Q (cfs) = 7.62
Highlighted
Depth (ft) = 1.09
Q (cfs) = 7.620
Area (sqft) = 2.19
Velocity (ft/s) = 3.48
Top Width (ft) = 2.00
0 .5 1 1.5 2 2.5 3
Depth (ft) Design Point 3b Depth (ft)
-0.50 -0.50
0.00 0.00
0.50 0.50
1.00 1.00
1.50 1.50
2.00 2.00
Length (ft)
Weir W.S.
Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Jun 8 2020
Design Point 7
Rectangular Weir
Crest = Sharp
Bottom Length (ft) = 4.00
Total Depth (ft) = 1.25
Calculations
Weir Coeff. Cw = 3.33
Compute by: Known Q
Known Q (cfs) = 12.02
Highlighted
Depth (ft) = 0.93
Q (cfs) = 12.02
Area (sqft) = 3.74
Velocity (ft/s) = 3.22
Top Width (ft) = 4.00
0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5
Depth (ft) Design Point 7 Depth (ft)
-0.50 -0.50
0.00 0.00
0.50 0.50
1.00 1.00
1.50 1.50
2.00 2.00
Length (ft)
Weir W.S.
APPENDIX G
Storm Line Calculations
APPENDIX H
Riprap Calculations
Circular
D or Da
,
Pipe
Diameter
(ft)
H or Ha
,
Culvert
Height
(ft)
W,
Culvert
Width
(ft)
Yt
/D Q/D
1.5
Q/D
2.5
Yt
/H Q/WH
0.5
Storm Line A 6.20 2.00 1.20 0.60 2.19 1.10 N/A N/A 6.50 1.10 1.03 -7.40 Type L 7.00 9.00 1.5
Storm Line B 13.24 2.00 1.20 0.60 4.68 2.34 N/A N/A 6.50 2.34 2.21 -1.05 Type L 8.00 9.00 1.5
Storm Line C 4.70 1.25 0.75 0.60 3.36 2.69 N/A N/A 6.50 2.69 0.78 -1.34 Type L 5.00 7.00 1.5
Storm Line D 5.95 1.25 0.75 0.60 4.26 3.41 N/A N/A 6.00 3.41 0.99 0.43 Type L 5.00 7.00 1.5
Rain Garden 1 2.89 0.25 115.00 0.25 0.60 N/A N/A 1.00 0.05 6.00 0.20 0.48 10.06 Type L 20.00 5.00 1.5
Rain Garden 2 67.90 0.25 115.00 0.25 0.60 N/A N/A 1.00 1.18 7.00 4.72 11.32 315.12 Type M 30.00 10.00 1.5
Project: 1324-001
Urban Drainage
pg MD-107
L=
1/(2tanq)*
[At/Yt)-W]
(ft)
Expansion
Factor
1/(2tanq)
(From
Figure
MD-23 or
MD-24)
Yt
,
Tailwater
Depth
(ft)
Culvert Parameters
CALCULATIONS FOR RIPRAP PROTECTION AT PIPE OUTLETS
Circular
Pipe
(Figure MD-21)
Rectangular
Pipe
(Figure MD-22) Spec
Width
of
Riprap
(ft)
DRAINAGE CRITERIA MANUAL (V. 1) MAJOR DRAINAGE
Figure MD-21—Riprap Erosion Protection at Circular Conduit Outlet Valid for Q/D
2.5 ≤ 6.0
Rev. 04/2008 MD-107
Urban Drainage and Flood Control District
DRAINAGE CRITERIA MANUAL (V. 1) MAJOR DRAINAGE
Figure MD-23—Expansion Factor for Circular Conduits
Rev. 04/2008 MD-109
Urban Drainage and Flood Control District
APPENDIX I
Erosion Control Report
Country Club Reserve
Final Erosion Control Report
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) have been
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.
MAP POCKET
Drainage Exhibit
V.P.
V.V.P. P.
A.R.V.
GAS
GAS
V.P.
V.P.
X X
X X X X
G
G
G
G
G
G
G
G
G
G
G G
G
G
G
G
G
G
G
G
G
G
G G
G
G
G
/ / / / / / / /
X
X
X
X
X
V.P.
X
X
X
X
X
X X X
X
X
X X X
X
X
X
X
X
X
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
M
X
X
X
X
F
E
S
M
M
F
E
S
F
E
S
MM
X
T
ELE
F.O.
TELE
F
E
S
F
E
S
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
M
GAS
X X
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / / / / / / / / / /
F
E
S
M
F
E
S
T
ELE
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
X
/ / / / / / / /
F
E
S
M
F
E
S
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
X
X X X
/ / / / / / / / / / / / / / / /
/ / / / / / / /
X
W
S
O
X
X
V.P.
VAULT
CABLE
BOX
CABLE
M
M
H2O
X
GAS
V.P.
GAS
OHE OHE OHE
OHE
OHE OHE OHE OHE
OHE
OHE
OHE
B
B
B
B
B
B
B
B
/ / / / / / / /
/ / / / / / / /
ST ST
AW
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / / / / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
G
W
UD
UD
UD
UD
IR
IR
16" W
16" W 16" W
16" W 16" W
16" W 16" W
16" W
16" W 16" W
4
2
7
8
5b
3b 5b
4 5a
3b
2
7
8
10
6
6
1a
1a
10
OS1b
OS1b
OS2
OS2
5a
1b
1b
9a
9
OS3
OS4
OS3
OS4
OS5
OS5
OS1a
OS1a
SIDEWALK CHASE
NATURAL HABITAT
BUFFER ZONE
OUTFALL
PROPOSED FES
EXISTING 24" CMP
PROPOSED FES
SWALE
INLET
INLET
PLEASE SEE DRAINAGE
REPORT FOR HISTORIC
DRAINAGE EXHIBIT
SHOWING FULL EXTENTS
OF OFFSITE BASINS
AND HISTORIC CALCULATIONS
FOR BASINS OS3 - OS5
INLET
INLET
WINGED FOOT DR.
KIAWAH DR.
ROYAL TROON AVE.
E. DOUGLAS ROAD
CARNOUSTIE DR.
BALTUSROL DR.
BETHPAGE DR.
POND 1
RAIN GARDEN 3
RAIN GARDEN 2
TURNBERRY ROAD
RAIN GARDEN 1
INLET (2)
BALTUSROL CT.
PLEASE SEE DRAINAGE
REPORT FOR HISTORIC
DRAINAGE EXHIBIT
SHOWING FULL EXTENTS
OF OFFSITE BASINS
AND HISTORIC CALCULATIONS
FOR BASIN OS4
NO. 8 DITCH
NO. 8 DITCH
RAIN GARDEN 3
100-YEAR OVERFLOW AREA RAIN GARDEN 1
100-YEAR OVERFLOW AREA
RAIN GARDEN 2
100-YEAR OVERFLOW AREA
3a
3a
POND 2
CONCRETE
WEIR
CONCRETE
WEIR
CONCRETE
WEIR
INLET
OUTFALL
RIPRAP
DR1
DRAINAGE EXHIBIT
67
NORTH
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'sbelow.
Call before you dig.
R
( IN FEET )
1 inch = ft.
120 0 120 Feet
120
240 360
Sheet
of 74
COUNTRY CLUB RESERVE 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
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
E NGINEER ING
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
LEGEND:
PROPOSED CONTOUR
PROPOSED STORM SEWER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
DESIGN POINT A
OVERLAND FLOW
DRAINAGE BASIN LABEL
BASIN
DESIGNATION
BASIN
AREA (AC)
DRAINAGE BASIN BOUNDARY
B2
1.45 ac
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
NOTES:
1. REFER TO THE FINAL DRAINAGE REPORT FOR COUNTRY CLUB RESERVE DATED
09.02.2020 FOR ADDITIONAL INFORMATION.
DIRECT FLOW
DRAINAGE SUMMARY TABLE
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C2 C100 Tc
(min)
Q2
(cfs)
Q100
(cfs)
1a 1a 8.90 0.29 0.36 23.5 3.8 16.5
1b 1b 2.89 0.25 0.31 25.3 1.0 4.5
2 2 2.96 0.57 0.71 17.7 2.9 12.7
3 3 5.04 0.63 0.79 13.4 6.3 27.5
4 4 6.88 0.32 0.40 16.5 4.0 17.2
5a 5a 0.68 0.73 0.91 9.7 1.1 4.9
5b 5b 2.75 0.62 0.77 13.5 3.4 14.7
6 6 8.17 0.32 0.40 24.8 3.7 16.3
7 7 12.99 0.57 0.71 19.2 12.1 52.8
8 8 10.72 0.29 0.37 22.6 4.7 20.6
9a 9a 2.47 0.33 0.42 22.2 1.3 5.5
9b 9b 7.52 0.27 0.33 19.4 3.3 14.4
10 10 2.63 0.25 0.31 21.4 1.0 4.5
OS1a OS1a 1.91 0.67 0.84 22.9 1.9 8.4
OS1b OS1b 2.41 0.68 0.86 24.6 2.4 10.4
OS2 OS2 0.26 0.73 0.91 9.5 0.4 1.9
LID Treatment Summary Table
Raingarden ID Total Drainage
Area (Ac.)
Raingarden
Req'd Min.
Volume
(Cu.-Ft.)
Raingarden#1 8.02 5423
Raingarden#2 15.54 8294
Raingarden#3 6.32 3836
Total Newly Developed Area
Treated 29.88 Ac.
Total Newly Developed Area 33.43 Ac.
Percent of Newly Developed Area
Treated 89.38 %
POND SUMMARY TABLE
Pond ID
100-Yr.
Detention
Vol. (Ac-Ft)
Water Quality
Capture Volume
(Ac-Ft)
Total Req'd
Vol. (Ac-Ft)
100-Yr.
WSEL (Ft)
Peak
Release
(cfs)
Pond 1 11.41 0.32 11.73 5066.90 0.82
Pond 3 3.85 N/A 3.85 5080.85 4.80
2*d50
,
Depth
of
Riprap
(ft)
for L/2
Froude
Parameter
Q/D
2.5
Max 6.0
or
Q/WH
1.5
Max 8.0
Riprap
Type
(From
Figure
MD-21 or
MD-22)
By: BPM
CALCULATE
Date: 06.09.2020
At
=Q/V (ft)
INPUT
Storm
Line/Culvert
Label
Design
Discharge
(cfs)
OUTPUT
Spec
Length
of
Riprap
(ft)
Box Culvert
2
0 . 8 tan θ
S
F
E
S
F
E
S
E
E
F
E
S
X
MH
/ / / / / / / /
M
F
E
S
F
E
S
MM
F
E
S
F
E
S
M M
GAS
F
E
S
E E
F
E
S
X
M TELE
X
/ / / / / / / /
/ / / / / / / /
F
E
S
M
F
E
S
TELE
/ / / / / / / /
/ / / / / / / /
F
E
S
M
F
E
S
/ / / / / / / /
/ / / / / / / /
X X
/ / / / / / / /
/ / / / / / / /
X
V.P. X
VAULT
CABLE
BOX
CABLE
M
M
V.GAS P.
GAS
TH
TH
TH
B
B
B
B
B
B
B
B
/ / / / / / / /
ST
AW
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / / / / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
/ / / / / / / /
W W
W W W
W
1
4"W 1976 (AC)
14"W 1976 (AC)
14"W 1976 (AC)
/ / / / / / / /
UD
15" SS 15" SS 15" SS 15" SS
12" W 12" W 12" W 12" W 12" W 12" W
12" W 12" W
16" W 16" W 16" W 16" W
IR
IR
RAIN GARDEN 2
RAIN GARDEN 3
RAIN GARDEN 1
TURNBERRY ROAD
E. DOUGLAS ROAD
TURNBERRY ROAD
E. DOUGLAS ROAD
LID EXHIBIT
FORT COLLINS, CO
COUNTRY CLUB RESERVE
ENGINEER ING
N O R T H E RN
10.15.2019
D:\PROJECTS\1324-001\DWG\EXHIBITS\1324-001_LID ROUTING.DWG
LEGEND:
RAIN GARDEN 1
RAIN GARDEN 2
( IN FEET ) RAIN GARDEN 3
0
1 INCH = 250 FEET
250 250
LID Treatment Summary Table
Raingarden ID Total Drainage Area
(Ac.)
Raingarden Req'd
Min. Volume (Cu.-Ft.)
Raingarden#1 8.02 5423
Raingarden#2 15.54 8294
Raingarden#3 6.32 3836
Total Newly Developed Area Treated 29.88 Ac.
Total Newly Developed Area 33.43 Ac.
Percent of Newly Developed Area Treated 89.38 %
Survey Area Data: Version 10, Sep 22, 2015
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr 28,
2011
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
25
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 10, Sep 22, 2015
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr 28,
2011
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
9
5a 5a No 0.25 61 2.00% 9.7 312 2.50% 3.16 1.6 0 0.00% N/A N/A 11.3 9.7 9.7
5b 5b No 0.25 58 2.00% 9.4 724 2.20% 2.97 4.1 0 0.00% N/A N/A 13.5 14.3 13.5
6 6 No 0.25 118 2.00% 13.4 0 0.00% N/A N/A 1643 2.60% 2.42 11.3 24.8 29.5 24.8
7 7 No 0.25 80 2.00% 11.1 1539 2.50% 3.16 8.1 0 0.00% N/A N/A 19.2 18.9 18.9
8 8 No 0.25 221 3.50% 15.3 0 0.00% N/A N/A 470 0.50% 1.06 7.4 22.6 24.1 22.6
9a 9a No 0.25 117 2.60% 12.3 0 0.00% N/A N/A 632 0.50% 1.06 9.9 22.2 25.8 22.2
9b 9b No 0.25 377 3.80% 19.4 0 0.00% N/A N/A 0 0.00% N/A N/A 19.4 20.3 19.4
10 10 No 0.25 283 2.10% 20.5 0 0.00% N/A N/A 118 2.10% 2.17 0.9 21.4 21.8 21.4
OS1a OS1a No 0.25 35 2.00% 7.3 1573 0.50% 1.41 18.5 0 0.00% N/A N/A 25.9 22.9 22.9
OS1b OS1b No 0.25 35 2.00% 7.3 1833 0.50% 1.41 21.6 0 0.00% N/A N/A 28.9 24.6 24.6
OS2 OS2 No 0.25 35 2.00% 7.3 204 0.50% 1.41 2.4 0 0.00% N/A N/A 9.7 9.5 9.5
Design
Point
Basin
ATC
September 1, 2019
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
7 536908 12.33 1.84 1.40 2.62 0.00 6.47 0.58 0.58 0.73 44.2%
8 411642 9.45 0.00 0.15 0.51 0.00 8.79 0.30 0.30 0.37 6.3%
9a 107416 2.47 0.00 0.07 0.23 0.00 2.17 0.33 0.33 0.42 10.9%
9b 366775 8.42 0.00 0.04 0.14 0.00 8.24 0.26 0.26 0.33 1.9%
10 114654 2.63 0.00 0.00 0.00 0.00 2.63 0.25 0.25 0.31 0.0%
OS1a 83262 1.91 1.15 0.00 0.00 0.00 0.76 0.67 0.67 0.84 60.0%
OS1b 104787 2.41 1.49 0.00 0.00 0.00 0.91 0.68 0.68 0.86 62.0%
OS2 11236 0.26 0.18 0.00 0.00 0.00 0.08 0.73 0.73 0.91 68.0%
DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Runoff Coefficients and Frequency Factors are taken from the City of Fort Collins amendments to the USDCM, Tables RO-11 and RO-12. % Impervious values taken from USDCM, Volume I.
10-year Cf = 1.00
September 1, 2019
Release
(cfs)
Pond 1 8.76 0.32 5059.80 9.08 5063.40 0.88
Pond 2 1.70 N/A N/A 1.70 5079.90 3.20
(Pond 1 Vol and EM Overflow) 19.97 N/A 19.97 9.67
10.15
0
9.60
9. The proposed project site is a residential subdivision. Associated site work, water,
and sewer lines will be constructed with the development. Onsite detention and
water quality treatment is proposed and will consist of several features which are
discussed in Section IV, below.
Figure 2– Proposed Site Plan
10. There are no known active irrigation laterals crossing the site.
11. The proposed land use is single-family residential.