HomeMy WebLinkAboutFOX GROVE PHASE 2 - PDP190002 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTJune 19, 2019
PRELIMINARY DRAINAGE AND
EROSION CONTROL REPORT FOR
FOX GROVE SECOND FILING
Fort Collins, Colorado
Prepared for:
Imago Enterprises
140 Palmer Dr.
Fort Collins, CO 80525
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 335-017
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.
June 19, 2019
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report for
Fox Grove Second Filing
Dear Staff:
Northern Engineering is pleased to submit this Final Drainage and Erosion Control Report for your
review. This report accompanies the Project Development Plan submittal for the proposed Fox
Grove Second Filing 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, PE
Project Engineer
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 4
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 5
A. Major Basin Description .................................................................................................................... 5
B. Sub-Basin Description ....................................................................................................................... 5
III. DRAINAGE DESIGN CRITERIA ................................................................................... 5
A. Regulations........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 6
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 7
F. Modifications of Criteria ................................................................................................................... 7
IV. DRAINAGE FACILITY DESIGN .................................................................................... 7
A. General Concept ............................................................................................................................... 7
B. Specific Details .................................................................................................................................. 8
V. CONCLUSIONS ........................................................................................................ 9
A. Compliance with Standards .............................................................................................................. 9
B. Drainage Concept .............................................................................................................................. 9
References ....................................................................................................................... 10
APPENDICES:
APPENDIX A -Hydrologic Computations
APPENDIX B -Water Quality Design Computations
APPENDIX C -Water Quality Design Computations
APPENDIX D -Stormwater Management Model (SWMM)
APPENDIX E -Erosion Control Report
APPENDIX F -Approved LOMR Map
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report
LIST OF TABLES AND FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 3
Figure 3 – Existing Floodplains ............................................................................................. 4
Figure 4 – Revised Floodplain Mapping .................................................................................. 5
MAP POCKET:
Proposed Drainage Exhibit
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the northwest quarter of Section 15, Township 7 North,
Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado .
3. The proposed development site is located southeast of the I-25/Mulberry (State
Highway 14) interchange in Fort Collins, Colorado. The site is situated along the
existing I-25 east frontage road, just south of the existing Interchange Business Park
development.
4. The proposed development site is in the City of Fort Collins Boxelder Creek Basin.
Detention requirements for this basin are to detain the difference between the 100-
year developed inflow rate and the historic 2-year release rate.
5. The existing Interchange Business Park site is located just north of the project site.
Boxelder Creek runs along the west property boundary.
6. No offsite flows are received by the project site.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 2
B. Description of Property
1. The development area is roughly 13 net acres
Figure 1 – Aerial Photograph
2. The subject property is currently leased for farming purposes. The ground cover
generally consists of row crops. Existing ground slopes are mild to moderate (i.e., 1 -
6±%) through the interior of the property. General topography slopes from north to
south.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey website:
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx,
the site consists of Kim Loam (Hydrologic Soil Group B) and Nunn Clay Loam
(Hydrologic Soil Group C).
4. The proposed project site plan is composed of residential development. Associated
roadways, water and sewer lines will be constructed with the development.
Detention/Water Quality will be placed near the southwest corner of the site and will
treat the majority of developed runoff prior to discharge into the adjacent Boxelder
Creek.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 3
Figure 2– Proposed Site Plan
5. Boxelder Creek runs along the west property boundary.
6. The proposed land use is residential.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 4
C. Floodplain
1. The project site is currently located outside of the adjacent FEMA defined 100-year
floodplain of Boxelder Creek per LOMR effective February 21, 2019 (Case No.: 17-
08-1354P). Please see Figure 3, below, and a FIRMETTE of the overall area
provided in Appendix F.
Figure 3 –Area Floodplain Mapping
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 5
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The proposed development site is in the City of Fort Collins Boxelder Creek Basin.
Detention requirements for this basin are to detain the difference between the 100-
year developed inflow rate and the historic 2-year release rate. A historic 2-year
release rate of 7.2 cfs was calculated for the overall Fox Grove site (35.84 acres) in
the “Final Drainage and Erosion Control Report for Fox Grove”, dated May 10, 2016,
by Northern Engineering (Ref. 6). The current development site was anticipated as a
future filing of Fox Grove in the 2016 final drainage report.
B. Sub-Basin Description
2. The subject property historically drains overland from north to south. There is an
existing drainage channel that runs along the southern boundary of the site, which
has historically collected the majority of onsite runoff and has directed runoff west,
into Boxelder Creek. The existing drainage channel receives discharge from an existing
offsite detention pond just to the east of the project site.
3. Design of the offsite detention pond just to the east of the project site is detailed in
the report entitled, “Final Drainage and Erosion Control Report for Clydesdale Park
PUD” (Ref. 6).The report specifies a release rate from the offsite detention pond of
12.7 cfs.
4. The project site will direct the majority of runoff into the onsite Detention/Water
Quality pond, which, combined with the existing Fox Grove First Filing ponds will
discharge into Boxelder Creek at no greater than the historic 2-year rate of 7.2 cfs. A
more detailed description of the project drainage patterns follows in Section IV.A.4.,
below.
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.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 6
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 extended detention 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 where none previously existed,
sediment with erosion potential is removed from the downstream drainageway systems.
Furthermore, this project will pay one-time stormwater development fees, as well as
ongoing monthly stormwater utility fees, both of which help achieve City-wide drainageway
stability.
Step 4 – Implement Site Specific and Other Source Control BMPs.
The proposed project will improve upon site specific source controls compared to historic
conditions:
Trash, waste products, etc. that were previously left exposed with the historic trailer
park will no longer be allowed to exposure to runoff and transport to receiving
drainageways. The proposed development will eliminate these sources of potential
pollution.
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.
As previously mentioned, overall drainage patterns of the existing site will be
maintained.
Elevations of existing downstream facilities that the subject property will release to
will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 7
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above, portions of the subject property are located in a FEMA regulatory
floodplain and floodway.
4. The proposed project does not propose to modify any natural drainageways.
F. Modifications of Criteria
1. The proposed development is not requesting any modifications to criteria at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of the project drainage design are to maintain existing drainage
patterns, and to ensure no adverse impacts to any adjacent properties.
2. Onsite detention and water quality treatment will be provided within the four onsite
ponds. The ponds will treat the majority of developed runoff prior to discharge into
Boxelder Creek. PLD features will also be incorporated in three of the ponds and will
provide further water quality treatement.
3. The drainage patterns anticipated for proposed drainage basins are described below.
Basins 1 – 3
Basins 1 through 3, consist of residential development including single-family
residential lots and public Right of Way areas. These basins will drain generally via
street curb and gutter to storm drain systems which will direct developed runoff to the
onsite detention/water quality pond. Pre-treatment will occur within a proposed
raingarden, as discussed further in Section IV.B, below.
Basin 4
Basin 4 consists of a small portion of the site, which will drain east into the
neighboring Fox Grove First Filing site. The basin consists of portions of backs of lots
of 2 single-family residential lots. This basin will drain generally via sheet flow into an
existing swale in Fox Grove First Filing, and ultimately into an existing detention pond
located within Fox Grove First Filing (“Pond 3”).
Basin 5
Basin 5 consists primarily of the area encompassing the proposed onsite raingarden
and detention pond. This basin will drain generally via sheet flow into the proposed
raingarden and detention pond.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 8
Basins 6, OS1
Basins 6 and OS1, consist of residential development including single-family
residential lots and public Right of Way areas. Basin 6 encompasses proposed Fox
Grove Second Filing areas, Basin OS1 encompasses existing Fox Grove First Filing
Areas. These basins will drain generally via street curb and gutter to storm drain
systems which will direct developed runoff to the onsite detention/water quality pond.
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. Detention and water quality treatment in the form of extended detention will
be provided for the proposed development within the lower stage of Pond 1.
Additionally, a proposed LID feature, in the form of an elevated (above
detention pond volume) raingarden will be provided as a pre-treatment
measure. Table 1, below outlines preliminary detention and extended
detention volume requirements.
2. The combined release rate from Pond 1, and existing Fox Grove First Filing
Ponds 2 through 4 is 7.0 cfs, which does not exceed the allowable release
rate established for the overall site of 7.2 cfs. This release rate has been
established in the final approved drainage report for Fox Grove First Filing (Ref.
6).
TABLE 1 –Pond Summary
Pond
ID
Vol.
(Ac-
Ft)
100-Yr
WSEL
(Ft)
WQ
Capture
Vol. (Ac-Ft)
WQ WSEL
(Ft)
Total
Req'd Vol.
(Ac-Ft)
100-Yr
Release
(cfs)
1 3.70 TBD 0.12 TBD 3.82 5.10
3. The drainage features associated with the proposed project are all private facilities,
located on private property.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 9
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 the Boxelder Creek
Master Plan.
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.
4. The proposed development will be designed at Final in compliance with Chapter 10 of
City Code.
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 extended
detention.
2. The drainage concept for the proposed development is consistent with the Boxelder
Creek Master Plan.
Fox Grove Second Filing
Preliminary Drainage & Erosion Control Report 10
References
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
6. Final Drainage and Erosion Control Report for Fox Grove, May 10, 2016, Northern
Engineering.
APPENDIX A
Hydrologic Computations
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 335-017
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…………………………...………………..…………………………………………….. 0.50 40%
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.
1 36831 0.85 0.19 0.04 0.17 0.00 0.44 0.58 0.58 0.73 45.0%
2 139358 3.20 0.70 0.16 0.66 0.00 1.68 0.58 0.58 0.73 45.0%
3 56366 1.29 0.28 0.06 0.27 0.00 0.68 0.58 0.58 0.73 45.0%
4 2083 0.05 0.01 0.00 0.01 0.00 0.03 0.58 0.58 0.73 45.0%
5 100353 2.30 0.51 0.12 0.47 0.00 1.21 0.58 0.58 0.73 45.0%
6 122949 2.82 0.62 0.14 0.58 0.00 1.48 0.58 0.58 0.73 45.0%
OS1 73435 1.69 0.00 0.08 0.10 0.00 1.50 0.33 0.33 0.41 10.0%
COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I.
Overland Flow, Time of Concentration:
Project: 335-017
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
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Is Length
>500' ?
C*Cf
(2-yr
Cf=1.00)
C*Cf
(10-yr
Cf=1.00)
C*Cf
(100-yr
Cf=1.25)
Length,
L
(ft)
Slope,
S
(%)
Ti
2-yr
(min)
Ti
10-yr
(min)
Ti
100-yr
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Rational Method Equation: Project: 335-017
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 0.85 12 12 11 0.58 0.58 0.73 2.05 3.50 7.42 1.01 1.72 4.57
2 2 3.20 17 17 17 0.58 0.58 0.73 1.75 2.99 6.20 3.26 5.57 14.44
3 3 1.29 12 12 11 0.58 0.58 0.73 2.09 3.57 7.42 1.58 2.69 6.99
4 4 0.05 6 6 5 0.58 0.58 0.73 2.76 4.72 9.95 0.08 0.13 0.35
5 5 2.30 14 14 13 0.58 0.58 0.73 1.92 3.29 6.92 2.58 4.42 11.61
6 6 2.82 18 18 17 0.58 0.58 0.73 1.73 2.95 6.20 2.84 4.84 12.74
OS1 OS1 1.69 17 17 16 0.33 0.33 0.41 1.78 3.04 6.30 0.98 1.68 4.35
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
RUNOFF COMPUTATIONS
C100
Design
Point
Flow,
Q100
(cfs)
Flow,
Q2
(cfs)
10-yr
Tc
(min)
2-yr
Tc
(min)
C2
Flow,
Q10
(cfs)
Intensity,
i100
(in/hr)
Basin(s)
ATC
June 17, 2019
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Q C f C i A
APPENDIX B
USDA Soil Mapping
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
January 21, 2019
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
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Contents
Preface.................................................................................................................... 2
How Soil Surveys Are Made..................................................................................5
Soil Map.................................................................................................................. 8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................ 11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado...................................................................... 13
24—Connerton-Barnum complex, 0 to 3 percent slopes............................ 13
34—Fort Collins loam, 0 to 1 percent slopes.............................................. 14
53—Kim loam, 1 to 3 percent slopes.......................................................... 16
55—Kim loam, 5 to 9 percent slopes.......................................................... 17
73—Nunn clay loam, 0 to 1 percent slopes.................................................18
92—Riverwash............................................................................................20
References............................................................................................................21
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
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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
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Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
4491400 4491450 4491500 4491550 4491600 4491650 4491700 4491750 4491800
4491400 4491450 4491500 4491550 4491600 4491650 4491700 4491750 4491800
500000 500050 500100 500150 500200 500250 500300
500000 500050 500100 500150 500200 500250 500300
40° 34' 37'' N
105° 0' 0'' W
40° 34' 37'' N
104° 59' 46'' W
40° 34' 23'' N
105° 0' 0'' W
40° 34' 23'' N
104° 59' 46'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,040 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
24 Connerton-Barnum complex, 0
to 3 percent slopes
0.0 0.1%
34 Fort Collins loam, 0 to 1 percent
slopes
0.2 1.1%
53 Kim loam, 1 to 3 percent slopes 2.9 20.1%
55 Kim loam, 5 to 9 percent slopes 1.3 9.1%
73 Nunn clay loam, 0 to 1 percent
slopes
10.0 68.5%
92 Riverwash 0.2 1.1%
Totals for Area of Interest 14.6 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
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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.
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Larimer County Area, Colorado
24—Connerton-Barnum complex, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpvw
Elevation: 5,000 to 6,000 feet
Mean annual precipitation: 15 to 18 inches
Mean annual air temperature: 47 to 49 degrees F
Frost-free period: 115 to 130 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Connerton and similar soils: 50 percent
Barnum and similar soils: 40 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Connerton
Setting
Landform: Fans, flood plains, stream terraces
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 8 inches: fine sandy loam
H2 - 8 to 60 inches: loam, sandy loam
H2 - 8 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: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20
to 0.60 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 16.6 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: Loamy Foothill (R049BY202CO)
Hydric soil rating: No
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Description of Barnum
Setting
Landform: Fans, valleys, terraces
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 10 inches: loam
H2 - 10 to 60 inches: stratified loamy fine sand to clay loam
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: Occasional
Frequency of ponding: None
Calcium carbonate, maximum in profile: 5 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: High (about 9.7 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: Overflow (R049XY036CO)
Hydric soil rating: No
Minor Components
Otero
Percent of map unit: 5 percent
Hydric soil rating: No
Garrett
Percent of map unit: 5 percent
Hydric soil rating: No
34—Fort Collins loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: jpw7
Elevation: 4,800 to 5,500 feet
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Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Fans, terraces
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 8 inches: loam
H2 - 8 to 18 inches: loam, clay loam
H2 - 8 to 18 inches: loam, silt loam, fine sandy loam
H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
H3 - 18 to 60 inches:
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Very high (about 26.0 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Stoneham
Percent of map unit: 6 percent
Hydric soil rating: No
Larim
Percent of map unit: 5 percent
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Hydric soil rating: No
Ascalon
Percent of map unit: 4 percent
Hydric soil rating: No
53—Kim loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpwx
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
Kim and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform: Fans
Landform position (three-dimensional): Base slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium
Typical profile
H1 - 0 to 7 inches: loam
H2 - 7 to 60 inches: loam, clay loam, sandy clay loam
H2 - 7 to 60 inches:
H2 - 7 to 60 inches:
Properties and qualities
Slope: 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: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 26.5 inches)
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Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Fort collins
Percent of map unit: 6 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 3 percent
Hydric soil rating: No
Aquic haplustolls
Percent of map unit: 1 percent
Landform: Swales
Hydric soil rating: Yes
55—Kim loam, 5 to 9 percent slopes
Map Unit Setting
National map unit symbol: jpwz
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Farmland of local importance
Map Unit Composition
Kim and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform: Fans
Landform position (three-dimensional): Base slope, side slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium
Typical profile
H1 - 0 to 7 inches: loam
H2 - 7 to 60 inches: loam, clay loam, sandy clay loam
H2 - 7 to 60 inches:
H2 - 7 to 60 inches:
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Properties and qualities
Slope: 5 to 9 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water storage in profile: Very high (about 26.5 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: Loamy Plains (R067XY002CO)
Hydric soil rating: No
Minor Components
Thedalund
Percent of map unit: 10 percent
Hydric soil rating: No
Stoneham
Percent of map unit: 5 percent
Hydric soil rating: No
73—Nunn clay loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: 2tlng
Elevation: 4,100 to 5,700 feet
Mean annual precipitation: 14 to 15 inches
Mean annual air temperature: 48 to 52 degrees F
Frost-free period: 135 to 152 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform: Terraces
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Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Pleistocene aged alluvium and/or eolian deposits
Typical profile
Ap - 0 to 6 inches: clay loam
Bt1 - 6 to 10 inches: clay loam
Bt2 - 10 to 26 inches: clay loam
Btk - 26 to 31 inches: clay loam
Bk1 - 31 to 47 inches: loam
Bk2 - 47 to 80 inches: loam
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 7 percent
Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Minor Components
Heldt
Percent of map unit: 10 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Wages
Percent of map unit: 5 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
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92—Riverwash
Map Unit Setting
National map unit symbol: jpy9
Elevation: 4,000 to 8,500 feet
Mean annual precipitation: 12 to 20 inches
Mean annual air temperature: 45 to 52 degrees F
Frost-free period: 75 to 150 days
Farmland classification: Not prime farmland
Map Unit Composition
Riverwash: 100 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Riverwash
Setting
Landform: Overflow stream channels, flood plains, outwash terraces
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Sandy and gravelly alluvium
Typical profile
H1 - 0 to 6 inches: very gravelly sand
H2 - 6 to 60 inches: stratified very gravelly sand to clay
Properties and qualities
Slope: 0 to 3 percent
Natural drainage class: Somewhat excessively drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00
to 20.00 in/hr)
Frequency of flooding: Frequent
Calcium carbonate, maximum in profile: 5 percent
Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 2.0
Available water storage in profile: Very low (about 2.3 inches)
Interpretive groups
Land capability classification (irrigated): 6w
Land capability classification (nonirrigated): 7w
Hydrologic Soil Group: A
Hydric soil rating: Yes
Custom Soil Resource Report
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References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
21
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
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APPENDIX C
Water Quality Design Computations
Project: 335-017
By: ATC
Date: 6/15/19
LID ID Basin (s) Total Basin (s)
Area (Ac.)
LID Raingarden/WQCV
Req'd Min. Volume (Cu.-
Ft.)
RG 1 1, 2,3 5.33 3096
EDB 1 1 - 6, OS1* 6.31 5303
Total Newly Developed Area: 9.86 Ac.
Total Area Treated: 5.33 Ac.
Percent of New Impervious Area Treated: 54.06%
*Extended Detention Basin (EDB) responsible to treat 50% of
contributory area.
LID / Water Quality Treatment Summary Table
WATER QUALITY CAPTURE VOLUME DESIGN CALCULATIONS
40-Hour Extended Detention (Pond Lower Stage)
Project: 335-017
By: ATC
Date: 1/15/19
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA (50% of Contributory Area) = 6.310 <-- 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 USDCM Vol.3, Figure 3-2
WQCV (ac-ft) = 0.122 <-- CALCULATED from USDCM Vol.3, EQ 3-3
WQ Depth (ft) = TBD* <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in2) = TBD* <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = TBD* <-- INPUT from Figure 5
n = TBD* <-- INPUT from Figure 5
t (in) = TBD* <-- INPUT from Figure 5
number of rows = TBD* <-- CALCULATED from WQ Depth and row spacing
*To Be Determined at Final Design
WATER QUALITY DESIGN CALCULATIONS
Rain Garden 1
Rain Garden Water Quality Capture Volume (12-Hr. PLD)
Project: 335-017
By: ATC
Date: 1/21/19
REQUIRED STORAGE & OUTLET WORKS:
TREATMENT AREA (ac) = 5.330 <-- INPUT from impervious calcs
PERCENT IMPERVIOUSNESS = 45.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.4500 <-- CALCULATED
WQCV (watershed inches) = 0.160 <-- CALCULATED from Figure EDB-2
WQCV (cu-ft) = 3096 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
APPENDIX D
Stormwater Management Model (SWMM)
SWMM Modeling Results and Pond Summary Table
Project: 335-017
By: ATC
Date: 6/15/19
Pond ID Vol. (Ac-Ft)
100-Yr
WSEL (Ft)
WQ Capture
Vol. (Ac-Ft)
WQ WSEL
(Ft)
Total Req'd
Vol. (Ac-Ft)
100-Yr
Release (cfs)
1 3.70 4921.50 0.12 TBD 3.82 5.10
Pond Stage-Storage Curve
Pond:
Project: 335-017
By: ATC
Date: 6/15/19
Stage
(FT)
Contour Area
(SF)
Volume
(CU.FT.)
Volume
(AC-FT)
4,915.40 28.09 0 0.000
4,915.60 291.94 27.37 0.001
4,915.80 669.31 120.93 0.003
4,916.00 1,266.02 311.31 0.007
4,916.20 2,390.65 671.07 0.015
4,916.40 4,196.35 1321.36 0.030
4,916.60 6,306.23 2364.48 0.054
4,916.80 9,114.51 3897.96 0.089
4,917.00 12,502.76 6050.78 0.139
4,917.20 15,250.86 8821.6 0.203
4,917.40 18,070.55 12149.75 0.279
4,917.60 21,276.28 16080.08 0.369
4,917.80 24,872.58 20690.29 0.475
4,918.00 28,479.43 26021.42 0.597
4,918.20 31,309.69 31998.1 0.735
4,918.40 33,004.06 38428.73 0.882
4,918.60 34,690.61 45197.49 1.038
4,918.80 35,838.81 52250.12 1.199
4,919.00 36,719.08 59505.74 1.366
4,919.20 37,607.04 66938.17 1.537
4,919.40 38,502.40 74548.94 1.711
4,919.60 39,403.68 82339.37 1.890
4,919.80 40,307.94 90310.36 2.073
4,920.00 41,215.00 98462.49 2.260
4,920.20 42,122.09 106796.03 2.452
4,920.40 43,035.69 115311.65 2.647
4,920.60 43,964.73 124011.52 2.847
4,920.80 44,901.77 132898.01 3.051
4,921.00 45,846.94 141972.71 3.259
4,921.20 46,800.72 151237.32 3.472
4,921.40 47,763.60 160693.59 3.689
4,921.60 48,748.58 170344.64 3.911
4,921.80 49,817.89 180201.09 4.137
4,922.00 50,964.07 190279.07 4.368
4,922.20 52,158.29 200591.08 4.605
4,922.40 53,360.25 211142.7 4.847
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 ............ 11/21/2012 00:00:00
Ending Date .............. 11/21/2012 06:00:00
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 ...... 9.155 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 2.166 0.868
Surface Runoff ........... 6.942 2.782
SWMM 5 Page 1
Final Storage ............ 0.103 0.041
Continuity Error (%) ..... -0.611
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 6.942 2.262
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 2.870 0.935
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 ...... 4.070 1.326
Continuity Error (%) ..... 0.028
********************************
Highest Flow Instability Indexes
********************************
Link O2 (16)
Link C1 (1)
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 30.00 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
--------------------------------------------------------------------------------------------------------
B2 3.67 0.00 0.00 0.75 2.90 0.47 44.00 0.790
B3 3.67 0.00 0.00 0.87 2.78 0.53 47.91 0.757
B4 3.67 0.00 0.00 0.87 2.78 0.32 28.77 0.757
B1 3.67 0.00 0.00 0.92 2.73 0.94 85.65 0.745
******************
Node Depth Summary
******************
---------------------------------------------------------------------------------
Average Maximum Maximum Time of Max Reported
Depth Depth HGL Occurrence Max Depth
Node Type Feet Feet Feet days hr:min Feet
---------------------------------------------------------------------------------
J1 JUNCTION 0.22 0.24 101.24 0 02:02 0.24
BoxelderCreek OUTFALL 0.22 0.24 100.24 0 02:02 0.24
P2 STORAGE 0.17 0.96 105.96 0 00:51 0.91
P3 STORAGE 4.52 5.56 111.56 0 02:10 5.55
P4 STORAGE 3.71 4.35 111.35 0 02:15 4.35
P1 STORAGE 3.27 4.02 106.02 0 02:10 4.01
*******************
Node Inflow Summary
*******************
-------------------------------------------------------------------------------------------------
Maximum Maximum Lateral Total Flow
Lateral Total Time of Max Inflow Inflow Balance
Inflow Inflow Occurrence Volume Volume Error
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal Percent
-------------------------------------------------------------------------------------------------
J1 JUNCTION 0.00 7.00 0 02:02 0 0.935 0.000
SWMM 5 Page 3
BoxelderCreek OUTFALL 0.00 7.00 0 02:02 0 0.935 0.000
P2 STORAGE 44.00 44.00 0 00:40 0.467 0.467 0.143
P3 STORAGE 47.91 47.91 0 00:40 0.534 0.534 -0.002
P4 STORAGE 28.77 28.77 0 00:40 0.32 0.32 -0.002
P1 STORAGE 85.65 98.57 0 00:40 0.94 1.41 0.002
*********************
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
--------------------------------------------------------------------------------------------------
P2 2.154 0 0 0 18.548 1 0 00:51 16.85
P3 45.824 27 0 0 61.498 36 0 02:09 1.60
P4 32.648 19 0 0 40.391 24 0 02:15 0.40
P1 117.097 12 0 0 161.489 16 0 02:10 5.00
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg Max Total
Freq Flow Flow Volume
Outfall Node Pcnt CFS CFS 10^6 gal
-----------------------------------------------------------
BoxelderCreek 97.08 5.97 7.00 0.935
-----------------------------------------------------------
System 97.08 5.97 7.00 0.935
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
-----------------------------------------------------------------------------
C1 CONDUIT 7.00 0 02:02 13.92 0.00 0.02
O2 DUMMY 16.85 0 00:51
O3 DUMMY 1.60 0 00:48
O4 DUMMY 0.40 0 01:26
O1 DUMMY 5.00 0 02:02
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Mon Jan 21 13:01:11 2019
Analysis ended on: Mon Jan 21 13:01:11 2019
Total elapsed time: < 1 sec
SWMM 5 Page 5
Node P1 Volume (ft3)
Elapsed Time (hours)
0 1 2 3 4 5 6 7
Volume (ft3)
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 O1 Flow (CFS)
Elapsed Time (hours)
0 1 2 3 4 5 6 7
Flow (CFS)
5.0
4.0
3.0
2.0
1.0
0.0
SWMM 5 Page 1
Link C1 Flow (CFS)
Elapsed Time (hours)
0 1 2 3 4 5 6 7
Flow (CFS)
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
SWMM 5 Page 1
APPENDIX E
Erosion Control Report
Fox Grove Second Filing
Preliminary Erosion Control Report
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included
with the final construction drawings. It should be noted, however, that any such Erosion and
Sediment Control Plan serves only as a general guide to the Contractor. Staging and/or phasing of
the BMPs depicted, and additional or different BMPs from those included may be necessary during
construction, or as required by the authorities having jurisdiction.
It shall be the responsibility of the Contractor to ensure erosion control measures are properly
maintained and followed. The Erosion and Sediment Control Plan is intended to be a living
document, constantly adapting to site conditions and needs. The Contractor shall update the
location of BMPs as they are installed, removed or modified in conjunction with construction
activities. It is imperative to appropriately reflect the current site conditions at all times.
The Erosion and Sediment Control Plan shall address both temporary measures to be implemented
during construction, as well as permanent erosion control protection. Best Management Practices
from the Volume 3, Chapter 7 – Construction BMPs will be utilized. Measures may include, but are
not limited to, silt fencing along the disturbed perimeter, gutter protection in the adjacent roadways
and inlet protection at existing and proposed storm inlets. Vehicle tracking control pads, spill
containment and clean-up procedures, designated concrete washout areas, dumpsters, and job site
restrooms shall also be provided by the Contractor.
Grading and Erosion Control Notes can be found on the Utility Plans. The Final Plans will contain a
full-size Erosion Control sheet as well as a separate sheet dedicated to Erosion Control Details. In
addition to this report and the referenced plan sheets, the Contractor shall be aware of, and adhere
to, the applicable requirements outlined in the Development Agreement for the development. Also,
the Site Contractor for this project will be required to secure a Stormwater Construction General
Permit from the Colorado Department of Public Health and Environment (CDPHE), Water Quality
Control Division – Stormwater Program, prior to any earth disturbance activities. Prior to securing
said permit, the Site Contractor shall develop a comprehensive StormWater Management Plan
(SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will further describe and
document the ongoing activities, inspections, and maintenance of construction BMPs.
APPENDIX F
FEMA FIRMETTE; Approved FEMA LOMR Documentation
MAP POCKET
SS SS
SS SS
SS SS SS SS
SS
SS
SS SS SS SS
SS
SS
SS
SS
SS
SS SS
SS SS SS SS
SS
SS SS
SS SS SS
X X X X
X
X
X
X X
X
X X
X X
X
X
D MH
SMH
8" W 8" W
8" W 8" W 8" W
8" W
8" W
8" W
8" W
S
S
S
S
S
S
SS SS
SS
SS
SS SS
SS
SS
SS
SS
SS
SS
SS SS SS SS SS SS SS SS SS
SS
SS
SS SS
VAULT
ELEC
W
X X
G
MH
MH
MH
MH
MH
S
S
S
S
S
W
S S S
S
S
W
W
S
S S
S
W
W
W
W
W W
W
S S S
S
S
S
M
H
MH
MH
W W
W
W
W
W
W
W
W
W
FOX DEN
COURT
ROLLINS DEN DRIVE
VIXEN DR
RAIN GARDEN
DETENTION POND 1
SUNFLOWER SUBDIVISION
(SINGLE FAMILY)
CW SUBTRUST C/O AGUR FOUNDATION
INDUSTRIAL DISTRICT
(UNDEVELOPED)
LOT 1
LEE MLD
(UNDEVELOPED)
INTERCHANGE BUSINESS PARK
GENERAL COMMERCIAL DISTRICT
(UNDEVELOPED)
FOX GROVE
(SINGLE FAMILY)
EXISTING DETENTION
POND 2
FEMA 100-YR FLOODWAY
FEMA 100-YR HIGH RISK FRINGE
FEMA 100-YR HIGH RISK FRINGE
FOX GROVE DR
BFE: 4926
BFE: 4922
1
1 2
3 2
3
4 4
5
5
6
6
OS1
PROPOSED 7
STORM DRAIN
PROPOSED
INLETS
CONNECT TO
EXISTING STORM
DRAIN
PROPOSED
STORM DRAINS
PROPOSED
INLETS
PROPOSED
INLET
PROPOSED
INLETS
UTILITY
EASEMENT
UTILITY
EASEMENT
3' GRAVEL
SHOULDERS
6' GRAVEL
SHOULDER
2' CONCRETE
PAN
10' GRAVEL
TRAIL
EXISTING 2'
CONCRETE PAN
4' CONCRETE
TRAIL
4' CONCRETE
TRAIL
EXISTING OUTLET
STRUCTURE
100-YR POND
EXTENTS
100-YR
OVERFLOW
WEIRS
4' CONCRETE
TRAIL
4' CONCRETE
TRAIL
4' CONCRETE
TRAIL
30' TRAIL
EASEMENT (TYP.)
18' FUTURE TRAIL
SECTION
30' TRAIL
EASEMENT (TYP.)
10' GRAVEL
TRAIL
18' FUTURE TRAIL
SECTION
SS
X
X
D MH
SMH
S
S
S
S
S
S
S
SS
SS
SS
VAULT
ELEC
W
G
ELEC
T
T
ELEC
BRKR
ELEC
BRKR
MH
MH
MH
MH
MH
MH
MH
KEYMAP
I-25
FOX GROVE DR
VIXEN DR
Sheet
FOX GROVE SUBDIVISION SECOND FILING 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
E NGINEER ING
N O R T H E RN
FORT COLLINS: 301 North Howes Street, Suite 100, 80521
GREELEY: 820 8th Street, 80631
970.221.4158
northernengineering.com
of 9
DR1
DRAINAGE EXHIBIT
9
NORTH
( IN FEET )
0
1 INCH = 50 FEET
50 50 100 150
DR1
City Engineer Date
Date
Date
Date
Date
Stormwater Utility
Parks & Recreation
Traffic Engineer
Date
Water & Wastewater Utility
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
Environmental Planner
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
Call before you dig.
R
LEGEND:
PROPOSED EASEMENT
EXISTING RIGHT OF WAY
PROPOSED LOT LINE
PROPERTY BOUNDARY
PROPOSED CURB AND GUTTER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CONTOUR
PROPOSED STORM INLET
PROPOSED STORM SEWER
EXISTING STORM SEWER
PROPOSED RIGHT OF WAY
A
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
B2
1.45 ac
DESIGN POINT
FLOW ARROWS
1. EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE
UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST
INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT
GUARANTEE THE ACCURACY OF SUCH INFORMATION. EXISTING UTILITY
MAINS AND SERVICES MAY NOT BE STRAIGHT LINES OR AS INDICATED
ON THESE DRAWINGS. THE CONTRACTOR SHALL BE RESPONSIBLE TO
CALL ALL UTILITY COMPANIES (PUBLIC AND PRIVATE) PRIOR TO ANY
CONSTRUCTION TO VERIFY EXACT UTILITY LOCATIONS.
2. REFER TO THE "PRELIMINARY DRAINAGE REPORT FOR FOX GROVE
SUBDIVISION SECOND FILING" BY NORTHERN ENGINEERING, DATED
JUNE 19, 2019 FOR ADDITIONAL INFORMATION.
3. ALL PROJECT DATA IS ON THE CITY OF FORT COLLINS VERTICAL DATUM;
NAVD88. SEE COVER SHEET FOR BENCHMARK REFERENCES.
4. REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT
DIMENSIONS, UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER
SURVEY INFORMATION.
NOTES:
BASIN
DESIGNATION
BASIN
AREA (AC)
PROPOSED SWALE 1 1
FLOODPLAIN NOTES:
1. FLOOD ZONE DESIGNATION: ACCORDING TO FEMA MAP NUMBER
08069C1003G, DATED MAY 2, 2012, A PORTION OF THIS TRACT OF LAND IS
WITHIN A FEMA DESIGNATED SPECIAL FLOOD HAZARD AREA (SFHA), AND IS
SUBJECT TO INUNDATION BY THE 1% ANNUAL CHANCE (100-YEAR) FLOOD.
THIS AREA IS ALSO INCLUDED IN A LETTER OF MAP REVISION (LOMR) CASE
NUMBER 17-08-1354P EFFECTIVE FEBRUARY 21, 2019.
2. REFER TO Preliminary Drainage Report for Fox Grove Subdivision Second Filing
DATED JUNE 19, 2019 FOR MORE INFORMATION REGARDING THE DRAINAGE
PLAN.
3. PORTIONS OF THIS PROPERTY ARE LOCATED IN THE FEMA-REGULATORY
100-YR BOXELDER CREEK HIGH-RISK FLOOD FRINGE, AND MUST COMPLY
WITH THE FLOODPLAIN REQUIREMENTS OF CHAPTER 10 OF THE CITY OF
FORT COLLINS MUNICIPAL CODE.
4. ANY AND ALL CONSTRUCTION ACTIVITIES IN THE FLOOD FRINGE MUST BE
PRECEDED BY AN APPROVED FLOODPLAIN USE PERMIT.
5. FEMA CROSS-SECTIONS (CSL) ELEVATIONS ARE SHOWN BASED ON THE
NAVD88 DATUM.
6. STORAGE OF EQUIPMENT AND MATERIALS (TEMPORARY OR PERMANENT) IS
NOT ALLOWED IN THE FLOODWAY.
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
Project Datum: NGVD88
Benchmark #1
Fort Collins Benchmark 25-01: East side of the East frontage road of I-25
approx. 0.5 miles North of Prospect Road on the North end of a head
wall to an irrigation canal.
Elevation: 4921.60
Benchmark #2
Fort Collins Benchmark 26-01: South side of Highway 14 (East Mulberry
St.), approx. 0.4 miles East of the centerline of I-25, on the bridge
parapet wall, on a brass cap stamped "Colo. Dept of Highways". (City of
Fort Collins designation not stamped on cap).
Elevation: 4940.45
Note:If NGVD29 Datum is required for any purpose, the following
equation should be used: NGVD29 = NAVD88 Unadjusted - 3.19'
Basis of Bearings
The Basis of Bearings is the South line of the Northwest Quarter, Section
15, Township 7 North, Range 68 West of the 6th P.M. as bearing North
89°38'50" West.
PROJECT BENCHMARKS:
Pond ID Vol. (Ac-Ft)
100-Yr
WSEL (Ft)
WQ Capture
Vol. (Ac-Ft)
WQ WSEL
(Ft)
Total Req'd
Vol. (Ac-Ft)
100-Yr
Release (cfs)
1 3.70 4921.50 0.12 TBD 3.82 5.10
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C2 C100
2-yr
Tc
(min)
100-yr
Tc
(min)
Q2
(cfs)
Q100
(cfs)
1 1 0.85 0.58 0.73 12.2 11.4 1.0 4.6
2 2 3.20 0.58 0.73 17.5 16.5 3.3 14.4
3 3 1.29 0.58 0.73 11.8 11.0 1.6 7.0
4 4 0.05 0.58 0.73 5.6 5.2 0.1 0.3
5 5 2.30 0.58 0.73 14.1 13.1 2.6 11.6
6 6 2.82 0.58 0.73 17.7 16.7 2.8 12.7
OS1 OS1 1.69 0.33 0.41 16.9 16.1 1.0 4.4
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 13, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Sep 20, 2015—Oct
21, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10
Tt
(min)
2-yr
Tc
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
1 1 No 0.25 0.25 0.31 72 2.00% 10.7 10.7 9.9 139 0.60% 1.55 1.5 0 0.00% N/A N/A 12 12 11
2 2 No 0.25 0.25 0.31 110 2.00% 13.2 13.2 12.3 394 0.60% 1.55 4.2 0 0.00% N/A N/A 17 17 17
3 3 No 0.25 0.25 0.31 65 2.00% 10.2 10.2 9.5 148 0.60% 1.55 1.6 0 0.00% N/A N/A 12 12 11
4 4 No 0.25 0.25 0.31 20 2.00% 5.6 5.6 5.2 0 0.00% N/A N/A 0 0.00% N/A N/A 6 6 5
5 5 No 0.25 0.25 0.31 125 2.00% 14.1 14.1 13.1 0 0.00% N/A N/A 0 0.00% N/A N/A 14 14 13
6 6 No 0.25 0.25 0.31 120 2.00% 13.8 13.8 12.8 359 0.60% 1.55 3.9 0 0.00% N/A N/A 18 18 17
OS1 OS1 No 0.25 0.25 0.31 80 2.00% 11.3 11.3 10.5 522 0.60% 1.55 5.6 0 0.00% N/A N/A 17 17 16
TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
June 17, 2019
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
10-year Cf = 1.00
June 17, 2019