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Addendum to Final Drainage Report
Kechter Farm Townhomes
Fort Collins, Colorado
March 24, 2021
Prepared for:
Russell Baker
Homestead North, LLC
772 Whalers Way, #200
Fort Collins, Colorado 80525
Prepared by:
301 N. Howes Street Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158
www.northernengineering.com
Project Number: 1124-006
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 necessary, we recommend double-sided printing.
March 24, 2021
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
RE: PDP Drainage Report for Kechter Farm Townhomes
Addendum to Kechter Farm Development
Dear Staff:
Northern Engineering is pleased to submit this PDP Report for your review. This report
accompanies the combined Preliminary Plan submittal for the proposed Kechter Farm
Townhomes. Kechter Farm Townhomes is intended to tie into infrastructure completed with
Kechter Farm Development – Filing 1. The approved utility plans for Kechter Farm – Filing 1
were prepared by JVA, Inc., and dated April 9, 2014. The approved Final Drainage Report for
the Kechter Farm Development, entitled “Final Drainage Report for Kechter Farm
Development” was prepared by JVA, Inc., and dated January 21, 2014.
The purpose of this addendum is to document conformance with the assumptions made
regarding the development of subject property and to update the stormwater conveyance,
infrastructure design, grading and erosion control necessary for the Kechter Farm Subdivision
improvement plans. This report has been prepared in accordance with the Fort Collins
Stormwater Criteria Manual (FCSCM). We understand that review by the City of Fort Collins 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.
Carlos Ortiz García Shane Ritchie, PE
Project Engineer Project Manager
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Table of Contents
Table of Contents
I. General Location and Description ....................................................................... 1
II. Drainage Basins and Sub-Basins ........................................................................ 4
III. Drainage Design Criteria ...................................................................................... 4
IV. Drainage Facility Design ....................................................................................... 6
V. Conclusions ........................................................................................................... 7
VI. References ............................................................................................................. 8
Tables and Figures
Figure 1 – Vicinity Map .................................................................................... 1
Figure 2 – Aerial Photograph .......................................................................... 2
Figure 3 – FEMA Firmette (Map Number 08069C0994F) ............................... 3
Appendices
Appendix A – Hydrologic Computations
Appendix B – Hydraulic Computations
Appendix C – Erosion Control Report
Appendix D – USDA Soils Report
Appendix E – FEMA Firmette
Map Pocket
FIG 2.4 Ketchter Filing 1 Drainage Map
H-DRN – Historic Drainage Exhibit
DR1 – Drainage Exhibit
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Page 1 of 9
I. General Location and Description
A. Location
1. Vicinity Map
Figure 1 – Vicinity Map
2. The Kechter Farm Townhomes project site is in the northeast quarter of Section 8,
Township 6 North, Range 68 West of the 6th Principal Meridian, County of
Larimer, State of Colorado.
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Page 2 of 9
3. The project site (refer to Figure 1) is bordered to the north by E. Trilby Road; to
the southwest by existing development, to the south by Lot 3 at Kechter Farm,
and to the east by Ziegler Road.
4. The project site is surrounded to the north by Per Kinard Junior High School; to
the southwest by Kechter Farm Filing 1, to the south by Lot 3 at Kechter Farm,
and to the east by Fossil Lake PUD First Filing
5. The site is included in the Fossil Creek Master Drainage Basin.
B. Description of Property
1. The Kechter Farm Townhomes is comprised of ± 2.66 acres.
2. The site currently is undeveloped, and an existing stormwater inlet is located on
the east side of the site and on the west side of the site adjacent to the site along
Ziegler Road.
Figure 2 – Aerial Photograph
3. The existing ground cover consists of native grasses. The existing on-site runoff
can be divided in two sections. The north half section generally drains from the
south to north, and then east along a swale, routing runoff to the northeast
corner of the site, then is collected via curb and gutter to an existing inlet at E.
Trilby Road. The slopes across this area vary between 12%± and 0.5%±. The south
half section generally drains from north to south and then east along a swale,
Project Site
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Kechter Farm Townhomes Page 3 of 9
routing runoff to the northeast corner of the site, then is collected via curb and
gutter to an existing inlet at E. Trilby Road. The slopes across this area vary
between 12%± and 1%±.
4. 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 primarily of Nunn clay loam (Hydrologic Soil Group C). A copy
of the soils report is included in the appendices.
5. Fossil Creek reservoir is the closest receiving water to the project site, located
directly to the south.
6. The proposed development will consist of 26 Town Homes on the property, one
mixed-use dwelling unit, and an outdoor gathering place with seating and a
shelter. Other proposed improvements include a new asphalt drive, new
sidewalks, and new landscaping.
7. The proposed land use is single-family attached. This is a permitted use in the
Low-Density Mixed-Use District (LMN).
C. Floodplain
The subject property is not located in a FEMA regulatory floodplain. In particular,
the project site is not located within a FEMA designated 100-year floodplain per Map
Number 08069CO994F (Effective date: December 19, 2006).
Figure 3 – FEMA Firmette (Map Number 08069C0994F)
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Kechter Farm Townhomes Page 4 of 9
II. Drainage Basins and Sub-Basins
A. Major Basin Description
The Kechter Farm Townhomes project is located within the City of Fort Collins
Fossil Creek major drainage basin. Specifically, the project site is situated in the
northeastern side of this major drainage basin. The Fossil Creek drainage basin
extends along the south end of Fort Collins, from the foothills across Interstate 25
past County Road 5. It encompasses 32 square miles in the city of Fort Collins and
Larimer County.
The Site has been defined as Basin D3 in the Final Drainage Report for Kechter Farm
Development, dated January 21, 2014 by JVA Inc.
B. Sub-Basin Description
1. The Final Drainage Report for Kechter Farm Development, dated January 21,
2014 by JVA Inc., shows Inlet D3 as outfall for the site. See Developed Drainage
Map Figure 2.4 at the end of this report.
2. The existing subject site can be defined with two (2) sub-basins that encompass
the entire project site.
3. The existing site runoff generally can be divided in two sections. The north half
section generally drains from the south to north then east along a swale, and the
south half section generally drains from north to south and then east along a
swale. Both sections drain to an existing inlet located on the west side of E. Trilby
Road.
4. The project site does not receive notable runoff from contiguous off-site
properties.
III. Drainage Design Criteria
The project site is part of Kechter Farm PLD Filing 1 development. The site conforms to
the drainage design of the approved development plans. Any items not clearly defined in
the development plans will conform to the FCSCM and are described in greater depth
herein.
A. Optional Provisions
There are no optional provisions outside of the FCSCM proposed with The Kechter
Farm Townhomes.
B. Development Criteria Reference and Constraints
1. The subject property is part of the Final Drainage Report for Kechter Farm
Development, dated January 21, 2014 by JVA Inc.
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Kechter Farm Townhomes Page 5 of 9
2. The site plan is constrained on the north and east by a public street (E. Trilby
Road), on the east by a public street (Ziegler Road), on the west by Kechter Farm
Filing 1, and by Kechter Farm Lot 3 along the south side.
C. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as
depicted in Figure 3.4-1 of the FCSCM, serve as the source for all hydrologic
computations associated with The Kechter Farm Townhomes development.
Tabulated data contained in Table 3.4-1 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. Detention storage calculations are not required for the project.
4. Two separate design storms have been utilized to address distinct drainage
scenarios. The first event analyzed is the “Minor,” or “Initial” Storm, which has a
two-year recurrence interval. The second event considered is the “Major Storm,”
which has a 100-year recurrence interval.
D. Hydraulic Criteria
1. The drainage facilities proposed with Kechter Farm Townhomes project are
designed in accordance with criteria outlined in the FCSCM and/or the Mile
High Flood District’s (MHFD) Urban Storm Drainage Criteria Manual.
2. As stated in Section I.C.1, above, the subject property is located next to a City of
Fort Collins designated floodplain but is not located within the floodplain limits.
E. Floodplain Regulations Compliance
As previously mentioned, this project is located outside of the floodplain, and as
such, it will not be subject to any floodplain regulations.
F. Modifications of Criteria
No formal modifications are requested at this time. City staff has previously
determined that detention will not be required with this project.
G. Conformance with Water Quality Treatment Criteria
City Code requires that 100% of runoff from a project site receive some sort of water
quality treatment. Water quality treatment for this project is provided off-site by two
level spreaders in Fossil Creek Reservoir as described in the Final Drainage Report
for Kechter Farm Development, dated January 21, 2014 by JVA Inc.
While the area on-site will not receive formal water quality treatment, some areas
will receive treatment as runoff is directed through the landscaped areas.
PDP/Final Drainage Report May 5, 2021
Kechter Farm Townhomes Page 6 of 9
H. Conformance with Low Impact Development (LID)
LID for this project has been included in the Final Drainage Report for Kechter Farm
Development, dated January 21, 2014 by JVA Inc. for LID techniques. The project site
will receive 100% LID treatment with the rain gardens that currently exist, not the
level spreaders.
IV. Drainage Facility Design
A. General Concept
1. The main objective of the Kechter Farm Townhomes drainage design is to
maintain existing drainage patterns, while not adversely impacting adjacent
properties.
2. No notable off-site runoff passes directly through the project site.
3. A list of tables and figures used within this report can be found in the Table of
Contents at the front of the document. The tables and figures are located within
the sections to which the content best applies.
4. In general, all runoff generated by the site is captured by the stormwater network
on-site and conveyed to an existing stormwater main previously designed to
receive the developed flows from the site.
5. This drainage report will be an amendment to the Kechter Farms drainage
report. The overall site drainage has been designed to adhere to (and utilize) the
design items described in the original report.
6. Drainage for the project site has been analyzed using thirteen (13) drainage sub-
basins, designated as Sub-Basins A1 to A13. The drainage patterns anticipated
for the basins are further described below.
Sub-Basin A1, A5 and A11
These sub-basins encompass approximately 0.47, 0.72 and 0.20 Ac. respectively.
These sub-basins are comprised primarily of roof area, pavement, sidewalks,
driveways, and landscaped areas. Runoff will drain via curb and gutter and will
be captured by storm inlets which will then convey flows from the basin through
the storm drain system connected to an existing 24” storm drain utilized by the
site.
Sub-Basin A2, A3, A4 and 13
These sub-basins encompass approximately 0.7, 0.10, 0.46 and 0.25 Ac.
respectively. These sub-basins are comprised primarily of roof area, sidewalks,
and landscaped areas. Runoff will drain via swales and then will be captured by
inlets which will then convey flows from the basin through the storm drain
system connected to an existing 24” storm drain utilized by the site.
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Page 7 of 9
Sub-Basin A6, A9 and A10
These sub-basins encompass approximately 0.07, 0.08 and 0.08 Ac. respectively
and are comprised primarily of roof area. Runoff will drain via roof drains and
will be captured by storm drains which will then convey flows from the basin
through the storm drain system connected to an existing 24” storm drain utilized
by the site.
Sub-Basin A7 and A8
These sub-basins encompass approximately 0.10 and 0.26 Ac. respectively These
sub-basins are comprised primarily of sidewalks and landscaped areas. The
majority of the runoff will sheet flow to inlets in sump which will then convey
flows from the basins through the storm drain system connected to an existing
24” storm drain utilized by the site.
Sub-Basin A12
Sub-basin A12 encompass approximately 0.05 Ac. This sub-basin is comprised
primarily of landscaped areas. Runoff will sheet flow to an inlet in sump which
will then convey flows from the basin through the storm drain system connected
to an existing 24” storm drain utilized by the site.
B. Specific Details
1. Since detention is not required with this site, the existing impervious area has not
been considered in determining allowable release from the property.
2. The impervious value assigned to the site in the original Kechter Farms Drainage
Report equals 62%. The impervious value utilized for analysis in this report
equals 59% and is outlined in the attached spreadsheets. As such, no additional
detention or water quality treatment is required as per City guidance.
C. Sizing of LID Facilities
LID facilities were previously sized and installed to capture the future developed
runoff flows from the site. This process is outlined in the 2014 Master Drainage
Report by JVA.
V. Conclusions
A. Compliance with Standards
1. The drainage design proposed with Kechter Farm Townhomes complies with the
City of Fort Collins Master Drainage Plan for the Fossil Creek Basin.
2. There are no FEMA regulatory floodplains associated with Kechter Farm
Townhomes development.
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Page 8 of 9
3. The drainage plan and stormwater management measures proposed with
Kechter Farm Townhomes project 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 potential
damage associated with its stormwater runoff.
2. Kechter Farm Townhomes development will not impact the Master Drainage
Plan recommendations for Fossil Creek major drainage basin.
VI. References
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.
Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by
Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins
Municipal Code.
Soils Resource Report for Larimer County Area, Colorado, Natural Resources
Conservation Service, United States Department of Agriculture.
Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood
Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April
2008.
Final drainage report for Kechter Farm Development, dated January 21, 2014 by JVA,
Inc.
Appendix A
Hydrologic Computations
Runoff
Coefficient 1
Percent
Impervious1
0.95 100%
0.95 90%
0.50 40%
0.55 50%
0.20 2%
0.20 2%
Basin ID Basin Area
(sq.ft.)
Basin Area
(acres)
Asphalt,
Concrete (acres)Rooftop (acres) Gravel (acres)
Residential: Low
Density (acres)
Undeveloped:
Greenbelts,
Agriculture
(acres)
Lawns, Clayey
Soil, Flat Slope <
2% (acres)
Percent
Impervious
C2*Cf
Cf = 1.00
C5*Cf
Cf = 1.00
C10*Cf
Cf = 1.00
C100*Cf
Cf = 1.25
H1 61,463 1.41 0.000 0.000 0.000 0.000 0.000 1.411 2%0.20 0.20 0.20 0.25
H2 54,510 1.25 0.000 0.000 0.000 0.000 0.000 1.251 2%0.20 0.20 0.20 0.25
A1 20,628 0.47 0.194 0.125 0.000 0.000 0.000 0.155 65%0.70 0.70 0.70 0.88
A2 3,255 0.07 0.005 0.026 0.000 0.000 0.000 0.043 40%0.52 0.52 0.52 0.64
A3 4,213 0.10 0.011 0.027 0.000 0.000 0.000 0.059 38%0.50 0.50 0.50 0.62
A4 9,203 0.21 0.005 0.040 0.000 0.000 0.000 0.166 21%0.36 0.36 0.36 0.45
A5 31,308 0.72 0.323 0.328 0.000 0.000 0.000 0.067 86%0.88 0.88 0.88 1.00
A6 2,912 0.07 0.000 0.067 0.000 0.000 0.000 0.000 90%0.95 0.95 0.95 1.00
A7 4,690 0.11 0.007 0.000 0.000 0.000 0.000 0.100 9%0.25 0.25 0.25 0.31
A8 10,765 0.25 0.030 0.000 0.000 0.000 0.000 0.217 14%0.29 0.29 0.29 0.37
A9 3,527 0.08 0.000 0.081 0.000 0.000 0.000 0.000 90%0.95 0.95 0.95 1.00
A10 3,527 0.08 0.000 0.081 0.000 0.000 0.000 0.000 90%0.95 0.95 0.95 1.00
A11 8,892 0.20 0.110 0.071 0.000 0.000 0.000 0.023 85%0.86 0.86 0.86 1.00
A12 2,079 0.05 0.000 0.000 0.000 0.000 0.000 0.048 2%0.20 0.20 0.20 0.25
A13 10,799 0.25 0.043 0.067 0.000 0.000 0.000 0.138 43%0.53 0.53 0.53 0.67
SITE 115,798 2.66 0.729 0.913 0.000 0.000 0.000 1.016 59%0.66 0.66 0.66 0.83
RUNOFF COEFFICIENT CALCULATIONS
Asphalt, Concrete
Rooftop
Gravel
Residential: Low Density
Kechter Townhomes
C. Ortiz
March 22, 2021
Project:
Calculations By:
Date:
Character of Surface
Streets, Parking Lots, Roofs, Alleys, and Drives:
Lawns and Landscaping:
Combined Basins
2) Composite Runoff Coefficient adjusted per Table 3.2-3 of the Fort Collins
Stormwater Manual (FCSM).
Lawns, Clayey Soil, Flat Slope < 2%
USDA SOIL TYPE: B
Undeveloped: Greenbelts, Agriculture Composite Runoff Coefficient 2
1) Runoff coefficients per Tables 3.2-1 & 3.2 of the FCSM. Percent impervious per Tables 4.1-2 & 4.1-3 of the FCSM.
Historic Basins
Developed Basins
Page 1 of 3
Length
(ft)
Elev
Up
Elev
Down
Slope
(%)
Ti
2-Yr
(min)
Ti
10-Yr
(min)
Ti
100-Yr
(min)
Length
(ft)
Elev
Up
Elev
Down
Slope
(%)
Velocity
(ft/s)
Tt
(min)
Length
(ft)
Elev
Up
Elev
Down
Slope
(%)
Velocity
(ft/s)
Tt
(min)
Comp.
Tc 2-Yr
(min)
Max.
Tc 2-Yr
(min)
Tc
2-Yr
(min)
Comp.
Tc 10-Yr
(min)
Max.
Tc 10-Yr
(min)
Tc
10-Yr
(min)
Comp.
Tc 100-Yr
(min)
Max.
Tc 100-Yr
(min)
Tc
100-Yr
(min)
h1 H1 183 26.42 25.06 0.74%25.2 25.2 23.8 N/A N/A N/A 352 25.06 21.50 1.01% 1.51 3.89 29.05 12.97 12.97 29.05 12.97 12.97 27.65 12.97 12.97
h2 H2 104 27.93 26.00 1.86%13.9 13.9 13.2 N/A N/A N/A 363 26.00 22.27 1.03% 1.52 3.98 17.92 12.59 12.59 17.92 12.59 12.59 17.15 12.59 12.59
a1 A1 53 25.88 24.93 1.78%4.4 4.4 2.5 179 24.93 23.35 0.88 1.88 1.59 N/A N/A N/A 6.04 11.29 6.04 6.04 11.29 6.04 4.05 11.29 5.00
a2 A2 21 25.38 24.98 1.94%4.0 4.0 3.1 N/A N/A N/A 42 24.98 24.27 1.70% 1.95 0.36 4.33 10.35 5.00 4.33 10.35 5.00 3.46 10.35 5.00
a3 A3 24 25.84 24.66 5.00%3.2 3.2 2.5 N/A N/A N/A 39 24.66 23.98 1.77% 1.99 0.32 3.53 10.35 5.00 3.53 10.35 5.00 2.87 10.35 5.00
a4 A4 24 25.81 24.50 5.49%3.8 3.8 3.4 N/A N/A N/A 126 24.50 23.73 0.61% 1.17 1.79 5.61 10.83 5.61 5.61 10.83 5.61 5.14 10.83 5.14
a5 A5 42 25.87 25.04 1.98%2.1 2.1 1.0 N/A N/A N/A 255 25.04 23.67 0.54% 1.10 3.87 6.00 11.65 6.00 6.00 11.65 6.00 4.84 11.65 5.00
a6 A6 33 10.0%0.7 0.7 0.5 10 1.00 2.00 0.09 N/A N/A N/A 0.83 10.24 5.00 0.83 10.24 5.00 0.58 10.24 5.00
a7 A7 69 25.23 21.50 5.44%7.5 7.5 6.9 45 21.50 21.28 0.49 1.40 0.53 N/A N/A N/A 8.00 10.63 8.00 8.00 10.63 8.00 7.45 10.63 7.45
a8 A8 69 25.23 21.50 5.41%7.1 7.1 6.5 56 21.50 20.93 1.01 2.01 0.47 N/A N/A N/A 7.61 10.70 7.61 7.61 10.70 7.61 6.96 10.70 6.96
a9 A9 33 10.0%0.7 0.7 0.5 10 1.00 2.00 0.08 N/A N/A N/A 0.83 10.24 5.00 0.83 10.24 5.00 0.58 10.24 5.00
a10 A10 33 10.0%0.7 0.7 0.5 10 1.00 2.00 0.08 N/A N/A N/A 0.83 10.24 5.00 0.83 10.24 5.00 0.58 10.24 5.00
a11 A11 24 25.41 24.83 2.43%1.6 1.6 0.7 91 24.83 23.74 1.20 2.19 0.69 N/A N/A N/A 2.29 10.64 5.00 2.29 10.64 5.00 1.37 10.64 5.00
a12 A12 18 25.46 24.99 2.68%5.1 5.1 4.8 N/A N/A N/A 71 24.99 24.63 0.51% 1.07 1.10 6.18 10.49 6.18 6.18 10.49 6.18 5.90 10.49 5.90
a13 A13 29 25.15 24.50 2.28%4.3 4.3 3.3 N/A N/A N/A 136 24.50 23.82 0.50% 1.06 2.13 6.44 10.91 6.44 6.44 10.91 6.44 5.43 10.91 5.43
Rational Equation: Q = CiA (Equation 6-1 per MHFD)
Velocity (Swale Flow), V = 15·S ½
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS (MHFD)
Overland Flow, Time of Concentration:
Kechter Townhomes
Gutter/Swale Flow, Time of Concentration:C. Ortiz
Tt = L / 60V (Equation 6-4 per MHFD)March 22, 2021
Tc = Ti + Tt (Equation 6-2 per MHFD)
Velocity (Gutter Flow), V = 20·S ½
Project:
Calculations By:
Date:
Intensity, i (per Table 3.4-1 of the Fort Collins Stormwater Manual)
Time of Concentration
Combined Basins
Design
Point Basin
Overland Flow Channelized Flow Swale Flow
Historic Basins
Developed Basins
(Equation 6-4 per MHFD)
(Equation 3.3-2 per Fort Collins
}
=1.87 1.1 − ∗
Notes:
1) Add 4900 to all elevations.
2)
Page 2 of 3
Tc2Tc10Tc100C2C10C100I2(in/hr)I10(in/hr)I100(in/hr)Q2(cfs)Q10(cfs)Q100(cfs)h1H11.41112.9712.9712.970.200.200.252.023.457.040.61.02.5h2H21.25112.5912.5912.590.200.200.252.023.457.040.50.92.2a1A10.4746.046.045.000.700.700.882.674.569.950.91.54.2a2A20.0755.005.005.000.520.520.642.854.879.950.10.20.5a3A30.0975.005.005.000.500.500.622.854.879.950.10.20.6a4A40.2115.615.615.140.360.360.452.764.729.950.20.41.0a5A50.7196.006.005.000.880.881.002.764.729.951.73.07.2a6A60.0675.005.005.000.950.951.002.854.879.950.20.30.7a7A70.1088.008.007.450.250.250.312.404.108.800.10.10.3a8A80.2477.617.616.960.290.290.372.464.219.060.20.30.8a9A90.0815.005.005.000.950.951.002.854.879.950.20.40.8a10A100.0815.005.005.000.950.951.002.854.879.950.20.40.8a11A110.2045.005.005.000.860.861.002.854.879.950.50.92.0a12A120.0486.186.185.900.200.200.252.674.569.630.00.00.1a13A130.2486.446.445.430.530.530.672.674.569.950.40.61.6Velocity (Gutter Flow), V = 20·S½DEVELOPED DIRECT RUNOFF COMPUTATIONS (MHFD)Overland Flow, Time of Concentration:Project:Kechter TownhomesGutter/Swale Flow, Time of Concentration:Calculations By:C. OrtizTt = L / 60V (Equation 6-4 per MHFD)Date:March 22, 2021Tc = Ti + Tt (Equation 6-2 per MHFD)Intensity, I from Fig. 3.4.1 Fort Collins Stormwater ManualCombined BasinsVelocity (Swale Flow), V = 15·S½Rational Equation: Q = CiA (Equation 6-1 per MHFD)DesignPointBasinArea(acres)Tc (Min)Runoff C Intensity FlowHistoric BasinsDeveloped Basins(Equation 6-4 per MHFD)}=1.871.1 − ∗ (Equation 3.3-2 per Fort Collins Stormwater Manual)Page 3 of 3
Appendix B
Hydraulic Calculations
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Page 9 of 9
This section intentionally left blank.
Hydraulic calculation will be provided during Final Plan.
Appendix C
Erosion Control Report
PDP/Final Drainage Report March 24, 2021
Kechter Farm Townhomes Erosion Control Report
Erosion Control Report
A comprehensive Erosion and Sediment Control Plan (along with associated details) has 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 and/or wattles along the disturbed
perimeter, gutter protection in the adjacent roadways and inlet protection at existing and
proposed storm inlets. Vehicle tracking control pads, spill containment and clean-up
procedures, designated concrete washout areas, dumpsters, and job site restrooms shall also be
provided by the Contractor.
Grading and Erosion Control Notes can be found on Sheet CS2 of the Utility Plans. The Final
Utility Plans will also contain a full-size Erosion Control Plan as well as a separate sheet
dedicated to Erosion Control Details. In addition to this report and the referenced plan sheets,
the Contractor shall be aware of, and adhere to, the applicable requirements outlined in any
existing Development Agreement(s) of record, as well as the Development Agreement, to be
recorded prior to issuance of the Development Construction Permit. Also, the Site Contractor
for this project may be required to secure a Stormwater Construction General Permit from the
Colorado Department of Public Health and Environment (CDPHE), Water Quality Control
Division – Stormwater Program, before commencing any earth disturbing activities. Prior to
securing said permit, the Site Contractor shall develop a comprehensive Storm Water
Management Plan (SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will
further describe and document the ongoing activities, inspections, and maintenance of
construction BMPs.
Appendix D
USDA Soils Report
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Area, Colorado
1124-006 Kechter Townhomes
Natural
Resources
Conservation
Service
March 23, 2021
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado......................................................................13
74—Nunn clay loam, 1 to 3 percent slopes.................................................13
115—Weld silt loam, 0 to 3 percent slopes.................................................14
Soil Information for All Uses...............................................................................17
Soil Properties and Qualities..............................................................................17
Soil Qualities and Features.............................................................................17
Hydrologic Soil Group (1124-006 Kechter Townhomes).............................17
References............................................................................................................22
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
4483500448352044835404483560448358044836004483620448364044835004483520448354044835604483580448360044836204483640498110 498130 498150 498170 498190 498210 498230 498250 498270 498290 498310
498110 498130 498150 498170 498190 498210 498230 498250 498270 498290 498310
40° 30' 12'' N 105° 1' 20'' W40° 30' 12'' N105° 1' 11'' W40° 30' 7'' N
105° 1' 20'' W40° 30' 7'' N
105° 1' 11'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 15 30 60 90
Meters
Map Scale: 1:1,040 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 15, Jun 9, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
74 Nunn clay loam, 1 to 3 percent
slopes
2.6 94.6%
115 Weld silt loam, 0 to 3 percent
slopes
0.1 5.4%
Totals for Area of Interest 2.8 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
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,
Custom Soil Resource Report
11
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
12
Larimer County Area, Colorado
74—Nunn clay loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlpl
Elevation: 3,900 to 5,840 feet
Mean annual precipitation: 13 to 17 inches
Mean annual air temperature: 50 to 54 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Pleistocene aged alluvium and/or eolian deposits
Typical profile
Ap - 0 to 9 inches: clay loam
Bt - 9 to 13 inches: clay loam
Btk - 13 to 25 inches: clay loam
Bk1 - 25 to 38 inches: clay loam
Bk2 - 38 to 80 inches: clay loam
Properties and qualities
Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:7 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Sodium adsorption ratio, maximum:0.5
Available water capacity:High (about 9.9 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: R067BY042CO - Clayey Plains
Hydric soil rating: No
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13
Minor Components
Heldt
Percent of map unit:10 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY042CO - Clayey Plains
Hydric soil rating: No
Satanta
Percent of map unit:5 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
115—Weld silt loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2x0hx
Elevation: 3,600 to 6,000 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 46 to 54 degrees F
Frost-free period: 115 to 155 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Weld and similar soils:80 percent
Minor components:20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Weld
Setting
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Calcareous loess
Typical profile
Ap - 0 to 3 inches: silt loam
Bt1 - 3 to 11 inches: silty clay
Bt2 - 11 to 15 inches: silty clay
Btk - 15 to 21 inches: silty clay
Custom Soil Resource Report
14
Bk - 21 to 31 inches: silt loam
C - 31 to 80 inches: silt loam
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:14 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Sodium adsorption ratio, maximum:5.0
Available water capacity:High (about 11.7 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Colby
Percent of map unit:7 percent
Landform:Hillslopes
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Adena
Percent of map unit:5 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Convex
Across-slope shape:Convex
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Keith
Percent of map unit:5 percent
Landform:Interfluves
Landform position (two-dimensional):Summit
Landform position (three-dimensional):Interfluve
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Custom Soil Resource Report
15
Rago, rarely flooded
Percent of map unit:2 percent
Landform:Drainageways
Down-slope shape:Linear
Across-slope shape:Concave
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
Pleasant, ponded
Percent of map unit:1 percent
Landform:Playas, closed depressions
Down-slope shape:Concave
Across-slope shape:Concave
Ecological site:R067BY010CO - Closed Upland Depression
Hydric soil rating: Yes
Custom Soil Resource Report
16
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 (1124-006 Kechter Townhomes)
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
17
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
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19
Custom Soil Resource Report
Map—Hydrologic Soil Group (1124-006 Kechter Townhomes)4483500448352044835404483560448358044836004483620448364044835004483520448354044835604483580448360044836204483640498110 498130 498150 498170 498190 498210 498230 498250 498270 498290 498310
498110 498130 498150 498170 498190 498210 498230 498250 498270 498290 498310
40° 30' 12'' N 105° 1' 20'' W40° 30' 12'' N105° 1' 11'' W40° 30' 7'' N
105° 1' 20'' W40° 30' 7'' N
105° 1' 11'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 15 30 60 90
Meters
Map Scale: 1:1,040 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 15, Jun 9, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
20
Table—Hydrologic Soil Group (1124-006 Kechter Townhomes)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
74 Nunn clay loam, 1 to 3
percent slopes
C 2.6 94.6%
115 Weld silt loam, 0 to 3
percent slopes
C 0.1 5.4%
Totals for Area of Interest 2.8 100.0%
Rating Options—Hydrologic Soil Group (1124-006 Kechter
Townhomes)
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
21
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
22
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
23
Appendix E
FEMA Firmette
National Flood Hazard Layer FIRMette
0 500 1,000 1,500 2,000250
Feet
Ü
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
SPECIAL FLOOD
HAZARD AREAS
Without Base Flood Elevation (BFE)
Zone A, V, A99
With BFE or DepthZone AE, AO, AH, VE, AR
Regulatory Floodway
0.2% Annual Chance Flood Hazard, Areas
of 1% annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mileZone X
Future Conditions 1% Annual
Chance Flood HazardZone X
Area with Reduced Flood Risk due to
Levee. See Notes.Zone X
Area with Flood Risk due to LeveeZone D
NO SCREEN Area of Minimal Flood Hazard Zone X
Area of Undetermined Flood HazardZone D
Channel, Culvert, or Storm Sewer
Levee, Dike, or Floodwall
Cross Sections with 1% Annual Chance
17.5 Water Surface Elevation
Coastal Transect
Coastal Transect Baseline
Profile Baseline
Hydrographic Feature
Base Flood Elevation Line (BFE)
Effective LOMRs
Limit of Study
Jurisdiction Boundary
Digital Data Available
No Digital Data Available
Unmapped
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
authoritative NFHL web services provided by FEMA. This map
was exported on 3/16/2021 at 6:41 PM and does not
reflect changes or amendments subsequent to this date and
time. The NFHL and effective information may change or
become superseded by new data over time.
This map image is void if the one or more of the following map
elements do not appear: basemap imagery, flood zone labels,
legend, scale bar, map creation date, community identifiers,
FIRM panel number, and FIRM effective date. Map images for
unmapped and unmodernized areas cannot be used for
regulatory purposes.
Legend
OTHER AREAS OF
FLOOD HAZARD
OTHER AREAS
GENERAL
STRUCTURES
OTHER
FEATURES
MAP PANELS
8
B 20.2
The pin displayed on the map is an approximate
point selected by the user and does not represent
an authoritative property location.
1:6,000
105°1'33"W 40°30'22"N
105°0'56"W 40°29'55"N
Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020
Map Pocket
FIG 2.4 Kechter Filing 1 Drainage map
H-DRN Historic Drainage Exhibit
DR1 –Drainage Exhibit
H2O
V.P.
H2O
V.P.C.O.S
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
W
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR CONTROL
IRR
CONTROL
IRRI S
OIS
O
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRRCONTROL
IRR
CONTROL
IRRCONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRRCONTROL
IRRCONTROL
IRRCONTROL
IRR
VAULT
F.O.
D
S
S FOFOFOFOFOFOIRRIRRIRRIRRIRRIRR
IRRIRRIRRIRR
IRR
IR
R
IRR
IRR
IRR IRR IRR IRR IRR IRR IRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRRIRR
X XXXXXXXXXFO
FO
FO
FO
FO
FO
FO FO FO
FO
FO
FO FO FO FO FO
FOSTSTSTSTSTSTST284.0'SSSSSSSS
SS
EAST TRILBY ROAD
ZIEGLER ROADD
D
D
EXISTING
STORM DRAIN
PROJECT BOUNDARY
H1
H2
EXISTING
STORM DRAIN
h1
h2
SheetKECHTER TOWNHOMESThese drawings areinstruments of serviceprovided by NorthernEngineering Services, Inc.and are not to be used forany type of constructionunless signed and sealed bya Professional Engineer inthe employ of NorthernEngineering Services, Inc.NOT FOR CONSTRUCTIONREVIEW SETENGINEERNGIEHTRONRNFORT COLLINS: 301 North Howes Street, Suite 100, 80521GREELEY: 820 8th Street, 80631970.221.4158northernengineering.comof 25
H-DRNPLANHISTORIC DRAINAGE EXHIBIT26
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.
before you dig.Call
R
NORTH
( IN FEET )
0
1 INCH = 40 FEET
40 40 80 120
PROPOSED CONTOUR
PROPOSED STORM SEWER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
A
DESIGN POINT
FLOW ARROW
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
PROPOSED SWALE SECTION
11
NOTES:
1.REFER TO THE Preliminary Drainage Report, dated March 17, 2021 FOR ADDITIONAL
INFORMATION.
LEGEND:
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
A
DRAINAGE SUMMARY
Design
Point Basin ID
Total
Area
(acres)
C2 C100 2-Yr Tc
(min)
100-Yr Tc
(min)
Q2
(cfs)
Q100
(cfs)
Developed Basins
h1 H1 1.411 0.20 0.25 12.97 12.97 0.57 2.48
h2 H2 1.251 0.20 0.25 12.59 12.59 0.50 2.20
VAULT
F.O.
D
S FOFOFOFOFOFOX XXXXXXXXXFO
FO
FO
FO
FO
FO
FO FO FO
FO
FO
FO FO FO FO FO
FOEAST TRILBY ROAD
ZIEGLER ROADD
D
D
STORM DRAIN A
SEE SHEET ST1
STORM DRAIN A2
SEE SHEET ST3
STORM DRAIN A(S)
SEE SHEET ST2
STORM DRAIN A(S)-1
SEE SHEET ST2
STORM DRAIN A2-5.1
SEE SHEET ST4
STORM DRAIN A2-5
SEE SHEET ST4
24'
FL-FLPROJECT BOUNDARY
BUILDING 1
BUILDING 2
BUILDING 3
BUILDING 4
BUILDING 5BUILDING 6
30' UTILITY EASEMENT
A10 A9
A6
A5
A3 A2
A1
A8
A7
A4
A12
A11
A13
a13
a1a2
a3
a4
a5
a6
a9a10
a8
a7
a11
a12
SheetKECHTER TOWNHOMESThese drawings areinstruments of serviceprovided by NorthernEngineering Services, Inc.and are not to be used forany type of constructionunless signed and sealed bya Professional Engineer inthe employ of NorthernEngineering Services, Inc.NOT FOR CONSTRUCTIONREVIEW SETENGINEERNGIEHTRONRNFORT COLLINS: 301 North Howes Street, Suite 100, 80521GREELEY: 820 8th Street, 80631970.221.4158northernengineering.comof 25
DR1 PLANDRAINAGE EXHIBIT26
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.
before you dig.Call
R
NORTH
( IN FEET )
0
1 INCH = 40 FEET
40 40 80 120
PROPOSED CONTOUR
PROPOSED STORM SEWER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
A
DESIGN POINT
FLOW ARROW
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
PROPOSED SWALE SECTION
11
NOTES:
1.REFER TO THE Preliminary Drainage Report, dated March 17, 2021 FOR ADDITIONAL
INFORMATION.
LEGEND:
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
A
DRAINAGE SUMMARY
Developed Basins
a1 A1 0.474 0.70 0.88 6.04 5.00 0.89 4.15
a2 A2 0.075 0.52 0.64 5.00 5.00 0.11 0.48
a3 A3 0.097 0.50 0.62 5.00 5.00 0.14 0.60
a4 A4 0.211 0.36 0.45 5.61 5.14 0.21 0.95
a5 A5 0.719 0.88 1.00 6.00 5.00 1.74 7.15
a6 A6 0.067 0.95 1.00 5.00 5.00 0.18 0.67
a7 A7 0.108 0.25 0.31 8.00 7.45 0.06 0.30
a8 A8 0.247 0.29 0.37 7.61 6.96 0.18 0.82
a9 A9 0.081 0.95 1.00 5.00 5.00 0.22 0.81
a10 A10 0.081 0.95 1.00 5.00 5.00 0.22 0.81
a11 A11 0.204 0.86 1.00 5.00 5.00 0.50 2.03
a12 A12 0.048 0.20 0.25 6.18 5.90 0.03 0.11
a13 A13 0.248 0.53 0.67 6.44 5.43 0.35 1.64