HomeMy WebLinkAboutUNCOMMON (310 S. COLLEGE) - PDP - PDP150013 - REPORTS - DRAINAGE REPORTSeptember 2, 2015
PRELIMINARY DRAINAGE AND
EROSION CONTROL REPORT FOR
UNCOMMON
Fort Collins, Colorado
Prepared for:
CA Ventures
161 N. Clark St., Suite 2050
Chicago, IL 60601
Prepared by:
301 N. Howes St., Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 1104-001
This Drainage Report is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy is absolutely necessary, we recommend double-sided printing.
September 2, 2015
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report for
UNCOMMON
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report
for your review. This report accompanies the Project Development Plan submittal for the
proposed Uncommon development project.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed project. We
understand that review by the City is to assure general compliance with standardized criteria
contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Aaron Cvar, PhD, PE
Senior Project Engineer
Uncommon
Preliminary Drainage 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 .................................................................................... 6
A. Regulations ........................................................................................................................................ 6
B. Four Step Process .............................................................................................................................. 6
C. Development Criteria Reference and Constraints ............................................................................ 7
D. Hydrological Criteria ......................................................................................................................... 7
E. Hydraulic Criteria .............................................................................................................................. 7
F. Modifications of Criteria ................................................................................................................... 8
IV. DRAINAGE FACILITY DESIGN ..................................................................................... 8
A. General Concept ............................................................................................................................... 8
B. Specific Details .................................................................................................................................. 9
V. CONCLUSIONS ........................................................................................................ 10
A. Compliance with Standards ............................................................................................................ 10
B. Drainage Concept ............................................................................................................................ 10
APPENDICES:
APPENDIX A.1 - Rational Method Hydrologic Computations
APPENDIX A.2 - Existing and Proposed Impervious Areas Exhibit
APPENDIX A.3 - LID Compliance Computations
APPENDIX B.1 - Erosion Control Report
APPENDIX C.1 - USDA Soils Report
Uncommon
Preliminary Drainage Report
LIST OF FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 3
Figure 3 – Existing Floodplains ............................................................................................. 4
Figure 4 – LID Stormwater Planter Box Concept…..……………………………………………………9
MAP POCKET:
Proposed Drainage Exhibit
Floodplain Exhibit
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Preliminary Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
Vicinity Map
1. The project site is located in the southwest quarter of Section 12, Township 7 North,
Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado.
2. The project site is located at the southeast corner of College Avenue and Olive Street.
3. The project site lies within the Old Town Basin. A portion of the site drains to the
existing storm sewer system in College Avenue, which is conveyed north in College
Avenue. The majority of the site drains via surface flow into the adjacent curb and
gutter of Olive Street. Runoff is conveyed to existing inlets and storm system within
Olive Street. Water quality treatment for 100% of the site is provided for in the Udall
Natural Area water treatment facility. Per the Old Town Basin Master Plan
requirements, as long as site imperviousness is not increased by more than 5000
square feet, detention is not required for the site. The proposed site plan proposes
less than a 5000 square foot increase in imperviousness; therefore, detention is not
required. However, the site still must meet current City Low Impact Development
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Preliminary Drainage Report 2
(LID) requirements. Several water quality filtering methods are proposed for the site,
and are described in further detail below.
4. As this is an infill site, the area surrounding the site is fully developed.
5. No offsite flows enter the site from the north, south, west, or east. Adjacent areas to
the south and east are directed via sheet flow into adjacent alleyways. Adjacent areas
to the north and west are directed into the adjacent curb and gutters of College Ave.
and Olive St. A small offsite basin, noted on the Drainage Exhibit as Basin OS1,
contributes 1.6 cfs in a 100-year event to the adjacent alley to the east of the
property. This flow will be conveyed within the proposed inverted crown section of
the improved alley.
B. Description of Property
1. The development area is roughly 0.8 net acres.
Figure 1 – Aerial Photograph
2. The subject property is currently composed of existing buildings, and a large paved
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Preliminary Drainage Report 3
parking area. Previously, the “Perkins” restaurant occupied the property. Existing
ground slopes are mild to moderate (i.e., 1 - 6±%) through the interior of the
property. General topography slopes from southwest to northeast.
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 Fort Collins loam (Hydrologic Soil Group C).
4. The proposed project site plan (please see Figure 2, below) is composed of mixed-
use development and a multi-level parking structure. A portion of the parking
structure will be sub-surface. Associated site work, water, and sewer lines will be
constructed with the development. Current City Low Impact Development (LID)
requirements will be implemented with the project, and will consist of several LID
features which are discussed in Section IV, below.
Figure 2– Proposed Site Plan
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Preliminary Drainage Report 4
5. There are no known irrigation laterals crossing the site.
6. The proposed land use is a mixed-use development (commercial and residential).
C. Floodplain
1. The project site is encroached by a City designated 100-year floodplain and floodway,
as shown in Figure 3, below. Portions of proposed structures are located within the
100-year floodplain. No proposed structures are located within the College Avenue
floodway. The proposed development will be designed at Final to be in compliance
with Chapter 10 of City Code.
Figure 3 –Area Floodplain Mapping
2. A minimum of 18-inches of freeboard will be provided at Final design from base
(100-year) flood elevation in adjacent Right of Way. This freeboard level will be
applied to either the design of finished floor elevations, or the minimum level of flood
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Preliminary Drainage Report 5
proofing measures. HVAC is planned for the roof of the structure, and will be well
above flood elevation. Oz Architecture is coordinating floodproofing measures for all
proposed structures. We understand that the underground parking structure will be
floodproofed utilizing automated flood gates for drive entries and manual flood gates
for pedestrian entries; however, please refer to the preliminary flood protection plan
prepared by Oz Architecture.
3. The base (100-year) flood elevation in the vicinity of the proposed structures is
4995.60, which is referenced to the NAVD 88 Datum. This flood elevation was
provided by the City of Fort Collins Stormwater Utility, and was interpolated at the
upstream (southwest) corner of the proposed structure.
4. The vertical datum utilized for site survey work is the City of Fort Collins Benchmark
#29-97 (Elevation=4978.01; NAVD 88).
5. It is noted that surrounding developments have used the NGVD 29 (unadjusted)
datum. The conversion from NAVD 88 to NGVD 29 (unadjusted) datum is -3.17-ft.
6. Foundation for the retail/residential structures will be a combination of slab on grade
and a basement foundation. There will be an underground parking structure below a
portion of the retail/residential structure, which we consider to be a basement
foundation.
7. All requirements per City of Fort Collins “Floodproofing Guidelines”
(http://www.fcgov.com/utilities/img/site_specific/uploads/fp-floodproofing.pdf) will be
met.
8. A floodplain use permit will be required for each structure and each site construction
element (detention ponds, bike paths, parking lots, utilities, etc.) in the floodplain.
9. A FEMA elevation and floodproofing certificate will be completed before the CO is
issued.
10. A small amount of grading may be necessary within the floodway. No-Rise analysis
will be provided at Final design level, once final grading is completed.
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
7. The project site lies within the Old Town Basin. Water quality treatment for 100% of
the site is provided for in the Udall Natural Area water treatment facility. Per the Old
Town Basin Master Plan requirements, as long as site imperviousness is not increased
by more than 5000 square feet, detention is not required for the site. The proposed
site plan proposes less than a 5000 square foot increase in imperviousness; therefore,
detention is not required. However, the site still must meet current City Low Impact
Development (LID) requirements. Several water filtering locations are proposed for
the site, and are described in further detail below.
B. Sub-Basin Description
1. The subject property historically drains overland from southwest to northeast. Runoff
from the majority of the site has historically been collected in the existing Montezuma
Fuller Alleyway which directs flows north into the south flowline of Olive Street. The
proposed site plan will generally maintain existing runoff patterns.
2. A more detailed description of the project drainage patterns is provided below.
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Preliminary Drainage Report 6
III. DRAINAGE DESIGN CRITERIA
A. Regulations
There are no optional provisions outside of the FCSCM proposed with the proposed
project.
B. Four Step Process
The overall stormwater management strategy employed with the proposed project utilizes
the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters.
The following is a description of how the proposed development has incorporated each
step.
Step 1 – Employ Runoff Reduction Practices. The first consideration taken in trying
to reduce the stormwater impacts of this development is the site selection itself. By
choosing an already developed site with public storm sewer currently in place, the
burden is significantly less than developing a vacant parcel absent of any
infrastructure. The second site planning component falling into this category is the
preservation of the large street trees along College Avenue and Olive Street. Not only
does this encourage infiltration and evapotranspiration, but it also adds shade and a
great site amenity. Another consideration also comes by way of the site plan layout
and an early, integrated and deliberate design goal of the project team. That is,
stormwater planter boxes have been designed to emphasize multiple controls
throughout the development as opposed to a centralized treatment facility. These areas
have been closely coordinated between the Architect, Owner, Landscape Architect and
Civil Engineer.
Uncommon aims to reduce runoff peaks, volumes and pollutant loads by implementing
Low Impact Development (LID) strategies. At least 50% of the site’s runoff will be
routed through the aforementioned stormwater planters. This LID practice reduces the
overall amount of impervious area, while also Minimizing Directly Connected
Impervious areas (MDCIA). Most downspouts will be routed through the planter boxes.
Since rooftops comprise a majority of the project’s impervious area, this achieves a
high degree of MDCIA. The combined LID/MDCIA techniques will be implemented
throughout the development, thereby slowing runoff, filtering stormwater and otherwise
helping to improve the pre-development hydrologic regime.
Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV)
with Slow Release. The efforts taken in Step 1 will help to minimize runoff; however,
urban development of this intensity will still have stormwater runoff leaving the site.
However, The Uncommon project will capture and treat the majority of rooftop runoff
before releasing it at a slow rate to downstream facilities. The primary WQCV will
occur in the stormwater planter boxes. The on-site water quality facilities are further
described in greater detail in Section IV.B, below.
Step 3 – Stabilize Drainageways. As stated in Section I.B.3, above, there are no
major drainageways in or near the subject property. While this step may not seem
applicable to the Uncommon development, the proposed project indirectly helps
achieve stabilized drainageways nonetheless. Once again, site selection has a positive
effect on stream stabilization. By repurposing an already developed, under-utilized site
with existing stormwater infrastructure, combined with LID, MDCIA and WQCV
strategies, the likelihood of bed and bank erosion is greatly reduced. Furthermore, this
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Preliminary Drainage Report 7
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. This step typically
applies to industrial and commercial developments; however, the District at Campus
West project does contain two components warranting site specific consideration for
source control. Those two components are the outdoor pool and parking structure.
Chemicals for the pool will be stored and handled in a manner so as to minimize the
potential for pollutants to enter the stormwater system. See the Hazardous Materials
Impact Analysis submitted with this project for additional information on the pool
chemicals. The parking structure will be equipped with a Sand Filter (SF) to trap and
collect pollutants associated with the vehicles. The lease agreement will explicitly
prohibit residents from performing fluid changes or similar vehicle maintenance within
the parking garage. Additionally, the overall operations and maintenance procedures to
be implemented by Uncommon’s professional staff will be done with a conscious
awareness of source control BMPs, including: storage, handling and spill containment
and control.
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 to which the subject property releases
to will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
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Preliminary Drainage Report 8
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above, the subject property is located in a City designated 100-year
floodplain (Old Town Basin, College Ave. Floodplain). The proposed project does not
propose to modify any natural drainageways.
F. Modifications of Criteria
1. The proposed development is not requesting any modifications to criteria at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of the project drainage design are to maintain existing drainage
patterns, and to ensure no adverse impacts to any adjacent properties.
2. Onsite LID features consisting primarily of raised planter boxes which will enhance
water quality. These measures are discussed further below.
3. Drainage patterns anticipated for drainage basins shown in the Drainage Exhibit are
described below. Drainage basins have been defined for preliminary design purposes
and are subject to change at Final design; however, general drainage patterns and
concepts are not expected to be significantly altered.
Basin 1
Basin 1 will generally drain via rooftop flow and roof drains which will direct drainage
into the adjacent College Avenue Right of Way. Drainage within College Avenue is
directed into a series of combination inlets located just south of the intersection of
College and Olive Street.
Basin 2
Basin 2 will generally drain via sheet flow into LID features (further described below)
and then into the adjacent alley to the east of the project site. The alley currently
accepts the majority of historic flows from the property and will continue with this
pattern. The alley currently consists of a concrete paved section with a reverse crown
and drains from south to north into the south flowline of Olive Street. This historic
drainage pattern will be maintained with the proposed site plan.
Basin 3
Basin 3 will generally drain via sheet flow into the adjacent alley running along the
east project boundary, which will convey flows into Olive Street. Spot elevations
showing positive drainage to the alley will be provided at Final design.
Basin OS1
Basin OS1 consists of offsite areas, which are primarily paved parking and drive areas
to the south and east, as well as the adjacent alley east of the project site. This basin
will sheet flow into the alley and be conveyed within the reverse crown of the alley
north into the south flowline of Olive Street.
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Preliminary Drainage Report 9
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report. Runoff computations for these basins based on the Rational Method is
provided in Appendix A.
B. Specific Details
1. As stated previously, water quality treatment for 100% of the site is provided
for in the Udall Natural Area water treatment facility. The proposed onsite LID
measures are being provided to satisfy the 50% LID requirement. The primary
Low Impact Development (LID) measure consists of stormwater planter boxes
as shown on the drainage exhibit.
Figure 4 –LID Stormwater Planter Box Concept
Additional details of this design will be provided at Final design. Preliminary
locations of paver fields are noted on the Drainage Exhibit.
2. The current site plan utilizes a multi-level parking structure for all onsite parking.
Because of this, the site is exempt from the 25% permeable pavement metric.
3. Final design details, construction documentation, and Standard Operating
Procedures (SOP) Manual shall be provided to the City of Fort Collins for
review prior to Final Development Plan approval. A final copy of the approved
SOP manual shall be provided to City and must be maintained on-site by the
entity responsible for the facility maintenance. Annual reports must also be
prepared and submitted to the City discussing the results of the maintenance
program (i.e. inspection dates, inspection frequency, volume loss due to
sedimentation, corrective actions taken, etc.).
4. Proper maintenance of the drainage facilities designed with the proposed
development is a critical component of their ongoing performance and
effectiveness.
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Preliminary Drainage Report 10
V. CONCLUSIONS
A. Compliance with Standards
1. The drainage design proposed with the proposed project complies with the City of Fort
Collins’ Stormwater Criteria Manual.
2. The drainage design proposed with this project complies with requirements for the Old
Town Basin.
3. The drainage plan and stormwater management measures proposed with the
proposed development are compliant with all applicable State and Federal regulations
governing stormwater discharge.
4. The proposed development will be designed at Final to be 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 compliance with requirements set
forth in current City master plans.
2. The drainage concept for the proposed development is consistent with requirements
for the Old Town Basin.
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Preliminary Drainage Report 11
References
1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
2. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
4. Old Town Master Drainage Plan, Baseline Hydraulics, Volume II, Anderson Consulting,
July 15, 2003.
5. Downtown River District Final Design Report, Ayres, February 2012.
6. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
APPENDIX A.1
RATIONAL METHOD HYDROLOGIC COMPUTATIONS
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 1104-001
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC
Asphalt ……....……………...……….....…...……………….………………………………….. 0.95 100% Date:
Concrete …….......……………….….……….………………..….……………………………… 0.95 90%
Gravel ……….…………………….….…………………………..………………………………. 0.50 40%
Roofs …….…….………………..……………….…………………………………………….. 0.95 90%
Pavers…………………………...………………..…………………………………………….. 0.40 22%
Lawns and Landscaping
Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0%
Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf
= 1.00 100-year Cf = 1.25
Basin ID
Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Pavers
(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 4213 0.10 0.00 0.00 0.10 0.00 0.00 0.98 0.98 1.23 0.94
2 28668 0.66 0.00 0.00 0.62 0.00 0.04 0.91 0.91 1.00 0.85
3 2148 0.05 0.00 0.00 0.00 0.05 0.00 0.40 0.40 0.50 0.22
OS1 20862 0.48 0.00 0.00 0.00 0.05 0.43 0.27 0.27 0.33 0.02
DEVELOPED 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.
10-year Cf = 1.00
August 15, 2015
Overland Flow, Time of Concentration:
Project: 1104-001
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = Ti + Tt (Equation RO-2)
Velocity (Gutter Flow), V = 20·S½
Velocity (Swale Flow), V = 15·S½
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)
Tt
(min)
2-yr
Tc
Rational Method Equation: Project: 1104-001
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 0.10 5 5 5 0.98 0.98 1.23 2.85 4.87 9.95 0.27 0.46 1.18
2 2 0.66 5 5 5 0.91 0.91 1.00 2.85 4.87 9.95 1.71 2.92 6.55
3 3 0.05 5 5 5 0.40 0.40 0.50 2.85 4.87 9.95 0.06 0.10 0.25
OS1 OS1 0.48 6 6 5 0.27 0.27 0.33 2.76 4.72 9.95 0.35 0.60 1.58
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
DEVELOPED 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
August 15, 2015
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
DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF
Figure RO-1—Estimate of Average Overland Flow Velocity for Use With the Rational Formula
2007-01 RO-13
Urban Drainage and Flood Control District
DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF
Table RO-3—Recommended Percentage Imperviousness Values
Land Use or
Surface Characteristics
Percentage
Imperviousness
Business:
Commercial areas 95
Neighborhood areas 85
Residential:
Single-family *
Multi-unit (detached) 60
Multi-unit (attached) 75
Half-acre lot or larger *
Apartments 80
Industrial:
Light areas 80
Heavy areas 90
Parks, cemeteries 5
Playgrounds 10
Schools 50
Railroad yard areas 15
Undeveloped Areas:
Historic flow analysis 2
Greenbelts, agricultural 2
Off-site flow analysis
(when land use not defined)
45
Streets:
Paved 100
Gravel (packed) 40
Drive and walks 90
Roofs 90
Lawns, sandy soil 0
Lawns, clayey soil 0
* See Figures RO-3 through RO-5 for percentage imperviousness.
C A = K A + ( 1 . 31 i 3 − 1 . 44 i 2 + 1 . 135 i − 0 . 12 ) for CA ≥ 0, otherwise CA = 0 (RO-6)
C CD = K CD + ( 0 . 858 i 3 − 0 . 786 i 2 + 0 . 774 i + 0 . 04 ) (RO-7)
C B = (CA + C CD ) 2
2007-01 RO-9
Urban Drainage and Flood Control District
DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF
Table RO-5— Runoff Coefficients, C
Percentage
Imperviousness Type C and D NRCS Hydrologic Soil Groups
2-yr 5-yr 10-yr 25-yr 50-yr 100-yr
0% 0.04 0.15 0.25 0.37 0.44 0.50
5% 0.08 0.18 0.28 0.39 0.46 0.52
10% 0.11 0.21 0.30 0.41 0.47 0.53
15% 0.14 0.24 0.32 0.43 0.49 0.54
20% 0.17 0.26 0.34 0.44 0.50 0.55
25% 0.20 0.28 0.36 0.46 0.51 0.56
30% 0.22 0.30 0.38 0.47 0.52 0.57
35% 0.25 0.33 0.40 0.48 0.53 0.57
40% 0.28 0.35 0.42 0.50 0.54 0.58
45% 0.31 0.37 0.44 0.51 0.55 0.59
50% 0.34 0.40 0.46 0.53 0.57 0.60
55% 0.37 0.43 0.48 0.55 0.58 0.62
60% 0.41 0.46 0.51 0.57 0.60 0.63
65% 0.45 0.49 0.54 0.59 0.62 0.65
70% 0.49 0.53 0.57 0.62 0.65 0.68
75% 0.54 0.58 0.62 0.66 0.68 0.71
80% 0.60 0.63 0.66 0.70 0.72 0.74
85% 0.66 0.68 0.71 0.75 0.77 0.79
90% 0.73 0.75 0.77 0.80 0.82 0.83
95% 0.80 0.82 0.84 0.87 0.88 0.89
100% 0.89 0.90 0.92 0.94 0.95 0.96
TYPE B NRCS HYDROLOGIC SOILS GROUP
0% 0.02 0.08 0.15 0.25 0.30 0.35
5% 0.04 0.10 0.19 0.28 0.33 0.38
10% 0.06 0.14 0.22 0.31 0.36 0.40
15% 0.08 0.17 0.25 0.33 0.38 0.42
20% 0.12 0.20 0.27 0.35 0.40 0.44
25% 0.15 0.22 0.30 0.37 0.41 0.46
30% 0.18 0.25 0.32 0.39 0.43 0.47
35% 0.20 0.27 0.34 0.41 0.44 0.48
40% 0.23 0.30 0.36 0.42 0.46 0.50
45% 0.26 0.32 0.38 0.44 0.48 0.51
50% 0.29 0.35 0.40 0.46 0.49 0.52
55% 0.33 0.38 0.43 0.48 0.51 0.54
60% 0.37 0.41 0.46 0.51 0.54 0.56
65% 0.41 0.45 0.49 0.54 0.57 0.59
70% 0.45 0.49 0.53 0.58 0.60 0.62
75% 0.51 0.54 0.58 0.62 0.64 0.66
80% 0.57 0.59 0.63 0.66 0.68 0.70
85% 0.63 0.66 0.69 0.72 0.73 0.75
90% 0.71 0.73 0.75 0.78 0.80 0.81
95% 0.79 0.81 0.83 0.85 0.87 0.88
100% 0.89 0.90 0.92 0.94 0.95 0.96
2007-01 RO-11
Urban Drainage and Flood Control District
RUNOFF DRAINAGE CRITERIA MANUAL (V. 1)
TABLE RO-5 (Continued)—Runoff Coefficients, C
Percentage
Imperviousness Type A NRCS Hydrologic Soils Group
2-yr 5-yr 10-yr 25-yr 50-yr 100-yr
0% 0.00 0.00 0.05 0.12 0.16 0.20
5% 0.00 0.02 0.10 0.16 0.20 0.24
10% 0.00 0.06 0.14 0.20 0.24 0.28
15% 0.02 0.10 0.17 0.23 0.27 0.30
20% 0.06 0.13 0.20 0.26 0.30 0.33
25% 0.09 0.16 0.23 0.29 0.32 0.35
30% 0.13 0.19 0.25 0.31 0.34 0.37
35% 0.16 0.22 0.28 0.33 0.36 0.39
40% 0.19 0.25 0.30 0.35 0.38 0.41
45% 0.22 0.27 0.33 0.37 0.40 0.43
50% 0.25 0.30 0.35 0.40 0.42 0.45
55% 0.29 0.33 0.38 0.42 0.45 0.47
60% 0.33 0.37 0.41 0.45 0.47 0.50
65% 0.37 0.41 0.45 0.49 0.51 0.53
70% 0.42 0.45 0.49 0.53 0.54 0.56
75% 0.47 0.50 0.54 0.57 0.59 0.61
80% 0.54 0.56 0.60 0.63 0.64 0.66
85% 0.61 0.63 0.66 0.69 0.70 0.72
90% 0.69 0.71 0.73 0.76 0.77 0.79
95% 0.78 0.80 0.82 0.84 0.85 0.86
100% 0.89 0.90 0.92 0.94 0.95 0.96
RO-12 2007-01
Urban Drainage and Flood Control District
DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF
Figure RO-3— Watershed Imperviousness, Single-Family Residential Ranch Style Houses
2007-01 RO-15
Urban Drainage and Flood Control District
RUNOFF DRAINAGE CRITERIA MANUAL (V. 1)
Figure RO-4—Watershed Imperviousness, Single-Family Residential Split-Level Houses
RO-16 2007-01
Urban Drainage and Flood Control District
DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF
Figure RO-5—Watershed Imperviousness, Single-Family Residential Two-Story Houses
Figure RO-6—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic
Soil Group A
2007-01 RO-17
Urban Drainage and Flood Control District
RUNOFF DRAINAGE CRITERIA MANUAL (V. 1)
Figure RO-7—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic
Soil Group B
Figure RO-8—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic
Soil Groups C and D
RO-18 2007-01
Urban Drainage and Flood Control District
APPENDIX A.2
EXISTING AND PROPOSED IMPERVIOUS AREAS EXHIBIT
W
W
E E E E
W
W
T
T
FO
FO
E
E
E
E E
E E
T
T
T
T
CTV
CTV
CTV
CTV
FO FO
FO FO
G
G G
G
G
E
E
E
E
E
E
E
E E E
E
LIGHTED "PERKINS"
SIGN
SINGLE STORY
COMMERCIAL W/BRICK,
WOOD & STUCCO
FFE = 4994.28
SS SS SS SS
6'x10'
SHED
MH
ELEC
ELEC
T
VAULT
CABLE
S
ELEC
ELEC
VAULT T
ELEC
VAULT
ELEC
VAULT
APPENDIX A.3
LID COMPLIANCE COMPUTATIONS
Reference: Fort Collins Stormwater Criteria Manual Project Name:
Volume 3, Chapter 1, Section 4.1, Runoff Reduction Practices Project No.:
Calculations By:
Minimum Impervious Area to be treated by LID Technique(s) : 50% Date:
Percent of newly added pavement that is permeable : N.A.
LID Treatment Technique
North Courtyard Planters 8,276 sq.ft. 1,328 sq.ft. 6.2 :1 320 cu.ft. 2.9 in. 664 cu.ft.
South Courtyard Planters 11,541 sq.ft. 1,188 sq.ft. 9.7 :1 424 cu.ft. 4.3 in. 594 cu.ft.
Paseo Planter 1,051 sq.ft. 302 sq.ft. 3.5 :1 35 cu.ft. 1.4 in. 151 cu.ft.
Sub-total 20,868 sq.ft. 2,818 sq.ft.
Total Area Treated by LID: 23,685 sq.ft.
Total Site Impervious Area: 35,031 sq.ft.
Percent LID Treatment: 68% > 50%
N. Haws
August 28, 2015
Reference: Ordinance No. 152, 2012 of the Council of the City of Fort Collins, Amending Chapter 26 of the Code of the City of Fort Collins and the Fort Collins Stormwater Criteria Manual
LOW-IMPACT DEVELOPMENT (LID) COMPLIANCE
Uncommon
1104-001
Volume
Provided at
6-in. Depth
Rooftop
Run-on
Area
Surface
Area of LID
Facilities
Run-on
Ratio
Required
12-hr
WQCV
Depth at
Required
Volume
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 100.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 1.000
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.40 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 9,604 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 320 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 6in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 0.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 213 sq ft
D) Actual Flat Surface Area AActual = 1328 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 1328 sq ft
F) Rain Garden Total Volume VT= 664 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
12" thick layer of Fort Collins Bioretention Sand Media over 6" thick layer of
pea gravel over 8" thick layer of CDOT No. 4 aggregate
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y= 2.2 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = 320 cu ft
iii) Orifice Diameter, 3/8" Minimum DO = 0.41 in
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
North Courtyard Planters
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.03_North-Planters, RG 8/27/2015, 10:59 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
PROVIDE A 30 MIL (MIN) PVC LINER WITH CDOT CLASS B
GEOTEXTILE ABOVE IT. USE THE SAME GEOTEXTILE BELOW
THE LINER IF THE SUBGRADE IS ANGULAR
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
North Courtyard Planters
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.03_North-Planters, RG 8/27/2015, 10:59 AM
TEMPORARY IRRIGATION FOR ESTABLISHMENT.
PERMANENT IRRIGATION TO BE DETERMINED.
This information remains preliminary at this time. The primary objective is to confirm that enough planter area is generally provided for on the site to treat the respective
rooftop run-on areas, and that the corresponding depths of 12-hr WQCV remain reasonable. Refer to Site and Landscape Plans (by others) for additional information on
plantings and other planter details. Additional design detail and refinement will be provided during Final Plan.
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 100.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 1.000
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.40 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 12,729 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 424 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 6in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 0.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 283 sq ft
D) Actual Flat Surface Area AActual = 1188 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 1188 sq ft
F) Rain Garden Total Volume VT= 594 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
12" thick layer of Fort Collins Bioretention Sand Media over 6" thick layer of
pea gravel over 8" thick layer of CDOT No. 4 aggregate
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y= 2.2 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = 424 cu ft
iii) Orifice Diameter, 3/8" Minimum DO = 0.47 in
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
South Courtyard Planters
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.03_South-Planters, RG 8/27/2015, 11:06 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
PROVIDE A 30 MIL (MIN) PVC LINER WITH CDOT CLASS B
GEOTEXTILE ABOVE IT. USE THE SAME GEOTEXTILE BELOW
THE LINER IF THE SUBGRADE IS ANGULAR
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
South Courtyard Planters
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.03_South-Planters, RG 8/27/2015, 11:06 AM
TEMPORARY IRRIGATION FOR ESTABLISHMENT.
PERMANENT IRRIGATION TO BE DETERMINED.
This information remains preliminary at this time. The primary objective is to confirm that enough planter area is generally provided for on the site to treat the respective
rooftop run-on areas, and that the corresponding depths of 12-hr WQCV remain reasonable. Refer to Site and Landscape Plans (by others) for additional information on
plantings and other planter details. Additional design detail and refinement will be provided during Final Plan.
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 100.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 1.000
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.40 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 1,051 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 35 cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 6in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 0.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 23 sq ft
D) Actual Flat Surface Area AActual = 302 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 302 sq ft
F) Rain Garden Total Volume VT= 151 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
12" thick layer of Fort Collins Bioretention Sand Media over 6" thick layer of
pea gravel over 8" thick layer of CDOT No. 4 aggregate
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y= 2.2 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = 35 cu ft
iii) Orifice Diameter, 3/8" Minimum DO = 0.13 in MINIMUM DIAMETER = 3/8"
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
Paseo Planter
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.03_Paseo-Planter, RG 8/27/2015, 11:10 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
PROVIDE A 30 MIL (MIN) PVC LINER WITH CDOT CLASS B
GEOTEXTILE ABOVE IT. USE THE SAME GEOTEXTILE BELOW
THE LINER IF THE SUBGRADE IS ANGULAR
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
Nick Haws
Northern Engineering
August 27, 2015
Uncommon | 310 S. College Ave.
Paseo Planter
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.03_Paseo-Planter, RG 8/27/2015, 11:10 AM
TEMPORARY IRRIGATION FOR ESTABLISHMENT.
PERMANENT IRRIGATION TO BE DETERMINED.
This information remains preliminary at this time. The primary objective is to confirm that enough planter area is generally provided for on the site to treat the respective
rooftop run-on areas, and that the corresponding depths of 12-hr WQCV remain reasonable. Refer to Site and Landscape Plans (by others) for additional information on
plantings and other planter details. Additional design detail and refinement will be provided during Final Plan.
APPENDIX B.1
WATER EROSION CONTROL REPORT
Uncommon
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 C.1
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
Natural Area, Colorado
Resources
Conservation
Service
July 14, 2015
Preface
Soil surveys contain information that affects land use planning in survey areas. They
highlight soil limitations that affect various land uses and provide information about
the properties of the soils in the survey areas. Soil surveys are designed for many
different users, including farmers, ranchers, foresters, agronomists, urban planners,
community officials, engineers, developers, builders, and home buyers. Also,
conservationists, teachers, students, and specialists in recreation, waste disposal,
and pollution control can use the surveys to help them understand, protect, or enhance
the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil properties
that are used in making various land use or land treatment decisions. The information
is intended to help the land users identify and reduce the effects of soil limitations on
various land uses. The landowner or user is responsible for identifying and complying
with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some cases.
Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/
nrcs/main/soils/health/) and certain conservation and engineering applications. For
more detailed information, contact your local USDA Service Center (http://
offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic
tank absorption fields. A high water table makes a soil poorly suited to basements or
underground installations.
The National Cooperative Soil Survey is a joint effort of the United States Department
of Agriculture and other Federal agencies, State agencies including the Agricultural
Experiment Stations, and local agencies. The Natural Resources Conservation
Service (NRCS) has leadership for the Federal part of the National Cooperative Soil
Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs
and activities on the basis of race, color, national origin, age, disability, and where
applicable, sex, marital status, familial status, parental status, religion, sexual
orientation, genetic information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not all prohibited
bases apply to all programs.) Persons with disabilities who require alternative means
2
for communication of program information (Braille, large print, audiotape, etc.) should
contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a
complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272
(voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and
employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................7
Soil Map................................................................................................................8
Legend..................................................................................................................9
Map Unit Legend................................................................................................10
Map Unit Descriptions........................................................................................10
Larimer County Area, Colorado......................................................................12
35—Fort Collins loam, 0 to 3 percent slopes..............................................12
References............................................................................................................13
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous areas
in a specific area. They include a description of the soils and miscellaneous areas and
their location on the landscape and tables that show soil properties and limitations
affecting various uses. Soil scientists observed the steepness, length, and shape of
the slopes; the general pattern of drainage; the kinds of crops and native plants; and
the kinds of bedrock. They observed and described many soil profiles. A soil profile is
the sequence of natural layers, or horizons, in a soil. The profile extends from the
surface down into the unconsolidated material in which the soil formed or from the
surface down to bedrock. The unconsolidated material is devoid of roots and other
living organisms and has not been changed by other biological activity.
Currently, soils are mapped according to the boundaries of major land resource areas
(MLRAs). MLRAs are geographically associated land resource units that share
common characteristics related to physiography, geology, climate, water resources,
soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically
consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that is
related to the geology, landforms, relief, climate, and natural vegetation of the area.
Each kind of soil and miscellaneous area is associated with a particular kind of
landform or with a segment of the landform. By observing the soils and miscellaneous
areas in the survey area and relating their position to specific segments of the
landform, a soil scientist develops a concept, or model, of how they were formed. Thus,
during mapping, this model enables the soil scientist to predict with a considerable
degree of accuracy the kind of soil or miscellaneous area at a specific location on the
landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented by
an understanding of the soil-vegetation-landscape relationship, are sufficient to verify
predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them to
identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character of
soil properties and the arrangement of horizons within the profile. After the soil
scientists classified and named the soils in the survey area, they compared the
5
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that have
similar use and management requirements. Each map unit is defined by a unique
combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components of
the map unit. The presence of minor components in a map unit in no way diminishes
the usefulness or accuracy of the data. The delineation of such landforms and
landform segments on the map provides sufficient information for the development of
resource plans. If intensive use of small areas is planned, onsite investigation is
needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape, and
experience of the soil scientist. Observations are made to test and refine the soil-
landscape model and predictions and to verify the classification of the soils at specific
locations. Once the soil-landscape model is refined, a significantly smaller number of
measurements of individual soil properties are made and recorded. These
measurements may include field measurements, such as those for color, depth to
bedrock, and texture, and laboratory measurements, such as those for content of
sand, silt, clay, salt, and other components. Properties of each soil typically vary from
one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists interpret
the data from these analyses and tests as well as the field-observed characteristics
and the soil properties to determine the expected behavior of the soils under different
uses. Interpretations for all of the soils are field tested through observation of the soils
in different uses and under different levels of management. Some interpretations are
modified to fit local conditions, and some new interpretations are developed to meet
local needs. Data are assembled from other sources, such as research information,
production records, and field experience of specialists. For example, data on crop
yields under defined levels of management are assembled from farm records and from
field or plot experiments on the same kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on such
variables as climate and biological activity. Soil conditions are predictable over long
periods of time, but they are not predictable from year to year. For example, soil
scientists can predict with a fairly high degree of accuracy that a given soil will have
a high water table within certain depths in most years, but they cannot predict that a
high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
identified each as a specific map unit. Aerial photographs show trees, buildings, fields,
roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
6
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of soil
map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
7
8
Custom Soil Resource Report
Soil Map
4492510 4492520 4492530 4492540 4492550 4492560 4492570 4492580 4492590 4492600
4492510 4492520 4492530 4492540 4492550 4492560 4492570 4492580 4492590 4492600
493490 493500 493510 493520 493530 493540 493550
493490 493500 493510 493520 493530 493540 493550
40° 35' 3'' N
105° 4' 37'' W
40° 35' 3'' N
105° 4' 34'' W
40° 35' 0'' N
105° 4' 37'' W
40° 35' 0'' N
105° 4' 34'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 20 40 80 120
Feet
0 5 10 20 30
Meters
Map Scale: 1:462 if printed on A portrait (8.5" x 11") sheet.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
35 Fort Collins loam, 0 to 3 percent
slopes
1.0 100.0%
Totals for Area of Interest 1.0 100.0%
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, onsite investigation is needed to
define and locate the soils and miscellaneous areas.
Custom Soil Resource Report
10
An identifying symbol precedes the map unit name in the map unit descriptions. Each
description includes general facts about the unit and gives important soil properties
and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major horizons
that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity,
degree of erosion, and other characteristics that affect their use. On the basis of such
differences, a soil series is divided into soil phases. Most of the areas shown on the
detailed soil maps are phases of soil series. The name of a soil phase commonly
indicates a feature that affects use or management. For example, Alpha silt loam, 0
to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps. The
pattern and proportion of the soils or miscellaneous areas are somewhat similar in all
areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present or
anticipated uses of the map units in the survey area, it was not considered practical
or necessary to map the soils or miscellaneous areas separately. The pattern and
relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-
Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas that
could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion of
the soils or miscellaneous areas in a mapped area are not uniform. An area can be
made up of only one of the major soils or miscellaneous areas, or it can be made up
of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil material
and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
11
Larimer County Area, Colorado
35—Fort Collins loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlnc
Elevation: 4,020 to 6,730 feet
Mean annual precipitation: 14 to 16 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 143 to 154 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform: Interfluves
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Pleistocene or older alluvium derived from igneous, metamorphic
and sedimentary rock and/or eolian deposits
Typical profile
Ap - 0 to 4 inches: loam
Bt1 - 4 to 9 inches: clay loam
Bt2 - 9 to 16 inches: clay loam
Bk1 - 16 to 29 inches: loam
Bk2 - 29 to 80 inches: loam
Properties and qualities
Slope: 0 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high
(0.20 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 12 percent
Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4c
Hydrologic Soil Group: C
Ecological site: Loamy Plains (R067BY002CO)
Custom Soil Resource Report
12
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
13
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
14
MAP POCKET
DRAINAGE EXHIBITS
MH
CONTROL
IRR
CONTROL
IRR
ST ST ST ST ST ST ST ST ST ST
OLIVE STREET
(100' PUBLIC R.O.W.)
SOUTH COLLEGE AVENUE
(140' PUBLIC R.O.W.)
MONTEZUMA FULLER ALLEY
(20' PUBLIC R.O.W.)
OWNER:
330 LLC
2775 IRIS AVE
BOULDER, CO 80304
OWNER:
REMINGTON PROPERTIES, LLC
1054 MESSARA DRIVE
FORT COLLINS, CO 80524
OWNER:
REMINGTON RENTAL
PROPERTIES, LLC
1054 MESSARA DRIVE
FORT COLLINS, CO 80524
OWNER:
ADP SCREENING AND
SELECTION SERVICES INC.
MAILSTOP 325
ROSELAND, NJ 07068-1728
1
2
3
3
1 2
EXISTING
INLETS
EXISTING STORM DRAIN PROPOSED
STORM MANHOLE
PROPOSED PRIVATE
STORM DRAIN
PROPOSED INLET
LID/PLANTER AREAS
LID/PLANTER AREAS
LID/PLANTER AREAS
LID/PLANTER AREAS
OS1
OS1
LID/PLANTER
AREAS (BELOW)
NORTH
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
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M
H
VAULT
CABLE
CONTROL
IRR
CONTROL
IRR
ST ST ST ST ST ST ST ST ST ST
OLIVE STREET
(100' PUBLIC R.O.W.)
SOUTH COLLEGE AVENUE
(140' PUBLIC R.O.W.)
MONTEZUMA FULLER ALLEY
(20' PUBLIC R.O.W.)
OWNER:
330 LLC
2775 IRIS AVE
BOULDER, CO 80304
OWNER:
REMINGTON PROPERTIES, LLC
1054 MESSARA DRIVE
FORT COLLINS, CO 80524
OWNER:
REMINGTON RENTAL
PROPERTIES, LLC
1054 MESSARA DRIVE
FORT COLLINS, CO 80524
OWNER:
ADP SCREENING AND
SELECTION SERVICES INC.
MAILSTOP 325
ROSELAND, NJ 07068-1728
4995.17 (NAVD88)
4994.17 (NAVD88)
PARKING
GARAGE
OPENING
NORTH
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
N O R T H E RN
09/02/15
301 North Howes Street, Suite 010
Fort Collins, Colorado 80521
www.northernengineering.com
Phone: 970.221.4158
Of 8 Sheets
C601
( IN FEET )
1 inch = ft.
20 0 20 Feet
20
40 60
NOTES:
FOR STORMWATER REVIEW ONLY
NOT FOR CONSTRUCTION
1. REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT DIMENSIONS,
UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER SURVEY INFORMATION
2. THIS PROJECT IS LOCATED WITHIN THE CITY-REGULATED OLD TOWN 100-YEAR
FLOODWAY AND FLOOD FRINGE AND MUST COMPLY WITH CHAPTER 10 OF THE CITY
CODE.
3. ALL ELEVATIONS DEPICTED IN PLAN VIEW AND BENCHMARKS LISTED HEREON ARE
PER NAVD 88 DATUM.
4. ANY ITEMS LOCATED IN THE FLOODWAY THAT CAN FLOAT (E.G., PICNIC TABLES,
BIKE RACKS, ETC.) MUST BE ANCHORED.
5. THE LOWEST FLOOR AND THE FINISHED FLOOR FOR ANY BUILDING IN THE
FLOODPLAIN SHALL BE FLOODPROOFED UP TO THE REGULATORY FLOOD
PROTECTION ELEVATION.
6. A FLOODPLAIN USE PERMIT SHALL BE REQUIRED FOR EACH STRUCTURE AND EACH
SITE CONSTRUCTION ELEMENT IN THE FLOODPLAIN.
7. A FLOODPLAIN USE PERMIT AND NO RISE CERTIFICATION IS REQUIRED PRIOR TO
PERFORMING ANY WORK WITHIN THE FLOODWAY (I.E., CURB CUT REMOVAL,
LANDSCAPING).
8. THE FLOODPLAIN USE PERMIT FOR THE BUILDING WILL BE SUBMITTED AT THE TIME
OF THE BUILDING PERMIT APPLICATION.
9. A FLOODPROOFING CERTIFICATE SHALL BE COMPLETED AND APPROVED BEFORE
THE CERTIFICATE OF OCCUPANCY IS ISSUED FOR ANY STRUCTURE IN THE
FLOODPLAIN.
10. THE FLOODPROOFING REQUIREMENTS OF CHAPTER 10 OF THE CITY CODE WILL BE
SATISFIED PRIOR TO ISSUANCE OF A BUILDING PERMIT.
11. NO STORAGE OF MATERIALS OR EQUIPMENT SHALL BE ALLOWED IN THE
FLOODWAY, WHETHER TEMPORARY (DURING CONSTRUCTION) OR PERMANENT.
LANDSCAPING SHALL ALSO MEET THE REQUIREMENTS FOR NO RISE IN THE
FLOODWAY.
12. REFER TO THE PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR
UNCOMMON DATED SEPTEMBER 2, 2015 FOR ADDITIONAL INFORMATION.
13. ALL HVAC EQUIPMENT IS TO BE LOCATED ON THE ROOFTOP OF THE STRUCTURE.
14. REFER TO ARCHITECTURAL DOCUMENTS FOR ADDITIONAL FLOODPROOFING
INFORMATION.
DETAIL
FIELD SURVEY BY:
BENCHMARKS:
NORTHERN ENGINEERING SERVICES, INC.
PROJECT NO. 1104-001
DATE: MAY 2015
MIXED-USE BUILDING
SUMMARY
LEGEND:
PROPOSED CONTOUR
EXISTING STORM SEWER
PROPOSED STORM SEWER
ST
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
EXISTING 100-YEAR CITY FLOODWAY
PROPOSED STORM INLET
PROPOSED CONCRETE
CROSS PAN (TYP.)
PEDESTRIAN ACCESS RAMPS
/ / / / / / / / / / / / / / / / / / / / / / / / / / /
PROPERTY BOUNDARY
CROSS-SECTION (CSL)
BASE FLOOD ELEVATION (BFE)
EXISTING 100-YEAR CITY FLOODPLAIN
ELEVATION NGVD 88 5000
XS#: 2446
PROJECT DATUM: NAVD88
CITY OF FORT COLLINS BENCHMARK 06-00
ON A CATCH BASIN AT THE NORTHWEST CORNER OF MULBERRY STREET AND COLLEGE
AVENUE.
ELEV.= 4993.85
CITY OF FORT COLLINS BENCHMARK 29-97
NORTHEAST CORNER OF MULBERRY ST. AND WHEDBEE STREET, ON A CONCRETE TRAFFIC
SIGNAL BASE.
ELEV.= 4978.01
PLEASE NOTE: THIS PLAN SET IS USING NAVD88 FOR A VERTICAL DATUM. SURROUNDING
DEVELOPMENTS HAVE USED NGVD29 UNADJUSTED FOR THEIR VERTICAL DATUMS.
IF NGVD29 UNADJUSTED DATUM IS REQUIRED FOR ANY PURPOSED, THE FOLLOWING
EQUATION SHOULD BE USED:
NGVD29 UNADJUSTED = NAVD88 - 3.17'
Engineering Services, Inc.
NOT FOR CONSTRUCTION
N O R T H E RN
09/02/15
301 North Howes Street, Suite 010
Fort Collins, Colorado 80521
www.northernengineering.com
Phone: 970.221.4158
Of 8 Sheets
C600
( IN FEET )
1 inch = ft.
20 0 20 Feet
20
40 60
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
R
LEGEND:
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
1 1
NOTES:
1. REFER TO THE PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR
UNCOMMON DATED SEPTEMBER 2, 2015 FOR ADDITIONAL INFORMATION.
2. REFER TO THE FLOODPLAN EXHIBIT ON SHEET C601 FOR ADDITIONAL
INFORMATION.
PROPOSED CONCRETE PAVING
PROPOSED SUBDRAIN SD
BENCHMARK
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
HYDROLOGY SUMMARY
C
DRAINAGE SUMMARY TABLE
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C2 C100
2-yr
Tc
(min)
100-yr
Tc
(min)
Q2
(cfs)
Q100
(cfs)
1 1 0.10 0.98 1.23 5.0 5.0 0.3 1.2
2 2 0.66 0.91 1.00 5.0 5.0 1.7 6.5
3 3 0.05 0.40 0.50 5.0 5.0 0.1 0.2
OS1 OS1 0.48 0.27 0.33 5.9 5.0 0.4 1.6
PROJECT DATUM: NAVD88
CITY OF FORT COLLINS BENCHMARK 06-00
ON A CATCH BASIN AT THE NORTHWEST CORNER OF MULBERRY STREET
AND COLLEGE AVENUE.
ELEV.= 4993.85
CITY OF FORT COLLINS BENCHMARK 29-97
NORTHEAST CORNER OF MULBERRY ST. AND WHEDBEE STREET, ON A
CONCRETE TRAFFIC SIGNAL BASE.
ELEV.= 4978.01
PLEASE NOTE: THIS PLAN SET IS USING NAVD88 FOR A VERTICAL DATUM.
SURROUNDING DEVELOPMENTS HAVE USED NGVD29 UNADJUSTED FOR
THEIR VERTICAL DATUMS.
IF NGVD29 UNADJUSTED DATUM IS REQUIRED FOR ANY PURPOSED, THE
FOLLOWING EQUATION SHOULD BE USED:
NGVD29 UNADJUSTED = NAVD88 - 3.17'
BASIS OF BEARINGS
BASIS OF BEARINGS IS THE WEST LINE OF BLOCK 123 AS BEARING
1257+
($67 $6680('%($5,1*
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 9, Sep 22, 2014
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr 28,
2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Custom Soil Resource Report
9
ELEC
CONTROL
IRR
CONTROL
IRR
T
TELE
VAULT
ELEC
ST ST ST
W
W
E E E E
W
W
T T
FO
FO
E
E
E
T T E T E
T
CTV
CTV
CTV
CTV
FO FO FO FO
G
G
G
G
G
E
E
E
SS E SS E SS E SS
M
H
ELEC
T
VAULT
CABLE
S
ELEC
ELEC
VAULT T
ELEC
VAULT
ELEC
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
T
TELE
VAULT
ELEC
ST ST ST
DRAWN BY:
SCALE:
ISSUED:
UNCOMMON
EXHIBIT
EXISTING & PROPOSED
IMPERVIOUS AREAS ATC
1 in=60 ft
September 1, 2015 1
ROOFTOP
CONCRETE
ASPHALT
LANDSCAPE
SURFACE
AREA (SF) % IMPERV.
IMPERV.
AREA (SF)
5,032
2,508
24,468
1,716
100%
100%
100%
0% 0
TOTAL 33,724 TOTAL= 32,008
ROOFTOP
CONCRETE
ASPHALT
PERMEABLE
PAVERS
SURFACE
AREA (SF) % IMPERV.
IMPERV.
AREA (SF)
31,494
2230
0
0
100%
100%
100%
22%
TOTALS 33,724 TOTAL= 33,724
EXISTING PROPOSED
0
LANDSCAPE 0 0% 0
301 N. Howes Street, Suite 100
Fort Collins, Colorado 80521
N O R T H E RN
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5,032
2,508
24,468
31,494
2230
0
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
11No0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 229 0.40% 1.26 3.0 0 0.00% N/A N/A 5 5 5
22No0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 134 0.50% 1.41 1.6 0 0.00% N/A N/A 5 5 5
33No0.95 0.95 1.00 45 1.00% 1.9 1.9 1.3 215 1.00% 2.00 1.8 0 0.00% N/A N/A 5 5 5
OS1 OS1 No 0.95 0.95 1.00 80 0.60% 3.0 3.0 2.0 317 0.80% 1.79 3.0 0 0.00% N/A N/A 6 6 5
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
August 15, 2015
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
Ti C Cf L