HomeMy WebLinkAboutJEFFERSON & LINDEN RESTAURANT - PDP - PDP160030 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTSeptember 28, 2016
PRELIMINARY DRAINAGE AND
EROSION CONTROL REPORT FOR
JEFFERSON AND LINDEN RESTAURANT
Fort Collins, Colorado
Prepared for:
Blue Ocean Enterprises
401 W. Mountain Ave.
Fort Collins, CO 805211
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 838-014
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 28, 2016
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report for
JEFFERSON AND LINDEN RESTAURANT
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 Jefferson and Linden Restaurant 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
Jefferson and Linden Restaurant
Preliminary Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 3
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 4
A. Major Basin Description .................................................................................................................... 4
B. Sub-Basin Description ....................................................................................................................... 5
III. DRAINAGE DESIGN CRITERIA ................................................................................... 5
A. Regulations........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 6
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 6
F. Modifications of Criteria ................................................................................................................... 6
IV. DRAINAGE FACILITY DESIGN .................................................................................... 6
A. General Concept ............................................................................................................................... 6
B. Specific Details .................................................................................................................................. 7
V. CONCLUSIONS ........................................................................................................ 8
A. Compliance with Standards .............................................................................................................. 8
B. Drainage Concept .............................................................................................................................. 8
APPENDICES:
APPENDIX A - Hydrologic Computations
APPENDIX B - USDA Soils Information
APPENDIX C - LID Preliminary Design Information
APPENDIX D - Water Quality Computations
APPENDIX E - Master Basin Modeling Summary
APPENDIX F - Erosion Control Report
MAP POCKET:
Preliminary Drainage Exhibit
Jefferson and Linden Restaurant
Preliminary Drainage Report
LIST OF FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 3
Figure 3 – Existing Floodplains ............................................................................................. 4
MAP POCKET:
Proposed Drainage Exhibit
Jefferson and Linden Restaurant
Preliminary Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in Block 7 of Fort Collins, which is within the northwest
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.
3. The project site is located just north of the intersection of Linden Street and Jefferson
Street.
4. The project site lies within the Old Town Basin, and must detain and release at the
Historic 2-year release rate. Additionally, the site still must provide water quality
treatment. Water quality treatment methods in the form of permeable pavers and
extended detention are proposed for the site, and are described in further detail
below.
5. As this is an infill site, the area surrounding the site is fully developed.
6. No offsite flows enter the site.
Jefferson and Linden Restaurant
Preliminary Drainage Report 2
B. Description of Property
1. The development area is roughly 0.57 net acres.
Figure 1 – Aerial Photograph
2. The subject property is currently a park. Existing ground slopes are mild to moderate
(i.e., 1 - 6±%) through the interior of the property. General topography slopes from
northwest to southeast.
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 Paoli Fine Sandy Loam, which falls into Hydrologic Soil Group A.
4. The proposed project site plan is composed of the development of a restaurant.
Parking for the restaurant will be provided offsite. Associated landscaping, water and
sewer lines, and other improvements will be constructed with the development.
Onsite water quality treatment is proposed and will consist of several features which
are discussed in Section IV, below.
Project Site
Jefferson and Linden Restaurant
Preliminary Drainage Report 3
Figure 2– Proposed Site Plan
5. There are no known irrigation laterals crossing the site.
6. The proposed land use is a restaurant.
C. Floodplain
1. The project site is not encroached by any FEMA or City designated 100-year
floodplain.
Jefferson and Linden Restaurant
Preliminary Drainage Report 4
Figure 3 –Area Floodplain Mapping
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site lies within the Old Town Basin. In this basin, typical detention
requirements are to detain the difference between the 100-year developed inflow rate
and the historic 2-year release rate. We have been in discussion with City Staff on
the possibility of releasing all developed site drainage undetained into the newly
constructed storm system in Jefferson Street. The site is located within the study area
identified in the “Downtown River District (DTRD) Final Design Report”, by Ayres
Associates, dated February 2012. The site lies within several master plan sub-
basins, specifically Basins 110, 111, 206, and 210, as shown in DTRD Plan noted
as “Exhibit B-Future Development Map for DTRD Area” (Provided in Appendix E). As
discussed with City Staff, this project would take portions of Basins 110, 111, and
210, with a sum total of 0.40 acre, and incorporate these portions into Basin 206.
In doing so, we will be routing the project site into the recently completed Downtown
River District “Storm Line B”. Thus, we are introducing an additional 0.40 acres of
undetained drainage area into this system. Based on the modeling summary provided
in Appendix E, the site will not be required to detain developed flows. Briefly put, the
modeling we have completed adequately addresses any potential concerns related to
storm line capacity in the recently completed Downtown River District “Storm Line B”.
The study shows there is negligible impact due to the proposed minor adjustments to
master plan Basins 110, 111, 206, and 210.
Project Site
Jefferson and Linden Restaurant
Preliminary Drainage Report 5
B. Sub-Basin Description
1. The subject property historically drains overland from northwest to southeast. Runoff
from the majority of the site has historically been collected in the existing storm
systems within Linden Street and Jefferson Street.
2. A more detailed description of the project drainage patterns is provided below.
III. DRAINAGE DESIGN CRITERIA
A. Regulations
There are no optional provisions outside of the FCSCM proposed with the proposed
project.
B. Four Step Process
The overall stormwater management strategy employed with the proposed project utilizes
the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters.
The following is a description of how the proposed development has incorporated each
step.
Step 1 – Employ Runoff Reduction Practices
Several techniques have been utilized with the proposed development to facilitate the
reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the
current use by implementing multiple Low Impact Development (LID) strategies including:
Conserving existing amenities in the site including existing vegetated areas and
mature trees.
Providing vegetated landscape islands in the parking lot to reduce the overall
impervious area and to minimize directly connected impervious areas (MDCIA).
Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with
Slow Release
The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban
development of this intensity will still generate stormwater runoff that will require
additional BMPs and water quality. The majority of stormwater runoff from the site will
ultimately be intercepted and treated using extended detention methods prior to exiting the
site.
Step 3 – Stabilize Drainageways
There are no major drainageways within the subject property. While this step may not
seem applicable to proposed development, the project indirectly helps achieve stabilized
drainageways nonetheless. By providing water quality treatment, where none previously
existed, sediment with erosion potential is removed from downstream drainageway
systems. Furthermore, this project will pay one-time stormwater development fees, as
well as ongoing monthly stormwater utility fees, both of which help achieve City-wide
drainageway stability.
Step 4 – Implement Site Specific and Other Source Control BMPs.
The proposed project will improve upon site specific source controls compared to historic
conditions:
The proposed development will provide LID and water quality treatment; thus,
eliminating sources of potential pollution previously left exposed to weathering and
runoff processes.
Jefferson and Linden Restaurant
Preliminary Drainage Report 6
C. Development Criteria Reference and Constraints
The subject property is surrounded by currently developed properties. Thus, several
constraints have been identified during the course of this analysis that will impact the
proposed drainage system including:
Existing elevations along the property lines will generally be maintained.
As previously mentioned, overall drainage patterns of the existing site will be
maintained.
Elevations of existing downstream facilities that the subject property will release to
will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above, the 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 water quality treatment will be provided, and is discussed further below.
3. Drainage patterns anticipated for drainage basins shown in the Drainage Exhibit are
Jefferson and Linden Restaurant
Preliminary Drainage Report 7
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 consists of the landscaped area and rooftop, and will generally drain via sheet
flow and roof drain system into the proposed Porous Landscaped Detention (PLD)
noted on the Drainage Exhibit. The raingarden will drain under the existing sidewalk
running along the north side of Jefferson Street via a sidewalk chase.
Basin 2
Basin 2 will consist of landscaped areas, rooftop, and a decorative concrete patio
area. Storm runoff will be directed primarily via roof piping systems and surface flow
into an underground LID treatment chamber system as shown on the Drainage Exhibit.
Please see further discussion of water quality and LID features in Section IV.B, below.
Basin 3
Basin 3 consists of a small strip of landscaped area along the north side of the
proposed building that will sheet flow onto the neighboring railroad right of way.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report.
B. Specific Details
1. Two primary onsite LID features have been incorporated in the design of the
proposed site, consisting of a Porous Landscaped Detention (PLD) area and an
underground LID chamber system.
2. The majority of the proposed impervious area (mainly rooftop area, and
decorative concrete patio area) will be conveyed into the proposed
underground LID chamber system located under the decorative concrete patio
at the southeast corner of the site. This chamber system will outfall to the
newly improved storm line system within Jefferson Street.
3. A portion of the proposed rooftop area will be conveyed into the proposed
Porous Landscaped Detention (PLD) area located on the northwest side of the
building. The PLD will be graded such as to allow the outfall to daylight
through a curb chase under the existing sidewalk along Jefferson Street, into
the north curb flowline of Jefferson Street.
4. Current City of Fort Collins code minimums are being exceeded with the
current site plan as summarized in the LID Design information provided in
Appendix D.
5. The drainage features associated with the proposed project are all private
facilities, located on private property, with the exception of the two site
outfalls, which will be a sidewalk chase within Jefferson Street Street Right of
Way and a storm line tie-in also within Jefferson Street Street Right of Way.
Jefferson and Linden Restaurant
Preliminary Drainage Report 8
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. As noted in Section II.A, the site will not detain flows based on
modeling submitted for this project.
3. The drainage plan and stormwater management measures proposed with the
proposed development are compliant with all applicable State and Federal regulations
governing stormwater discharge.
B. Drainage Concept
1. The drainage design proposed with this project will effectively limit any potential
damage associated with its stormwater runoff by providing detention and water
quality mitigation features.
2. The drainage concept for the proposed development is consistent with requirements
for the Old Town Basin.
Jefferson and Linden Restaurant
Preliminary Drainage Report 9
References
1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
2. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
4. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
APPENDIX A
Hydrologic Computations
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 838-014
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 8307 0.19 0.000 0.012 0.035 0.000 0.144 0.35 0.35 0.43 22%
2 10331 0.24 0.000 0.100 0.086 0.000 0.051 0.78 0.78 0.97 71%
3 837 0.02 0.000 0.000 0.000 0.000 0.019 0.15 0.15 0.19 0%
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
9/25/16
Overland Flow, Time of Concentration:
Project: 838-014
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: 838-014
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 0.19 15 15 14 0.35 0.35 0.43 1.90 3.24 6.71 0.13 0.21 0.56
2 2 0.24 9 9 9 0.78 0.78 0.97 2.30 3.93 8.21 0.42 0.72 1.89
3 3 0.02 5 5 5 0.15 0.15 0.19 2.85 4.87 9.95 0.01 0.01 0.04
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
9/25/16
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
Q C f C i A
APPENDIX B
USDA Soils Information
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Natural Area, Colorado
Resources
Conservation
Service
September 26, 2016
Preface
Soil surveys contain information that affects land use planning in survey areas. They
highlight soil limitations that affect various land uses and provide information about
the properties of the soils in the survey areas. Soil surveys are designed for many
different users, including farmers, ranchers, foresters, agronomists, urban planners,
community officials, engineers, developers, builders, and home buyers. Also,
conservationists, teachers, students, and specialists in recreation, waste disposal,
and pollution control can use the surveys to help them understand, protect, or enhance
the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil properties
that are used in making various land use or land treatment decisions. The information
is intended to help the land users identify and reduce the effects of soil limitations on
various land uses. The landowner or user is responsible for identifying and complying
with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some cases.
Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/
nrcs/main/soils/health/) and certain conservation and engineering applications. For
more detailed information, contact your local USDA Service Center (http://
offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic
tank absorption fields. A high water table makes a soil poorly suited to basements or
underground installations.
The National Cooperative Soil Survey is a joint effort of the United States Department
of Agriculture and other Federal agencies, State agencies including the Agricultural
Experiment Stations, and local agencies. The Natural Resources Conservation
Service (NRCS) has leadership for the Federal part of the National Cooperative Soil
Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs
and activities on the basis of race, color, national origin, age, disability, and where
applicable, sex, marital status, familial status, parental status, religion, sexual
orientation, genetic information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not all prohibited
bases apply to all programs.) Persons with disabilities who require alternative means
2
for communication of program information (Braille, large print, audiotape, etc.) should
contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a
complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272
(voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and
employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................7
Soil Map................................................................................................................8
Legend..................................................................................................................9
Map Unit Legend................................................................................................10
Map Unit Descriptions........................................................................................10
Larimer County Area, Colorado......................................................................12
81—Paoli fine sandy loam, 0 to 1 percent slopes.......................................12
References............................................................................................................14
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
4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250
4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250
493610 493620 493630 493640 493650 493660 493670 493680 493690 493700 493710 493720 493730 493740 493750 493760
493610 493620 493630 493640 493650 493660 493670 493680 493690 493700 493710 493720 493730 493740 493750 493760
40° 35' 24'' N
105° 4' 31'' W
40° 35' 24'' N
105° 4' 25'' W
40° 35' 20'' N
105° 4' 31'' W
40° 35' 20'' N
105° 4' 25'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 35 70 140 210
Feet
0 10 20 40 60
Meters
Map Scale: 1:740 if printed on A landscape (11" x 8.5") sheet.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
81 Paoli fine sandy loam, 0 to 1
percent slopes
0.7 100.0%
Totals for Area of Interest 0.7 100.0%
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
81—Paoli fine sandy loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: jpxx
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Paoli and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Paoli
Setting
Landform: Stream terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 30 inches: fine sandy loam
H2 - 30 to 60 inches: fine sandy loam, sandy loam, loamy sand
H2 - 30 to 60 inches:
H2 - 30 to 60 inches:
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Very low
Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water storage in profile: Very high (about 16.5 inches)
Interpretive groups
Land capability classification (irrigated): 1
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: A
Ecological site: Overflow (R067BY036CO)
Hydric soil rating: No
Minor Components
Caruso
Percent of map unit: 6 percent
Custom Soil Resource Report
12
Hydric soil rating: No
Table mountain
Percent of map unit: 6 percent
Hydric soil rating: No
Fluvaquentic haplustolls
Percent of map unit: 3 percent
Landform: Terraces
Hydric soil rating: Yes
Custom Soil Resource Report
13
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
14
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
15
APPENDIX C
LID Preliminary Design Information
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: Jefferson & Linden Restaurant
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: A. Reese
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
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Pavers (ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1 0.22 0.00 0.01 0.04 0.00 0.00 0.17 0.42 0.42 0.52 22%
2 0.25 0.00 0.10 0.09 0.00 0.00 0.05 0.80 0.80 1.00 70%
Total 0.47 0.00 0.11 0.13 0.00 0.00 0.22 0.62 0.62 0.77 47%
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
September 28, 2016
Project Title Date:
Project Number Calcs By:
Client
Basins
0.8
WQCV = Watershed inches of Runoff (inches) 19.00%
a = Runoff Volume Reduction (constant)
i = Total imperviousness Ratio (i = Iwq/100) 0.089 in
A = 0.22 ac
V = 0.0016 ac-ft
V = Water Quality Design Volume (ac-ft)
WQCV = Water Quality Capture Volume (inches)
A = Watershed Area (acres)
Jefferson & Linden Restaurant September 28, 2016
838-014 A. Reese
Bioretention Basin (PLD)
71 cu. ft.
Drain Time
a =
i =
WQCV =
Figure EDB-2 - Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event
0.089
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
WQCV (watershed inches)
Total Imperviousness Ratio (i = Iwq/100)
Water Quality Capture Volume
6 hr
12 hr
24 hr
40 hr
WQCV = a ( 0.91 i 3 - 1 . 19 i 2 + 0 . 78 i )
WQCV = a ( 0.91 i 3 - 1 . 19 i 2 + 0 . 78 i )
V * A
12
WQCV
÷
ø
ö
Project Title Date:
Project Number Calcs By:
Client
Basins
0.8
WQCV = Watershed inches of Runoff (inches) 67.00%
a = Runoff Volume Reduction (constant)
i = Total imperviousness Ratio (i = Iwq/100) 0.210 in
A = 0.26 ac
V = 0.0045 ac-ft
V = Water Quality Design Volume (ac-ft)
WQCV = Water Quality Capture Volume (inches)
A = Watershed Area (acres)
Jefferson & Linden Restaurant September 28, 2016
838-014 A. Reese
Vaults
198 cu. ft.
Drain Time
a =
i =
WQCV =
Figure EDB-2 - Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event
0.210
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
WQCV (watershed inches)
Total Imperviousness Ratio (i = Iwq/100)
Water Quality Capture Volume
6 hr
12 hr
24 hr
40 hr
WQCV = a ( 0.91 i 3 - 1 . 19 i 2 + 0 . 78 i )
WQCV = a ( 0.91 i 3 - 1 . 19 i 2 + 0 . 78 i )
V * A
12
WQCV
÷
ø
ö
APPENDIX D
Water Quality Computations
WATER QUALITY DESIGN CALCULATIONS
Water Quality Capture Volume (12-Hr. PLD)
Project: 838-014
By: ATC
Date: 9/15/16
REQUIRED STORAGE & OUTLET WORKS:
ROOFTOP AREA (ac) = 0.081 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 90.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.9000 <-- CALCULATED
WQCV (watershed inches) = 0.320 <-- CALCULATED from Figure EDB-2
WQCV (cu-ft) = 94 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
Calculating the WQCV and Volume Reduction Chapter 3
3-6 Urban Drainage and Flood Control District August 2011
Urban Storm Drainage Criteria Manual Volume 3
Once the WQCV in watershed inches is found from Figure 3-2 or using Equation 3-1 and/or 3-2, the
required BMP storage volume in acre-feet can be calculated as follows:
𝑉 = �
WQCV
12
� 𝐴 Equation 3-3
Where:
V = required storage volume (acre-ft)
A = tributary catchment area upstream (acres)
WQCV = Water Quality Capture Volume (watershed inches)
Figure 3-2. Water Quality Capture Volume (WQCV) Based on BMP Drain Time
APPENDIX E
Master Basin Modeling Summary
1
Modeling Summary Report
Date: September 8, 2016
Project: Jefferson and Linden Restaurant
Fort Collins, Colorado
Attn: Mr. Shane Boyle
Fort Collins Utilities
700 Wood Street
Fort Collins, Colorado 80524
Dear Mr. Boyle:
This modeling summary report is intended to supplement the PDP and FP Drainage reports for
the Jefferson and Linden Restaurant project. The proposed development site is located just
northwest of the intersection of Jefferson Street and Lindon Street in Fort Collins, Colorado.
The site is located within the study area identified in the “Downtown River District (DTRD) Final
Design Report”, by Ayres Associates, dated February 2012. The site lies within several master
plan sub-basins, specifically Basins 110, 111, 206, and 210, as shown in on the attached “Exhibit
B-Future Development Map for DTRD Area” (Please see Attachment 1). As we have discussed
with you, we would like to take portions of Basins 110, 111, and 210, with a sum total of 0.40
acre, and incorporate these portions into Basin 206. In doing so, we will be routing the
Jefferson and Linden Restaurant project site into the recently completed Downtown River
District “Storm Line B”. Thus, we are introducing an additional 0.40 acres of undetained
drainage area into this system.
Hydrologic modeling was completed in this report utilizing the computer program EPA SWMM
5. Specifically, the proposed site is located within SWMM Basin 206, and the updated modeling
completed for this study incorporates an additional 0.40 acres as discussed above. We note
that Basin 206 had an assumed percent impervious value of 90% in the original Ayres model,
and we have not changed this parameter. The proposed site plan will not exceed this percent
impervious assumption. Please see the disk provided in Attachment 3 for an electronic copy of
the modified master plan SWMM Model.
Table 1, below, summarizes changes in Peak 100-year discharge at SWMM Links B6 (site tie-in
point) through B3 (several links downstream of the site). Table 2, below. summarizes changes
in 100-year HGL at SWMM Manholes MHB6 through B3. Please see Attachment 2 for selected
portions of the Downtown River District “Storm Line B” plan set, and we note that the minor
2
increases in HGL summarized in Table 1, below will not bring HGL above junction rim elevation
at any junction.
TABLE 1 – Summary of Changes in Peak 100-year Flow
Link
Original Ayres
Model Peak
100-yr Flow
Revised Model
Peak 100-yr
Flow
Change in
Peak 100-yr
Flow (CFS)
B3 302.49 304.01 1.52
B4 285.26 287.26 2
B5 151.59 153.22 1.63
B6 109.55 111.64 2.09
TABLE 2 – Summary of Changes in 100-year HGL
Node
Original Ayres
Model Peak
100-yr
Manhole
Depth
Original Ayres
Model 100-yr
HGL
Revised Model
Peak 100-yr
Manhole
Depth
Revised Model
100-yr HGL
Change 100-yr
HGL (FT)
MHB3 5.4 4964.02 5.49 4964.11 0.09
MHB4 6.02 4964.9 6.09 4964.97 0.07
MHB5 6.26 4966.78 6.39 4966.91 0.13
MHB6 6.11 4969.45 6.3 4969.64 0.19
In summary, the modeling provided adequately addresses any potential concerns related to
storm line capacity in the recently completed Downtown River District “Storm Line B”. This
study shows there is negligible impact due to the proposed minor adjustments to master plan
Basins 110, 111, 206, and 210.
Please feel free to contact me with any questions you may have.
Sincerely
NORTHERN ENGINEERING
Aaron Cvar, PhD, PE
Senior Project Engineer
Attachment 1
Annotated Exhibit B-Future Development Map for DTRD Area
Attachment 2
Selected Portions of Downtown River District “Storm Line B”
Plan Set
Attachment 3
Modified Master Plan SWMM Model (on Disk)
APPENDIX F
Erosion Control Report
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.
MAP POCKET
VAULT
ELEC
VAULT
ELEC
T
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC
VAULT
ELEC
VAULT
ELEC
ELEC
ELEC
VAULT
ELEC
VAULT
ELEC
TRAFFIC
VAULT
TRAFFIC
VAULT
TRAFFIC
VAULT
CONTROL
IRR
S
VAULT
ELEC
MW
C.O.
X
X
X
X
X
X
X
X X
X
10" W
10" W
10" W
10" W
10" W 10" W 10" W 10" W
6" W
6" W
6" SS
6" SS
6" SS
6" SS 6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
6" SS
15" SS 15" SS
15" SS
15" SS
15" SS 15" SS
15" SS 15" SS
15" SS
15" SS 15" SS
TF
X
X
X
X
X
X
X X X
X
X X
X X
X X X X
X
X
X
25.01'
EXISTING INLET
E
E
E
E
E
E E
E
E
E
UD UD
CHAMBER
OUTLET STRUCTURE
CHAMBER OUTFALL
EXISTING INLET
1
2
1
JEFFERSON STREET
(70' PUBLIC R.O.W.)
LINDEN STREET
(100' PUBLIC R.O.W.)
2
3
3
No. Revisions: By: Date:
REVIEWED BY:
N. Haws
DESIGNED BY:
DRAWN BY:
SCALE:
PROJECT:
838-014
Sheet
JEFFERSON AND LINDEN RESTAURANT These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.
NOT FOR CONSTRUCTION
REVIEW SET
E NGINEER ING
N O R T H E RN
09/28/16
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
www.northernengineering.com
Phone: 970.221.4158
DATE:
SEPTEMBER 28,
2016
of 8
C400
DRAINAGE EXHIBIT
N. Haws
A. Boese
1"=20'
( IN FEET )
0
1 INCH = 20 FEET
20 20 40 60
NORTH
LEGEND:
4953
PROPOSED CONTOUR 93
PROPOSED STORM DRAIN
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
DESIGN POINT 1
FLOW ARROW
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
PROJECT BENCHMARKS
NOTES:
1. REFER TO THE "PRELIMINARY DRAINAGE & EROSION CONTROL REPORT FOR
JEFFERSON AND LINDEN RESTAURANT" BY NORTHERN ENGINEERING, DATED
SEPTEMBER 28, 2016 FOR ADDITIONAL INFORMATION.
BASIN
DESIGNATION
BASIN
AREA (AC)
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
PROPOSED UNDERDRAIN UD
PERMEABLE PAVERS
PROJECT DATUM: NAVD 88
BENCHMARK #1:
City of Fort Collins Benchmark 5-00
NAVD88 Elevation= 4978.05
BENCHMARK #2:
City of Fort Collins Benchmark 1-13
NAVD88 Elevation= 4979.75
1
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE, OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
Call before you dig.
R
7
DRAINAGE SUMMARY TABLE
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C10 C100 10-yr
Tc
(min)
100-yr
Tc
(min)
Q10
(cfs)
Q100
(cfs)
1 1 0.19 0.35 0.43 15.0 14.4 0.21 0.56
2 2 0.24 0.78 0.97 9.0 8.7 0.72 1.89
3 3 0.02 0.15 0.19 5.0 5.0 0.01 0.04
ç
è
= æ
12 hr
D:\Projects\838-014\Drainage\LID\838-014_Water Quality Volume_Vaults.xls
ç
è
= æ
12 hr
D:\Projects\838-014\Drainage\LID\838-014_Water Quality Volume_PLD.xls
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 10, Sep 22, 2015
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr 28,
2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Custom Soil Resource Report
9
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
1 1 No 0.15 0.15 0.19 93 1.50% 15.0 15.0 14.4 0 0.00% N/A N/A 0 0.00% N/A N/A 15 15 14
2 2 No 0.15 0.15 0.19 35 2.00% 8.3 8.3 8.0 60 0.50% 1.41 0.7 0 0.00% N/A N/A 9 9 9
3 3 No 0.15 0.15 0.19 5 2.00% 3.2 3.2 3.0 0 0.50% N/A N/A 0 0.00% N/A N/A 5 5 5
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
9/25/16
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti