HomeMy WebLinkAboutKING SOOPERS #146 MIDTOWN GARDENS MARKETPLACE - PDP200012 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPREPARED FOR:
Dillon Companies/King Soopers, Inc.
55 Tejon Street
Denver, Colorado 80223
Phone: (303) 778-3053
PREPARED BY:
Galloway & Company, Inc.
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
DATE:
July 28, 2020
MIDTOWN GARDENS MARKETPLACE
KING SOOPERS STORE #146
Fort Collins, Colorado
PRELIMINARY DRAINAGE REPORT
Galloway & Company, Inc. Page 2 of 18
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884 • GallowayUS.com
Galloway & Company, Inc. Page 3 of 18
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884 • GallowayUS.com
PRELIMINARY DRAINAGE REPORT
Midtown Gardens Marketplace
King Soopers Store #146
Legal Description
Lots 1,2, and 4 of K-Mart Plaza, and all of Lot 2 of the extension of K-Mart Plaza, situated in the
Southeast 1/4 of Section 23, Township 7 North, Range 69 West, of the 6th Principle Meridian, City
of Fort Collins, County of Larimar, State of Colorado.
Preparation Date
July 28, 2020
Prepared for
Dillon Companies/King Soopers, Inc.
55 Tejon Street
Denver, Colorado 80223
Phone: (303) 778-3053Client
Address
City, State, Zip
Prepared by: Reviewed by:
________________________________________ ____________________________
Name Name
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ENGINEER’S STATEMENT
I hereby attest that this report and plan for the preliminary drainage design for Midtown Gardens
Marketplace was prepared by me or under my direct supervision, in accordance with the provisions of the
Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not
assume liability for drainage facilities designed by others.
Phil Dalrymple, PE # 41171 Date
For and on behalf of Galloway & Company, Inc.
DEVELOPER’S CERTIFICATION
“King Soopers, Inc. hereby certifies that the drainage facilities for Midtown Gardens Marketplace shall be
constructed according to the design presented in this report. I understand that the City of Fort Collins
does not and will not assume liability for the drainage facilities designed and/or certified by my engineer
and that the City of Fort Collins review))s drainage plans pursuant to the Municipal Code; but cannot, on
behalf of Midtown Gardens Marketplace, guarantee that final drainage design review will absolve King
Soopers, Inc. and/or their successors and/or assigns of future liability for improper design.”
Authorized Signature Date
King Soopers, Inc.
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I. General Location and Existing Information ................................................................................................ 6
Location ............................................................................................................................................ 6
Description of Property..................................................................................................................... 6
II. Master Drainage Basin Description .......................................................................................................... 6
Major Basin Description ................................................................................................................... 6
Sub- Basin Description..................................................................................................................... 7
III. Floodplain Information .............................................................................................................................. 7
IV. Project Description ................................................................................................................................... 7
V. Drainage Design Criteria .......................................................................................................................... 7
Regulations ...................................................................................................................................... 7
The Four Step Process (Low Impact Development) ........................................................................ 7
Development Criteria Reference and Constraints ........................................................................... 8
Hydrologic Criteria ............................................................................................................................ 8
Hydraulic Criteria .............................................................................................................................. 9
VI. Proposed Drainage Facilities ................................................................................................................. 10
General Concept ............................................................................................................................ 10
Specific Details ............................................................................................................................... 10
VII. Variance Requests ............................................................................................................................... 11
VIII. Erosion Control .................................................................................................................................... 11
Construction Material & Equipment ............................................................................................... 11
Maintenance ................................................................................................................................... 12
IX. Conclusions ........................................................................................................................................... 12
Compliance with Standards ........................................................................................................... 12
Variances ....................................................................................................................................... 12
Drainage Concept .......................................................................................................................... 12
VI. References ............................................................................................................................................ 13
VII. Appendices ........................................................................................................................................... 14
A. Exhibits & Figures ............................................................................................................... 14
B. Hydrologic Computations .................................................................................................... 14
C. Hydraulic Computations ...................................................................................................... 14
D. Drainage Maps .................................................................................................................... 14
TABLE OF CONTENTS
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I. General Location and Existing Information
Location
Midtown Gardens Marketplace (hereafter referred to as “the site” or “project site”) will be located at
the northwest corner of South College Avenue and West Drake Road. It is bounded on north by an
existing commercial development; on the south by West Drake Road (including a Jiffy Lube and Loaf
‘N Jug to remain); on the east by College Avenue; and on the west by the MAX-BRT Bus Line.
Spring Creek is located north of the site. More specifically, the site is located in the Southeast Quarter
of Section 23, Township 7 North, Range 69 West in the City of Fort Collins, County of Larimer and
State of Colorado. Refer to Appendix A for a Vicinity Map.
Description of Property
The project site is approximately 11.34 acres, and consists of a currently vacant Kmart store, a small
retail building at the northeast corner of the site, and an existing Loaf N’ Jug fueling station. Existing
grades on the site range from one to four percent, with historic runoff generally draining to the north
and east across the site. There are no major drainage ways passing through the project site.
According to the USDA NRCS Web Soil Survey, ‘Nunn Clay loam, 0 to 1 percent slopes’ covers the
entire project site. This soil is associated with Hydrologic Soil Group (HSG) ‘C’. HSG ‘C’ soils have a
slow infiltration rate when thoroughly wet and consist chiefly of soils having a layer that impedes the
downward movement of water or soils of moderately fine texture or fine texture. These soils have a
slow rate of water transmission. Refer to Appendix A for additional soils information.
The Midtown Gardens Marketplace will be developed in one phase and is approximately 11.34 acres.
The existing vacant Kmart building along with the vacant retail building at the northeast corner of the
site will be removed. A new King Soopers Marketplace will replace the Kmart, while a new King
Soopers fueling station will replace the vacant retail building. The existing parking lot will be
reconstructed to accommodate the new structures. The lot containing the Loaf N’ Jug will remain
vacant for future development but is included in this report in its developed condition.
During the water quality storm event, surface runoff will flow into one of several stormwater quality
features located on the site. The stormwater quality features include the use of an underground
storage system. During the minor (i.e., 2-year) and major (i.e., 100-year) storm events, runoff volume
in excess of the water quality event will bypass the WQ system and and enter the existing storm
sewer system.
II. Master Drainage Basin Description
Major Basin Description
The project site is located in the Spring Creek drainage basin. According to the City of Fort Collins
website (http://www.fcgov.com/utilities/what-we-do/stormwater/drainage-basins/spring-creek-basin),
this basin “is a major watercourse that flow from Spring Canyon Dam at Horsetooth Reservoir to its
confluence with the Poudre River. The basin is dominated by residential development, but also
includes open space, parks, and isolated areas of commercial and industrial development.”
According to the City of Fort Collins, detention storage for the site is provided offsite near Spring
Creek. Therefore, on-site detention storage is not required for the site. Water quality for the site has
been provided in accordance with the City of Fort Collins LID requirements for the redeveloped
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portions of the site. Water Quality structures have been sized for the redeveloped portions of the site
in the form of an underground water quality basin. Preliminary calculations for underground basin
have been provided, and can be found in Appendix C.
Sub- Basin Description
The site historically drains north and east towards the adjacent commercial development and College
Avenue. There are several storm inlets along the northern property line and throughout the site which
collect runoff. These storm sewer mains ultimately drain to Spring Creek. The historic drainage
patterns for the site will remain unchanged as part of the redevelopment of the site with minor
rerouting due to the proposed site layout.
At the sub-basin level, no offsite runoff is anticipated to enter the site, with the exception of a small
amount of runoff at the southwest corner or the site coming from the MAX/BRT bus station, which is
currently tributary to the site. A portion of the site along W Drake Rd. and S College Ave. will drain
offsite, which is consistent with the current drainage pattern. The site has been broken into four
basins, each with their own set of sub-basins. A description of each basin and their characteristics
can be found later in the report.
There are no irrigation, reservoir, or other facilities that influence, or are influenced by, the local
drainage.
III. Floodplain Information
The project site is shown on FEMA Map Number 08069C0987G (refer to Appendix A for FEMA
Firmette). This map shows that the project is not impacted by an existing floodplain/floodway. Refer to
Appendix A for a copy of the Firmette.
IV. Project Description
The Midtown Gardens Marketplace will be developed in one phase and is approximately 11.34 acres.
The existing vacant Kmart building along with the vacant retail building at the northeast corner of the
site will be removed. A new King Soopers Marketplace will replace the Kmart, while a new King
Soopers fueling station will replace the vacant retail building. The existing parking lot will be
reconstructed to accommodate the new structures. The lot containing the Loaf N’ Jug will remain
vacant for future development but is included in this report in its developed condition.
V. Drainage Design Criteria
Regulations
This preliminary drainage design presented herein is prepared in accordance with the Fort Collins
Stormwater Criteria Manual, November 2017 (FCSCM), the Mile High Flood District (MHFD) Urban
Storm Drainage Criteria Manual, January 2016 (USDCM), and Chapter 10, Flood Prevention and
Protection, of the Fort Collins City Code. No other drainage reports could be provided for the site by
the City of Fort Collins.
The Four Step Process (Low Impact Development)
At this preliminary stage of the design process, we developed a commensurate implementation of the
‘The Four-Step Process’ for stormwater quality management. Per Ordinance No. 007, 2016, ‘No less
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than seventy-five percent (75%) of any developed or redeveloped area . . . must be treated using one
or a combination of LID techniques.’ As previously mentioned, the developer proposes to replace the
existing Kmart with a new King Soopers Marketplace. The runoff for the modified areas collected
onsite will be treated using and underground LID water quality system. Appropriate spill containment
will be provided in the area of the proposed fuel station.
Step 1 - Employ runoff reduction practices
The attached drainage map (see Appendix D) delineates the proposed drainage basins, each of
which drains to a proposed underground water quality system. Underground systems are an
accepted LID method when surface BMPs are infeasible, and consist of an underground chamber
that provide stormwater quality treatment via sedimentation, screening, filtration, and other physical
and chemical processes.
Step 2 - Implement BMPs that provide a Water Quality Capture Volume (WQCV)
Due to site constraints, and underground storage system will provide the necessary Water Quality
Capture Volume.
Step 3 - Stabilize drainageways
The developed runoff generated by the proposed redevelopment will drain to an existing storm drain
system located along the west side of South College Avenue. This system drains north and outfalls
into Spring Creek. Our work assumes that an appropriate level of stabilization exists at the outfall into
Spring Creek.
Step 4 - Implement site specific and other source control BMPs
Site specific considerations such as material handling/storage and other site operations will be
addressed in the Stormwater Management Plan (SWMP).
Development Criteria Reference and Constraints
This preliminary drainage design presented herein is prepared in accordance with the Fort Collins
Stormwater Criteria Manual, November 2017 (FCSCM) and the Mile High Flood District (MHFD)
Urban Storm Drainage Criteria Manual, January 2016 (USDCM). No other drainage reports could be
provided for the site by the City of Fort Collins.
Existing runoff for the proposed site generally drains to the north and east across the site. The
majority of the on-site runoff is captured by an existing storm sewer system which has three
connections to the offsite system downstream. The site drains into an existing 24” storm pipe just
north of the site (2 connections), and a 15” storm pipe along College Avenue. Capacity calculations
for the proposed and existing portions of the storm sewer system have been provided in Appendix C.
Hydrologic Criteria
For urban catchments that are not complex and are generally 160 acres or less in size, it is
acceptable that the design storm runoff be analyzed using the Rational Method. The Rational Method
is often used when only the peak flow rate or total volume of runoff is needed (e.g., storm sewer
sizing or simple detention basin sizing). The Rational Method was used to estimate the peak flow at
each design point. Routing calculations (i.e., time attenuation) that aggregate the basins draining to a
specific design point are include in the Rational Method calculations in Appendix B.
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The Rational Method is based on the Rational Formula:
Q = CiA
Where:
Q = the maximum rate of runoff, cfs
C = a runoff coefficient that is the ratio between the runoff volume from an area and the average
rate of rainfall depth over a given duration for that area
i = average intensity of rainfall in inches per hour for a duration equal to the Time of
Concentration (Tc)
A = area, acres
Runoff Coefficients were determined based on Tables 3.2-1, 3.2-2, and 3.2-3 of the the FCSCM. The
one-hour rainfall Intensity-Duration-Frequency tables for use with the Rational Method of runoff
analysis are provided in Table 3.4-1 of the FCSCM.
The 2-year and 100-year storm events serve as the basis for the drainage system design. The 2-year
storm is considered the minor storm event. It has a fifty percent probability of exceedance during any
given year. The 100-year storm is considered the major storm event. It has a one percent probability
of exceedance during any given year.
The 2-year drainage system, at a minimum, must be designed to transport runoff from the 2-year
recurrence interval storm event with minimal disruption to the urban environment. The 100-year
drainage system, as a minimum, must be designed to convey runoff from the 100-year recurrence
interval flood to minimize life hazards and health, damage to structures, and interruption to traffic and
services.
Hydraulic Criteria
There are three on-site basins which drain to the existing and proposed storm sewer system, which
are identified in the proposed drainage map (Appendix D) as Basins A, B, and C. Runoff from each
basin will be collected by storm sewer inlets and pipes and conveyed offsite to existing detention
ponds and ultimately Spring Creek, approximately 1 mile north of the site. Basin A is collected by a
storm sewer system on the west side of the proposed building and discharges to an existing storm
sewer pipe just north of the site. Basin B discharges to an existing storm sewer pipe along the west
side of College Avenue. Basin C is collected by a storm sewer system on the northeast corner of the
site and discharges to an existing storm sewer pipe just north of the site. Additional areas for the site
not collected by the proposed storm drain system are designated as Off Site Basins (OS) and will
drain offsite to existing storm drain infrastructure, consistent with the existing drainage pattern. Runoff
from these offsite basins will be released undetained toward W Drake Rd, S College Ave, and
existing inlet north of the site.
Inlet Capacity Analysis
Inlet calculations are not required to be included with this preliminary report and will provided with the
Final Drainage Report.
Storm Drain Capacity Analysis
The preliminary storm drain system is typically sized to convey the sum of the 100-year developed
runoff at each design point draining into the system. The pipes are sized to convey this runoff without
surcharging (full-flow capacity). This method should provide a conservative estimate of total runoff
and pipe sizes. It appears that the 100-year developed runoff for the site will not be able to be
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conveyed in the existing storm sewer system downstream of the site. Therefore, the preliminary
design of the storm sewer system for the site has been sized to handle a minimum of the 2-year
storm event. For this preliminary Drainage Study, Flowmaster was used to size the proposed
system, and provide capacity calculations, using a minimum slope of 0.5%. The Flowmaster
summaries in Appendix C show the max flows for the proposed storm drains at the minimum slope.
VI. Proposed Drainage Facilities
General Concept
This final design presents the detailed design of the proposed system for collecting and conveying
developed runoff from current and proposed development at the Midtown Gardens Marketplace site
to the Stormwater quality features and offsite regional facilities. The existing site runoff drains to
existing storm sewer inlets within the parking lot. The proposed design matches this existing
drainage pattern and includes the implementation of and underground Stormtech system to provide
water quality for the site.
Specific Details
The site has been broken into three basins, each with their own set of sub-basins. A description of
each basin and their characteristics can be found below. The intent of the drainage design is to have
the runoff from the majority of the site collected and drain through water quality facilities prior to
entering the existing storm sewer system offsite. An underground Stormtech system has been sized
based on the City of Fort Collins LID requirements for the necessary portions of the site, which will be
located at the various connection points to the existing storm drain system. The stormwater from the
site will travel in the existing storm sewer system, and ultimately reach Spring Creek in accordance
with the existing drainage pattern.
Basin A
Basin A consists of the western half of the site and is comprised of 6 sub-basins. The basin includes
the proposed building, the south parking lot, and the areas to the west of the proposed building.
Runoff from Basin A will be collected by the proposed storm sewer system and conveyed north, and
ultimately discharge into the existing storm sewer system just north of the site. An underground water
quality facility will be provided just upstream of the tie-in point with the existing system.
Basin B
Basin B consists of the southeastern portion of the site and is comprised of 4 sub-basins. The basin
includes the southern portion of the access drive, the southeast portion of the main parking lot, and
the existing Loaf N’ Jug site (which will remain vacant as part of this project but is included in the
drainage calculations in its future developed condition). Runoff from Basin B will be collected by the
proposed storm sewer system and conveyed north and east, and ultimately discharge into the
existing storm sewer system in College Ave. An underground water quality facility will be provided
just upstream of the tie-in point with the existing system.
Basin C
Basin C consists of the eastern half of the site and is comprised of 4 sub-basins. The basin includes
the proposed fuel center and the northern portion of the main parking lot. Runoff from Basin C is
collected by the proposed storm sewer system and conveyed north and ultimately discharges into the
existing storm sewer system just north of the site. An underground water quality facility will be
provided just upstream of the tie-in point with the existing system.
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Offsite Basins
The remainder of the site consists of basins that flow offsite, as is current with the existing drainage
pattern. These basins are located along W Drake Rd, S College Ave, and the northern portion of the
site between the building and the adjacent property. These basins include sidewalk, tree lawn, and
landscape areas between the sidewalk and the parking lot, and access drives off of S College Ave
and W Drake Rd, as well as paved areas joining the site with the adjacent property. Flows from these
areas historically sheet flow to either the existing roadways adjacent to the site or to existing inlets on
the adjacent property north of the site, and ultimately drain to an existing inlet located in College
Avenue near the northeast corner of the site and an existing inlet at the northwest corner of College
and Drake. The characteristics of the tributary areas draining to these inlets will remain virtually the
same, so anticipated flow rates generated should be the same and not negatively impact the existing
storm sewer system. Once in the existing storm sewer inlets, the stormwater from this basin is
conveyed through the existing storm sewer system and ultimately reaches Spring Creek.
VII. Variance Requests
No variances are being requested with the proposed improvements described herein.
VIII. Erosion Control
A General Permit for Stormwater Discharge Associated with Construction Activities issued by the
Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division
(WQCD), will be acquired for the site. A Stormwater Management Plan (SWMP) should be prepared
to identity the Best Management Practices (BMPs) which, when implemented, will meet the
requirements of said General Permit. Below is a summary of SWMP requirements which may be
implemented on-site.
The following temporary BMPs may be installed and maintained to control on-site erosion and
prevent sediment from traveling off-site during construction:
• Silt Fence – a woven synthetic fabric that filters runoff. The silt fence is a temporary barrier that is
placed at the base of a disturbed area.
• Vehicle Tracking Control – a stabilized stone pad located at points of ingress and egress on a
construction site. The stone pad is designed to reduce the amount of mud transported onto public
roads by construction traffic.
• Straw Wattles – wattles act as a sediment filter. They are a temporary BMP and require proper
installation and maintenance to ensure their performance.
• Inlet protection – Inlet protection will be used on all existing and proposed storm inlets to help
prevent debris from entering the storm sewer system. Inlet protection generally consists of straw
wattles or block and gravel filters.
Compliance with Erosion Control Criteria and all Erosion Control Materials in greater detail will be
provided with the Final Drainage Report
Construction Material & Equipment
The contractor shall store all construction materials and equipment and shall provide maintenance
and fueling of equipment in confined areas on-site from which runoff will be contained and filtered.
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Maintenance
The temporary BMPs will be inspected by the contractor at a minimum of once every two weeks and
after each significant storm event. The property owner will be responsible for routine and non-routine
maintenance of the temporary BMPs. Routine maintenance includes:
• Remove sediment from the bottom of the temporary sediment basin when accumulated sediment
occupies about 20% of the design volume or when sediment accumulation results in poor
drainage.
• Debris and litter removal-remove debris and litter to minimize outlet clogging and improve
aesthetics as necessary.
• Inspection of the facility-inspect the facility annually to ensure that it functions as initially intended.
• Cleaning and repair of BMP’s is required when sediment has built up or the BMP is not working
properly.
IX. Conclusions
Compliance with Standards
The design presented in this final drainage report for the Midtown Gardens Marketplace has been
prepared in accordance with the design standards and guidelines presented in the Fort Collins
Stormwater Criteria Manual and the MHFD Urban Storm Drainage Criteria Manual.
Variances
No variances are being requested with the proposed improvements described herein.
Drainage Concept
The proposed Midtown Gardens Marketplace storm drainage improvements should provide adequate
collection and Water Quality protection for the developed site. The proposed drainage design will
sufficiently drain the proposed development and should not negatively impact the existing condition of
the overall storm drainage system.
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VI. References
1. Fort Collins Stormwater Criteria Manual, November 2017
2. Urban Storm Drainage Criteria Manual, Mile High Flood District, January 2016 (with current
revisions).
3. Flood Insurance Rate Map – Larimer County, Colorado and Incorporated Areas Community
Panel No. 08069C0987G, Effective May 2, 2012.
4. Soil Map – Larimer County Area, Colorado as available through the Natural Resources
Conservation Service National Cooperative Soil Survey web site via Web Soil Survey 2.0.
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VII. Appendices
A. Exhibits & Figures
· Vicinity Map
· USGS Soil Survey Data
· FEMA Flood Insurance Rate Map
B. Hydrologic Computations
· Basin characteristics
· Rational Method computations
· Minor and major storm runoff computations for developed runoff conditions
· Water quality volume required and provided calculations
C. Hydraulic Computations
· Flowmaster pipe capacity calculations
D. Drainage Maps
· Impervious Area Exhibit
· Proposed Drainage Map
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APPENDIX A
Exhibits and Figures
VICINITY MAP
SITE
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 22, 2020
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
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Contents
Preface.................................................................................................................... 2
How Soil Surveys Are Made..................................................................................5
Soil Map.................................................................................................................. 8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................ 11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado...................................................................... 13
73—Nunn clay loam, 0 to 1 percent slopes.................................................13
74—Nunn clay loam, 1 to 3 percent slopes.................................................14
References............................................................................................................16
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How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
4489060 4489100 4489140 4489180 4489220 4489260 4489300 4489340 4489380 4489420
4489060 4489100 4489140 4489180 4489220 4489260 4489300 4489340 4489380 4489420
493220 493260 493300 493340 493380 493420 493460 493500
493220 493260 493300 493340 493380 493420 493460 493500
40° 33' 19'' N
105° 4' 48'' W
40° 33' 19'' N
105° 4' 36'' W
40° 33' 7'' N
105° 4' 48'' W
40° 33' 7'' N
105° 4' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,820 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
73 Nunn clay loam, 0 to 1 percent
slopes
16.4 99.1%
74 Nunn clay loam, 1 to 3 percent
slopes
0.2 0.9%
Totals for Area of Interest 16.5 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
Custom Soil Resource Report
11
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
12
Larimer County Area, Colorado
73—Nunn clay loam, 0 to 1 percent slopes
Map Unit Setting
National map unit symbol: 2tlng
Elevation: 4,100 to 5,700 feet
Mean annual precipitation: 14 to 15 inches
Mean annual air temperature: 48 to 52 degrees F
Frost-free period: 135 to 152 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Pleistocene aged alluvium and/or eolian deposits
Typical profile
Ap - 0 to 6 inches: clay loam
Bt1 - 6 to 10 inches: clay loam
Bt2 - 10 to 26 inches: clay loam
Btk - 26 to 31 inches: clay loam
Bk1 - 31 to 47 inches: loam
Bk2 - 47 to 80 inches: loam
Properties and qualities
Slope: 0 to 1 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 7 percent
Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Custom Soil Resource Report
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Minor Components
Heldt
Percent of map unit: 10 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Wages
Percent of map unit: 5 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
74—Nunn clay loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlpl
Elevation: 3,900 to 5,840 feet
Mean annual precipitation: 13 to 17 inches
Mean annual air temperature: 50 to 54 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Pleistocene aged alluvium and/or eolian deposits
Typical profile
Ap - 0 to 9 inches: clay loam
Bt - 9 to 13 inches: clay loam
Btk - 13 to 25 inches: clay loam
Bk1 - 25 to 38 inches: clay loam
Bk2 - 38 to 80 inches: clay loam
Custom Soil Resource Report
14
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 7 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.1 to 2.0
mmhos/cm)
Sodium adsorption ratio, maximum in profile: 0.5
Available water storage in profile: High (about 9.9 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Minor Components
Heldt
Percent of map unit: 10 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Clayey Plains (R067BY042CO)
Hydric soil rating: No
Satanta
Percent of map unit: 5 percent
Landform: Terraces
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Ecological site: Loamy Plains (R067BY002CO)
Hydric soil rating: No
Custom Soil Resource Report
15
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
16
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
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Midtown Gardens Marketplace
7/28/2020
APPENDIX B
Hydrologic Computations
Tributary Area tc | 2-Year tc | 100-Year Q2 Q100
Sub-basin (acres) (min) (min) (cfs) (cfs)
A-1 0.35 0.81 1.00 5.8 5.0 0.8 3.5
A-2 0.25 0.87 1.00 5.0 5.0 0.6 2.5
A-3 0.15 0.95 1.00 5.0 5.0 0.4 1.5
A-4 0.44 0.86 1.00 5.0 5.0 1.1 4.4
A-5 0.47 0.84 1.00 5.2 5.0 1.1 4.7
A-6 1.43 0.88 1.00 5.0 5.0 3.6 14.3
A-7 1.56 0.95 1.00 5.0 5.0 4.2 15.6
A-8 0.65 0.95 1.00 5.0 5.0 1.8 6.5
A-9 0.56 0.95 1.00 5.0 5.0 1.5 5.6
B-1 0.77 0.91 1.00 5.0 5.0 2.0 7.7
B-2 0.49 0.88 1.00 5.8 5.0 1.2 4.9
B-3 0.75 0.91 1.00 5.0 5.0 2.0 7.5
B-4 0.09 0.93 1.00 5.0 5.0 0.2 0.9
B-5 0.87 0.80 0.99 5.5 5.0 1.9 8.6
B-6 0.12 0.95 1.00 5.0 5.0 0.3 1.2
C-1 0.34 0.90 1.00 5.0 5.0 0.9 3.4
C-2 0.66 0.92 1.00 5.0 5.0 1.7 6.6
C-3 0.11 0.95 1.00 5.0 5.0 0.3 1.1
C-4 0.12 0.95 1.00 5.0 5.0 0.3 1.2
C-5 0.02 0.95 1.00 5.0 5.0 0.1 0.2
OS-1 0.66 0.67 0.84 13.6 13.6 0.9 3.8
OS-2 0.41 0.80 1.00 6.6 5.0 0.9 4.1
OS-3 0.13 0.92 1.00 5.0 5.0 0.3 1.3
OS-4 0.32 0.93 1.00 5.0 5.0 0.8 3.2
OS-5 0.71 0.87 1.00 5.0 5.0 1.8 7.1
OS-6 0.24 0.84 1.00 5.0 5.0 0.6 2.4
BASIN SUMMARY TABLE
C2 C100
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.Page
1 of xls 1 7/27/2020
Subdivision: Midtown Gardens Marketplace Project Name: King Soopers Store #146
Location: CO, Fort Collins Project No.:
Calculated By: E. Mowinckel
Checked By: P. Dalrymple
Date: 7/27/20
Single-Family Alley-Loaded SF Duplex/AttachedMulti-Family
95% 5% 62.5% 70% 75% 80%
A-1 0.35 95 0.28 77 20 0.07 4 95 0.00 0 0.81
A-2 0.25 95 0.22 85 20 0.03 2 95 0.00 0 0.87
A-3 0.15 95 0.15 95 20 0.00 0 95 0.00 0 0.95
A-4 0.44 95 0.39 84 20 0.05 2 95 0.00 0 0.86
A-5 0.47 95 0.40 82 20 0.07 3 95 0.00 0 0.84
A-6 1.43 95 1.30 87 20 0.13 2 95 0.00 0 0.88
A-7 1.56 95 0.00 0 20 0.00 0 95 1.56 95 0.95
A-8 0.65 95 0.00 0 20 0.00 0 95 0.65 95 0.95
A-9 0.56 95 0.00 0 20 0.00 0 95 0.56 95 0.95
B-1 0.77 95 0.73 90 20 0.04 1 95 0.00 0 0.91
B-2 0.49 95 0.45 87 20 0.04 2 95 0.00 0 0.88
B-3 0.75 95 0.71 90 20 0.04 1 95 0.00 1 0.91
B-4 0.09 95 0.09 93 20 0.00 0 95 0.00 0 0.93
B-5 0.87 95 0.69 75 20 0.18 4 95 0.00 0 0.80
B-6 0.12 95 0.00 0 20 0.00 0 95 0.12 95 0.95
C-1 0.34 95 0.32 88 20 0.02 1 95 0.00 0 0.90
C-2 0.66 95 0.64 91 20 0.02 1 95 0.00 0 0.92
C-3 0.11 95 0.11 95 20 0.00 0 95 0.00 0 0.95
C-4 0.12 95 0.00 0 20 0.00 0 95 0.12 95 0.95
C-5 0.02 95 0.00 0 20 0.00 0 95 0.02 95 0.95
OS-1 0.66 95 0.41 59 20 0.25 7 95 0.00 0 0.67
OS-2 0.41 95 0.33 76 20 0.08 4 95 0.00 0 0.80
OS-3 0.13 95 0.12 91 20 0.01 1 95 0.00 0 0.92
OS-4 0.32 95 0.31 92 20 0.01 1 95 0.00 0 0.93
OS-5 0.71 95 0.63 85 20 0.08 2 95 0.00 0 0.87
OS-6 0.24 95 0.20 81 20 0.04 3 95 0.00 0 0.84
Basin A 5.86 0.91
Basin B 3.09 0.88
Basin C 1.25 0.92
Basin OS 2.47 0.81
Total 12.67 0.88
COMPOSITE RUNOFF COEFFICIENTS
Area (ac)
Area
Weighted
Asphalt + Concrete Walks Lawns, Heavy Soil: Flat <2%
Area Weighted
Runoff
Coefficient
Area (ac)
KSS000018.02
Area
Weighted
C2
Basin ID Total Area (ac)
Runoff
Coefficient
Area (ac)
Building Roof
Runoff
Coefficient
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/27/2020
Subdivision: Midtown Gardens Marketplace Project Name: King Soopers Store #146
Location: CO, Fort Collins Project No.:
Calculated By: E. Mowinckel
Checked By: P. Dalrymple
Date: 7/27/20
Single-Family Alley-Loaded SF Duplex/AttachedMulti-Family
95% 5% 62.5% 70% 75% 80%
A-1 0.35 100 0.28 81 2 0.07 0 90 0.00 0 0.82
A-2 0.25 100 0.22 90 2 0.03 0 90 0.00 0 0.90
A-3 0.15 100 0.15 100 2 0.00 0 90 0.00 0 1.00
A-4 0.44 100 0.39 88 2 0.05 0 90 0.00 0 0.88
A-5 0.47 100 0.40 86 2 0.07 0 90 0.00 0 0.86
A-6 1.43 100 1.30 91 2 0.13 0 90 0.00 0 0.91
A-7 1.56 100 0.00 0 2 0.00 0 90 1.56 90 0.90
A-8 0.65 100 0.00 0 2 0.00 0 90 0.65 90 0.90
A-9 0.56 100 0.00 0 2 0.00 0 90 0.56 90 0.90
B-1 0.77 100 0.73 95 2 0.04 0 90 0.00 0 0.95
B-2 0.49 100 0.45 91 2 0.04 0 90 0.00 0 0.91
B-3 0.75 100 0.71 94 2 0.04 0 90 0.00 1 0.95
B-4 0.09 100 0.09 98 2 0.00 0 90 0.00 0 0.98
B-5 0.87 100 0.69 79 2 0.18 0 90 0.00 0 0.80
B-6 0.12 100 0.00 0 2 0.00 0 90 0.12 90 0.90
C-1 0.34 100 0.32 93 2 0.02 0 90 0.00 0 0.93
C-2 0.66 100 0.64 96 2 0.02 0 90 0.00 0 0.96
C-3 0.11 100 0.11 100 2 0.00 0 90 0.00 0 1.00
C-4 0.12 100 0.00 0 2 0.00 0 90 0.12 90 0.90
C-5 0.02 100 0.00 0 2 0.00 0 90 0.02 90 0.90
OS-1 0.66 100 0.41 63 2 0.25 1 90 0.00 0 0.63
OS-2 0.41 100 0.33 80 2 0.08 0 90 0.00 0 0.80
OS-3 0.13 100 0.12 96 2 0.01 0 90 0.00 0 0.96
OS-4 0.32 100 0.31 97 2 0.01 0 90 0.00 0 0.97
OS-5 0.71 100 0.63 89 2 0.08 0 90 0.00 0 0.89
OS-6 0.24 100 0.20 85 2 0.04 0 90 0.00 0 0.86
Basin A 5.86 0.90
Basin B 3.09 0.90
Basin C 1.25 0.95
Basin OS 2.47 0.82
Total 10.20 0.89
COMPOSITE % IMPERVIOUSNESS
KSS000018.02
Asphalt + Concrete Walks Lawns, Heavy Soil: Flat <2% Building Roof
% Imp
Basin ID Total Area (ac) % Imp Area (ac)
Area
Weighted
Area Weighted % Imp Area (ac)
Area
Weighted
% Imp Area (ac)
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/27/2020
Subdivision: Midtown Gardens Marketplace Project Name: King Soopers Store #146
Location: CO, Fort Collins Project No.:
Calculated By: E. Mowinckel
Checked By: P. Dalrymple
Date: 7/27/20
1 2 3 4 5 6 7 8 9 10 13 15 16 17 18 19 20 21 22 23 24
BASIN D.A. Hydrologic C2 C5 C100 L S Ti | 2-Year Ti | 100-Year L S Cv VEL. Tt COMP. Tc | 2-Year COMP. Tc | 100-Year TOTAL Urbanized Tc Tc | 2-Year Tc | 100-Year
ID (AC) Soils Group Cf=1.00 Cf=1.00 Cf=1.25 (FT) (%) (MIN) (MIN) (FT) (%) (FPS) (MIN) (MIN) (MIN) LENGTH(FT) (MIN) (MIN) (MIN)
A-1 0.35 C 0.81 0.81 1.00 150 1.50 5.8 2.0 0 1.00 20 2.0 0.0 5.8 2.0 150 10.8 5.8 5.0
A-2 0.25 C 0.87 0.87 1.00 80 1.50 3.3 1.5 0 1.00 20 2.0 0.0 3.3 1.5 80 10.4 5.0 5.0
A-3 0.15 C 0.95 0.95 1.00 80 7.00 1.3 0.9 0 1.00 20 2.0 0.0 1.3 0.9 80 10.4 5.0 5.0
A-4 0.44 C 0.86 0.86 1.00 120 1.50 4.3 1.8 0 1.00 20 2.0 0.0 4.3 1.8 120 10.7 5.0 5.0
A-5 0.47 C 0.84 0.84 1.00 200 2.20 5.2 2.0 0 1.00 20 2.0 0.0 5.2 2.0 200 11.1 5.2 5.0
A-6 1.43 C 0.88 0.88 1.00 200 2.00 4.5 2.1 0 1.00 20 2.0 0.0 4.5 2.1 200 11.1 5.0 5.0
A-7 1.56 C 0.95 0.95 1.00 270 2.00 3.7 2.4 0 1.00 20 2.0 0.0 3.7 2.4 270 11.5 5.0 5.0
A-8 0.65 C 0.95 0.95 1.00 270 2.00 3.7 2.4 0 1.00 20 2.0 0.0 3.7 2.4 270 11.5 5.0 5.0
A-9 0.56 C 0.95 0.95 1.00 270 2.00 3.7 2.4 0 1.00 20 2.0 0.0 3.7 2.4 270 11.5 5.0 5.0
B-1 0.77 C 0.91 0.91 1.00 250 2.20 4.3 2.3 75 1.25 20 2.2 0.6 4.9 2.8 325 11.8 5.0 5.0
B-2 0.49 C 0.88 0.88 1.00 250 2.20 4.9 2.3 100 1.00 20 2.0 0.8 5.8 3.1 350 11.9 5.8 5.0
B-3 0.75 C 0.91 0.91 1.00 200 3.00 3.5 1.8 0 1.00 20 2.0 0.0 3.5 1.8 200 11.1 5.0 5.0
B-4 0.09 C 0.93 0.93 1.00 100 4.00 2.0 1.2 0 1.00 20 2.0 0.0 2.0 1.2 100 10.6 5.0 5.0
B-5 0.87 C 0.80 0.80 0.99 170 2.50 5.5 1.9 0 1.00 20 2.0 0.0 5.5 1.9 170 10.9 5.5 5.0
B-6 0.12 C 0.95 0.95 1.00 20 2.50 0.9 0.6 0 1.00 20 2.0 0.0 0.9 0.6 20 10.1 5.0 5.0
C-1 0.34 C 0.90 0.90 1.00 80 2.00 2.7 1.3 0 1.00 20 2.0 0.0 2.7 1.3 80 10.4 5.0 5.0
C-2 0.66 C 0.92 0.92 1.00 170 2.50 3.2 1.8 0 1.00 20 2.0 0.0 3.2 1.8 170 10.9 5.0 5.0
C-3 0.11 C 0.95 0.95 1.00 45 1.50 1.6 1.1 75 1.00 20 2.0 0.6 2.3 1.7 120 10.7 5.0 5.0
C-4 0.12 C 0.95 0.95 1.00 20 2.00 1.0 0.7 0 1.00 20 2.0 0.0 1.0 0.7 20 10.1 5.0 5.0
C-5 0.02 C 0.95 0.95 1.00 15 2.00 0.9 0.6 0 1.00 20 2.0 0.0 0.9 0.6 15 10.1 5.0 5.0
OS-1 0.66 C 0.67 0.67 0.84 50 1.75 4.7 2.9 600 0.20 20 0.9 11.2 15.9 14.1 650 13.6 13.6 13.6
OS-2 0.41 C 0.80 0.80 1.00 40 2.00 2.8 1.0 450 1.00 20 2.0 3.8 6.6 4.7 490 12.7 6.6 5.0
OS-3 0.13 C 0.92 0.92 1.00 85 4.00 2.0 1.1 0 1.00 20 2.0 0.0 2.0 1.1 85 10.5 5.0 5.0
OS-4 0.32 C 0.93 0.93 1.00 150 2.50 2.9 1.7 0 1.00 20 2.0 0.0 2.9 1.7 150 10.8 5.0 5.0
OS-5 0.71 C 0.87 0.87 1.00 170 2.00 4.5 1.9 0 1.00 20 2.0 0.0 4.5 1.9 170 10.9 5.0 5.0
OS-6 0.24 C 0.84 0.84 1.00 124 3.00 3.8 1.4 0 1.00 20 2.0 0.0 3.8 1.4 124 10.7 5.0 5.0
NOTES:
Ti = (1.87*(1.1 - CCf)*(L)^0.5)/((S)^0.33), S in % Cv
Tt=L/60V (Velocity From Fig. 501) 2.5
Velocity V=Cv*S^0.5, S in ft/ft 5
Tc Check = 10+L/180 7
For Urbanized basins a minimum Tc of 5.0 minutes is required. 10
For non-urbanized basins a minimum Tc of 10.0 minutes is required 15
Paved areas and shallow paved swales 20
Type of Land Surface
Heavy Meadow
Tillage/field
Short pasture and lawns
Nearly bare ground
Grassed waterway
DATA (Tt) (URBANIZED BASINS)
FINAL
INITIAL/OVERLAND
(Ti)
TRAVEL TIME
STANDARD FORM SF-2
TIME OF CONCENTRATION
SUB-BASIN Tc CHECK
KSS000018.02
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/27/2020
Project Name: King Soopers Store #146
Subdivision: Midtown Gardens Marketplace Project No.: KSS000018.02
Location: CO, Fort Collins Calculated By: E. Mowinckel
Design Storm: Checked By: P. Dalrymple
Date:
TRAVEL TIME
STREET
Design Point
Basin ID
Area (Ac)
Runoff Coeff. | C 2
Tc | 2-Year (min)
C*A (Ac)
I (in/hr)
Q (cfs)
Tc (min)
C*A (Ac)
I (in/hr)
Q (cfs)
Slope (%)
Street Flow (cfs)
Design Flow (cfs)
Slope (%)
Pipe Size (inches)
Length (ft)
Velocity (fps)
Tt (min)
REMARKS
A1 A-1 0.35 0.81 5.8 0.28 2.71 0.8
A2 A-2 0.25 0.87 5.0 0.22 2.85 0.6
A3 A-3 0.15 0.95 5.0 0.14 2.85 0.4
A4 A-4 0.44 0.86 5.0 0.38 2.85 1.1
A5 A-5 0.47 0.84 5.2 0.40 2.81 1.1
A6 A-6 1.43 0.88 5.0 1.26 2.85 3.6
A7 A-7 1.56 0.95 5.0 1.48 2.85 4.2
A8 A-8 0.65 0.95 5.0 0.62 2.85 1.8
A9 A-9 0.56 0.95 5.0 0.53 2.85 1.5
B1 B-1 0.77 0.91 5.0 0.70 2.85 2.0
B2 B-2 0.49 0.88 5.8 0.43 2.71 1.2
B3 B-3 0.75 0.91 5.0 0.68 2.85 1.9
B4 B-4 0.09 0.93 5.0 0.08 2.85 0.2
B5 B-5 0.87 0.80 5.5 0.69 2.76 1.9
B6 B-6 0.12 0.95 5.0 0.11 2.85 0.3
C1 C-1 0.34 0.90 5.0 0.31 2.85 0.9
C2 C-2 0.66 0.92 5.0 0.61 2.85 1.7
C3 C-3 0.11 0.95 5.0 0.10 2.85 0.3
C4 C-4 0.12 0.95 5.0 0.11 2.85 0.3
C5 C-5 0.02 0.95 5.0 0.02 2.85 0.1
O1 OS-1 0.66 0.67 13.6 0.44 1.94 0.9
O2 OS-2 0.41 0.80 6.6 0.33 2.58 0.8
O3 OS-3 0.13 0.92 5.0 0.12 2.85 0.3
O4 OS-4 0.32 0.93 5.0 0.30 2.85 0.8
O5 OS-5 0.71 0.87 5.0 0.62 2.85 1.8
O6 OS-6 0.24 0.84 5.0 0.20 2.85 0.6
Basin A 5.86 5.0 5.32 2.85 15.1
Basin B 3.09 5.0 2.71 2.85 7.7
Basin C 1.25 5.0 1.15 2.85 3.3
Basin OS 1.57 5.0 1.56 2.85 4.4
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
STANDARD FORM SF-3
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Project Name: King Soopers Store #146
Subdivision: Midtown Gardens Marketplace Project No.: KSS000018.02
Location: CO, Fort Collins Calculated By: E. Mowinckel
Design Storm: Checked By: P. Dalrymple
Date:
TRAVEL TIME
STREET
Design Point
Basin ID
Area (Ac)
Runoff Coeff. | C 100
Tc | 100-Year
(min)
C*A (Ac)
I (in/hr)
Q (cfs)
Tc (min)
C*A (Ac)
I (in/hr)
Q (cfs)
Slope (%)
Street Flow (cfs)
Design Flow (cfs)
Slope (%)
Pipe Size (inches)
Length (ft)
Velocity (fps)
Tt (min)
REMARKS
A1 A-1 0.35 1.00 5.0 0.35 9.95 3.5
A2 A-2 0.25 1.00 5.0 0.25 9.95 2.5
A3 A-3 0.15 1.00 5.0 0.15 9.95 1.5
A4 A-4 0.44 1.00 5.0 0.44 9.95 4.4
A5 A-5 0.47 1.00 5.0 0.47 9.95 4.7
A6 A-6 1.43 1.00 5.0 1.43 9.95 14.2
A7 A-7 1.56 1.00 5.0 1.56 9.95 15.5
A8 A-8 0.65 1.00 5.0 0.65 9.95 6.5
A9 A-9 0.56 1.00 5.0 0.56 9.95 5.6
B1 B-1 0.77 1.00 5.0 0.77 9.95 7.7
B2 B-2 0.49 1.00 5.0 0.49 9.95 4.9
B3 B-3 0.75 1.00 5.0 0.75 9.95 7.5
B4 B-4 0.09 1.00 5.0 0.09 9.95 0.9
B5 B-5 0.87 0.99 5.0 0.86 9.95 8.6
B6 B-6 0.12 1.00 5.0 0.12 9.95 1.2
C1 C-1 0.34 1.00 5.0 0.34 9.95 3.4
C2 C-2 0.66 1.00 5.0 0.66 9.95 6.6
C3 C-3 0.11 1.00 5.0 0.11 9.95 1.1
C4 C-4 0.12 1.00 5.0 0.12 9.95 1.2
C5 C-5 0.02 1.00 5.0 0.02 9.95 0.2
O1 OS-1 0.66 0.84 13.6 0.55 6.79 3.7
O2 OS-2 0.41 1.00 5.0 0.41 9.95 4.1
O3 OS-3 0.13 1.00 5.0 0.13 9.95 1.3
O4 OS-4 0.32 1.00 5.0 0.32 9.95 3.2
O5 OS-5 0.71 1.00 5.0 0.71 9.95 7.1
O6 OS-6 0.24 1.00 5.0 0.24 9.95 2.4
Basin A 5.86 5.0 5.86 9.95 58.3
Basin B 3.09 5.0 3.08 9.95 30.7
Project Number: King Soopers Store #146 Date: 7/27/2020
Project Location: CO, Fort Collins
Calculations By: E. Mowinckel
Checked By: P. Dalrymple
Pond Description: WQ-A
User Input Cell: Blue Text
1/2 2-year 3231
0.91 0.07
5.86
1.66
minutes seconds in/hr cubic feet cubic feet cubic feet acre-feet
5 300 1.43 2272 498 1774 0.04
10 600 1.11 3524 996 2528 0.06
15 900 0.94 4473 1494 2979 0.07
20 1200 0.81 5135 1992 3143 0.07
25 1500 0.72 5701 2490 3211 0.07
30 1800 0.65 6219 2988 3231 0.07
35 2100 0.59 6530 3486 3044 0.07
40 2400 0.54 6825 3984 2841 0.07
45 2700 0.50 7104 4482 2622 0.06
50 3000 0.46 7335 4980 2355 0.05
55 3300 0.44 7630 5478 2152 0.05
60 3600 0.41 7846 5976 1870 0.04
65 3900 0.39 8085 6474 1611 0.04
70 4200 0.37 8149 6972 1177 0.03
75 4500 0.35 8372 7470 902 0.02
80 4800 0.33 8420 7968 452 0.01
85 5100 0.32 8675 8466 209 0.00
90 5400 0.31 8754 8964 -210 0.00
95 5700 0.29 8786 9462 -676 -0.02
100 6000 0.28 8930 9960 -1030 -0.02
105 6300 0.27 9042 10458 -1416 -0.03
110 6600 0.26 9121 10956 -1835 -0.04
115 6900 0.26 9352 11454 -2102 -0.05
120 7200 0.25 9376 11952 -2576 -0.06
Modified FAA Method- Storage Colume Calculations
Inputs | Tributary Area Output | Detention Volume
Return Period for Detention Control: Required Storage, cubic feet:
Catchment 'C': Required Storage, ac-ft:
Average
Outflow
Storage
Volume
Storage
Volume
Catchment Drainage Area, ac:
Release Rate, cfs:
Storm
Duration
Time
Rainfall
Intensity
Inflow Volume
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 1 of 2 7/27/2020
Release rate based on 0.35 gpm/sf of filter fabric area
0
2
4
6
8
10
12
0 20 40 60 80 100 120 140
Series1
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 2 of 2 7/27/2020
Project Number: King Soopers Store #146 Date: 7/27/2020
Project Location: CO, Fort Collins
Calculations By: E. Mowinckel
Checked By: P. Dalrymple
Pond Description: WQ-B
User Input Cell: Blue Text
1/2 2-year 485
0.88 0.01
3.09
2.24
minutes seconds in/hr cubic feet cubic feet cubic feet acre-feet
5 300 1.43 1157 672 485 0.01
10 600 1.11 1794 1344 450 0.01
15 900 0.94 2277 2016 261 0.01
20 1200 0.81 2614 2688 -74 0.00
25 1500 0.72 2902 3360 -458 -0.01
30 1800 0.65 3166 4032 -866 -0.02
35 2100 0.59 3324 4704 -1380 -0.03
40 2400 0.54 3474 5376 -1902 -0.04
45 2700 0.50 3616 6048 -2432 -0.06
50 3000 0.46 3734 6720 -2986 -0.07
55 3300 0.44 3884 7392 -3508 -0.08
60 3600 0.41 3994 8064 -4070 -0.09
65 3900 0.39 4115 8736 -4621 -0.11
70 4200 0.37 4148 9408 -5260 -0.12
75 4500 0.35 4262 10080 -5818 -0.13
80 4800 0.33 4286 10752 -6466 -0.15
85 5100 0.32 4416 11424 -7008 -0.16
90 5400 0.31 4456 12096 -7640 -0.18
95 5700 0.29 4473 12768 -8295 -0.19
100 6000 0.28 4546 13440 -8894 -0.20
105 6300 0.27 4602 14112 -9510 -0.22
110 6600 0.26 4643 14784 -10141 -0.23
115 6900 0.26 4761 15456 -10695 -0.25
120 7200 0.25 4773 16128 -11355 -0.26
Modified FAA Method- Storage Colume Calculations
Inputs | Tributary Area Output | Detention Volume
Return Period for Detention Control: Required Storage, cubic feet:
Catchment 'C': Required Storage, ac-ft:
Average
Outflow
Storage
Volume
Storage
Volume
Catchment Drainage Area, ac:
Release Rate, cfs:
Storm
Duration
Time
Rainfall
Intensity
Inflow Volume
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 1 of 2 7/27/2020
Release rate based on 0.35 gpm/sf of filter fabric area
0
2
4
6
8
10
12
0 20 40 60 80 100 120 140
Series1
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 2 of 2 7/27/2020
Project Number: King Soopers Store #146 Date: 7/27/2020
Project Location: CO, Fort Collins
Calculations By: E. Mowinckel
Checked By: P. Dalrymple
Pond Description: WQ-C
User Input Cell: Blue Text
1/2 2-year 384
0.92 0.009
1.25
0.65
minutes seconds in/hr cubic feet cubic feet cubic feet acre-feet
5 300 1.43 492 195 297 0.01
10 600 1.11 763 390 373 0.01
15 900 0.94 969 585 384 0.01
20 1200 0.81 1112 780 332 0.01
25 1500 0.72 1235 975 260 0.01
30 1800 0.65 1347 1170 177 0.00
35 2100 0.59 1414 1365 49 0.00
40 2400 0.54 1478 1560 -82 0.00
45 2700 0.50 1538 1755 -217 0.00
50 3000 0.46 1589 1950 -361 -0.01
55 3300 0.44 1652 2145 -493 -0.01
60 3600 0.41 1699 2340 -641 -0.01
65 3900 0.39 1751 2535 -784 -0.02
70 4200 0.37 1765 2730 -965 -0.02
75 4500 0.35 1813 2925 -1112 -0.03
80 4800 0.33 1823 3120 -1297 -0.03
85 5100 0.32 1879 3315 -1436 -0.03
90 5400 0.31 1896 3510 -1614 -0.04
95 5700 0.29 1903 3705 -1802 -0.04
100 6000 0.28 1934 3900 -1966 -0.05
105 6300 0.27 1958 4095 -2137 -0.05
110 6600 0.26 1975 4290 -2315 -0.05
115 6900 0.26 2025 4485 -2460 -0.06
120 7200 0.25 2031 4680 -2649 -0.06
Modified FAA Method- Storage Colume Calculations
Inputs | Tributary Area Output | Detention Volume
Return Period for Detention Control: Required Storage, cubic feet:
Catchment 'C': Required Storage, ac-ft:
Average
Outflow
Storage
Volume
Storage
Volume
Catchment Drainage Area, ac:
Release Rate, cfs:
Storm
Duration
Time
Rainfall
Intensity
Inflow Volume
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 1 of 2 7/27/2020
Release rate based on 0.35 gpm/sf of filter fabric area
0
2
4
6
8
10
12
0 20 40 60 80 100 120 140
Series1
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 2 of 2 7/27/2020
Basin Area (ac) % Imp
Drain Time
(hrs) a WQCV
Volume
(ac-ft)
Volume
(cf)
A 5.86 90% 12 0.8 0.32 0.188 8,199
B 3.09 90% 12 0.8 0.32 0.099 4,324
C 1.25 95% 12 0.8 0.36 0.045 1,949
REQUIRED WATER QUALITY VOLUME
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 1 of 1 7/27/2020
(i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) (xii)
Vault ID
Total
Required WQ
Volume (cf)
Flow, WQ
(cfs)
Chamber
Type
Chamber
Release Rate
(cfs)
Chamber
Volume (cf)
Installed
Chamber
Volume with
Aggregate
(cf)
Minimum No.
of Chambers
Total Release
Rate
(cfs)
Required
Storage
Volume by
FAA Method
(cf)
Minimum No.
of Chambers
Storage
Provided
within the
Chambers
(cf)
Total
Installed
System
Volume (cf)
A 8,199 7.55 MC-3500 0.036 109.9 178.9 46 1.656 3,231 30 5055 8229
B 4,324 3.85 SC-310 0.016 14.7 31.0 140 2.240 485 33 2058 4340
C 1,949 1.65 SC-740 0.024 45.9 74.9 27 0.648 384 9 1239 2022
(i) Calculated WQCV
(ii) 1/2 of the 2-year developed flow rate for the basin being sized (use half of the 2-year intensity for the time of concentration used in the calc - i.e. for 5 min Tc, use 1.425)
(iii) Per ADS, these equate to different chamber sizes they have available.
(iv) Flow rate thru the bottom of the Isolator Row chamber which is equal to the area of the bottom of the chamber multiplied by the flow rate per unit area (.35 gpm/sf).
(v) Volume within chamber only, not accounting for void spaces in surrounding aggregate.
(vi) Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit.
(vii) Number of chambers required to provide full WQCV within total installed system, including aggregate. (i) / (vi)
(viii) Release rate per chamber times number of chambers. (iv) * (vii)
(ix) FAA calc based on Flow, WQ and Total Release Rate.
(x) Number of chambers required to provide required FAA storage volume stored within the chamber only (no aggregate storage). (ix) / (v)
(xi) Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume. Greater of (vii) or (x) * (v)
(xii) System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required WQCV. Greater of (vi) or (x) * (vi)
WQ System Calculation Summary
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/27/2020
Chamber
Dimensions Width (in) Length (in) Height (in) Floor Area (sf)
Chamber
Volume (cf)
Chamber w/
Aggregate
Volume (cf)
Flow Rate /
Chamber (cfs)
SC-160 25.0 85.4 12.0 14.8 6.85 15.0 0.01156
SC-310 34.0 85.4 16.0 20.2 14.70 31.0 0.01572
SC-740 51.0 85.4 30.0 30.2 45.90 74.9 0.02359
DC-780 51.0 85.4 30.0 30.2 46.20 78.4 0.02359
MC-3500 77.0 86.0 45.0 46.0 109.90 178.9 0.03586
MC-4500 100.0 48.3 60.0 33.5 106.50 115.3 0.02616
Flow Rate* 0.35 gpm / sf
1 cf = 7.4805 gal
1 gal = 0.1337 cf
1 gpm = 0.0022 cfs
*Flow rate based on 1/2 of Nov 07 Qmax in Figure 17 of UNH Testing Report
Chamber Flow Rate Conversion (gpm/sf to cfs)
STORMTECH CHAMBER DATA
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Page Rational_1 of
1 Routing.7/27/2020 xls
Midtown Gardens Marketplace
7/28/2020
APPENDIX C
Hydraulic Computations
Project Description
Friction Method Manning Formula
Solve For Discharge
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00500 ft/ft
Normal Depth 1.00 ft
Diameter 1.00 ft
Results
Discharge 2.52 ft³/s
Flow Area 0.79 ft²
Wetted Perimeter 3.14 ft
Hydraulic Radius 0.25 ft
Top Width 0.00 ft
Critical Depth 0.68 ft
Percent Full 100.0 %
Critical Slope 0.00770 ft/ft
Velocity 3.21 ft/s
Velocity Head 0.16 ft
Specific Energy 1.16 ft
Froude Number 0.00
Maximum Discharge 2.71 ft³/s
Discharge Full 2.52 ft³/s
Slope Full 0.00500 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Worksheet for 12" RCP Max Q @ 0.5%
7/27/2020 9:34:20 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Upstream Velocity Infinity ft/s
Normal Depth 1.00 ft
Critical Depth 0.68 ft
Channel Slope 0.00500 ft/ft
Critical Slope 0.00770 ft/ft
Worksheet for 12" RCP Max Q @ 0.5%
7/27/2020 9:34:20 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Discharge
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00500 ft/ft
Normal Depth 1.50 ft
Diameter 1.50 ft
Results
Discharge 7.43 ft³/s
Flow Area 1.77 ft²
Wetted Perimeter 4.71 ft
Hydraulic Radius 0.38 ft
Top Width 0.00 ft
Critical Depth 1.06 ft
Percent Full 100.0 %
Critical Slope 0.00703 ft/ft
Velocity 4.20 ft/s
Velocity Head 0.27 ft
Specific Energy 1.77 ft
Froude Number 0.00
Maximum Discharge 7.99 ft³/s
Discharge Full 7.43 ft³/s
Slope Full 0.00500 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Worksheet for 18" RCP Max Q @ 0.5%
7/27/2020 9:34:53 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Upstream Velocity Infinity ft/s
Normal Depth 1.50 ft
Critical Depth 1.06 ft
Channel Slope 0.00500 ft/ft
Critical Slope 0.00703 ft/ft
Worksheet for 18" RCP Max Q @ 0.5%
7/27/2020 9:34:53 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Discharge
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00500 ft/ft
Normal Depth 2.00 ft
Diameter 2.00 ft
Results
Discharge 16.00 ft³/s
Flow Area 3.14 ft²
Wetted Perimeter 6.28 ft
Hydraulic Radius 0.50 ft
Top Width 0.00 ft
Critical Depth 1.44 ft
Percent Full 100.0 %
Critical Slope 0.00662 ft/ft
Velocity 5.09 ft/s
Velocity Head 0.40 ft
Specific Energy 2.40 ft
Froude Number 0.00
Maximum Discharge 17.21 ft³/s
Discharge Full 16.00 ft³/s
Slope Full 0.00500 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Worksheet for 24" RCP Max Q @ 0.5%
7/27/2020 9:35:15 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Upstream Velocity Infinity ft/s
Normal Depth 2.00 ft
Critical Depth 1.44 ft
Channel Slope 0.00500 ft/ft
Critical Slope 0.00662 ft/ft
Worksheet for 24" RCP Max Q @ 0.5%
7/27/2020 9:35:15 AM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Midtown Gardens Marketplace
7/28/2020
APPENDIX D
Drainage Map
CO
CO
E
EVT
ECB
GM
E
E
E
E
TL
TL
TV
E
TL
GM
IR
TL
W
EKM
PJD
7/28/2020
PROPOSED DRAINAGE MAP
1
SCALE: 1"=40'
0 20 40
-
-
-
-
-
-
-
-
-
-
-
-
-
-
STAMP
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College & Drake\CADD\Exhibits\KSS146_Drainage_Proposed.dwg - Erland Mowinckel - 7/28/2020
# Date Issue / Description Init.
THESE PLANS ARE AN INSTRUMENT OF SERVICE
AND ARE THE PROPERTY OF GALLOWAY, AND MAY
NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED
WITHOUT THE WRITTEN CONSENT OF GALLOWAY.
COPYRIGHTS AND INFRINGEMENTS WILL BE
ENFORCED AND PROSECUTED.
COPYRIGHT
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884
Planning. Architecture. Engineering.
O
www.gallowayUS.com
C 2016. Galloway & Company, Inc. All Rights Reserved
PRELIMINARY
NOT FOR BIDDING
NOT FOR CONSTRUCTION
Date:
Drawn By:
Project No:
Checked By:
KSS000146
OF 1
UTILITY PLANS FOR
MIDTOWN GARDENS MARKETPLACE
KING SOOPERS MARKETPLACE #146
S. COLLEGE AVE. & DRAKE RD.
FORT COLLINS, COLORADO
BASIN SUMMARY TABLE
Tributary Area
C2 C100
tc | 2-Year tc | 100-Year Q2 Q100
Sub-basin (acres) (min) (min) (cfs) (cfs)
A-1 0.35 0.81 1.00 5.8 5.0 0.8 3.5
A-2 0.25 0.87 1.00 5.0 5.0 0.6 2.5
A-3 0.15 0.95 1.00 5.0 5.0 0.4 1.5
A-4 0.44 0.86 1.00 5.0 5.0 1.1 4.4
A-5 0.47 0.84 1.00 5.2 5.0 1.1 4.7
A-6 1.43 0.88 1.00 5.0 5.0 3.6 14.3
A-7 1.56 0.95 1.00 5.0 5.0 4.2 15.6
A-8 0.65 0.95 1.00 5.0 5.0 1.8 6.5
A-9 0.56 0.95 1.00 5.0 5.0 1.5 5.6
B-1 0.77 0.91 1.00 5.0 5.0 2.0 7.7
B-2 0.49 0.88 1.00 5.8 5.0 1.2 4.9
B-3 0.75 0.91 1.00 5.0 5.0 2.0 7.5
B-4 0.09 0.93 1.00 5.0 5.0 0.2 0.9
B-5 0.87 0.80 0.99 5.5 5.0 1.9 8.6
B-6 0.12 0.95 1.00 5.0 5.0 0.3 1.2
C-1 0.34 0.90 1.00 5.0 5.0 0.9 3.4
C-2 0.66 0.92 1.00 5.0 5.0 1.7 6.6
C-3 0.11 0.95 1.00 5.0 5.0 0.3 1.1
C-4 0.12 0.95 1.00 5.0 5.0 0.3 1.2
C-5 0.02 0.95 1.00 5.0 5.0 0.1 0.2
OS-1 0.66 0.67 0.84 13.6 13.6 0.9 3.8
OS-2 0.41 0.80 1.00 6.6 5.0 0.9 4.1
OS-3 0.13 0.92 1.00 5.0 5.0 0.3 1.3
OS-4 0.32 0.93 1.00 5.0 5.0 0.8 3.2
OS-5 0.71 0.87 1.00 5.0 5.0 1.8 7.1
OS-6 0.24 0.84 1.00 5.0 5.0 0.6 2.4
Basin C 1.25 5.0 1.25 9.95 12.4
Basin OS 1.57 5.0 2.36 9.95 23.5
PIPE
100-Year
DIRECT RUNOFF TOTAL RUNOFF STREET
7/28/20
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/28/2020
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
2-Year
7/28/20
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\KSS 146_Rational_Routing.xls
Page 1 of 1 7/28/2020
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 15, Jun 9, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10