HomeMy WebLinkAboutLEMAY AVENUE CRAFT BREWERY & SELF-STORAGE FACILITY - PDP - PDP150009 - REPORTS - DRAINAGE REPORTPDP DRAINAGE REPORT
FOR
LEMAY AVENUE CRAFT BREWERY &
SELF-STORAGE FACILITY
Prepared For:
FORT COLLINS SELF-STORAGE, LLC
5013 Bluestem Court
Fort Collins, CO 80525
July 1, 2015
Project No. 39708.02
Prepared By:
JR Engineering, LLC
2900 South College Avenue, Suite 3D
Fort Collins, CO 80525
Page i
TABLE OF CONTENTS
Table of Contents ............................................................................................................................................... i
Vicinity Map ......................................................................................................................................................... 1
General Description and Location .................................................................................................................. 2
Location And Existing Site Characteristics ................................................................................................. 2
Site Soils ........................................................................................................................................................... 2
Floodplain ........................................................................................................................................................ 2
Drainage Basins and Sub-Basins ....................................................................................................................... 3
Major Basin ...................................................................................................................................................... 3
Historic Sub-Basins ........................................................................................................................................ 3
Developed Sub-Basins.................................................................................................................................... 4
Drainage Design Criteria .................................................................................................................................. 6
Regulations ...................................................................................................................................................... 6
Low-Impact Development ............................................................................................................................ 6
Hydrologic Criteria ........................................................................................................................................ 6
Hydraulic Criteria........................................................................................................................................... 6
Drainage Facility Design .................................................................................................................................... 8
General Concept ............................................................................................................................................ 8
Water Quality/ Detention Facilities ............................................................................................................ 8
Stormwater Pollution Prevention ..................................................................................................................10
Temporary Erosion Control ......................................................................................................................10
Permanent Erosion Control .......................................................................................................................10
Summary & Conclusions .................................................................................................................................11
References .........................................................................................................................................................12
APPENDIX
Appendix A – Site & Soil Descriptions and Characteristics
Appendix B – Hydrologic Calculations
Appendix C – Hydraulic Calculations
Appendix D – Existing & Proposed Drainage Plans
Appendix E – LID Exhibit
Page ii
Engineer’s Certification Block
I hereby certify that this Project Development Plan Drainage Report for Lemay Avenue Craft
Brewery & Self-Storage Facility was prepared by me (or under my direct supervision) for JR
Engineering, LLC and the owners thereof and meets or exceeds the criteria of the City of Fort
Collins Stormwater Design Standards.
________________________________________
Timothy J. Halopoff, PE
Registered Professional Engineer
State of Colorado No. 37953
Page 1
VICINITY MAP
Page 2
GENERAL DESCRIPTION AND LOCATION
LOCATION AND EXISTING SITE CHARACTERISTICS
Lemay Avenue Craft Brewery & Self- Storage is located in the northeast quarter of Section 12,
Township 7 North, Range 69 West of the 6th Principal Meridian in the City of Fort Collins, Larimer
County, Colorado. More specifically, the Lemay Avenue Craft Brewery & Self- Storage site is a
6.35 acre property that is currently undeveloped. The site is zoned I (Industrial) and will support
the proposed craft brewery and self-storage facilities.
The proposed use of the site is split into three lots. The first lot contains the craft brewery building
with 7,912 total square feet. The second lot contains the self-storage facilities with 8 buildings
totaling 104,000 square feet. The third lot is for a future development and will be a lawn area until
the lot is developed, at which time the owner will be responsible for any additional water quality
and detention necessary for the development of the site.
The existing site generally slopes from the north to south with slopes ranging between 0.60% and
2.5%. The property is generally covered with sparse native grasses. The site currently drains to the
southeast corner of the site where runoff is collected in an existing 30” CMP culvert and piped
south in the City’s Lemay Avenue Right-Of-Way.
SITE SOILS
The Lemay Avenue Craft Brewery & Self- Storage site soils consist of loamy soil, predominately
Nunn clay loam. Nunn clay loam belongs to hydrologic soils Group C. Group C soils have a slow
infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the
downward movement of water or soils of moderately fine texture or fine texture. These soils have
a slow rate of water transmission. Nunn clay loam with 0-3 percent slopes generally has a
combined surface layer thickness of approx. 30 inches. Runoff is moderately high, and the hazards
of wind erosion are moderately low. Supporting figures can be found in the Appendix, page A-1.
FLOODPLAIN
The site is shown on FEMA FIRM panel 08069C0983H, dated May 2, 2012. The site lies within an
area determined to be outside the 100yr floodplain, but within the 500yr floodplain. The “City of
Fort Collins Floodplain Review Checklist for 50% Submittals” checklist is not applicable for this PDP
Drainage Report.
Page 3
DRAINAGE BASINS AND SUB-BASINS
MAJOR BASIN
The proposed Lemay Avenue Craft Brewery & Self-Storage site is located in the Dry Creek major
basin. The Dry Creek drainage basin is tributary to the Cache la Poudre River and extends from
the Wyoming border to where it joins the river near Mulberry and Timberline. The Dry Creek
basin is approximately 23 miles long and six miles wide and encompasses approximately 62 square
miles. The land used in the upper and middle portion of the basin is primarily rangeland and
irrigated hay meadows and pastures. The majority of the lower portion of the basin is developed
and includes commercial, industrial and residential uses. The project site is a part of the lower Dry
Creek basin.
There are no major drainageways located within or immediately adjacent to the site. The site is
shown on FEMA FIRM panel 08069C0983H, dated May 2, 2012. The site lies within an area
determined to be outside the 100yr floodplain, but within the 500yr floodplain. An annotated
FIRM exhibit is included in Appendix A.
HISTORIC SUB-BASINS
Lemay Avenue Craft Brewery & Self-Storage is an infill development piece of property. It is
governed by the City’s Reasonable Use policy, in which the proposed drainage basins will need to
follow the generally accepted principle of releasing the 100-year developed condition flow rate at
the same location and at a magnitude of 0.2cfs/acre as the pre-development condition. There are
no offsite areas that flow across the proposed development site. Referring to the “Existing
Drainage Plan”, included in the Appendix, the following describes the existing condition drainage
basins.
Existing Onsite Sub-Basins:
The site has two existing onsite drainage basins.
Sub-basin EX1 consists of a 6.20 acre area of undeveloped open space with native grasses
and weeds covering the majority of the ground and is assumed to be 2% impervious. Runoff
generally flows to the southeast across basin EX-1, at slopes ranging from 0.50% to 2.0%,
generally leaving the site at the southeast corner, where it is piped south off-site through an
existing 30” CMP culvert.
Sub-basin EX2 consists of a 1.51 acre area of undeveloped open space with the same
ground cover and percentage imperviousness as sub-basin EX-1. Runoff in sub-basin EX-1
collects in a roadside swale and flows south to the southeast corner, of the site where it is
piped south, off-site through an existing 30” CMP culvert.
Page 4
DEVELOPED SUB-BASINS
The proposed developed condition sub-basins have been designed to mimic the historic basins’
runoff patterns. The following describes the proposed conditions on-site drainage basins. Refer to
the “Proposed Drainage Plan” in the appendix for review.
Proposed Onsite Sub-Basins:
Sub-basin A consists of 0.93 acres on the northern portion of the subject property.
Runoff from the proposed building and parking lot travels west to an LID basin in the
northwest corner of the property. From the LID basin, runoff flows south in a swale
through another LID basin and into the proposed detention pond on the southern edge of
the property.
Sub-basin B consists of 0.85 acres on the northwest corner of the subject property.
Runoff from sub-basin b is collected in an LID basin on the northwest corner of the
property. From the LID basin, runoff flows south in a swale through another LID basin and
into the proposed detention pond on the southern edge of the property.
Sub-basin C consists of 0.41 acres near the northwest corner of the subject property.
Runoff from the proposed building and driveways travels west to an LID basin on the
western edge of the property. From the LID basin, runoff flows south in a swale through
another LID basin and into the proposed detention pond on the southern edge of the
property.
Sub-basin D consists of 0.16 acres on the western edge of the subject property. Runoff is
captured in a proposed soft swale and then flows south through and LID basin and into the
proposed detention pond on the southern edge of the property.
Sub-basin E consists of 0.39 acres in the western portion of the subject property. Runoff
from the proposed building and driveways is conveyed to a proposed LID basin near the
southwest corner of the site and then flows south into the proposed detention pond on the
southern edge of the property.
Sub-basin F consists of 0.16 acres on the east side of the subject on the western edge of
the subject property. Runoff is captured in a proposed soft swale and then flows south
through and LID basin and into the proposed detention pond on the southern edge of the
property.
Sub-basin G consists of 0.77 acres in the center of the subject property. Runoff from the
proposed building and driveways is conveyed to a proposed LID basin and then flows south
into the proposed detention pond on the southern edge of the property.
Page 5
Sub-basin H consists of 0.68 acres in the center of the subject property. Runoff from the
proposed building and driveways is conveyed to a proposed LID basin near the eastern edge
of the property, and then flows south via a swale, through another LID basin and into the
proposed detention pond on the southern edge of the property.
Sub-basin I is comprised of 0.82 acres in the center of the subject property. Runoff from
the proposed lawn area is conveyed to a proposed LID basin near the eastern edge of the
property, and then flows south via a swale, through another LID basin and into the
proposed detention pond on the southern edge of the property.
Sub-basin J is comprised of 0.19 acres at the eastern edge of the subject property. Runoff
from this basin is captured in a swale and flows south through an LID basin and into the
proposed detention pond on the southern edge of the property.
Sub-basin K is comprised of 0.32 acres near the southeast corner of the subject property.
Runoff from the proposed building and driveways is conveyed to a proposed LID basin near
the southeast corner of the site and then flows south into the proposed detention pond on
the southern edge of the property.
Sub-basin L is comprised of 0.76 acres and contains the proposed detention pond area.
Runoff from this basin is collected in the proposed detention pond on the southern edge of
the property.
Sub-basin M is comprised of 0.59 acres on the northern edge of the subject property.
Runoff from this basin is collected in a proposed sump inlet along Buckingham Street.
Captured flows are piped east to the corner of Buckingham Street and Lemay Avenue
where they are release into a swale that flows south along Lemay Avenue to the southeast
corner of the site. Runoff is then piped south, off-site through and existing 30” CMP culvert.
Sub-basin N is comprised of 1.48 acres on the eastern edge of the subject property.
Runoff from this basin is collected in a swale that flows south along Lemay Avenue to the
southeast corner of the site. Runoff is then piped south, off-site through and existing 30”
CMP culvert.
Sub-basin O is comprised of 0.10 acres on the southern edge of the subject property.
Runoff from this basin sheet flow south off-site.
Page 6
DRAINAGE DESIGN CRITERIA
REGULATIONS
This report was prepared to meet or exceed the City of Fort Collins stormwater criteria. The City
of Fort Collins Storm Drainage Design Criteria and Construction Manual (with all current 2011
Revisions)(FCSDDCCM) and the Urban Drainage Flood Control District’s (UDFCD) Drainage
Criteria Manual (USDCM) Volumes 1, 2 and 3 were referenced as guidelines for this design.
LOW-IMPACT DEVELOPMENT
Volume reduction is an important part of the Four Step Process and is fundamental to effective
stormwater management. Per City criteria, a minimum of 50 percent of new impervious surface
area must be treated by a Low-Impact Development (LID) best management practice (BMP). The
proposed LID BMPs will have the effect of slowing runoff through the site lot and increasing
infiltration and rainfall interception by encouraging infiltration and careful selection of vegetative
cover. The improvements will decrease the runoff coefficient from the site and are expected to
have no adverse impact on the timing, quantity, or quality of stormwater runoff. Site-specific LID
BMPs are discussed in the following sections of this report and an illustrative LID/Surface map is
provided in Appendix E.
HYDROLOGIC CRITERIA
The rational method was performed to calculate the peak runoff rates for each basin. Weighted
percent imperviousness and weighted runoff coefficients were calculated for each basin using
USDCM Tables RO-3 and RO-5 based on Natural Resources Conservation Service (NRCS) Type C
hydrologic soil classification and surface characteristics of each basin. The time of concentration
was calculated using USDCM Equation RO-3 and the intensity was calculated using the
corresponding storm rainfall depth and USDCM Equation RA-3. To more closely match the City of
Fort Collins IDF Curve, Coefficient 3 of the UDFCD’s intensity formula was adjusted to 0.7867.
The City of Fort Collins area has 2-year, 1-hour rainfall depth of 0.82 inches and a 100-year, 1- hour
rainfall depth of 2.86 inches. These depths do account for the 1997 adjusted rainfall depths. The 2-
hour 100-year rainfall total is 3.67 inches, based on the rainfall frequencies adopted by the City of
Fort Collins.
HYDRAULIC CRITERIA
This report demonstrates that the proposed stormwater detention concept is able to reduce the
100-year developed condition flows to a flow rate of 0.2 cfs/ acre; thereby satisfying the City’s
Reasonable Use requirements. The Rational Formula-based Federal Aviation Administration (FAA)
method is used to preliminarily size the detention pond in accordance with City criteria, as the
tributary area is less than 20 acres in size. The resulting storage volume is increased by a factor of
twenty (20) percent to better match the result that would be obtained from SWMM modeling, per
City criteria.
Page 7
The ultimate Lemay Avenue Craft Brewery & Self-Storage storm drainage system will be designed
to convey the minor and major storm events through the property with the proposed inlets, storm
sewer pipes, soft swales, and LID measures for the flows being calculated by this report. Per the
requirements provided by the City of Fort Collins Storm Drainage Design Criteria and
Construction Manual, all inlets and storm pipes will be designed to convey the 100-year storm
flows. During the major developed condition 100-year storm, the accumulated water depth in the
ponds will be held to a maximum level of one-foot below all building finished floor elevations.
Additionally, this report summarizes if any, the expected changes to offsite conditions or flows. This
project will eventually show that the flow rate released downstream is less than would historically
be experienced, and that the sedimentation is lessened through increase infiltration.
All swale and pipe outlets will be protected with turf mat or riprap; whichever is most appropriate.
Storm sewer pipe outlets will be protected using the requirements set by the USDCM for the
protection of downstream conveyance channels and culverts. Lid measures have been integrated
into this design on higher levels than most City of Fort Collin’s projects to date. In all, 85% of this
project’s impervious areas pass through and are treated in LID’s prior to reaching the detention
pond.
Page 8
DRAINAGE FACILITY DESIGN
GENERAL CONCEPT
The proposed improvements to the Lemay Avenue Craft Brewery & Self-Storage site will result in
developed condition runoff being conveyed around the proposed buildings and to the south via
concrete pans and swales. Low-impact development best management practices are proposed to
improve the quality of runoff and aid in reducing peak flows. Specifically, permeable pavement
systems are proposed for portions of the parking lot, Lid infiltration forebay basins to treat roof
and driveway drainage, and grass lined bio-swales (soft-swales) are proposed on the west and east
sides of the site to improve water quality.
Runoff from the site is captured in LID basins and swales located around the self-storage site and in
open areas adjacent to the building. Runoff is conveyed via sheet flow, concrete pans and bio-
swales in a southerly direction to the proposed detention pond at the southern end of the site.
The existing drainage outfall from the site is in the southeast corner of the property. The proposed
detention pond is sized to detain the 100 year flows from the site and release at a rate of
0.2cfs/acre to the southeast corner of the property. Runoff collected from Buckingham Street and
Lemay Avenue will combine with flows released from the proposed detention pond and will
continue to flow south off-site through an existing 30” CMP culvert, similar to historic conditions.
WATER QUALITY/ DETENTION FACILITIES
Water quality will be provided for the site through the use of LID basins and swales. Detention will
be provided for the site through the proposed detention pond on the southern edge of the site.
Within the detention pond is located an underground gravel storm water infiltration basin for LID
measures. The voids provided by the porous graded gravel in the depression increases infiltration
with the supportive soils. The proposed detention pond will detain the 100 year flows from the site
and release at a rate of 0.2cfs/acre to the southeast corner of the property.
The most recent version of the UD-Detention software (Version 2.35, January 2015) was used to
determine the ultimate detention volume requirements. Per City of Fort Collins requirements, the
calculated detention volume using the FAA method was increased by a factor of 1.20. This increase
in detention volume will be provided via the void space in the gravel stormwater infiltration basin
located at the bottom of the proposed detention pond and one-foot of freeboard is provided in this
detention configuration. See Table 1, below, for detention pond sizing and release rates.
Page 9
Table 1: Detention Pond Values
Storage
Volume
Required
(acre-ft)
WQCV Volume
Required (acre-ft)
(provided in LID
basins and swales)
Total Volume
Required (acre-ft)
Volume required *1.2
Storage
Volume
Provided
(acre-ft)
100-yr Max
Inflow Rate
(cfs)
100-yr Max
Release Rate
(cfs)
1.2 0.14 1.44 1.44 49.5 1.29
Page 10
STORMWATER POLLUTION PREVENTION
TEMPORARY EROSION CONTROL
A temporary erosion control plan is to be implemented for the site during construction.
Temporary erosion control measures include, but are not limited to, slope and swale protection,
silt fence placed around downstream areas of disturbance, construction vehicle tracking pad at
entrances, a designated concrete truck washout basin, designated vehicle fueling areas, inlet
protection, and others. All temporary erosion control measures are to be removed after they are
deemed unnecessary.
PERMANENT EROSION CONTROL
Permanent erosion control measures include, but are not limited to, the constructed
detention/water quality ponds, riprap pads placed for culvert outlet protection, seeding and mulch
placed to enable and established vegetative growth, etc. Long-term maintenance of these erosion
control measures shall be the responsibility of the owner of the property. JR will provide a detailed
Storm Water Management and Erosion Control Plan at the time of the FDP submittal that will meet
all requirements of the City of Fort Collins.
Page 11
SUMMARY & CONCLUSIONS
The existing conditions drainage has two onsite sub-basins with the same outfall point in the
southeast corner of the subject property. The proposed drainage condition was designed to mimic
the historic basins’ runoff patterns. The existing conditions drainage patterns are maintained in the
design of the project. The proposed improvements will have positive impacts on the timing, flow
rate, and quality of runoff leaving the site; and will reduce potential impacts for flooding
downstream of this site.
The hydrologic and retention/detention calculations were performed using the required methods as
outlined in the City of Fort Collins Amendments to the Urban Drainage and Flood Control District
Criteria Manual. The proposed drainage improvements meet or exceed the City’s requirements.
This PDP Drainage Report and the complimenting drainage plans and LID plans propose
appropriate grading, permanent landscaping, LID BMPs, and onsite facilities (e.g. storm sewer, inlets,
detention facilities) that are shown in their preliminary configuration and will be designed for
construction in the Final Drainage Report along with supporting calculations.
The proposed concept for the development of the Lemay Avenue Craft Brewery & Self-Storage site
involves routing developed condition flows to a proposed onsite detention pond. LID site
enhancements will treat the site runoff at the source before allowing the runoff to be conveyed to
the proposed detention pond. The site’s stormwater facilities are sixed to meet the City of Fort
Collins “Storm Drainage Criteria Manual and Construction Standards” for both detention and
water quality.
Page 12
REFERENCES
1. Urban Storm Drainage Criteria Manual (Volumes 1, 2, and 3), Urban Drainage and Flood
Control District, June 2001.
2. Storm Drainage Criteria Manual and Construction Standards, City of Fort Collins Storm Water
Utility, City of Fort Collins, Colorado, Updated January, 1997.
3. “Hydrologic Group Rating for Larimer County Area, Colorado”, USDA-Natural Resources
Conservation Service, National Cooperative Soil Survey. Web Soil Survey URL:
http://websoilsurvey.nrcs.usda.gov. [July 21, 2010]
APPENDIX A
SITE & SOIL DESCRIPTIONS AND CHARACTERISTICS
LEMAY AVE. CRAFT BREWERY & SELF-STORAGE DRAINAGE REPORT
Project No. 39708.02 FIGURE 2 - SOILS MAP
LEMAY AVE. CRAFT BREWERY & SELF-STORAGE DRAINAGE REPORT
Project No. 39708.02 FIGURE 3 - FIRM MAP
APPENDIX B
HYDROLOGIC CALCULATIONS
Subdivision: 0 Project Name: Lemay Ave. Craft Brewery & Self-Storage
Location: Fort Collins Project No.:
Calculated By: BAB
Checked By: 0
Date: 7/1/15
A 0.93 100 0.69 74.19 5 0.14 0.80 90 0.10 9.70 84.69
B 0.85 100 0.00 0.00 5 0.85 5.00 90 0.00 0.00 5.00
C 0.41 100 0.23 56.10 5 0.00 0.00 90 0.18 39.50 95.60
D 0.16 100 0.00 0.00 5 0.08 2.50 90 0.08 45.00 47.50
E 0.39 100 0.21 53.85 5 0.00 0.00 90 0.18 41.50 95.35
F 0.16 100 0.00 0.00 5 0.06 1.90 90 0.10 56.30 58.20
G 0.77 100 0.36 46.75 5 0.00 0.00 90 0.41 47.90 94.65
H 0.68 100 0.33 48.53 5 0.00 0.00 90 0.35 46.30 94.83
I 0.82 100 0.00 0.00 5 0.82 5.00 90 0.00 0.00 5.00
J 0.19 100 0.00 0.00 5 0.19 5.00 90 0.00 0.00 5.00
K 0.32 100 0.16 50.00 5 0.00 0.00 90 0.16 45.00 95.00
L 0.76 100 0.00 0.00 5 0.76 5.00 90 0.00 0.00 5.00
M 0.59 100 0.43 72.88 5 0.16 1.40 90 0.00 0.00 74.28
N 1.48 100 0.45 30.41 5 0.96 3.20 90 0.07 4.30 37.91
O 0.10 100 0.00 0.00 5 0.10 5.00 90 0.00 0.00 5.00
Basins Total
Weighted %
Basin ID Total Area (ac) % Imp. Area (ac) Imp.
Weighted
% Imp. % Imp. Area (ac)
Weighted
% Imp. % Imp.
39708.02
COMPOSITE % IMPERVIOUS CALCULATIONS
Paved Roads/ Drives Lawns Roof
Area (ac) Weighted
% Imp.
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
Subdivision: 0 Project Name: Lemay Ave. Craft Brewery & Self-Storage
Location: Fort Collins Project No.:
Calculated By: BAB
Checked By: 0
Date: 7/1/15
FINAL
BASIN D.A. Hydrologic Impervious C100 C
2 L S Ti
L S Cv VEL. Tt COMP. T
c TOTAL Urbanized Tc
Tc
ID (AC) Soils Group (%) (FT) (%) (MIN) (FT) (%) (FPS) (MIN) (MIN) LENGTH(FT) (MIN) (MIN)
A 0.93 C 84.7 0.78 0.65 70 1.4 6.2 200 1.0 20.0 2.0 1.7 7.8 270.0 11.5 7.8
B 0.85 C 5.0 0.52 0.08 20 5.0 4.9 95 0.5 15.0 1.1 1.5 6.4 115.0 10.6 6.4
C 0.41 C 95.6 0.90 0.81 15 3.0 1.4 150 0.8 20.0 1.8 1.4 2.8 165.0 10.9 5.0
D 0.16 C 47.5 0.60 0.32 35 20.0 3.1 150 0.8 15.0 1.3 1.9 5.0 185.0 11.0 5.0
E 0.39 C 95.4 0.90 0.81 15 3.0 1.4 150 0.8 20.0 1.8 1.4 2.8 165.0 10.9 5.0
F 0.16 C 58.2 0.63 0.39 35 20.0 2.8 150 0.8 15.0 1.3 1.9 4.7 185.0 11.0 5.0
G 0.77 C 94.7 0.89 0.80 35 2.0 2.6 150 0.6 20.0 1.5 1.6 4.2 185.0 11.0 5.0
H 0.68 C 94.8 0.89 0.80 50 2.8 2.8 250 0.5 20.0 1.4 2.9 5.7 300.0 11.7 5.7
I 0.82 C 5.0 0.52 0.08 120 1.6 17.5 140 1.5 15.0 1.8 1.3 18.8 260.0 11.4 11.4
J 0.19 C 5.0 0.52 0.08 10 20.0 2.2 150 1.3 15.0 1.7 1.5 3.6 160.0 10.9 5.0
K 0.32 C 95.0 0.89 0.80 50 2.8 2.8 120 1.6 20.0 2.5 0.8 3.5 170.0 10.9 5.0
L 0.76 C 5.0 0.52 0.08 50 6.0 7.3 200 1.0 15.0 1.5 2.2 9.5 250.0 11.4 9.5
M 0.59 C 74.3 0.70 0.53 40 2.0 5.2 230 0.4 20.0 1.3 3.0 8.3 270.0 11.5 8.3
N 1.48 C 37.9 0.58 0.27 30 13.0 3.5 430 1.4 15.0 1.8 4.0 7.6 460.0 12.6 7.6
O 0.10 C 5.0 0.52 0.08 10 20.0 2.2 130 1.5 20.0 2.4 0.9 3.1 140.0 10.8 5.0
NOTES:
Ti = (0.395*(1.1 - C
5)*(L)^0.5)/((S)^0.33), S in ft/ft
Tt=L/60V (Velocity From Fig. 501)
Velocity V=Cv*S^0.5, S in ft/ft
Tc Check = 10+L/180
For Urbanized basins a minimum Tc of 5.0 minutes is required.
For non-urbanized basins a minimum Tc of 10.0 minutes is required
Cv
2.5
5
7
10
15
20
Grassed waterway
TRAVEL TIME
(Tt)
Paved areas and shallow paved swales
Type of Land Surface
Heavy Meadow
Tillage/field
Short pasture and lawns
Nearly bare ground
STANDARD FORM SF-2
TIME OF CONCENTRATION
SUB-BASIN Tc CHECK
39708.02
DATA (URBANIZED BASINS)
INITIAL/OVERLAND
(Ti)
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
Project Name: Lemay Ave. Craft Brewery & Self-Storage
Subdivision: 0 Project No.:
Location: Fort Collins Calculated By: BAB
Design Storm: Checked By: 0
Date: 7/1/15
TRAVEL TIME
STREET
Design Point
Basin ID
Area (Ac)
Runoff Coeff.
Tc (min)
C*A (Ac)
I (in/hr)
Q (cfs)
Tc (min)
C*A (Ac)
I (in/hr)
Q (cfs)
Slope (%)
Flow (cfs)
Design Flow (cfs)
Slope (%)
Pipe Size (inches)
Length (ft)
Velocity (fps)
Tt (min)
REMARKS
1 A 0.93 0.65 7.8 0.60 2.81 1.7
1 B 0.85 0.08 6.4 0.07 3.01 0.21 7.8 0.67 2.81 1.88 0.8 1.88 150 1.8 1.4 Swale flow to DP2
2 C 0.41 0.81 5.0 0.33 3.22 1.06
2 D 0.16 0.32 5.0 0.05 3.22 0.16 5.00 0.38 3.22 1.22
Total flow at DP2 2 9.2 1.05 2.65 2.78 0.8 2.78 150 1.8 1.4 Swale flow to DP3
3 E 0.39 0.81 5.0 0.32 3.22 1.0
3 F 0.16 0.39 5.0 0.06 3.22 0.2 5.0 0.38 3.22 1.2
Total flow at DP3 3 10.6 1.43 2.51 3.6 1.0 3.6 100 2.0 0.8 Swale flow to DP8
4 G 0.77 0.80 5.0 0.62 3.22 2.0 1 2.0 100 2.0 0.8 Swale flow to DP8
5 H 0.68 0.80 5.7 0.54 3.11 1.7
5 I 0.82 0.08 11.4 0.07 2.43 0.2 11.4 0.61 2.43 1.5 1.3 1.5 150 2.3 1.1 Swale flow to DP6
6 J 0.19 0.08 5.0 0.02 3.22 0.1
Total flow at DP6 6 12.5 0.63 2.34 1.5 0.65 1.5 70 1.6 0.7 Swale flow to DP7
7 K 0.32 0.80 5.0 0.26 3.22 0.8
Total flow Flow at DP7 7 13.3 0.89 2.28 2.0 1.0 2.0 100 2.0 0.8 Swale flow to DP8
Detention Pond Area
8 L 0.76 0.08 9.5 0.06 2.62 0.2
Detention Pond Outlet
Total flow at DP8 8 14.1 4.32 2.22 9.6 Piped to DP10
Sump Inlet
9 M 0.59 0.53 8.3 0.31 2.76 0.9 1.4 0.9 700 2.4 4.9 Piped/ Swale flow to DP10
10 N 1.48 0.27 7.6 0.40 2.84 1.1
Total flow at DP 10 10 13.2 0.71 2.29 1.6
0.3
Total Release from site 10 1.9
Flow Off-site south O 0.10 0.08 5.0 0.01 3.22 0.03
Add Pond Release
Pond Release
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
2-Year
Project Name: Lemay Ave. Craft Brewery & Self-Storage
Subdivision: 0 Project No.:
Location: Fort Collins Calculated By: BAB
Design Storm: Checked By: 0
Date: 7/1/15
TRAVEL TIME
STREET
Design Point
Basin ID
Area (Ac)
Runoff Coeff.
Tc (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
1 A 0.93 0.65 7.8 0.60 7.91 4.7
1 B 0.85 0.08 6.4 0.07 8.45 0.6 7.8 0.67 7.91 5.3 0.8 5.30 150 1.8 1.4 Swale flow to DP2
2 C 0.41 0.81 5.0 0.33 9.06 3.0
2 D 0.16 0.32 5.0 0.05 9.06 0.5 5.00 0.38 9.06 3.4
Total flow at DP2 2 9.2 1.05 7.45 7.8 0.8 7.82 150 1.8 1.4 Swale flow to DP3
3 E 0.39 0.81 5.0 0.32 9.06 2.9
3 F 0.16 0.39 5.0 0.06 9.06 0.5 5.0 0.38 9.06 3.4
Total flow at DP3 3 10.6 1.43 7.05 10.1 1.0 10.1 100 2.0 0.8 Swale flow to DP8
4 G 0.77 0.80 5.0 0.62 9.06 5.6 1 5.6 100 2.0 0.8 Swale flow to DP8
5 H 0.68 0.80 5.7 0.54 8.73 4.7
5 I 0.82 0.08 11.4 0.07 6.84 0.5 11.4 0.61 6.84 4.2 1.3 4.2 150 2.3 1.1 Swale flow to DP6
6 J 0.19 0.08 5.0 0.02 9.06 0.2
Total flow at DP6 6 12.5 0.63 6.58 4.1 0.65 4.1 70 1.6 0.7 Swale flow to DP7
7 K 0.32 0.80 5.0 0.26 9.06 2.4
Total flow Flow at DP7 7 13.3 0.89 6.41 5.7 1.0 5.7 100 2.0 0.8 Swale flow to DP8
Detention Pond Area
8 L 0.76 0.08 9.5 0.06 7.37 0.4
Detention Pond Outlet
Total flow at DP8 8 14.1 7.94 6.24 49.5 Piped to DP10
Sump Inlet
9 M 0.59 0.53 8.3 0.31 7.76 2.4 1.4 2.4 700 2.4 4.9 Piped/ Swale flow to DP10
10 N 1.48 0.27 7.6 0.40 7.99 3.2
Total flow at DP 10 10 13.2 0.71 6.43 4.6
1.3
Total Release from site 10 5.9
Flow Off-site south O 0.10 0.08 5.0 0.01 9.06 0.1
Add Pond Release
Pond Release
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
39708.02
Subdivision: 0 Project Name: Lemay Ave. Craft Brewery & Self-Storage
Location: Fort Collins Project No.:
Calculated By: BAB
Checked By: 0
Date: 7/1/15
FINAL
BASIN D.A. Hydrologic Impervious C100 C
2 L S Ti
L S Cv VEL. Tt COMP. T
c TOTAL Urbanized Tc
Tc
ID (AC) Soils Group (%) (FT) (%) (MIN) (FT) (%) (FPS) (MIN) (MIN) LENGTH(FT) (MIN) (MIN)
EX1 1.51 C 2.0 0.51 0.06 30 3.0 7.2 750 0.6 5.0 0.4 32.3 39.5 780.0 14.3 14.3
EX2 6.20 C 12.3 0.54 0.12 350 0.9 34.8 200 1.5 5.0 0.6 5.4 40.2 550.0 13.1 13.1
NOTES:
Ti = (0.395*(1.1 - C
5)*(L)^0.5)/((S)^0.33), S in ft/ft
Tt=L/60V (Velocity From Fig. 501)
Velocity V=Cv*S^0.5, S in ft/ft
Tc Check = 10+L/180
For Urbanized basins a minimum Tc of 5.0 minutes is required.
For non-urbanized basins a minimum Tc of 10.0 minutes is required
Cv
2.5
5
7
10
15
20
(Tt)
Tillage/field
Short pasture and lawns
Nearly bare ground
Grassed waterway
Paved areas and shallow paved swales
DATA
Heavy Meadow
(URBANIZED BASINS)
Type of Land Surface
STANDARD FORM SF-2
EXISTING TIME OF CONCENTRATION
39708.02
SUB-BASIN INITIAL/OVERLAND TRAVEL TIME Tc CHECK
(Ti)
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
Project Name: Lemay Ave. Craft Brewery & Self-Storage
Subdivision: 0 Project No.:
Location: Fort Collins Calculated By: BAB
Design Storm: Checked By: 0
Date: 7/1/15
TRAVEL TIME
STREET
Design Point
Basin ID
Area (Ac)
Runoff Coeff.
Tc (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
Existing 2-yr Flows
EX1 EX1 1.51 0.06 14.3 0.09 1.90 0.2
EX2 6.20 0.12 13.1 0.74 1.98 1.5 14.3 0.83 1.90 1.6
Existing 100-yr Flows
EX1 EX1 1.51 0.51 14.3 0.77 6.63 5.1
EX2 6.20 0.54 13.1 3.35 6.92 23.2 14.3 4.12 6.63 27.3
STANDARD FORM SF-3
EXISTING STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
39708.02
2-Year
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
APPENDIX C
HYDRAULIC CALCULATIONS
Subdivision: 0 Project Name: Lemay Ave. Craft Brewery & Self-Storage
Location: Fort Collins Project No.: 39708.02
Calculated By: BAB
Checked By: 0
Date: 7/1/15
Basin EX1
Basin Area % Impervious
A 0.93 84.7
B 0.85 5.0
C 0.41 95.6
D 0.16 47.5
E 0.39 95.4
F 0.16 58.2
G 0.77 94.7
H 0.68 94.8
I 0.82 5.0
J 0.19 5.0
K 0.32 95.0
L 0.76 5.0
TOTAL 6.44 54.8
WQCV = 6,167 cf
WQCV = 0.14 acre-ft
Pond and Forebay Sizing
WQCV = (0.91I
3
- 1.19I
2
+ 0.78I) * A/12
Forebay release rate = 2% of 100-year in flow
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
Project:
Basin ID:
Design Information (Input): Design Information (Input):
Catchment Drainage Imperviousness Ia = 54.80 percent Catchment Drainage Imperviousness I
a = 54.80 percent
Catchment Drainage Area A = 6.440 acres Catchment Drainage Area A = 6.440 acres
Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C A, B, C, or D
Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc = 14 minutes Time of Concentration of Watershed Tc = 14 minutes
Allowable Unit Release Rate q = 0.04 cfs/acre Allowable Unit Release Rate q = 0.20 cfs/acre
One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P
1 = 2.86 inches
Design Rainfall IDF Formula i = C1* P1
/(C2+Tc
)^C3 Design Rainfall IDF Formula i = C1
* P1/(C2
+Tc)^C3
Coefficient One C1 = 28.50 Coefficient One C
1 = 28.50
Coefficient Two C2 = 10 Coefficient Two C
2 = 10
Coefficient Three C3 = 0.786 Coefficient Three C
3 = 0.786
Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C = 0.37 Runoff Coefficient C = 0.62
Inflow Peak Runoff Qp-in = 4.58 cfs Inflow Peak Runoff Qp-in = 26.77 cfs
Allowable Peak Outflow Rate Qp-out = 0.26 cfs Allowable Peak Outflow Rate Qp-out = 1.29 cfs
Mod. FAA Minor Storage Volume = 8,614 cubic feet Mod. FAA Major Storage Volume = 52,428 cubic feet
Mod. FAA Minor Storage Volume = 0.198 acre-ft Mod. FAA Major Storage Volume = 1.204 acre-ft
5 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet
(input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output)
5 2.78 0.046 1.00 0.26 0.002 0.044 5 9.70 0.267 1.00 1.29 0.009 0.258
10 2.22 0.073 1.00 0.26 0.004 0.069 10 7.74 0.426 1.00 1.29 0.018 0.408
15 1.86 0.092 0.97 0.25 0.005 0.087 15 6.49 0.536 0.97 1.25 0.026 0.510
20 1.61 0.106 0.85 0.22 0.006 0.100 20 5.63 0.619 0.85 1.09 0.030 0.589
25 1.43 0.117 0.78 0.20 0.007 0.110 25 4.98 0.685 0.78 1.00 0.035 0.651
30 1.29 0.127 0.73 0.19 0.008 0.119 30 4.49 0.740 0.73 0.94 0.039 0.701
35 1.17 0.135 0.70 0.18 0.009 0.126 35 4.09 0.787 0.70 0.90 0.043 0.744
40 1.08 0.142 0.68 0.17 0.010 0.132 40 3.77 0.828 0.68 0.87 0.048 0.780
45 1.00 0.148 0.66 0.17 0.010 0.137 45 3.49 0.865 0.66 0.84 0.052 0.812
50 0.94 0.154 0.64 0.16 0.011 0.142 50 3.26 0.897 0.64 0.82 0.057 0.840
55 0.88 0.159 0.63 0.16 0.012 0.146 55 3.06 0.927 0.63 0.81 0.061 0.866
60 0.83 0.163 0.62 0.16 0.013 0.150 60 2.89 0.954 0.62 0.79 0.066 0.888
65 0.78 0.167 0.61 0.16 0.014 0.153 65 2.74 0.979 0.61 0.78 0.070 0.909
70 0.75 0.171 0.60 0.15 0.015 0.157 70 2.60 1.002 0.60 0.77 0.075 0.927
75 0.71 0.175 0.59 0.15 0.016 0.159 75 2.48 1.024 0.59 0.76 0.079 0.945
80 0.68 0.179 0.59 0.15 0.017 0.162 80 2.37 1.044 0.59 0.76 0.083 0.960
85 0.65 0.182 0.58 0.15 0.018 0.164 85 2.27 1.063 0.58 0.75 0.088 0.975
90 0.63 0.185 0.58 0.15 0.018 0.166 90 2.18 1.081 0.58 0.74 0.092 0.989
95 0.60 0.188 0.57 0.15 0.019 0.169 95 2.10 1.098 0.57 0.74 0.097 1.001
100 0.58 0.191 0.57 0.15 0.020 0.170 100 2.03 1.114 0.57 0.73 0.101 1.013
105 0.56 0.193 0.57 0.15 0.021 0.172 105 1.96 1.130 0.57 0.73 0.106 1.024
110 0.54 0.196 0.56 0.15 0.022 0.174 110 1.89 1.145 0.56 0.73 0.110 1.035
115 0.53 0.198 0.56 0.14 0.023 0.175 115 1.83 1.159 0.56 0.72 0.114 1.045
120 0.51 0.201 0.56 0.14 0.024 0.177 120 1.78 1.173 0.56 0.72 0.119 1.054
125 0.49 0.203 0.56 0.14 0.025 0.178 125 1.72 1.186 0.56 0.72 0.123 1.063
130 0.48 0.205 0.55 0.14 0.026 0.180 130 1.68 1.199 0.55 0.71 0.128 1.071
Project:
Basin ID:
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.35, Released January 2015
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Lemay Ave. Craft Brewery & Self Storage
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 50 100 150 200 250 300 350
Volume (acre-feet)
Duration (Minutes)
Inflow and Outflow Volumes vs. Rainfall Duration
Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume
3970802 UD-Detention_v2.35.xls, Modified FAA 6/30/2015, 7:42 PM
APPENDIX D
EXISTING & PROPOSED DRAINAGE PLANS
A Westrian Company
LEMAY AVENUE CRAFT BREWERY & SELF-STORAGE FACILITY
EXISTING CONDITIONS DRAINAGE MAP
Know what's
tc Q5 Q100
C100 C5 (min) (cfs) (cfs)
EX1 1.51 0.51 0.06 14.3 0.2 4.8
EX2 6.20 0.54 0.12 13.1 1.7 21.6
Existing Runoff Summary Table
Basin ID Area (acres)
LEMAY AVENUE
BUCKINGHAM STREET
A Westrian Company
LEMAY AVENUE CRAFT BREWERY & SELF-STORAGE FACILITY
PROPOSED CONDITIONS DRAINAGE MAP
Know what's
tc Q5 Q100
C100 C5 (min) (cfs) (cfs)
A 0.98 0.78 0.65 7.8 1.6 5.4
B 0.85 0.52 0.08 6.4 0.2 0.6
C 0.41 0.90 0.81 5.0 0.9 3.2
D 0.16 0.60 0.32 5.0 0.1 0.5
E 0.39 0.90 0.81 5.0 0.9 3.1
F 0.16 0.63 0.39 5.0 0.2 0.6
G 0.77 0.89 0.80 5.0 1.7 6.0
H 0.68 0.89 0.80 5.7 1.4 5.0
I 0.82 0.52 0.08 11.4 0.1 0.5
J 0.19 0.52 0.08 5.0 0.1 0.2
K 0.32 0.89 0.80 5.0 0.7 2.5
L 0.76 0.52 0.08 9.5 0.1 0.5
M 0.53 0.70 0.53 8.3 0.7 2.3
N 1.48 0.58 0.27 7.6 1.0 3.4
O 0.10 0.52 0.08 5.0 0.03 0.1
Runoff Summary Table
Basin ID Area (acres)
LEMAY AVENUE
BUCKINGHAM STREET
APPENDIX E
LID EXHIBITS
Know what's
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
CityDate Engineer
WaterDate & Wastewater Utility
StormwaterDate Utility
ParksDate & Recreation
TrafficDate Engineer Date
EnvironmentalDate Planner
Date
New Impervious Area 228548 SF
Required Minimum Impervious Area to be Treated 114274 SF
Area of Paver Section #1 17280 SF
Run-on area for Paver Section #1 (up to 3:1 is permited) 21242 SF
Impervious Area Treated by LID Treatment Method #1 (LID SWALE) 43423 SF
Impervious Area Treated by LID Treatment Method #2 (LID BASIN)) 75766 SF
Total Impervious Area Treated 157711 SF
New Pavement Area 68778 SF
Required Minimum Area of Porous Pavement 17195 SF
Area of Paver Section #1 17280 SF
Total Porous Pavement Area 17280 SF
Actual % of Porous Pavement Provided 25.1 %
50% On-Site Treatment by LID Requirement
25% Porous Pavement Requirement
LID TREATED
AREA #1
LID TREATED
PAVER AREA #2
SECTION
#1
RUN-ON
AREA #1
LID SWALE #1
LID SWALE #1
LID BASIN #2
LID BASIN #2
LID TREATED
AREA #1
LEMAY AVENUE
BUCKINGHAM STREET
LID TREATED
AREA #2
135 0.47 0.207 0.55 0.14 0.026 0.181 135 1.63 1.211 0.55 0.71 0.132 1.079
140 0.46 0.209 0.55 0.14 0.027 0.182 140 1.59 1.223 0.55 0.71 0.137 1.086
145 0.44 0.211 0.55 0.14 0.028 0.183 145 1.55 1.234 0.55 0.71 0.141 1.093
150 0.43 0.213 0.55 0.14 0.029 0.184 150 1.51 1.245 0.55 0.70 0.145 1.100
155 0.42 0.215 0.55 0.14 0.030 0.185 155 1.47 1.256 0.55 0.70 0.150 1.106
160 0.41 0.217 0.54 0.14 0.031 0.186 160 1.44 1.266 0.54 0.70 0.154 1.112
165 0.40 0.218 0.54 0.14 0.032 0.187 165 1.41 1.276 0.54 0.70 0.159 1.118
170 0.39 0.220 0.54 0.14 0.033 0.187 170 1.38 1.286 0.54 0.70 0.163 1.123
175 0.39 0.222 0.54 0.14 0.034 0.188 175 1.35 1.296 0.54 0.70 0.168 1.128
180 0.38 0.223 0.54 0.14 0.034 0.189 180 1.32 1.305 0.54 0.69 0.172 1.133
185 0.37 0.225 0.54 0.14 0.035 0.190 185 1.29 1.314 0.54 0.69 0.177 1.138
190 0.36 0.226 0.54 0.14 0.036 0.190 190 1.27 1.323 0.54 0.69 0.181 1.142
195 0.36 0.228 0.54 0.14 0.037 0.191 195 1.24 1.332 0.54 0.69 0.185 1.147
200 0.35 0.229 0.54 0.14 0.038 0.191 200 1.22 1.341 0.54 0.69 0.190 1.151
205 0.34 0.231 0.53 0.14 0.039 0.192 205 1.20 1.349 0.53 0.69 0.194 1.155
210 0.34 0.232 0.53 0.14 0.040 0.192 210 1.18 1.357 0.53 0.69 0.199 1.158
215 0.33 0.234 0.53 0.14 0.041 0.193 215 1.15 1.365 0.53 0.69 0.203 1.162
220 0.33 0.235 0.53 0.14 0.042 0.193 220 1.13 1.373 0.53 0.68 0.208 1.165
225 0.32 0.236 0.53 0.14 0.042 0.194 225 1.12 1.381 0.53 0.68 0.212 1.169
230 0.31 0.238 0.53 0.14 0.043 0.194 230 1.10 1.388 0.53 0.68 0.216 1.172
235 0.31 0.239 0.53 0.14 0.044 0.195 235 1.08 1.396 0.53 0.68 0.221 1.175
240 0.30 0.240 0.53 0.14 0.045 0.195 240 1.06 1.403 0.53 0.68 0.225 1.177
245 0.30 0.241 0.53 0.14 0.046 0.195 245 1.05 1.410 0.53 0.68 0.230 1.180
250 0.30 0.242 0.53 0.14 0.047 0.196 250 1.03 1.417 0.53 0.68 0.234 1.183
255 0.29 0.244 0.53 0.14 0.048 0.196 255 1.02 1.424 0.53 0.68 0.239 1.185
260 0.29 0.245 0.53 0.14 0.049 0.196 260 1.00 1.430 0.53 0.68 0.243 1.187
265 0.28 0.246 0.53 0.14 0.049 0.196 265 0.99 1.437 0.53 0.68 0.247 1.190
270 0.28 0.247 0.53 0.14 0.050 0.197 270 0.97 1.444 0.53 0.68 0.252 1.192
275 0.27 0.248 0.53 0.14 0.051 0.197 275 0.96 1.450 0.53 0.68 0.256 1.194
280 0.27 0.249 0.53 0.14 0.052 0.197 280 0.95 1.456 0.53 0.68 0.261 1.196
285 0.27 0.250 0.52 0.14 0.053 0.197 285 0.93 1.463 0.52 0.68 0.265 1.197
290 0.26 0.251 0.52 0.14 0.054 0.197 290 0.92 1.469 0.52 0.68 0.270 1.199
295 0.26 0.252 0.52 0.13 0.055 0.198 295 0.91 1.475 0.52 0.67 0.274 1.201
300 0.26 0.253 0.52 0.13 0.056 0.198 300 0.90 1.481 0.52 0.67 0.279 1.202
305 0.25 0.254 0.52 0.13 0.057 0.198 305 0.89 1.487 0.52 0.67 0.283 1.204
Mod. FAA Minor Storage Volume (cubic ft.) = 8,614 Mod. FAA Major Storage Volume (cubic ft.) = 52,428
Mod. FAA Minor Storage Volume (acre-ft.) = 0.1978 Mod. FAA Major Storage Volume (acre-ft.) = 1.2036
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.35, Released January 2015
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Lemay Ave. Craft Brewery & Self Storage
3970802 UD-Detention_v2.35.xls, Modified FAA 6/30/2015, 7:42 PM
100-Year
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015
39708.02
DIRECT RUNOFF TOTAL RUNOFF STREET/SWALE PIPE
X:\3970000.all\3970802\Excel\Drainage\3970802Drainage_Calcs.xls Page 1 of 1 6/30/2015