HomeMy WebLinkAboutDrainage Reports - 06/16/2016Final Drainage Report
For
Houska Automotive Repair
Fort Collins, Colorado
Prepared for:
D and N Houska Family, LLC
c/o Dennis Houska
899 Riverside Drive
Fort Collins, Colorado
Prepared by:
PfPEX
ENGINEERING
908 Laporte Avenue
Fort Collins, CO 80521
(970) 219-2834
f port Collins Appgoyed Plans
(f (o - ua,
Final Drainage Report
For
Houska Automotive Rep
91
Fort Collins, Colorado
Prepared for:
D and N. Houska Family, LLC
c/o Dennis Houska
899 Riverside Drive
Fort Collins, Colorado
Prepared by:
OP EX
ENGINEERING
908 Laporte Avenue
Fort Collins, CO 80521
(970) 219-2834
May 11, 2016
ENGINEER'S CERTIFICATION
I hereby state that this Drainage Report for the Houska Automotive Repair project was
prepared by me or under my direct supervision for the owners' thereof and meets or
exceeds the criteria in the City of Fort Collins Storm Drainage Design Criteria and
Construction Standards.
Stacy J. Gowing
Registered Professional Engineer
State of Colorado No: 34290
O�ppO LI�F�
Ov, joHN G J'
G •V-1 O� FO
TABLE OF CONTENTS
I.
INTRODUCTION..................................................................................................... 1
II.
GENERAL LOCATION AND DESCRIPTION......................................................... 1
A.
Property Location.................................................................................................... I
B.
Description of Property ..........................................................................................2
C.
Developed Conditions...........................................................................................2
Ill.
DRAINAGE BASINS AND SU13-BASINS................................................................ 3
A.
Major Basin Description.............................................................................................3
IV.
DRAINAGE DESIGN CRITERIA..............................................................................3
A.
Four Step Process.........................................................................................................3
B.
Development Criteria Reference and Constraints...............................................4
C.
Hydrological and Hydraulic Criteria........................................................................5
V.
DRAINAGE FACILITY DESIGN............................................................................... 5
A.
General Concept..........................................................................................................5
B.
Specific Details - Detention.......................................................................................5
C.
Speck Details - Inlets and Storm Sewer...............................................................5
D.
Specific Details - Stormwater Quality ..................................................................... b
VI.
SEDIMENT/EROSION CONTROL......................................................•...................8
VII.
CONCLUSIONS.......................................................................................................8
A.
Compliance with standards......................................................................................8
B.
Drainage Concept........................................................................................................8
VIII.
REFERENCES........................................................................................................... 9
IX.
APENDICES............................................................................................................. 9
I. INTRODUCTION
This report presents the pertinent data, methods, assumptions, and references
used in analyzing and preparing the final drainage and water quality design for
the Houska Automotive Repair project (the "project").
II. GENERAL LOCATION AND DESCRIPTION
A. Property Location
The project is located on the south side of Riverside Avenue, just southeast
of the existing Houska Automotive site at 899 Riverside Avenue, and is
intended to function as an extension of the existing Houska Automotive use.
The site is an infill site completely surrounded by existing development.
� s
f b1::CJr'ry ',! is E Muibriry St 14
SITE
Vicinity Map, NTS
B. Description of Property
1. The project site is an undeveloped parcel located between the existing
Houska Automotive site and the private drive aisle into the Albertson's
shopping center along the south side of Riverside Avenue.
2. The project site is currently undeveloped; and is 2.28 acres in size.
3. The site is currently covered with weeds, native and volunteer
vegetation; with an existing vegetative cover of approximately 60%.
4. There is no significant off -site runoff entering the site, and the site drains
overland to the south curb and gutter of Riverside Avenue.
S. Existing surface soils, according to the National Resources Conservation
Service, consist of Satanta Loam. The soil type is classified as hydrologic
soil group B.
6. Existing soils underlying the proposed work are classed as clayey sand
(SC), as identified by a soils investigation prepared by Terracon.
7. There are no irrigation ditches or stormwater conveyance systems on
the property.
8. Portions of the project site are located within the City regulatory Old
Town 100 year floodplain. The property is located outside the City
regulatory Old Town 100 year floodway, however floodway is located
inside the Riverside right -of --way adjacent to the property, as shown on
the City's online floodplain mapping.
C. Developed Conditions
The proposed project consists of 3 buildings to support additional
automotive repair uses, such as tire maintenance and general
automotive repair. None of these buildings are located within the FEMA
or City of Fort Collins Old Town Masterplan 100-year floodplain or
floodway.
2. The project includes the relocation of the existing Houska access to
provide a single access for both the existing and proposed uses, which
necessitates the relocation of two existing inlets on Riverside. The
project also includes private drive aisles, parking, and associated
hardscape and landscaping.
3. None of the proposed buildings are located within the City regulatory
Old Town 100 year floodplain or floodway.
2
4. The improvements proposed within the floodplain include a driveway,
sidewalks, drainage improvements and miscellaneous site improvements.
5. The project is currently envisioned to be built in two phases. Phase one
includes building one, all the public infrastructure and a temporary
parking area. Phase two includes buildings two and three. The
drainage design for phase one encompasses all phases of the project.
b. The developed site will drain from south to north via overland flow and
swales to a proposed regional water quality pond located at the
northwest corner of the site.
III. DRAINAGE BASINS AND SUB -BASINS
A. Major Basin Description
1. The project site lies within the Old Town drainage basin.
2. The project site currently drains overland from south to north, exiting the
site along the western and northern lot lines. Runoff is received by the
existing storm drainage system in Riverside Avenue and the Locust Street
Outfall.
IV. DRAINAGE DESIGN CRITERIA
A. Four Step Process
The stormwater management strategy for the project is the "Four Step
Process", with the goal of minimizing adverse impacts of urbanization on
receiving waters. The following is a description of the steps employed to
achieve this goal.
1. Employ Runoff Reduction Practices
a. Two bioretention ponds are proposed for the project site. These
will collect much of the runoff from the developed areas.
Infiltration will be encouraged and directly connected impervious
areas will be minimized. This design, in combination with the
highly permeable underlying soils (clayey sands) results in
infiltration opportunities that do not currently exist on site.
b. The percentage of proposed impervious cover is 74%. This
impervious cover rate is less than allowed, and less than typical for
intensive commercial development.
3
c. The vegetated areas will be heavily landscaped, in contrast to the
sparse existing vegetation currently existing, allowing for
decreased effective runoff coefficients.
2. Implement BMP's That Provide a Water Capture Volume (WOCV) with
Slow Release.
a. The steps described above will provide attenuation for peak rates
of runoff.
b. Additionally, runoff attenuation and water quality treatment is
provided by a regional extended detention basin to be located on
the development site. This basin receives a large majority of runoff
from the site prior to exiting the site.
3. Stabilize Drainageways.
a. There are no drainageways or conveyances within the project site,
and the site drains directly to existing storm sewer systems.
However, off -site benefit is achieved through the use of
stormwater extended detention for a site that currently has none.
By providing these improvements, discharges are attenuated and
treated for water quality.
b. Stormwater impact fees and month stormwater utility fees will be
paid by this development. This additional revenue will contribute
to the overall City programs to stabilize drainageways throughout
the city.
4. Implement Site Specific and Other Source Control BMP's.
a. The combination of intensive vegetative establishment and water
quality treatment through Low Impact Development (LID)
techniques will allow for a reduction in particulates and adhered
pollutants as compared the existing condition.
B. Development Criteria Reference and Constraints
1. As previously discussed, historic drainage patterns are maintained with
the proposed project.
2. As an infill project, existing topography along the boundary is
maintained.
l 4
C. Hydrological and Hydraulic Criteria
I. Hydrologic and hydraulic criteria is as per the City of Fort Collins Storm
Drainage and Design Criteria and Construction Standards.
2. Analyses are performed using City of Fort Collins spreadsheets and the
methodologies presented in Urban Storm Drainage Criteria Manual
Volumes 1. 2 and 3: Urban Drainage and Flood Control District, Denver,
Colorado.
V. DRAINAGE FACILITY DESIGN
A. General Concept
The general direction of proposed storm water flow is from south to north.
Storm water runoff from the site is directed towards a proposed regional
water quality pond located on the northwest corner of the site. This pond
connects to the Locust Street Outfall, which runs south -to -north
immediately west of the site.
2. Existing drainage patterns are maintained by the project. Runoff from the
site in both conditions is collected by adjacent storm sewer systems.
3. Water quality treatment is provided with extended detention (through a
regional water quality pond located on site) and Low Impact Development
techniques as discussed below.
B. Specific Details - Detention
The project is located near at the bottom of the Old Town basin, adjacent
to the Locust Street Outfall. This regional outfall consists of a 108-inch
pipe directly connected to the Poudre River. Because of the location of the
site, detention on site would be counter -productive since it would only
serve to delay the site developed peak runoff to more closely coincide with
the peak runoff from the overall drainage basin. Stormwater is proposed
to runoff un-detained, allowing the runoff peak to flow into and through
the outfall pipe before the larger peak from the overall basin arrives.
2. City stormwater staff, as part of the overall cooperative effort on the
regional water quality pond, has modified the hydrologic modeling in the
Old Town Masterplan and verified that detention is not required, nor
advised, for the development. Detention is not included in the project.
C. Specific Details - Inlets and Storm Sewer
1. Two existing storm drain inlets are located under the proposed driveway
and must be relocated. It is expected that these inlets are adequately
E
sized, so identical inlets are being proposed for areas just outside of the
proposed driveway. Both inlets are relocated in such a way as to ensure
they continue to drain to the same receiving drainage system.
a. The 5' Type R curb inlet on the eastern side of the proposed
driveway is moved approximately 17' towards the east along
Riverside. To accomplish this, the existing pipe to the existing inlet
is extended to a new manhole behind the curb/gutter. The new
single curb inlet is connected to the new manhole.
b. The 15' Type R curb inlet on the western side of the driveway is
moved approximately 25' towards the west along Riverside
Avenue. This inlet drains to a new manhole placed on the existing
receiving storm pipe from the existing inlet. The existing and
proposed inlets drain to the storm vault along the Locust Street
Outfall.
2. Four storm drain pipes are proposed as part of the regional water quality
pond.
a. Two 24-inch storm drain pipes (storm pipes 6 and 7) are proposed
along the north boundary as part of the regional water quality
pond. Storm pipe 7 terminates at an area drain at a point near the
eastern boundary, and will serve to convey off -site discharges to the
proposed regional pond. The size and general locations of these
pipes are as per direction from City stormwater staff.
b. A 24-inch storm drain pipe (storm pipe 5), storm manhole and a 30-
inch storm drain pipe (storm drain 4) are proposed to connect the
outfall structure for the regional water quality pond to the existing
vault located on the Locust Street Outfall.
D. Specific Details — Stormwater Ouality
The City of Fort Collins, in cooperation with the developer, intends to
construct a regional water quality pond within the development site.
This pond will provide extended detention for a large regional drainage
area, and will also provide treatment for the project site. The regional
water quality pond has a storage volume of approximately 0.66 acre-feet
at elevation 4961.0'.
a. The City will acquire easements for the regional water quality pond
and conveyance elements as needed for the regional project.
b. Unfortunately, an area for Low Impact Development (LID)
treatment needed for the development project will be lost to
accommodate the regional project. In particular, the regional
conveyance is located within areas needed for LID treatment for
6
buildings 1 and 2. Because of this, the site's LID requirement of
75% treatment is reduced by 0.64 acres, which is the amount of LID
treatment originally proposed by the developer within the lost area.
The LID requirement for the development is reduced to 0.62 acres
of treated drainage area (which is 1.68 acres x 75%- 0.64 acres).
c. The City's regional water quality pond will also provide standard
water quality treatment for the development site through extended
detention.
d. The City will pay for the design, construction and other costs
associated with the regional water quality pond. These costs will be
offset by benefits to the development project as subsequently
negotiated.
e. An emergency spillway path is provided for the un-detained 100-
year flow through the water quality pond. This path is towards
Riverside Avenue, where the proposed elevations at the back of the
sidewalk are 4961.42. This area acts as a spillway with a level crest
length of 80 feet and a depth of 0.20 feet. The shallow depth
combined with the concrete sidewalk, curb/gutter and paving
results in a stable overflow path for emergency flows.
2. Low Impact Development (LID) water quality treatment is required for
75% of the proposed impervious area, minus 0.64 acres as previously
discussed. The modified LID water quality treatment area is 0.62 acres.
Two LID techniques are used to accomplish this, as follows:
a. Rain Garden Bioretention Pond 1 is located in the southwestern
portion of the site. This pond is located in an area that was
previously constructed as a bioswale for the existing development
in the Houska South development. This existing bioswale will be
redesigned and reconstructed as a rain garden and bioretention
pond. The new pond will handle 1.00 acres of Houska South
(identified as drainage basin 5 in the drainage report for that
project and drainage basin Q 1 B in this report) and 0.41 acres
(identified as basin OIA in this report) of new development. The
total area treated is 1.41 acres.
b. Rain Garden Bioretention Pond 2 is located in the northwestern
portion of the site. This pond receives runoff from the central drive
aisle and treats 0.29 acres.
c. The total LID treated drainage area is 0.70 acres, which is higher
than the required 0.62 acres as discussed above. The net LID
treatment percentage for the site is 79.7%, once the credit for the
lost LID treatment opportunity is accounted for.
7
3. The sizing calculations and an LID .summary are included in the
appendix.
VI. SEDIMENT/EROSION CONTROL
Temporary erosion control measures will be implemented with this project, as
detailed under a separate report entitled "Erosion and Sediment Control
Report", dated 3/30/2016, prepared by Apex Engineering. Please see that
document for more information on the temporary best management practices
proposed to control sediment and erosion during construction.
VII. CONCLUSIONS
A. Compliance with standards
1. All drainage design conforms to the criteria and requirements of City of
Fort Collins Storm Drainage Design Criteria and Construction Standards.
2. Proposed drainage improvements conform to the concepts and
recommendations of the Old Town Basin master plan.
B. Drainage Concept
1. The proposed drainage plan concept for the project will be effective for
the control of stormwater runoff and water quality for the proposed site
and conforms to City of Fort Collins standards.
VIII. REFERENCES
City of Fort Collins Storm Drainage and Design Criteria and Construction
Standards.
2. Old Town Drainage Master Plan: Anderson Consulting, July 15, 2003.
3. Urban Storm Drainage Criteria Manual Volume 1-3; Urban Drainage and
Flood Control District, Denver, Colorado, April 2008.
4. Geotechnical Engineering Report, Houska Large Truck Facility Terracon
(project number 20155048), dated 1 1/1 1/2015.
5. Final Drainage and Erosion Control Report, Houska Automotive Auto Parts
Warehouse; North Star Design, April 9, 2012.
IX. APENDICES
Appendix I - Hydrologic Calculations
■ Peak Discharge Calculations
Appendix If - Hydraulic and Water Ouality Calculations
■ LID Stormwater Management Summary Worksheet
■ 'Bioretention Sizing Worksheets
■ Outfall Pipe Sizing Worksheet
■ Emergency Spillway Sizing Report
Appendix III - Mapping and Plans
■ Annotated Flood Insurance Rate Map
■ Drainage Exhibit (24"x36")
Appendix I - Hydrology
d
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12
Appendix II - Hydraulics and Water Quality
Calculations
13
LID S tommater Management Summary
Houska Automtive Repar
5/112016
EAwting Site Data
Net Site Area =
Proposed Site Data:
Total Proposed Impervious Area =
Total Proposed Imperviousness =
2.28 acre
1.68 acre
73.7%
LID Treatment Area Required =
1.26 acre (75% of proposed imp. area)
LID credit for Regional WOL Pond =
0.64 acre
Resulting LID Required =
0.62 acre
LID Treatment Area Provided =
0.70 acre (Q1A+Q2)
Percent LID Treatment Provided
79 7::%
LID Treatment Basin Summary
Drainage
Drainage
Bottom
Top
Volume
Basin
Area Treated
LID Area
Area
Depth Provided
ID
(acres)
Type (SF)
(SF)
(inch) (CF)
O1A . 0.41 Bioretention 1 1388.0 2680.0 8.0 1356.0
02 0.29 Bioretention 2 281.0 600.0 12.0 440.5
0.700
14
�. Design Procedure Form: Extended Detention Basin (EDB)
1 Sheet 1 of 4
Designer.
BIG
Company:
Apex Engineering
Date:
May it, 2016
Project:
Houska- City Regional WQL Pond
Location:
Fart Collins. CO
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, I4
4 = 80.0
B) Tributary Area's Imperviousness Ratio (i = 1.1100)
1 = 0.800
C) Contributing Watershed Area
Area = 20.200 all
D) For Watersheds Outside of the Denver Region, Depth of Average
tlr = in
Runoff Producing Stonn
Choose One
E) Design Concept
(Select EURV when also designing for flood control)
Water Quality, capture Vdume (vVQLI�
06¢ess Urban Runoff Volume (Et1BV)
F) Design Volume (1.2 WQCV) Based on 40 hour Drain Time
Veesm. 0.80 ac-ft
(Ve,yre = (1.0' (D.91 -1'- 1.19 - iv + 0.78' t) / 12' Area' 1.2)
G) For Watersheds Outside of the Denver Region,
VoEslneorRER- ao-ft
Water Quality Capture Volume (WQCV) Design Volume
(Vwavonen = (do'(Voaaoe/0.43))
H) User Input of Water Quality Capture Volume(WQCV) Design Volume
Vuesoeu AE ac-ft
(Only a a different WQCV Design Volume is desired)
Choose One
1) Predominant Watershed NRCS Sail Group
0A
OB
OC/D
2. Basin Shape: Length to Width Relic
L : W = 2.0 .1
(A basin length to width ratio of at least 2:1 will improve TSS reduction.)
3. Basin Side Slopes
A) Basin Maximum Side Slopes
Z = 4.0D ft I It
(Horizontal distance per unit vertical, 4:1 a flafter preferred)
4 Intel
A) Describe means of prodding energy dissipation at concentrated
inflow locations.
Huuska Rain Garden 1 - UD-BMP V3.03.tdsm, EDB 5118/2016, 5:33 PM
i C
Design Procedure Form: Extended Detention Basin (EDB)
Sheet 2 of 4
Designer: BG
Company: Apex Engineenng
Date. May 11, 2(16
Project: Housks - City Regional WQL Pond
Location. For Collins, CO
5. Forebay
A) Minimum Forebay Volume
(Vr'.= 3% of the WQCV)
B) Actual Forebay Volume
C) Forebey, Depth
(DF = 18 inch maximum)
D) Forebay, Discharge
i) Undetained 100-year Peak Discharge
a) Forebay Discharge Design Flow
(OF = 0.02 • Q,aa)
E) Forebay, Discharge Design
Vvme = 0.017 ac-fl
VF ` 0.020 ac-ft
0,= In
Q,00 = CIS
Qr = cis
Choose One
Oeerm With Pipe (flow too small for bens w! pipe)
�Wa11 wth ReVL Notch
OWall with V-Noti Wert
G) Rectangular Notch Width
Calculated W e = 4DN/01 in
PROVIDE A CONSISTENT LONGITUDINAL
6. Trickle Channel
Choose One
SLOPE FROM FOREBAY TO MICROPOOL
OConcrete
WITH NO MEANDERING. RIPRAP AND
A) Type of Trickle Channel
F) Slope of Trickle Channel
Soft Bottom
S = 0.0010 fl/ ft
SOIL RIPRAP LINED CHANNELS ARE
NOT RECOMMENDED.
MINIMUM DEPTH OF 1.5 FEET
7. Mirropool and Outlet Structure
A) Depth of Mcropool (2.5-fed minimum)
B) Surface Area of Miv0000l (10 ft minimum)
C) Outlet Type
D) Depth of Design Volume (EURV or 1.2 W QCV) Based on the Design
Concept Chosen Under 1.E.
E) Volume to Drain Our prescribed Time
F) Drain Time
(Mot To for W QCV= 40 hours; Max To for EURV= 72 hours)
G) Recommended Maximum Outlet Area per Row, (k)
H) Onflce Dimensions:
1) Clrcudar Orifice Diameter or
Du- ft
Au= sgIf
Choo e O e
OOnf¢e Plate
Oodw (DP.mbe):
H = 4.70 feet
WQCV= 0.553 ac-ft
To = 40 hours
A. = 1.51 square inches
D„mv = 1-3/0 inches
I) Number of Columns n 1 number
J) Actual Design Outlet Area per Row (A„) Aa = 1.48 square inches
K) Number of Rows (1 ^� = 14 number
L) Total Outlet Area (Ae) A. ` 20.9 square inches
_ Houska Rain Garden 1 - UD-BMP_Y3.03.xlsm, EDB 511812016, 5:33 PM
Ic
Design Procedure Form: Extended Detention Basin (EDB)
Sheet 3 of 4
Designer. BG
Company: Apex 11ingineering
C Date: May 11, 2016
Project: Houska -City Regional WQL Pond
Location: Fort Collins, CO
8. Initial Surcharge Volume
A) Depth of Initial Surcharge Volume
D,s = in
(Mmmum recommended depth is 4 inches)
B) Minimum Initial Surcharge Volume
VIs = cu It
(Minimum volume of 0.3% of the WQCV)
C) Initial Surcharge Provided Abuve Micropcol
V,, cu ft
9. Trash Rack
Choose One
OOrcular (up to 1-114" diameter)
A) Type of Water Quality Orifice Used
Circular (greater than 1-1/4" diameter) OR Rectangular (2" high)
BI Water Quality Screen Open Area: q = Ant' 38.5"(s-0"s'0)
q _ 707 square inches
L Dose One
SS. Well Screen with 60% Open Area-
O(Xher (Describe):
D) For Circular Opening (greater than 1-114" diameter)
OR 2" High Rectangular Opening (See Fact Sheet T-12):
i) Width of Water Quality Screen Opening(W..,n)
W„od:ns= 1t
II) Height of Water Quality Screen(Hm)
Hra= }(
lii) Type of Screen, Describe H "Other"
Choose one
OAluminum Amim-Memo SR Senes (or equal)
OOthv (Describe):
v) Cross -bar Spacing
Inches
N) Minimum Bearing Bar Size
C_
`- Houska Rain Garden 1 - UD-BMP_v3.03.1dsm, EDB
5/18/2016, 5:33 PM
11 Design Procedure Form: Extended Detention Basin (EDB) 11
Designer:
BG
Company:
Apex Engineering
Date:
May 11. 2016
Project:
Hcuska - City Regional WOL Pond
Location:
Fort Collins. CO
10. Overflow Embankment
A) Descnbe embankment protection for 100-year and greater overtopping.
B) Slope of Overflow Embankment
(Honzontal distance per unit Vertmal. 4:1 or flatter prefenedl
2s' S0.00 ft i 0
11. Vegetation
Choose One
Irrigated
AVOID PLACING IRRIGATION HEADS
CINot Irgated IN THE BOTTOM OF THE BASIN
12. Access
A) Descnbe Sediment Removal Procedures-
Nolns
I� Houska Rain Garden 1 - UD-BMP_V3.03.1dsm, EDB 511 B/2016, 5:33 PM
Design Procedure Form: Rain Garden (RG) 1
Sheet 1 of 2
Designer: BG
Company:
Apex Engineering
Date:
Project:
May 11, 2016
Houska Rain Garden 1 (Basin 01A and Q1 B)
Location:
Fort Collins, CO
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ir
I, =
80.0
%
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = 1.1100)
1=
0.800
c) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time
WQCV =
026
watershed inches
(WQCV=0.8-(0.91-12-1.19'i2-0.78'i)
D) Contribuhng Watershed Area (including rain garden area)
Area =
61,420
sq ft
E) Water Quality Capture Volume (WQCV) Design Volume
VWom=
1,344
tuft
Vol = (WQCV / 12) - Area
F) For Watersheds Outside of the Denver Region, Depth of
ds =
in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region,
VWonv ova =
ou ft
Water Quality capture volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume
VWocv reEn=
ouft
(Only d a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum)
DWuw=
8
in
B) Rain Garden Side Slopes (Z = 4 min., honz dist par unit vertical)
Z =
4.00
ft / ft
(Use'9' if rain garden has vertical walls)
C) Mlmimum Flat Surface Area
Au,,, =
896
sq ft
D) Actual Flat Surface Area
Ae,,a =
1368
sq ft
E) Anse at Design Depth Crop Surface Area)
Ara, =
2680
sq ft
F) Rain Garden Total Volume
Vr=
1,356
cu ft
(V = ((A,. - Aanm) / 2)' Depth)
3. Growing Media
Choose One
018' Rain Garden Growing Media
Other (Explain):
4. Underdran System
raeos�
YES
A) Are underdreins provided?
ENO
B) Undadrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage
y =
NIA
ft
Volume to the Center of the Onfice
ii) Volume to Drain in 12 Hours
Vol,, =
NIA
cu ft
iii) Orifice Diameter, 3/e' Minimum
Dr, =
NIA
in
Houska Rain Garden 1 - UD-BMP_v3.03.Asm, RG 5/18/2016, 5:14 PM
Design Procedure Form: Rain Garden (RG)
Sheet 2 of 2
Designer: BG
Company: Apex Engineering
Date: May 11, 2016
Project Houska Rain Garden 1 (Basin 01A and 01 B)
Location: Fort Collins, CO
S. Impermeable Geomembrane Liner and Geotextile Separator fabric
Choose Dee
YES
A) Is an impermeable liner provided due to prmamdy
ONO
of structures or groundwater contamination?
6. Inlet / Outlet Control
Chaase One
�Shee[ How- No Energy Dissipation Required
I
A) Inlet Control
OConcentreted Flow- Energy Dissipation Provided
'. 'Jega4ation
Choose One
OSeed (Plan for frequent weed control)
SPlanfings
OSand Grown or Other Hlgh Inflhratbn Sod
F. Irrigation
rQho.se One
OYES
A) Will the rain garden be imgaled?
ENO
Notes:
Houska Rain Garden 1 - UD-BMP_v3.03.)dsm, RG
5/18/2016, 5:14 PM
1•
Design Procedure Form: Rain Garden (RG)
Sheet 1 of 2 11
Designer: BG
Company:
Apex Engineering
Date:
May 11, 2016
Project:
Houska Rain Garden 2 (Basin Q2)
Location:
Fort Collins, CO
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, I,
I„ =
100.0
%
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Aiea's Imperviousness Ratio (i = 1,11 GO)
i =
1.000
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time
WQCV =
0.40
watershed inches
(WQCV= 0.8' (0.91' 1'- 1.19' ia+ 0.78' i1
D) Contributing Watershed Area (including rain garden area)
Area =
12.600
sq ft
E) Water Quality Capture Volume (WQCV) Design Volume
Vwucv=
420
cu ft
Vol = (WQCV / 12) ' Area
Fj For Watersheds Outside of the Denver Region, Depth of
d,; =
in
Average Runoff Producing Storm
G) For W atersheds Outside of the Delver Region,
Vwo :v U, R =
cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume
Vw0c, DER =
cu ft
(Only if a drflerent WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12tinch maximum)
Dwcw=
12
in
B) Rain Garden Side Slopes (Z = 4 min., hodz. dist per unit vertical)
Z =
4.00
ft / ft
(Use "0' d rain garden has vertical walls)
C) Mimimum Flat Surface Area
Aug =
280
sq ft
D) Actual Flat Surface Area
A,,n,,,y =
281
sq ft
E) Area at Design Depth (Top Surface Area)
AT,,,, =
600
sq ft
F) Ran Garden Total Volume
VT=
441
cu 1t
(Vr ((A,,., - A�,_[) ) 2)' Depth)
3. Growing Media
1r Choose One
1018" Rain Garden Growing Media
Other (Explain):
4. Underdrain System
Chopsg One
A) Are undesdrains provided?
*NO
f/N0
B) Underdran system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage
y=
N/A
ft
Volume to the Center of the Orifice
if) Volume to Dram in 12 Hours
Vol,, =
NIA
cu ft
ili) Orifice Diameter, 319" Minimum
Do=
N/A
in
Hlluska Rain Garden 2 - UD-BMP v3.03.xlsm, RG 511 af2016, 5:15 PM
Design Procedure Form: Rain Garden (RG)
Sheet 2 of 2
Designer: BG
Company: Apex Engineering
Date: May 11, 2016
Project: Houska Rain Garden 2 (Basin 02)
Location: Fort Collins, CO
5. Impemreable Geornem brans Liner and Geotextile Separator Fabric
Choose Oqne
YES
A) Is an impermeable liner provided due to proximity
ONO
of structures or groundwater contamination?
5. Inlet I Outlet Control
Choose One
�$heet flow- No Energy Dsvpattan Required
A) Inlet Control
OConcentrnted Flow- Energy Dissipation Provided
7, Vegelnnnn
e One
Oe(Plan for Frequent weed control)
[,C;h,—ed
PWnbngs
OSerld Grown or Other High Infiltration Sod
8. Irrigation
�S
A) Will the rain garden be irrigated?
ENO
Notes:
Htluska Rain Garden 2 - UD-BMP v3.03.xlsm, RG
511812016, 5:15 Phl
CIRCULAR CONDUIT FLOW (Normal & Critical Depth Computation)
Project: Houska
Pipe ID: Calculation for 100-year flow through regional pond outfall pipe
f Tc
v
r
1 �
How and
>l
V
Invert Slope
Manning's n-value
Diameter
ign discharge
riow area
now wetted perimeter
Central Angle
flow capacity
Central Angle (0<Theta<3.14)
i area
width
ted perimeter
r depth
r velocity
Full Flow
Depth Froude Number
Central Angle (0<Theta-c<3.14)
al flow area
al top width
cal flow depth
al flow velocity
al Depth Froude Number
So = 0.0132 ft/ft
n = 0.0130
D = 24.00 inches
Q = 16.70 cfs
Af=
3.14
sgft
Pf =
6.28
ft
Theta =
3.14
radians
Qf =
26.06
cfs
Theta
An
Tn
Pn
Yn
Vn
Qn
Flow
Fr
Theta-c =radians
Ac =
2.48
sq ft
Tc=
1.76
ft
Yc =
1.47
ft
Vc =
6.73
fps
t•r� =
1.
UD-Culvert_v2.00c - HOUSKA pond outfall pipe.xls, Pipe
5/18/2016, 5:42 PM
Project Data
Project Title:
Designer.
Project Date:
Project Units:
Notes:
Oydraulic Analysis Report
Houska - Weir Calculations
Monday, November 23, 2015
U.S. Customary Units
Weir Analysis: Emergency Spillway
Notes:
Input Parameters
Weir Type: Rectangular
Coefficient: 3.1000
Length. 80.0000 ft
Flow: 16.8000 cfs
Result Parameters
Head: 0.1662 ft
Weir Analysis: WQL Outlet Structure
Notes:
Input Parameters
Weir Type: Rectangular
Coefficient: 3.1000
Length: 20.0000 ft
Flow: 16.8000 cfs
Result Parameters
Head: 0.4187 ft
22
•
Appendix III - Mapping and flans
23
24
\A
.(\\\ CITY HIGH \
`RISK 100-YEAR \\ A
ROODPLAIN ,\ A\\\� , f
? A \
r /
/ A
I \
�\ \ ` NNI \
Joy
I 1 `•F / / \ C
r
I EAST
A AUTO40TVE`
a> I \
RAIN GARDEN
BIORETENIION POND 2
BOTTOM ELEV - 4060.55
BOTTOM AREA - 281 SF -
DEPTH - 12'
VOLUME - "I CF
ma SEE DETAIL D-53
a
__ \
\
\
`A4-
LOT 1
HOUSKA SOUTH
SURD ASIOH I wu___ _
HOUSKA Or LED
699 RIVERSIDE AVENUE
RAISE RIM OF EXIST
INLET TO ELEV 4961.67
TO SERVE AS RAIN
GARDEN OVERFLOW INTO
EXIST HOPE STORM PIPE
BASIN 5
AREA - 1.00 AC
Ross - 0,54
RCNtpp = 0.68
IMPERNWS COVER = 76% .
AS PER UTUTY PLANS FOR
'HOUSKA AUTOMOTIVE AUTO
PARTS WAREHOUSE'
DAM 04/09/2012
Oes+`ae' s = �
1� \
I
1
I
I
1
LID Stormwater Management Summary
Houska Automotive Repair
SIT 12016
SrMBng site That
NO Site Area = 2.28 Me
Propoead site Date:
TOO Proposed lmperrinua Area = I an yore
Total PmpweOlmpbMousnecs• 73.7%
LID Ty nt Area RegWre.1= LN xre p5%plproposed imp. area)
LID cre]tl Or Re9bnM WCL Posed = 0.e4 Mro
RewNrg LID Rpurel= 0.82 arc
LID Trealmerd Arse PyWaed= 0.70 sera (OlAthal
Pement LIOTreaTenl PmYMed yeT%
6
DD Tnd Sell Summary4�
�.
Cmlm9e Dori Gomm Too
vdumar
amM Mee Treated LID Area Ani
Deple
pmY
d
ID (ac ai Typo (SF) (SF)
wk )
(CF)
O1A 0.41 BM w am I 1358.0 ZBB0.0
BA
1358A
02 0.29 BKNeMnllNr2 2a1.0 500.0
12.0
"Ors
REGIONAL ONAL VIOL BASIN
A VOL = 0.663 Al
\\ \ - 4981.00
\ WSE1m — 4961.41
a
46
am x `
ME Tit %\ \
TO SERVE \
AS RAIN CARD \ A
OVERFLOW \
ELivAnaM (rn) sD o ao
SCAt Maw
DSTANCE
FROM BLDG TO
ROGOPLAIN is
s DISTANCE \'/ „� . J
hill
in /\ \ FROM BLDC TO J
\? RIN1DPlAIN - 0.5'
BASIN In \\
+ DRAINAGE BASIN
AREA = 1.03 AC \
'
DISTANCE
FROM BLDG TO ... f1.DO3PIAIN - 14'
wt
RAIN GARDEN F
BIORET=NTION POND 1 \\
BOTTOM ELEV - 4961.00 \
BOTTOM AREA - 1388 9E \
DEPTH - Or I -
VOLUME - 1356 CF ' -\
SEE DETAIL D-9 rr - \\ /• \ //
' r
all
Alto
E II
_ _ _ _
1 / RIVERSIDE SHOPPINGPIO CENTER
8 g I 725 28002 IT THE
NORTHIEMAY PROPFA
EXIST PRIVATE DRIVE AISLE
NOTES:
@ 1. THIS SHEET IS PROVIDED BY INFORMATIONAL PURPOSES ONLY. SEE
APPNOPRNTE SHEET FOR CONSTRUCTION INFORMATION.
2, NO PROPOSED BUILDINGS ARE LOCATED WITHIN THE CITY OF FORT
COLLINS 100YFAR ROODPLAIN FRINGE. HOWEVER PORTIONS OF THE
PROJECT SITE ARE LOCATED WITHIN THE 101YEAR FLOOCVUIN FLOOD
FRINGE. WORK WITHIN THE FLOOD FRINGE (CONSISTING OF
LyTy CUR UTTER REPLACEMENT, DRIVEWAY. DRIVE AISLE. RELOCATED
100-YEAR STORM INLETS, UNDERGROUND UTILITIES AND SURFACE GRADING MUST
R«ay BE PROCEEDED BY AN APPROVED FLOOOPLAIN USE PERMIT.
3. NK) PART OF THE PROJECT PROPERTY IS LOCATED WITHIN THE CRY OF
FORT COLLINS 100.YEAA ROODWAY. HOWEVER PORTIONS OF
/ RIVERSIDE AVENUE ADJACENT TO THE PROJECT WE IS LOCATED WITH
THE FLOODVAY. WORK WITHIN THE FLCCOWAY (CONESTNG OF
r4 CURbGU1lER REPLACEMENT AND RELOCATED STORM DRAINAGE INLETS
AND PIPES MUST BE PROCEEDED BY AN APPROVED NO -RISE
\ CERTIFICATE.
I
I A\ \
it I
! I W
1 Y'
I <
I I I n
1 I
1
I
JMWRSIDE SHOPPING CENTER
PD 9T3128003
731 NORTH IEMAY
me5e dans have soon riverhad by Me cry of Fort Collins far
caxept only The - done notI ply nistrimilbalfity W the
reviewing assessment thin City Enfinshar. or the City ofFM Coal
for moral andcwred ribs beloostionds Fuldharmsere Me
hill dcea hotl dy that the qa ti f tho Items on Me plans are
the final quantifies required . Therevolowsmallnotbeconstrunal
mawn as wasedence ornnanclel responsibility by Me City Open
Claim for aJtlawal limntro s of Items sham that may be rpiiii
dump the control pnaH.
City of Fort Collins, Colorado
OTELITY PLAN Approval
APPROVED: �yng near DAT::
CHECKED BY: DATE:
WeW/Wmtenoter Utility
CHECKED BY:orm ww � DATE:
Y
CHECKED By: DATE
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CHECKED BY.
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