HomeMy WebLinkAboutPARK SOUTH COMMERCIAL PLAZA, 2ND FILING, LOT 2B, CARWASH - PDP - 37-94E - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTLOCATION:
ITEM:
COMPUTATIONS BY:
SUBMITTED BY:
Valvoline
Water Quality Pond Sizing
ppk
North Star Design, Inc
From Urban Storm Drainage Criterial Manual
Use 40-hour brim -full volume drain time for extended detention basin
Water Quality Capture Volume = WQCV = (required storage/12)'(tributary drainage area)
MAJOR
BASIN
Trib.
area
(ac)
% Imperv.
Req. Storage
(in. of runoff)
from Fig. SQ-2
WQCV
(ac-ft)
DWQ
(ft)
req. vol
WQCV'1.2
(ac-ft)
req. area/row
(in2/row)
from Fig. RP-3
POND #1
1.07
83.0
0.36
0.032
1.50
0.039
0.43
WO outlet sizing for pond 1
From Figure 5,
for 1 3/4 in. hole diameter
Area of hole =
0.44 in
# of columns =
1
Area provided/row =
0.44 in
Area Required/row =
0.43 in
Use 1 columns of 1 3/4' diam holes
MINIMUM DETENTION VOLUME REQUIRED INTERIM POND
FAA METHOD
(100-YEAR)
LOCATION: Valvoline
PROJECT NO: 170-04
COMPUTATIONS BY: PPK
SUBMITTED BY: North Star Design
DATE: 12/16/03
Equations:
Qo = CIA
Vi=TCIA=TQo
Vo =K QPo T
S=Vi -Vo
Rainfall intensity from City of Fort Collins IDF Curve
A trib. To pond =
1.04 acre
Cioo =
1.00
Developed C A =
1.0 acre
QPo =
8.10 cfs
K =
0.8
Storm
Duration, T
(min)
Rainfall
Intensity, i
(in/hr)
Qo
(cfs)
Vol. In
Vi
(ft')
Vol. Out
Vo
(ft)
Storage
S
(ft)
Storage
S
(ac-ft)
5
9.95
10.3
3104
1944
1160
0.03
10
7.72
8.0
4817
3888
929
0.02
20
5.60
5.8
6989
7776
-787
-0.02
30
4.52
4.7
8461
11664
-3203
-0.07
40
3.74
3.9
9335
15552
-6217
-0.14
50
3.23
3.4
10078
19440
-9362
-0.21
60
2.86
3.0
10708
23328
-12620
-0.290
70
2.46
2.6
10745
27216
-16471
-0.38
80
2.06
2.1
10284
31104
-20820
-0.48
90
1.90
2.0
10670
34992
-24322
-0.56
100
1.70
1.8
10608
38880
-28272
-0.65
110
1.57
1.6
10776
42768
-31992
-0.73
120
1.45
1.5
10858
46656
-35798
-0.82
130
1.36
1.4
11032
50544
-39512
-0.91
140
1.27
1.3
11095
54432
-43337
-0.99
150
1.19
1.2
11138
58320
-47182
-1.08
160
1.14
1.2
11382
62208
-50826
-1.17
170
1.09
1.1
11563
66096
-54533
-1.25
180
1.05
1.1
11794
69984
-58190
-1.336
Required Storage Volume: 1160 ft3
0.027 acre-ft
Allowable
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
LOCATION: Valvoline, Lot 2-B, Park South Commercial Plaza
DESIGN STORM: 100-YEAR DEVELOPED
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
Q = CCf iA
December 15, 2003
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.25
tc
(min)
i
(in/hr)
Q
(cfs)
1
1
0.62
0.86
1.00
5.0
9.95
6.2
2
2
0.35
0.88
1.00
5.0
9.95
3.5
3
3
0.07
0.39
1 0.49
5.0
9.95
0.3
3
1,2,3
1.04
0.84
1.00
6.9
8.85
9.2
Total to Pond
3
1,2,3
1.04
0.75
0.94
6.9
8.32
8.1
Allowable (old rainfall, lower impervious)
1of1
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION:
DESIGN STORM:
COMPUTATIONS BY:
SUBMITTED BY:
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Valvoline, Lot 2-B, Park South Commercial Plaza i
10-YEAR DEVELOPED
ppk
NORTH STAR DESIGN
Q=CC,iA
December 15, 2003
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.00
tc
(min)
i
(in/hr)
Q
(cfs)
1
1
0.62
0.86
0.86
6.0
4.56
2.44
2
2
0.35
0.88
0.88
5.8
4.62
1.43
3
3
0.07
0.39
0.39
5.0
1 4.87
0.13
3
1,2,3
1.04
0.84
0.84
9.4
3.82
3.33
Total to Pond
1of1
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION:
DESIGN STORM:
COMPUTATIONS BY:
SUBMITTED BY:
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Valvoline, Lot 2-B, Park South Commercial Plaza
2-YEAR DEVELOPED
ppk
NORTH STAR DESIGN
Q = CC(iA
December 15, 2003
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.00
tc
(min)
i
(in/hr)
Q
(cfs)
1
1
0.62
0.86
0.86
6.0
2.67
1.43
2
1 2
0.35
0.88
0.88
5.8
2.71
0.84
3
3
0.07
1 0.39
1 0.39
1 5.0
1 2.85
0.08
3
1,2,3
1.04
0.84
1 0.84
1 9.4
1 2.22
1.93
Total to Pond
toff
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
STANDARD FORM SF-8
LOCATION: Valvoline, Lot 2-B, Park South Commercial Plaza Minor Sub, 2nd Filing DATE: December 15. 2003
DESIGN STORM: 100 YEAR, Cf = 1.25 TIME OF CONCENTRATION
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
Val. from Mannino's Ea. fR=0.11
SU"ASIN
DATA
INITIAL /OVERLAND
TIME (ti)
TRAVEL TIME I GUTTER OR CHANNEL FLOW
(n)
tc CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
BASIN
DESIGN
POINT
Area
(ac)
C
C'Cf
Length
(ft)
Slope
(%)
8
(min)
Length
(ft)
Slope
(%)
n
Manning
Val.
(fps)
it
(min)
tc=
ti+n
Total
(ft)
tc=(U780)+10
(min)
(min)
1
1
0.62
0.86
1.00
70
1.00
1.6
210
0.6
0.016
1.56
2.2
3.8
280
11.6
5.0
MINMUM tc = 5
2
2
0.35
0.88
1.00
120
1.00
2.0
115
0.6
0.016
1.56
1.2
3.3
235
11.3
5.0
3
3
0.07
0.39
0.49
4
20.00
0.8
140
0.5
0.030
0.76
3.1
3.9
144
10.8
5.0
1.2.3
3
1.04
0.84
1.00
70
1.00
1.6
210
0.6
0,016
1.56
2.2
140
0.5
0.030
0.76
3.1
6.9
420
12.3
6.9
11117111111l
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
STANDARD FORM SF-8
LOCATION: Valvoline, Lot 2-B, Park South Commercial Plaza Minor Sub, 2nd Filing
DESIGN STORM: 2 YEAR, Cf = 1 TIME OF CONCENTRATION
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
Vel. from Manninn's Ea. (R=0.1)
DATE: December 15, 2003
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME (0)
TRAVEL TIME I GUTTER OR CHANNEL FLOW
(tt)
tc CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
BASIN
DESIGN
POINT
Area
(ac)
C
C'Cf
Length
M.
Slope
(%)
ti
(min)
Length
(ft)
Slope
(%)
n
Manning
Val.
(fps)
It
(min)
tc=
ti+It
Total
(ft)
tc=(11180)+10
(min)
(min)
1
1
0.62
0.86
0.86
70
1.0
3.7
210
0.6
0.016
1.56
2.2
6.0
280
11.6
6.0
MINMUM tc = 5
2
2
0.35
0.88
0.88
120
1.0
4.6
115
0.6
0.016
1.56
1.2
5.8
235
11.3
5.8
3
3
0.07
0.39
0.39
4
20.0
1.0
140
0.5
0.030
0.76
3.1
4.1
144
10.8
5.0
1,2,3
3
1.04
0.84
0.84
70
1.0
4.1
210
0.6
0.016
1.56
2.2
140
0.5
0.030
0.76
3.1
9.4
420
12.3
9.4
1 of 1
RUNOFF COEFFICIENTS & % IMPERVIOUS
LOCATION:
Valvoline
PROJECT NO:
170-04
COMPUTATIONS BY:
PPK
DATE:
12/15/03
Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria
Recommended % Impervious from Urban Storm Drainage Criteria Manual
Streets, parking lots (asphalt):
Sidewalks (concrete):
Roofs:
Lawns (flat <2%, heavy soil):
Runoff
%
coefficient
Impervious
C
0.95
100
0.95
96
0.95
90
0.20
0
SUBBASIN
DESIGNATION
TOTAL
AREA
(ac.)
TOTAL
AREA
(sq.ft)
ROOF
AREA
(sq.ft)
PAVED
AREA
(sq.ft)
SIDEWALK
AREA
(sq.ft)
LANDSCAPE
AREA
(sq.ft)
RUNOFF
COEFF.
(C)
%
Impervious
REMARKS
1
0.62
27,010
4,404
18,309
1,156
3,141
0.86
87
2
0.35
15,407
1,803
12,064
0
1,540
0.88
89
3
0.07
2,925
0
0
755
2,170
0.39
25
Total
1.04
45,342
6,207
30,373
1,911
6,851
0.84
83
Equations
- Calculated C coefficients & % Impervious are area weighted
C=E(Ci Ai) /At
Ci = runoff coefficient for specific area, Ai
Ai = areas of surface with runoff coefficient of Ci
n = number of different surfaces to consider
At = total area over which C is applicable; the sum of all Ai's
W
F
53
0
PROJECT
LOCATION
g
►
s
0
HORSETOOTHROAD
W
N
p
N
l
q {jY
e
3
x
J
SHEET 1 OF 1
DATE: 12/3/03
PARK
SOUTH COMMERCIAL
PLAZA
%North Star
SCALE: 1• - 2000•
2ND FILING, LOT 2-9
VALVOLINE
design, inc.
700 Automation Drive, Unit I
DESIGNED BY: TlN
VICINITY MAP
Windsor, Colorado 80550
Phone: 970-686-6939
JOB NO.: 170-04
Fax: 970-686-1188
APPENDIX
VICINITY MAP, HYDRAULIC & HYDROLOGIC CALCULATION
5. EROSION CONTROL
5.1 General Concept
This site lies within the Moderate Rainfall and Wind_Erodibility Zone per the City of Fort
Collins Zone Maps. The potential exists for silt movement from the site and into
downstream conveyances. Potential also exists for tracking of mud onto existing streets
which could then wash into existing storm systems.
The erosion control escrow amount will be calculated with the final design of this site.
5.2 Specific Details
To limit the amount of silt leaving the site several erosion control measures shall be
implemented during construction. All boundaries shall have silt fence installed and a
vehicle tracking pad shall be installed at the drive to control the mud being tracked onto
the street.
6. CONCLUSIONS
6.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
City of Fort Collins Erosion Control Reference Manual for Construction Sites and the
Storm Drainage Design Criteria Manual.
6.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
maintain the existing drainage patterns and the anticipated imperviousness for this site.
Conveyance elements have been designed to pass required storm flows and to minimize.
future maintenance.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit will be required.
3.4 Hydraulic Criteria
All preliminary hydraulic calculations within this report have been prepared in
accordance with the City of Fort Collins Drainage Criteria and are included in the
Appendix of this report. The detention pond sizing and the water quality pond sizing are
included in these calculations.
4. DRAINAGE FACILITY DESIGN
4.1 General Concept
All of the runoff from this site currently drains to the existing 18" storm pipe. It is
proposed that a similar runoff pattern be maintained with the development of this site.
4.2 Specific Flow Routing
A summary of the drainage patterns within each basin is provided in the following
paragraphs.
Basin 1 contains the north half of the site including the Phase 1 Valvoline and associated
drives and parking. Runoff from this basin will be conveyed to a curb opening in the
southeast corner of the basin and will be conveyed to the proposed detention pond.
Basin 2 contains the south half of the site including the Phase 2 car wash or similar use.
The associated drives are also included in this basin. The runoff from this basin flows
south and east into a curb opening and enters the proposed detention pond.
Basin 3 contains the eastern portion of the site including the detention pond and
landscaping. This basin collects runoff from Basins 1 and 2 and routes it to the existing
18" storm pipe.
4.3 Drainage Summary
The existing and proposed drainage facilities located outside the right of way will be
maintained by the site owner(s).
accounted for in the drainage report for the overall subdivision. The pond that was
construction with this subdivision was enlarged in May of 1998 to accommodate runoff
from the lots noted above and assumed a runoff coefficient of 0.75. The calculations
were also completed using the `old' rainfall criteria.
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations
This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage
Design Criteria Manual" specifications. Where applicable, the criteria established in the
"Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver
Regional Council of Governments, has been used.
3.2 Development Criteria Reference and Constraints
The runoff from this site has been routed to conform to the requirements of the City
Stormwater Department and the overall drainage report for Park South Commercial Plaza
Minor Sub. 2"d Filing. Detention will be provided to account for the increase in runoff
coefficient above the anticipated 0.75 and the change in the rainfall criteria. Water
quality extended detention will also be provided on site.
The majority of the site will be routed to the southeast corner of the site and will be
conveyed via a curb openings and a concrete channel to the proposed detention pond and
the existing 18" storm pipe. A small amount of landscape area on the north will discharge
directly to Horsetooth.
3.3 Hydrologic Criteria
Runoff computations were prepared for the 2-year minor and 100-year major storm
frequency utilizing the rational method.
All preliminary hydrologic calculations associated with the basins are included in the
Appendix of this report. Standard Form 8 (SF-8) provides time of concentration
calculations for all sub -basins. Standard Form 9 (SF-9) provides a summary of the design
flows for all Sub -basins and Design Points associated with this site.
1. GENERAL LOCATION AND DESCRIPTION
1.1 Location
The proposed Valvoline Site is located in southwest Fort Collins. This project is located
in the Northwest Quarter of Section 35, Township 7 North, Range 69 West of the Sixth
Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. See the
location map in the Appendix.
The project is located in the southeast corner of the intersection of Horsetooth Road and
Manhattan Avenue. The project is bounded on the north by Horsetooth Road, on the east
by the Carmike Theaters, on the south a private drive and west by an existing Autozone.
1.2 Description of Property
The entire project consists of approximately 1.2 acres of land. This property currently is
undeveloped and is covered in weeds and grasses. The land currently slopes to the
southeast at a range of approximately 1.5% to 1%.
The proposed development consists of a Valvoline building at the north end of the site to
be constructed with Phase 1. Phase 2 will consist of a car wash or other similar use.
Both phases of construction will also have drives and parking.
The site currently drains to the southeast and into an existing 18" storm pipe. This pipe
carves the water under the private drive and into an existing retention pond. This pond
was sized to accept runoff from this site (Lot 2-B) and Lots 3-A, 3-B, 3-C and 3-D.
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description
The proposed development lies within the McClellands / Mail Creek Master Drainage
Basin. This site is not located in a 100-year floodplain.
2.2 Sub -basin Description
This site is a part of the Park South Commercial Plaza Minor Sub. 2"d Filing and is
TABLE OF CONTENTS
..
TABLE OF CONTENTS ............................................................................................................... i�i
GENERAL LOCATION AND DESCRIPTION
1.1 Location...................................................................................................................1
1.2 Description of Property............................................................................................1
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description....................................................................I.....................1
2.2 Sub -Basin Description.............................................................................................2
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations..............................................................................................................2
3.2 Development Criteria Reference and Constraints....................................................2
3.3 Hydrologic Criteria..................................................................................................3
3.4 Hydraulic Criteria....................................................................................................3
4. DRAINAGE FACILITY DESIGN
4.1 General Concept.......................................................................................................4
4.2 Specific Flow Routing.............................................................................................4
4.3 Drainage Summary ...................................................................................................5
5. EROSION CONTROL
5.1 General Concept......................................................................................................5
5.2 Specific Details........................................................................................................5
6. CONCLUSIONS
6.1 Compliance with Standards....................................................................................6
6.2 Drainage Concept.....................................................................................................6
iii
North Star
�`, design, inc.
December 13, 2003
Basil Hamdan
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Preliminary Drainage and Erosion Control Study for Lot 2-B, Park South
Commercial Plaza Minor Sub. 2°d Filing (Valvoline)
Dear Basil,
I am pleased to submit for your review and approval, this revised Preliminary Drainage and
Erosion Control Study for Lot 2-B, Park South Commercial Plaza Minor Sub. 2"d Filing
(Valvoline) . I certify that this report for the drainage design was prepared in accordance with the
criteria in the City of Fort Collins Storm Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
(7;
Patricia Kroetch, P.E.
n
700 Automation Drive, Unit I Windsor, Colorado 80550
970-686-6939 Phone • 970-686-1188 Fax
PRELIMINARY DRAINAGE AND EROSION
CONTROL STUDY
For
Lot 2-B, Park South Commercial Plaza Minor Sub. 2nd Filing
(Valvoline)
Prepared for:
Oilmen Enterprises, LLC
5228 Lonetree Drive
Loveland, CO 80537
Prepared by:
North Star Design
700 Automation Drive, Unit I
Windsor, Colorado 80550
(970)686-6939
December 13, 2003
Job Number 170-04