HomeMy WebLinkAboutDrainage Reports - 05/05/20061
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City of Ft. Cd er! Plana
Kter-Mountain pate �► ��
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PROPERTY OF
FINAL DRAINAGE STUDY
FOR PORT COLUNS
PANDA EXPRESS
4600 SOUTH MASON STREET
CITY OF FORT COLLINS, COLORADO
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PREPARED FOR:
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CONCEPTS WEST ARCHITECTURE, INC.
SUITE 100
831 SOUTH NEVADA AVENUE
COLORADO SPRINGS, COLORADO 80903
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PROJECT NO. 06-9006
PREPARED BY:
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INTER -MOUNTAIN ENGINEERING
KAREN.KIDD, EI.
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ANDREW CORNELIUS, P.E.
APRIL 2006
8392 Continental Divide Road, Suite #107 • Littleton, Colorado 80127 • Phone: 303 948 6220 • Fax: 303 948 6526
' 40801 U.S. Hwy. 6, Suite 203 • P.O. Box 978 • Avon, Colorado 81620 • Phone: 970 949 5072 • Toll Free: 800 856 2258
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ENGINEER'S. CERTIFICATION
I hereby certify that this Final Drainage Study for Panda Express at 4600 Mason Street
was prepared by me (or under my direct supervision) in accordance with the provisions of
the City of Fort Collins Storm Drainage Design Criteria and Construction Standards for
the owners thereof.
Andrew Cornelius, Register%
Surveyor ,
Colorado Professional Engineer
and Registered Professional Land
GENERAL LOCATION AND DESCRIPTION
This Final Drainage Study has been completed for Concepts West Architecture in order
to present an effective stormwater management plan for the re -development of the site at
4600 Mason Street as a Panda Express. This study confirms the re -developed design of
the site meets the master drainage design criteria established within the original
development of the Amigos Restaurant at Arbor Plaza by RBD Engineering Consultants
in May 1993.
The proposed Panda Express site was originally developed as an Amigos Restaurant at
Arbor Plaza. The site is bounded to the north by Harmony Road, to the west by Mason
Street, to the south by an access road and'to the south and east by "Ultimate Electronics."
The site consists of 0.93 acres and is proposed to be re -developed as a Panda Express
Restaurant with a drive-thru. The proposed re -development of the site includes
resurfacing, adjustment to curb and gutter, replacement of utility service lines,
replacement of concrete surfacing adjacent to the building, incorporation of a swale and
sidewalk chase/concrete pan combination, and relocation of the trash enclosure.
DESCRIPTION OF PROPERTY
The existing site is mainly hardscape with either asphalt and concrete pavement or
concrete sidewalks, with landscaped areas around the perimeter of the parking lot and
directly adjacent to the building. The existing terrain is fairly mild, mainly draining to the
east with a small portion draining to the south. There is an existing Type R curb inlet on
the eastern portion of the site that collects the majority of the drainage; the remainder
drains south to the Access Drive.
IDRAINAGE BASINS AND SUB -BASINS
' The Grading, Drainage, Erosion Control, and Utility Plan by RBD Engineering
Consultants for the Amigos at Arbor Plaza PUD defined the drainage:basins and design
' points for the site. RBD Engineering Consultants identified the site as two major basins
labeled Basin I and Basin 2. Each basin has an associated design point or flow summary
point. The proposed re -development is contained within Basin 1, but maintains the same
basin boundary and the associated design point. The proposed re -developed includes the
establishment of Sub -Basin I to direct stormwater away from the proposed building by
incorporating a drainage swale and sidewalk chase/concrete pan combination. Basin 2 is
not affected by the re -development. The existing two major basins and the proposed sub -
basin are shown on the Drainage Basin Plan in the Appendix, Exhibit 1.
DRAINAGE DESIGN
' This study was prepared in accordance with the City of Fort Collins Storm Drainage
Design Criteria and Construction Standards.
The Rational Method
was used by RBD Engineering Consultants to develop peak
discharges corresponding to the 10-Year and 100-Year events for the original Amigos
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development. The proposed re -development is contained within Basin I and maintains
the same basin boundary, design point, time of concentration and resulting intensity.
Thus, this study will simply compare the runoff coefficients of the original development
and the proposed re -development to ensure the original drainage structures are adequate.
The runoff coefficients were derived from the City of Fort Collins Storm Drainage
Design Criteria and Construction Standards Table 3-3.
Basin I CIO Basin 1 Cioo
Original development 0.83 1.00
Proposed re -development as
0.80 1.00
a Panda Express
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The runoff coefficients calculated in this study for Basin 1 are less or equal to those
determined by RBD Engineering Consultants for the original development. Thus, the
' resulting discharge from the 10-Year and 100-Year events will be less than or equal to
that compiled by RBD Engineering Consultants for the original development.
The Rational Method was also used to assess the proposed sub -basin, Basin 1-A. The
stormwater flows within the basin resulting from the 10-Year and 100-Year storm events
were determined and the depth of water within the swale and concrete pan were assessed.
The detailed drainage calculations and flow computations can be found in the Appendix.
DRAINAGE FACILITY DESIGN
The Grading, Drainage, Erosion Control and Utility Plan by RBD Engineering ,
Consultants contains the initial storm and accommodates the major storm so there will be
no impact to the development lots. The proposed swale and sidewalk chase/concrete pan
combination contain the initial and major storm.
' WATER QUALITY
The water quality will be addressed with inlet protection and concrete washout basin as
Ishown on the Erosion and Sediment Control Plan in the Appendix, Exhibit 2.
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REFERENCES
1. City of Fort Collins, Colorado; Storm Drainage Design and Technical Criteria;
April 1997.
2. Grading, Drainage Erosion Control and Utility Plan; RBD Engineering
Consultants; May 1993.
3. Urban Drainage and Flood Control District, Urban Storm Drainage Criteria Manual
Volume 1, June 2001 (latest revision March 2005).
No Text
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100-Year Event Concrete Pan Assessment
Worksheet for Irregular Channel
Project Description
Project File j:\projects\06-9009\files\chase-pa.fm2
Worksheet Concrete Pan Assessment
Flow Element Irregular Channel
Method Manning's Formula
Solve For Water Elevation
Input Data
Channel Slope
0.005000 ft/ft
Elevation range: 35.10 ft to 35.18 ft.
Station (ft)
Elevation (ft) Start Station
0.00
35.18 0.00,
1.00
35.10
2.00
35.18
Discharge
0.07 cfs
Results
Md. Mannings Coefficient
0.013
Water Surface Elevation
35.18
ft
Flow Area
0.08
ft2
Wetted Perimeter
1.95
ft
Top Width
1.94
It
Height
0.08
It
Critical Depth
35.17
ft
Critical Slope
0.007484 ft/ft
Velocity
0.93
ft/s
Velocity'Head
0.01
ft
Specific Energy
35.19
ft
Froude Number
0.83
Flow is subcritical.
03/28/06
05:35:12 PM
End Station Roughness
2.00 0.013
FlowMaster v5.13
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708- (203) 755-1666 Page 1 of 1
10-Year Event Concrete Pan Assessment
Worksheet for Irregular Channel
Project Description
Project File
j:\projects\06-9009\files\chase-pa.fm2
'
Worksheet
Flow Element
Concrete Pan Assessment
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Input Data
' Channel Slope 0.005000 ft/ft
Elevation range: 35.10 ft to 35.18 ft.
' Station (ft) Elevation (ft) Start Station
' 0.00 35.18 0.00
1.00 35.10
2.00 35.18
Discharge 0.04 cfs
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03/28/06
' 05:34:48 PM
To
He
Wt
Wa
We
esults
d. Mannings Coefficient 0.013
ter Surface Elevation 35.16 ft
ow Area 0.05 ft2
tted Perimeter 1.58 ft
Width 1.58 . ft
0.06 ft
rifical Depth 35.16 ft
ritical Slope 0.008066 ft/ft
elocity 0.80 ft/s
elocity Head 0.01 ft
pecific Energy 35.17 ft
oude Number 0.80
ow is subcritical.
End Station Roughness
2.00 0.013.
FlowMaster v5.13
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
End Station Roughness
2.00 0.013.
FlowMaster v5.13
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
100- Year Sidewalk'Chase Assessment
Worksheet for Rectangular Channel
' Project Description
Project File
j:\projects\06-9009\files\chase-pa.fm2
Worksheet
Sidewalk Chase Assessment
'
Flow Element
Rectangular Channel
-
Method
Manning's Formula
Solve For
Channel Depth
Input Data
Mannings Coefficient
0.013
'
Channel Slope
0.005000 ft/ft
L
Bottom Width
1.00 ft
'
Discharge
0.07 cfs
Results
Depth
0.06
ft
Flow Area
0.06
ft2
Wetted Perimeter
1.12
ft
'
Top Width
1.00
ft
Critical Depth
0.05
ft
Critical Slope
0.007487
ft/ft
Velocity
1.16
ft/s
Velocity Head
0.02
ft
Specific Energy
0.08
ft
Froude Number
Flow is subcritical.
0.83
r 1
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e
'03/28/06
05:3:38:2525 PM
r
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMaster v5.13
Page 1 of 1
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10- Year Event Sidewalk Chase Assessment
Worksheet for Rectangular Channel
Project Description
Project File j:\projects\06-9009\files\chase-pa.fm2
Worksheet `Sidewalk Chase Assessment
Flow Element Rectangular Channel
Method Manning's Formula
Solve For Channel Depth
Input Data
Mannings Coefficient
0.013
Channel Slope
0.005000 ft/ft
Bottom Width
1.00 ft
Discharge
0.04 cfs
Results
Depth
0.0*
ft
Flow Area
0.04
ft'
Wetted Perimeter
1.09
ft
Top Width
1.00
ft
Critical Depth
0.04
ft
Critical Slope
0.008140 ft/ft
Velocity
0.94
ft/s
Velocity Head
0.01
ft
Specific Energy
0.06
ft
Froude Number
0.80
Flow is subcritical.
03/28/06 FlowMaster v5.13
05:37:29 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 - Page 1 of 1
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100-Year Storm Swale Assessment
Worksheet for Irregular Channel
Project Description
Project File
j:\projects106-9009\files\chase-pa.fm2
Worksheet
Swale Assessment
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Input Data
Channel Slope
0.020000 ft/ft
Elevation range: 35.12 ft to 36.71 ft.
Station (ft)
Elevation (ft) Start Station
0.00
35.74 0.00
5.00
35.12
7.00
35.12
20.73
36.71
Discharge
0.07 cfs
Results
Md. Mannings Coefficient
0.030
Water Surface Elevation
35.16
ft
Flow Area
0.09
ft'
Wetted Perimeter
2.67
ft
Top Width
2.67
ft
Height
0.04
ft
Critical Depth
35.15
ft
Critical Slope
0.042937 Wit
Velocity
0.15
ft/s
Velocity Head
0.01
ft .
Specific Energy
35.17
ft
Froude Number
0.71
Flow is subcritical.
End Station Roughness
20.73 0.030
03/24/06
10:14:26 AM Haestad Methods, Inc. 37. Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMasler v5.13
Page 1 of 1
10-Year Storm Swale Assessment
Worksheet for Irregular Channel
Project Description
Project File
j:\projects106-9009\files\chase-pa.fm2
Worksheet
Swale.Asse' sment
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Input Data
Channel Slope
0.020000 ff/ft
Elevation range: 35.12 ft to 36.71 ft.
Station (ft)
Elevation (ft) Start Station
0.00
35.74 0.00
5.00
35.12
7.00
35.12
211:73
36.71
Discharge
0.04 cfs
Results
Md. Mannings Coefficient
0.030
Water Surface Elevation
35.15
ft
Flow Area
0.06
ft'
Wetted Perimeter
2.49
ft
Top Width
2.48
ft
Height
0.03
ft
Critical Depth
35.14
ft
Critical Slope
0.047831 ft/ft
Velocity
0.62
fUs
Velocity Head
0.01
ft
Specific Energy
35.15
ft
Froude Number
0.67
Flow is subcritical.
03/28/06
05:35:45 PM
End Station Roughness
20.73 0.030
FlowMasler v5.13
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
LEGEND
1—DRAINAGE BASIN
0.844)RAINAGE BASIN AREA (ACHES)
A --
DRAINAGE BASIN DESIGN POINT
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GRAPHIC SCALE
' 30 0 18 x 60
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$ ( IN FEET )
I inch 30 &
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E00080H COMA NOTED
1. CONTRACTOR SHALL USE THIS EROSION AND SEDIMENT CONTROL PLAN AS
A BASIS FOR CONTROLLING SEDIMENT TRANSPORT FROM THE SITE
ADDITIONAL EROSION CONTROL PRACTICES MAY BE REQUIRED.
2. CONTRACTOR SHALL INSPECT THE INSTALLED EROSION CONTROL MEASURES ON
A PERIODIC BASIS TO ENSURE PROPER OPERATION. MAINTENANCE SHALL BE
CARRIED OUT IMMEDIATELY UPON DISCOVERY OF ANY PROBLEM AREAS
3. THE CONTRACTOR SHALL REMOVE TEMPORARY EROSION AND SEDIMENT
CONTROLS AFTER DISTURBED AREAS ARE FINALLY STABILIZED
AS DIRECTED BY THE ENGINEER OR THE LOCAL AUTHORITY.
4. TEMPORARY VEGETATION OR STABILIZED LANDSCAPING IS REQUIRED ON ALL
DISTURBED AREAS THAT WILL BE EJf "M FOR ONE YEAR OR LONGER PRIOR
TO FINAL STABILIZATION.
5. THE CONTRACTOR SHALL REMOVE ANY ACCUMULATED SEDIMENT FROM
PERMANENT DRAINAGE AND WATER QUALITY FACILITIES (SUCH AS INLETS, r
PIPE.% WATER TREATMENT STRUCTURES. MANHOLES, CULVERTS. DITCHES,
CHANNELS, ETC.) DURING FINAL CLEAN—UP.
I i
x
Z
GRAPHIC SCALE
15 70 6e
( IN FEET )
1 Inch = 90 fL.
120
5036"
w
pan
CIE] rm CURB INLET
GRAVEL FlLTER
CONCRETE
WASHOUT
BASIN
- .........