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J.C. SIPE JEWELERS
DRAINAGE SUMMARY
September 4, 2001
tOCA TION/DESCRIPTION
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This site is located at the northwest comer of 96th Street and Day Drive in Carmel, ana. The
site consists of approximately 1.04 acres:t and is currently undeveloped. The project consists of
the construction of a 4,300 S.F. store and associated parking areas.
EXISTING CONDITIONS
The current undeveloped site flows via overland flow to the 96th Street storm sewer. Based on
Hamilton County GIS topographical information, a peak 10-year Rational Method discharge was
determined to be 0.92 cfs (See Attachment - Preliminary Drainage, 10 to 100-year).
PROPOSED CONDITIONS
The proposed site will be drained by a combination of storm sewers, culverts, and open ditches.
Using the Rational Method, a detention basin was sized. The detention basin necessary to restrict
the 100-year post-developed runoff to the existing 10-year rate was found to be 0.09 acre-feet in
size. Using a 4" orifice, the 100-year elevation in the detention basin will be between 768' and
768.5' giving at least l' of free board. (See Attachment - Stage Storage and Stage Discharge
Calculations)
CONCLUSION
The development of a 4,300 S.F. jewelry store and associated parking areas will require detention
to meet with the City of Carmel's drainage ordinance. This required detention will be achieved
using a dry bottom detention basin, and a 4" orifice restrictor placed on the outlet pipe. No
adverse effects are anticipated from this design.
\\S174\c\IN2001\0517 Ie Sipe\in20010517 drainage report. doc
qime of Concentration computatQs
Project: J.C. Sipe Jewelers
By: PRS
Date: 08/06/01
Location: Carmel, IN
Description: Existing Conditions
Sheet Flow
Segment 10
Surface Description
Manning's Roughness Coefficient, n
Flow Length (ft)
Two-Year, 24-Hour Rainfall (in)
Land Slope (ft/ft)
Tt (hr)
Shallow Concentrated Flow
Segment 10
Surface Description
Flow Length (ft)
Watercourse Slope (ft/ft)
Average Velocity (ft/s)
Tt (hr)
Channel Flow
Segment 10
Cross Sectional Flow Area (ft~)
Wetted Perimeter (ft)
Hydraulic Radius (ft)
Channel Slope (ft/ft)
Manning's Roughness Coefficient, n
Velocity (ft/s)
Flow Length (ft)
Tt (hr)
AB
Open Space :
0.240
290
2.64
0.011
0.79 0.79 [
:
0.00
0.000 0.00 I'
CO
, 0
0.00 0.00 I
Tc (hr)= 0.79
Tc (min) = 47.6
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REQUIRED STORAGE USING RATIONAL METHOD
J.e. Sipe Jewelers
Job # tN20010517
DESIGN RETURN PERIOD
RELEASE RATE
WATERSHED AREA
DEVELOPED RUNOFF COEFFICIENT
10 YR EXISTING RUNOFF RATE = OUTFLOW RATE
100 YR
10 YR
1.09 ACRES
0.65
0.92 CFS
STORM RAINFALL OUTFLOW STORAGE REQUIRED
DURATION INTENSITY INFLOW RATE RATE RATE STORAGE
(HRS) (IN/HR) (CFS) (CFS) (CFS) (ACRE-FT)
0.08 9.69 6.87 0.92 5.95 0.04
0.17 7.77 5.51 0.92 4.59 0.06
0.25 6.53 4.63 0.92 3.71 0.08
0.5 4.50 3.19 0.92 2.27 0.09
1 2.88 2.04 0.92 1.12 0.09
2 1.75 1.24 0.92 0.32 0.05
3 1.29 0.91 0.92 0.00 0.00
6 0.75 0.53 0.92 0.00 0.00
12 0.43 0.30 0.92 0.00 0.00
24 0.25 0.18 0.92 0.00 0.00
REQUIRED STORAGE
0.09 ACRE-FT
0 0
STAGE STORAGE CALCULATIONS
SIPE JEWELERS
JOB NUMBER IN20010517
8/31/2001
PROPOSED DETENTION
764.05 0.0000 0.0000
0.0005 0.45 0.000
764.5 0.0009 0.0002
0.0014 0.5 0.001
765 0.0018 0.0009
0.0044 0.5 0.002
765.5 0.0071 0.0031
0.0097 0.5 0.005
766 0.0123 0.0079
0.0174 0.5 0.009
766.5 0.0225 0.0166
0.0275 0.5 0.014
767 0.0326 0.0304
0.0390 0.5 0.019
767.5 0.0454 0.0499
0.0517 0.5 0.026
768 0.0581 0.0758
0.0648 0.5 0.032
768.5 0.0714 0.1081
0.0781 0.5 0.039
769 0.085 0.1472
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STAGE DISCHARGE CALCULATIONS
Sipe Jewelers
IN20010517
PRS
8/31/01
PROPOSED STRUCTURE 1 ORIFICE CALCULATIONS
4 - INCH ORIFICE
1= 764.05
Q= CA(2gh)^1/2
C= 0.64
A= 0.09
g= 32.2
CENTER OF ORIFICE = 764.05 + 0.17 = 764.217
ELEV h Q
(ft) (cfs)
764.22 0.00 0.00
764.50 0.28 0.24
765.00 0.78 0.40
765.50 1.28 0.51
766.00 1.78 0.60
766.50 2.28 0.68
767.00 2.78 0.75
767.50 3.28 0.81
768.00 3.78 0.87
768.50 4.28 0.93
769.00 4.78 0.98
in20010517 design.xls, D~scharge
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