HomeMy WebLinkAboutHydrology Report Jan 2011VEOUA WATER INDIANAPOLIS, LLC
WHITE RIVER NORTH WATER TREATMENT PLANT
UV DISINFECTION FACILITY
HYDROLOGY REPORT
January 28, 2011
Prepared by:
Black Veatch Corporation
Indianapolis, Indiana
B &V Project 169576
BLACK VEATCH
Building a world of difference." TOC 1
City of Indianapolis Department of Waterworks
White River North Water Treatment Plant B &V Project 169576
UV Disinfection Facility B &V Fiile 34.200
Hydrology Report
January 28, 2011
TABLE OF CONTENTS
PROJECT NARRATIVE Page
Existing Conditions 1
Developed Conditions 1
Runoff Summary 1
Post Construction Stormwater Quality 2
APPENDICES
Appendix A Figures
Appendix B Calculations
BLACK VEATCH
Building a world of difference:
City of Indianapolis Department of Waterworks
White River North Water Treatment Plant
UV Disinfection Facility
Hydrology Report
Existing Conditions
Existing Conditions
BASIN E -1:
A =0.25 acre
CRatfona) 0.19
T 9 min.
Q2 0.19 cfs
Quo 0.26 cfs
Q100= 0.38 cfs
PROJECT NARRATIVE
Page 1
B &V Project 169576
B&V File 34.2000
January 28, 2011
The 0.83 acre project area at the existing White River North Water Treatment Plant property
address is 11825 River Road in Carmel, IN, near the intersection of River Road and Hoster
Road, as shown on Figure 1, Location Map. The property is in Section 34, Township 18 North,
Range 4 East, in Hamilton County. The existing plant site includes sedimentation, filtration, and
other water treatment facilities, paved parking areas, access drives, an existing stormwater
management area, and open grassy areas. The soils on the site are Ockley silt loam, Westland
silty clay loam, and Genesee silt loam, as delineated on Figure 2, Soils Map. Ockley silt loam
and Genesee silt loam are in hydrologic soil group B and the Westland silty clay loam is in
hydrologic soil group B/D, The site is adjacent to White River and part of the project area is
located within the 100 -year floodplain, as shown on Figure 3, Flood Map. The 100 -year flood
elevation is approximately 745.0 ft in this area. Elevations in the project area range from a high
of approximately 754 ft near the existing filter building down to about 742 ft north of the project
area. The existing project area currently drains via sheetflow offsite to the north, as shown on
Figure 4, Existing Conditions Drainage Map.
Developed Conditions
The proposed development includes a new 4,670 SF building to house an ultraviolet disinfection
facility for drinking water treatment, an engine generator, and a small amount of new paving.
Figure 5 shows the Developed Conditions Drain Map. The
by Drainage p proposed construction will
increase the impervious area on the site b 0.16 acre and will result in a disturbed area of 0.83
acres. Runoff from the new building will be piped to an onsite infiltration basin and dry well.
The infiltration basin is large enough to hold the 100 -year runoff volume. Due to less permeable
clay soils near the surface, the function of the dry well is to allow the runoff to infiltrate the
deeper, permeable sandy soils. Design calculations show that the 100 -year runoff volume
infiltrates the soil within 48 hours. Since the infiltration basin and dry well are designed to allow
the 100 -year storm event to infiltrate, the offsite runoff rate is zero, as shown in the following
section, Runoff Summary.
Runoff Summary
Developed Conditions
BASIN D -1:
A 0.25 acre (To Infiltration Basin)
CRaaonal 0.59
T 5 minutes
Q2 0.0 cfs
Qio= 0.Ocfs
Q,00= 0.0 cfs
BLACK VEATCH
Building a world of difference:
Post- Construction Stormwater Quality
Runoff from the new building will drain via a roof drain collector pipeline to the dry well structure.
The infiltration basin is sized to store the 100 -year runoff volume until it percolates into the soil
at the bottom of the dry well. Since the pipe conveying flow to the dry well is only collecting
runoff from the new roof, there is no need for a pretreatment BMP (i.e., there will be no debris in
the runoff from the roof).
City of Indianapolis Department of Waterworks
White River North Water Treatment Plant
UV Disinfection Facility
Hydrology Report
Page 2
B &V Project 169576
B&V File 34.2000
January 28, 2011