The URL can be used to link to this page

Home My WebLink AboutDrainage Calculations Drainage Calculations PROJECT: DRAINAGE REPORT for RANGELINE COMMERCIAL PREPARED FOR: I.E. INVESTMENTS, LLC DATE: 04/22/09 JOB NUMBER: 7310.002 The Schneider Corporation 8901 Otis Avenue Indianapolis, Indiana 46216 b 5 iksr�•° j k ��n' 317- 826 -7100 317- 826 -7300 Fax Schn 11 12 AM 9 tt LV M 0 24 w T: \7k \7310 \002 \drainage \4580001 drainrep.doc �b s 1� Ad eat. t. TABLE OF CONTENTS A. Drainage Narrative Al A4 B. Site Maps USGS Quadrangle Map B1 Soils Map B2 C. Existing Conditions Watershed Plan 01 Site Hydrologic Groups C2 Curve Number C3 Existing Time of Concentration C4 Existing Basin Input C5 Existing Basin Peak Discharge C6 D. Detention Analysis Watershed Plan 01 Nodal Diagram D2 Storm Sewer Rational Design D3 Storm Sewer Pipe Design D4 Time of Concentration D5 ICPR Input report Basin Input D6 Node Input D7 Pipe Input D8 Rainfall Chart D9 CN value table D10 Basin Results Comparisons D11 Results (node max. Condition) D12 Composite "c" Values D13 Runoff Coefficient D14 h a RECEIVED M J co DOGS cb T:\7k\7310\002\drainage\4580001drainrep.doc 40` �1 it 00 co -A- RECEIVED 1 N APR 2 4 2009 DRAINAGE NARRATIV DOCS "fr DESIGN CRITERIA t 1 01' 4 These drainage calculations are based on given data and design criteria as follows: Site location: The site is located at the northeast corner of Rangeline Road and 4 Street, Carmel, Hamilton County, Indiana. Terrain and existing ground condition: The site is currently 3 lots of a previously platted subdivision containing 3 existing homes. Two homes are slated to be removed, and 1 existing home will remain. Adjoining land conditions: North: residential /commercial South: residential /commercial East: residential /commercial West: residential /commercial Soil types: Soils maps from the United States Department of Agriculture Soil Conservation Service identify Crosby and Miami Silt Loam soils on the subject tract. Crosby (CrA silt loam) The main soil features that adversely affect engineering uses of this soil are a seasonal high water table, high potential frost action, moderate shrink -swell potential and moderate permeability. This soil has severe limitations for building sites. The site needs to be artificially drained to prevent wetness from becoming a problem. Dwellings with basements should not be constructed on this soil. This soil has severe limitations for local roads and streets because of seasonal high water table and high potential frost action. The base material for roads and streets should be replaced or strengthened with suitable material. T:\7k\7310\002\drainage\4580001drainrep.doc Miami (MmB2 silt loam) The main soil features that adversely affect engineering uses of this soil are moderate potential frost action, moderate shrink -swell potential, moderate permeability and low strength. In addition, erosion is a hazard during construction. This soil is suitable for building sites, but slope, clayey texture, shrinking and swelling, and low strength are moderate limitations that need to be overcome. This soil has severe limitations for local roads and streets because of low strength. The base material for roads and streets should be replaced or strengthened with suitable material. Design storm frequency: The storm sewers are designed for a 10 -year storm event. The detention areas are designed for the 100 -year, 10 -year, and 2 year 24 hour storm events with the SCS -II hydrograph. The applicable rainfall amounts for the 2yr, 10yr, and 100yr frequencies of the 24 hour storm duration are derived from the Technical Paper No. 40 of the National Weather Service provided from the State of Indiana Department of Natural Resources Division of Water. REFERENCES Design and data methods are based on the following references: 1. City of Carmel Stormwater Technical Standards Manual 2. Hamilton County Soils Survey OVERALL WATERSHED Morrow Follett Legal Drain UNDEVELOPED SITE DATA The existing site contains three existing homes. There are mature trees and established grass. The overall existing watershed drains in three directions. West into Rangeline Road, east to an alleyway and rearyards of existing homes, and then south into 4 Street. There are no existing storm sewers directly within the vicinity of the site. The existing watershed is approximately: EX -W 0.48 acres, EX -E 0.17 acres, and EX -S 0.14. The site has roughly 2.5 feet of fall across the site from the middle to the west and east. The following is a summary of the peak discharge rates: BASIN 2 -Year 10 -Year 100 -Year T:\7k\7310\002\drainage\4580001drainrep.doc EX -W 0.53 cfs 1.04 cfs 2.31 cfs EX -E 0.21 cfs 0.41 cfs 0.92 cfs EX -S 0.12 cfs 0.24 cfs 0.51 cfs DEVELOPED SITE DATA The proposed development will encompass renovating the existing home on the southwest corner of the property, relocated 1 historic home to the southeast corner, and then adding 3 mixed -use office /retail and residential buildings. A parking lot will be constructed in the middle to serve the mixed -use buildings and will utilize the existing curb cuts on Rangeline Road and 4 Street. There will be thre proposed watersheds for the development. One basin is defined as "602" (storm inlet structure number) and is located in the middle of the parking lot. All runoff from this watershed will be directed to this inlet where a 6" PVC pipe will serve as a reducer in the 12" RCP pipe. This reducer will allow water to stage in the inlet structure itself allow for detention on site. Stormwater quality for the parking lot impervious areas will be handled through a "treatment" train of pervious pavement and a Snout Catch Basin Insert, prior to leaving the site. The remaining two proposed watersheds will maintain the existing discharge locations to the south and west. The runoff from these direct basins will be through established grass acting as a filtering device and slowing velocity, via sheet flow. The following is a summary of the peak discharge rates: NODE 2 -Year 10 -Year 100 -Year PR-W 0.27 cfs 0.52 cfs 1.15 cfs PR -S 0.12 cfs 0.24 cfs 0.51 cfs 602 1.47 cfs 2.13 cfs 3.61 cfs 600 0.51 cfs 1.01 cfs 2.25 cfs FACILITY DESIGN The storm sewer facilities are designed to collect stormwater runoff and detain the release such that the peak discharge rates from the site are Tess than the allowable rate as discussed in the above topic of "Design storm frequency This is to be accomplished with a 6" reducer in the outfall pipe to stage water in the inlet structure. Below is a summation of this and their performance in the 100 year storm event. T:\7k\7310\002\drainage\4580001drainrep.doc Inlet Summary INVERT 100 yr Casting. Elevation Structure 602 830.00 ft 834.43 ft 834.00 ft SUMMARY The detention system is designed to release the developed site's storm runoff at as much of a reduced peak flow rate possible with a 6" reducer pipe at the inlet structure where the bulk of the impervious surface areas are located.. Node "602" EX -E Post Developed Rate (cfs) Pre Developed Rate (cfs) 100 year 1.99 cfs 0.92 cfs 10 year 1.86 cfs 0.41 cfs 2 year 1.34 cfs 0.21 cfs PR -W EX -W Post Developed Rate (cfs) Pre Developed Rate (cfs) 100 year 1.15 cfs 2.31 cfs 10 year 0.52 cfs 1.04 cfs 2 year 0.27 cfs 0.53 cfs PR -S EX -S Post Developed Rate (cfs) Pre Developed Rate (cfs) 100 year 0.51 cfs 0.51 cfs 10 year 0.24 cfs 0.24 cfs 2 year 0.12 cfs 0.12 cfs T: \7k \7310 \002 \drainage \4580001 drainrep.doc