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HomeMy WebLinkAboutStorm Water Management ReportDrainage Site Design Civil Engineering Site Planning Water Quality CIVIL SITE SOLUTIONS Civil Site Solutions, PC 337 Main Street, Suite B Beech Grove, Indiana 46107 317 459 -9804 FAX- 947 -0532 STORM -WATER MANAGEMENT REPORT PREPARED FOR: MILHAUS DEVELOPMENT 211 NORTH PENNSYLVANIA STREET ONE INDIANA SQUARE, SUITE 1800 INDIANAPOLIS, INDIANA 46204 Certified by: DECEMBER 16, 2010 David M. Griffee, PE PENN CIRCLE CARMEL, INDIANA o *IIIIti g1 oli Q" RF O'•� _o' N 't� -r PE19700377 STATE OF 11 NDI ANp: G�� ,p it4 /111111 1 %0 Erosion Control Floodplain Management Permitting Construction Services SUM MARY Penn Circle is located on an approximate 6.25 -acre tract of land bound by Pennsylvania Street to the west and Old Meridian Street to the east- southeast and located immediately north of the convergence of these two thoroughfares in the City of Carmel, Hamilton County, Indiana. The project will consist of the development of a multi family community. A developable lot will be reserved at the south end of the site for a future commercial or office use. The site currently drains to the WR Fertig Legal Drain by way of an existing 48 -inch diameter storm pipe that crosses Old Meridian Street at the east southeast property line. Different options for managing the storm -water runoff rate from the proposed project have been explored. The proposed plan is to modify the existing dry detention facility located on property adjacent to the north. This facility currently serves the Meijer store to the north and several other adjoining properties. The proposed plan is to convert the facility into a wet pond and to modify the outlet control structure so that allowable release rates established for the system will be maintained. A copy of the applicable Drainage Analysis prepared by Woolpert and dated April, 1993 is attached. The existing dry pond is designated as Detention Basin C within this report. Detention Basin C is served by a 38 -inch x 60 -inch elliptical pipe outlet and the report establishes an allowable peak 100 -year release rate of 109.25 cfs and a peak 100 -year ponding elevation of 855.31 for this facility. Technical Release 20, "Computer Program for Project Formulation Hydrology was used to assess the proposed project's impact on the above referenced parameters. The data file from Woolpert's report was first replicated then amended to include a runoff basin from the site: On -Site Drainage Area 6.25 acres Full Pennsylvania R -O -W along Site Frontage 1.71 acres Full Old Meridian R -O -W along Site Frontage 2.18 acres Total Drainage Area 10.14 acres 0.01584 mi Runoff Curve Number 95 Time of Concentration 10 min 0.17 hr The runoff operation was inserted as section 020. This runoff hydrograph was added at section 021 to the resultant addhyd hydrograph generated at section 019. This final resultant hydrograph was then routed through Detention Basin C at structure 03. 1 The proposed outlet facility will be a large pre -cast concrete box that will accommodate an attachment to the existing elliptical pipe and a 2 -feet high x 5.5 -feet wide opening set at the normal pool elevation of 850.50. The stage- discharge and stage- storage relationships for Structure 03 were adjusted per the attached computations. The modified TR -20 simulation shows that the proposed peak release rate will be 102.3 cfs and that the peak 100 -year flood elevation in the new wet pond will be 855.24. 2 Meijer, Inc. Woolpert TABLE OF CONTENTS PAGE Abstract 1 Pre Development and Post Development Conditions 1 Allowable Peak Discharge 3 Routing 4 Conclusion 6 Appendix A -1 Drainage Analysis February 1993 Meijer, Inc. 1 ABSTRACT Woolpert This report will establish stormwater detention requirements for the proposed Meijer Store located at the northeast corner of the intersection of Pennsylvania Street and 126th Street and adjacent to Old Meridian Street in the City of Carmel, Hamilton County, Indiana. The proposed development for this 28.7 acre site includes approximately 22.0 acres for a Meijer retail facility and parking areas and 6.7 acres for open lawns, landscaped areas, detention, and existing woods. Presently this site is covered with approximately 24.7 acres of fields /crops and 4.0 acres of woods. The detention facility as modeled in this report will detain the required runoff from the Meijer site and pass the drainage from the multiple tributary areas. These tributary areas include the drainage from Meridian Park Place II, a development to the west of U.S. 31, the undetained drainage from U.S. 31, the Duke property between U.S. 31 and Pennsylvania Street, and the drainage from the Summertrace development to the north of the Meijer property. Hydrographs will be created for each of these drainage areas and combined with the hydrographs for the Meijer property. This report shall analyze the post development runoff conditions for the site and determine the allowable peak discharge for the site, create hydrographs for each drainage area and establish adequate storage and outlet structures to accommodate the necessary detention for this site. This report follows methodology developed in "Urban Hydrology for Small Watersheds," Technical Release No. 55, dated June 1986. The runoff hydrographs and the detention basin routing will be performed using Technical Release No. 20, "Computer Program for Project Formulation Hydrology," dated May 1982. PRE DEVELOPMENT AND POST DEVELOPMENT CONDITIONS The land use classifications and corresponding curve numbers are listed below for the present and post -development conditions of the site. The hydrologic soil groups are determined by the soils permeability and infiltration rate. The CN number is a mass runoff coefficient for each subarea determined by the amount of rainfall and the soils infiltration rate (Soil types are shown for the site on the soil survey map in the Appendix). Pre- Development Condition 28.7 Ac.* Soil Group B Soil Group C Crosby Fallow Crop Open Space Miamian Fallow Crop Brookston Silt Loam Fallow Crop Good Condition Woods Good Condition Good Condition Good Condition Good Condition Drainage Analysis 30% CN 83 7% CN =55 50% CN =88 7% CN =70 6% CN 88 Weighted CN 83 February 1993 Meijer, Inc. 2 Woolperr Post Development Condition The Meijer site will be analyzed in five (5) subareas for the post development condition. The routing for the building and parking areas, consisting of 24.15 acres, will be split between detention areas A and B. Each detention area will have a separate subarea per the area of the site which is utilizes. The subarea for Detention Basin A is 0.55 acres. The subarea for Detention Basin B is 2.0 acres. The subarea for Detention Basin C is 2.0 acres. Site (two equal areas) 24.15 acres* Soil Group B Brookston Silt Loam Impervious Area 25% CN 98 Open Space Good Condition 12 CN 61 Soil Group C Crosby Impervious Area 37% CN 98 Open Space Good Condition 20 CN 74 Miamian Impervious Area 6% CN 98 Detention Basin A 0.55 acres Weighted CN 74 Detention Basin B 2.0 acres Weighted CN 64 Detention Basin C 2.0 acres Weighted CN 67 Tributary Drainage Weighted CN 89 *Worksheet 2 for Runoff Curve Numbers for each area are located in the Appendix. The tributary flows to this site were obtained from the Off -Site Drainage Exhibit, sheet 3 of 4 dated December 30, 1987, and the Preliminary Drainage and Utility Exhibit, sheet SD -1 dated May 19, 1989, developed by Paul I. Cripe, Inc. of Indianapolis, Indiana. (See Appendix Page 3). To the north of the Meijer property is an existing development, Summertrace, which has an existing detention basin that discharges directly onto the Meijer property. This drainage will be picked up in the Meijer storm sewer system. The peak discharge for the property was assumed to be 0.25 cfs /acre. To the west of U.S. 31 is an existing development, Meridian Park Place. Meridian Park Place has an existing detention basin that discharges to U.S. 31. The peak discharge was assumed to be 0.75 cfs /acre. The drainage from U.S. 31 is undetained and the peak flow was determined using the rational method. The Duke property has proposed two detention basins on site, one north of 126th Street, the other south of 126th street. The peak discharges for Duke were obtained from the "Addendum to Stormwater Management Design Calculations on Hamilton Crossing" dated June 1, 1989, and prepared by Paul I. Cripe, Inc. Drainage Analysis February 1993 Meijer, Inc. 3 An existing 29 -inch x 45 -inch pipe collects the Meridian Park Place outflow and the U.S. 31 drainage and outlets onto the Duke property. Duke has proposed to pick up this drainage with a 38 -inch x 60 -inch pipe, route it along 126th Street, add the discharges from their two detention basins and outlet it directly into the Meijer Detention Basin C. The Meijer detention facility'will pass this tributary drainage. The Drainage Area Characteristics (A, CN, Tc) for each of the tributary areas used in the TR -20 Hydrograph Generation were developed from estimated information to meet known peak discharges. Meridian Park Place US 31 Known peak discharge (0.75 cfs /acre) Known pond area, develop stage storage Known site area, assumed type of development, assumed time Trial and error with stage discharge to meet peak discharge Rational method to determine peak discharge Known area, determine CN, assumed time Trial and error to meet peak discharge Duke Site North and South From Paul I. Cripe, Inc. Summertrace Known peak discharge (0.25 cfs /acre) Known site area, assumed type of development, assumed time Trial and error to meet peak discharge The time to travel from the respective subareas to the Meijer property was then added to the developed time of concentration. ALLOWABLE PEAK DISCHARGE The allowable peak discharge (APD) is the amount of runoff allowed from the site. The allowable peak discharge for the site is 0.75 cfs /acre for the 100 -year storm as stated in a letter from Steve T. Cash from the Hamilton County Surveyor's office, dated June 10, 1991. The APD is calculated in the following manner: Woolpert Drainage Analysis February 1993 Meijer, Inc. 4 ROUTING A.P.D. 0.75 cfs /acre for the site tributary flows. Site 0.75 cfs /acre x 28.7 acres 21.53 cfs. Tributary areas: Summertrace 0.25 cfs /acre x 26.8 acres 6.70 cfs. Meridian Park Place 0.75 cfs /acre x 19 acres 14.25 cfs. U.S. 31 -Q= CIA =0.61x 5.8 x 15.8 55.90 cfs. Duke Property North 5.00 cfs. Duke Property South 5.87 cfs. A.P.D. 109.25 cfs. The detention facility for the Meijer property will consist of three (3) dry detention areas, Detention Basin A, B and C, as shown on page 3 of the appendix. The Meijer site has been split into five (5) different subareas per the storm drainage system and the detention basin locations. The hydrograph for the west half of the Meijer site is combined with the outflow hydrograph for Summertrace and the hydrograph for the Detention Basin A. This combined hydrograph is then routed through Detention Basin A. The controlling structure for this basin will be a 30 -inch orifice that will run under 126th Street and discharge into Detention Basin C. The hydrograph for the east half of the Meijer site is combined with the hydrograph for the Detention Basin B and routed through Detention Basin B. The controlling structure for this basin will he the existing twin 24 -inch x 36 -inch culverts that cross 126th Street. These pipes will discharge into Detention Basin C. The outlet hydrographs for Detention Basin A and Detention Basin B will then be combined with the hydrographs created for Meridian Park Place, U.S. 31, Duke North, Duke South and the hydrograph for the Detention Area C. The controlling structure for this basin will be a 38 -inch x 60 -inch pipe that will discharge into the Fertig Legal Drain. The detention facility will he modeled using a stage storage and stage discharge model created for each detention basin and outlet structure. Woolpert Drainage A ne/vsis February 1993 Meijer, Inc. 6 CONCLUSION Woolperr Results: Peak Discharge Elevation Detention Basin A Detention Basin B Detention Basin C 42.11 cfs 857.62 51.55 cfs 855.28 100.04 cfs 855.31 The results of this analysis show that adequate detention and storage is provided with the detention facility designed and modeled in this report. The allowable peak discharge as determined in this report is not exceed when routing the 100 -year storm through the detention facility. The peak elevation for the 100 -year storm for Detention Area A was 857.62, providing 1.38 feet of freeboard. The peak elevation for the 100 -year storm for Detention Area B was 855.28, providing 0.72 feet of freeboard. The peak elevation for the 100 -year storm for Detention Area C was 855.31, providing 1.19 feet of freeboard while the peak discharge of 100.04 cfs was below the allowable peak of 109.25 cfs. The outlet for Detention Basin C will be a 38 -inch x 60 -inch elliptical pipe that will be routed east along the south side of 126th Street to the intersection of Old Meridian Street and then south along the east side of OId Meridian Street to the Fertig Legal Drain. All worksheets, storm routing and other results used in this analysis are included in the Appendix with all input data. Drainage Analysis February 1993 Woolpert Meijer, Inc. A -1 APPENDIX USGS Drainage Map 1 Soils Map 2 Post Development Drainage Area Map 3 Runoff Curve Number Meijer Site Pre Developed 4 Meijer Site Post Developed 5 Detention Area A 6 Detention Area B 7 Detention Area C 8 Time of Concentration Meijer Site Post Developed 9 Detention Area A 10 Detention Area B 11 Detention Area C 12 Hydrograph Generation and Detention Basin Routing Hydrograph Flowchart for '1 -20 Routing 13 1"R -20 Input Data 14-15 TR -20 Output Data 16-34 TR -20 Summary Table 35 -37 Storm System Design Storm Line #1 38-43 Storm Line #2 44-47 Storm Line #3 48 Storm Line #4 49 Grate Analysis 50 Storm Drainage Map Insert Drainage Analyse February 1993