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HomeMy WebLinkAboutCorrespondence e e 05D ~ O()~?) Pt' t-.. EL ~ RfCffltED AlAY 1 2 2005 DOCS May 11,2005 ]Ai\1ES BRAJN.ARD, l'v1A"YOR Mr. J. Cort Crosby, PE The Schneider Corporation Historic Fort Harrison 8901 Otis Avenue Indianapolis, IN 46216-1037 RE: Runyon Hall Primary Plat-Preliminary Drainage Review Dear Mr. Crosby: The Department of Engineering has received the Preliminary Drainage Calculations submitted for the Runyon Hall Development. The Department of Engineering understands that the Plan Commission has requested assurance that the proposed drainage plan is feasible prior to moving for\vard with the process of approving the final plat. As we have discussed on the phone, the drainage aspects of a project are not typically reviewed at the Primary Plat stage. The Department of Engineering did not revie\v the submitted drainage calculations since the Department would expect no less than a systenl designed to meet the City requirements related to detention facility sizing. If there were a portion of a downstream or receiving system that would govern the allowable release rate from the Runyon Hall detention system, the Departn1ent \vould expect the detention facility to be sized in accordance with that most restrictive aspect of the downstream system. The Department will review the final calculations when they are provided. The Department did revie\v the proposed drainage plan as it relates to the existing Ashton and Woodfield Developments and the provisions made in these developments to accommodate the storm water runoff presently generated from the property that will become the Runyon Hall Development. Based on a review of the record drawings and drainage calculations for the Ashton and Woodfield Developments on file in the Department of Engineering, it is apparent that provisions have been made in the Ashton Development to receive runoff from an off-site \vatershed. It is also apparent from the record drawings that the runoff from the Woodfield detention pond has been routed around the Ashton Development and is not introduced into the Ashton drainage system. The pond sIzing calculations for the Ashton Development anticipated a 137-acre watershed. The Ashton Development is 74.40-acres total which would leave_62.60-acres for off-site contribution. The Department \vould not expect that drainage from Hazel Dell Parkway, Avian Glen or Cherry Tree Elementary would enter the Ashton drainage system. As the Woodfield drainage is routed around the Ashton Development, the Department would expect that the only runoff that could enter the Ashton drainage system is from any portions of Woodfield that are not directed into the Woodfield detention pond and the Runyon Hall watershed. The Runyon Hall watershed is 51.81-Acres (including some indirect contributions from off of the Runyon Hall property and an area that drains to\vards 146th Street) \vhich would leave 10.79-acres of other contributions that the Ashton detention pond could still accolllmodate. The Departnlent did not investigate the potential for drainage from 146th Street or for property north of 146th Street to enter the Runyon Hall drainage system as it would be expected that 146th Street drains to the east via the system of inlets and pipes within the existing road\\'ay. Record drawings for the Ashton Developnlent and pictures provided from The Schneider Corporation indicate that a 36-inch pipe was installed as a part of Section 2B of the Ashton Developnlent to accommodate off-site runoff. This pipe was installed to the property line. This 36-inch pipe was to have been COilllected to a 48-inch pipe installed as a part of Ashton Section 1. The connection was never made DEPART~lENT OF ET\GINEERING ONE CIVIC SQUAI\E, CARlvlEL, IN 46032 OFFICE 317.571.2441 FAX 317.571.2439 El\lAIL engineering@!ci.carn1el.in. us e e Mr. J. Cort Crosby, PE May 11,2005 Runyon Hall Primary Plat-Preliminary Drainage Review Page 2 of2 however. The discharge from the Section 2B system was discharged directly to the Ashton detention pond. The 48-inch pipe had a design flow of 86.5-cfs and a total capacity of 10 1.9-cfs that is indicative of a large watershed. It is also apparent that a swale has been installed along the eastern property line of Woodfield to direct runoff from the north (essentially the Runyon Hall watershed) to the existing 36-inch pipe. The Department is of the opinion that based on the existence of this swale that the Ashton drainage system is presently receiving runoff from the Runyon Hall watershed. As it is apparent that the Ashton drainage system is presently receiving runoff from the Runyon Hall watershed and it is apparent that provisions have been made in the original design of the Ashton drainage system to receive this offsite runoff, the Runyon Hall development should be allowed to discharge runoff into the Ashton drainage system. The calculations, in addition to what would otherwise be required to demonstrate that the Runyon Hall detention system meets the minimum City and/or County standards, must confirm that the downstream system did indeed accommodate the off-site acreage from the Runyon Hall watershed in the initial design. The Runyon Hall system must be designed with the most restrictive aspect of the Ashton Drainage system in mind, regardless of the allowable release rate based solely on the acreage of the existing Runyon Hall watershed. The Department requests that the calculations include an analysis of the effect that the runoff froll1 the Runyon Hall development will have on the existing Ashton detention ponds stage-storage levels and the 2, 10, and 1 OO-year pond elevations. Based upon a further review of the Runyon Hall preliminary drainage plan after my email dated May 9, 2005, the Department will consider a system that directs the majority of the runoff from Runyon Hall into the Ashton drainage system. The Department understands that approximately 15% of the Runyon Hall \vatershed presently drains into the Woodfield Development. The Department of Engineering certainly appreciates the consideration to help the existing drainage problems being experienced in the Woodfield Development provided that it is demonstrated in the calculations that the Ashton drainage system is able to receive the runoff from the entire Runyon Hall watershed. The Department of Engineering recommends that the Plan Commission allow the Runyon Hall Development to proceed to the Secondary Plat stage. The Department of Engineering will review the more detailed drainage calculations provided with the Construction Drawings and Secondary Plat submittal to confirm compliance with the City's standards and other restrictions that may govern the design of the Runyon Hall drainage system. The Department of Engineering reserves the right to request changes to the approved primary plat to the extent that they are necessary should the secondary plat review require modifications based on a review of the more detailed design. If you have questions, please call me at 571-2441. cc: Jon Dobosiewicz, Department of Con 1m unity Services Greg Ilko, Crossroads Engineers Greg Hoyes, Hamilton County Surveyor's Office Project File Engineering Departnlent Review \\Apps2\user data\eng\shared\gduncan\Runyon H.all Preliminary Drainage.doc " ~. .. e e NATURAL RESOURCES PLAN REVIEW AND COMMENT Hamilton County Soil and Water Conservation District 1108 South 9th Street, Noblesville IN 46060 Ph- 317-773-1432 or Email at .ohn-south Project Name- Runyon Hall Primary Location- South side of 1 46th St, ~ mile west of Hazel Dell. Acreage- 39 ac Owner/Developer- Estridge Development Engineer- Cort Crosby Schneider Corp. 8901 Otis Avenue Indianapolis, IN 46216 Plan Review Date: March 15, 2005 Soils Information: Br Brookston silty clay loam This is a poorly drained soil with a seasonal high water table at 0.0 to 1.0 ft. This soil is located on depressions and is subject to ponding; slopes are 0 to 2 percent. The native vegetation is water tolerant grasses and hardwood trees. The surface layer is silty clay loam and has moderate to high organic matter content (2.0 to 6.0 percent). Permeability is moderately slow (0.2 to 0.6 in!hr) in the most restrictive layer above 60 inches. Available water capacity is high (10.0 inches in the upper 60 inches). The pH of the surface layer in non-limed areas is 6.0 to 7.3. This soil is hydric. Wetness is a management concern for crop production. This soil responds well to tile drainage; it is designated not highly erodible (class 3) in the Highly Erodible Land (HEL) classification system. CrA Crosby silt loam, 0 to 3 percent slopes This is a somewhat poorly drained soil with a seasonal high water table at 0.5 to 2.0 ft. This soil is located on rises on till plains; slopes are 0 to 3 percent. The native vegetation is hardwood forest. The surface layer is silt loam and has moderately low to moderate organic matter content (1.0 to 3.0 percent). Permeability is very slow (< 0.06 in!hr) in the most restrictive layer above 60 inches. Available water capacity is moderate (6.2 inches in the upper 60 inches). The pH of the surface layer in non-limed areas is 5.1 to 6.5. Droughtiness and wetness are management concerns for crop production. This soil responds well to tile drainage; it is designated potentially highly erodible (class 2) in the Highly Erodible Land (HEL) classification system. MmA Miami silt loam, 0 to 2 percent slopes This is a well drained soil with a water table at a depth greater than 40 inches. This soil is located on rises on till plains; slopes are 0 to 2 percent. The native vegetation is hardwood forest. The surface layer is silt loam and has moderately low to moderate organic matter content (1.0 to 3.0 percent). Permeability is very slow (< 0.06 in!hr) in the most restrictive layer above