Loading...
HomeMy WebLinkAboutDrainageConn, Angelina V From: Sent: To: Cc: Subject: Attachments: Willie, Gary is comfortable with our results. Thank you, Eric Eric, If you have any questions, please fill free to call us or Gary. Eric A. Carter, R.L.A., ASLA Project Manager, Commercial Development Weihe Engineers, Inc. 3171846 6611 weihe. net TivV--e_ Eric Carter [cartere@weihe.net] Friday, July 23,2010 9:32 AM whall@crossroadengineers.com Greg Ilko; Duncan, Gary R; Jamie Shinneman; Jon C. Dobosiewicz (E- mail); Conn, Angelina V RE: Carmel Turkey Hill Store 602 review 10 yr.pdf; C105 Utility Plan.PDF We met with Gary Duncan today regarding his concerns. We provided to him calculations that include the downstream pipe under Carmel Drive to model it for a 10 yr event. (see attached) The model shows that the downstream pipe under Carmel Drive has capacity to handle the 10 -yr storm event from the Turkey Hill site, our eastern adjacent site, and Carmel Drive R/W. The attached updated utility plan reflects John Thomas' comments regarding water quality. We have added sumps with snouts and bio- skirts on inlets to aid stopping any oil and gas that might enter the system. Please accept this email as our final response for you to release us with approval. Original Message From: Duncan, Gary R [mailto:gduncan @carmel.in.gov] Sent: Monday, June 07, 2010 4:15 PM To: whall @crossroadengineers.com; Eric Carter Cc: Greg Ilko Subject: RE: Carmel Turkey Hill Store 602 review I know that when we talked about this project, I waived the requirement for the downstream analysis since we would consider this project under the City's redevelopment policy. Under a redevelopment scenario, if there is an existing site without a history of drainage issues and the downstream system also does not have a history of drainage issues, it is expected that the downstream system is able to accommodate the runoff from the existing 10 -year rain event. This is the case for this site and the reason for waiving the requirements of Section 302.12 of the Storm Water Technical Standards. 1 However, it has become apparent in the drainage design that the infrastructure under Carmel Drive is not appropriately sized for the 10 -year rain event from the site itself. This infrastructure must also receive runoff from a portion of the City right -of -way and the property to the east. This was not apparent when we met and discussed this project. An analysis needs to be conducted to establish if a more restrictive release rate is required for this site under the provision of Section 302.02 "Downstream Restrictions I am concerned that if the outfall for this site is considered an open /free discharge that in operation there may be negative impacts to the property and that water might stage on -site above the MPLAG and MFPG established. Any additional detention required to be provided may be in direct proportion to the ratio of the site watershed to the overall watershed draining to the pipe under Carmel Drive. Is the MFPG /MLAG established based on the 100 -year elevation in the on -site detention system, the water surface elevation of 1.25 times the inflow flowing over the overflow structure or the backwater due to the pipe restriction under Carmel Drive? The proposed storm management system appears to locate the overflow underground in a proposed structure. Since it is not apparent that the existing piping system would be able to accommodate such an overflow, it is expected that the overflow path would be via overland flow to the City right -of -way anyway in the event that the outfall is plugged. The Department would not oppose a design that provided for this type of overflow. Two recent project in the area (the KFC and the CVS) proposed such an surface overflow strategy. Also, the piping in the right -of -way must be RCP unless a full time, third party inspector (approved by the City) is present when the piping is being installed in the right -of -way. Payment for this third party inspector would be the responsibility of the developer. Thanks so much, Gary From: Willie Hall mailto :whall ©crossroadengineers.com] Sent: Friday, June 04, 2010 9:47 AM To: 'Eric Carter' Cc: Duncan, Gary R; 'Greg Ilko' Subject: RE: Carmel Turkey Hill Store 602 review Eric, I have completed our review of your resubmittal, and have had meetings with Gary Duncan to discuss. His comments and discussions should be forthcoming. Thanks, Willie William Hall, PE Crossroad Engineers, PC (317) 780 -1555 X 140 From: Eric Carter [mailto:cartere ©weihe.net] Sent: Friday, June 04, 2010 9:17 AM To: Willie Hall (E -mail) Subject: Carmel Turkey Hill Store 602 review 2