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HomeMy WebLinkAboutTract Map 3552 Lot 93 Hydrology -, - e ., City of Temecula Public Works Department 43200 Business Park Drive-Temecula, Gl92590-Mailing Address: PO. Box 9033-Temecula, GI 925B9-9033 1909/694-6411 - Fax 1909/694-6475 November 18, 2002 Chuck Gunderson 43925 El Lucero Place Temecula, California 92592 RE: Hydrology Review and Calculations for Property Located at Cabrillo Avenue and John Warner Drive (Lot 93 of Tract 3553, LD02-114GR) Dear Mr, Gunderson: I am in receipt of your hydrology report received by our office on November 12, 2002, The report provides a comparison of the before condition and after condition along with the presentation of mitigation measures in response to the City's letter dated October 28,2002. Our review of the report and the hydrology calculations have identified and confirmed that the redirection of storm waters to the southeast comer will change the characteristics of the present flows (before condition). The report identified two mitigation measures needed to protect the property downstream of Lot 93. . Raising the existing asphalt berm/asphalt dike from the southerly downstream channel to the easterly driveway entrance. . Raising the easterly driveway on the downstream property (Lot 80) with asphalt to provide drainage toward the street flow line, The recommended mitigation measures will provide protection to the southerly property (Lot 80) by directing the storm flows to the existing drainage channel downstream of the existing 2 - 12" culverts, at the John Warner Road and Cabrillo Avenue intersection. Although the proposed improvements to Lot 93 and Cabrillo Avenue will minimize the amount of storm waters that are collected in Cabrillo Avenue, the report indicates that the concentration (doubling the quantity) of the storm flows at the northeast comer ofCabrillo Avenue and John Warner Drive will make the flooding situation worse at the intersection, Prior to approval, your grading plan must be modified to include the proposed mitigation measures on Cabrillo Avenue and the installation of a storm drain system replacing the 2 - 12" culvert pipes currently in place, The improvement plans shall include plan and profile drawings along with upstream and downstream entry and outfall structures. The storm drain should be designed to convey the tributary 100- ~~ \ * Primed on Rec~'Cled Paper R:\hughesb\2002\letters\Gunderson Letter/ajp ? - e , Chuck Gunderson November 18, 2002 Page 2 Because the City recognizes that the 2 - 12" culverts are inadequate to handle the existing storm flows, I am prepared to recommend to the City Council that the City participate in half the costs of the storm drain improvements, Ilook forward to discussing the proposed revisions Thursday morning. Please feel free to contact me at (909) 694-641 L Sincerel~:r ~ J~flV '-- . William G, Hughes . Director of Public W orks/City Engineer R:\hughesb\2002\letters\Gunderson Letter/ajp U