6525 HARDESON RD BASE FILE 2016-01-01 MF Import

p�,-ntion Summarv The detention tacility for the site will be a combination detention / wet pond located in the northwest corner of the site. The Open Water cell has a bottom elevation of 502.50 and the Wetland Treatment cell has an average bottom elevation of 504.00. The pond has a nortnal water surface at elevation 505.50 and a maximum water surface elevation of 509.50 with a berm elevation of 512.00. The peak stage for the 100 year, 24 hour design storm event for the site is at elevation 508.94. The pond was oversized to provide additional dead and live volume for possible future project and property modifications as summarized below. Water quality enhancement will be provided in the form of dead storage. The dead storage volume is divided into two cells. The Open Water cell provides 61,861 cubic-feet of dead storage volume while the Wetland Treatment ceil provides 8,186 cubic-feet of dead storage volume. The volume of dead storage required is 52,793 cubic feet. As designed the pond pro��des 70,047 cubic-feet of dead storage volume. Therefore, the pond provides 17,254 cubic• feet of surplus dead storage volume which may be utilized by future project and property modifications. Stream bank erosion control will be provided in the form of live storage. The Seaway / Tract #3 site (21.84 acres) requires a live storage volume of 141,554 cubic-feet based upon allowable release rates and a volume correction factor of 47%. As designed, the pond provides four feet of live storage depth startirg at elevation 505.50 and ending at elevation 509.50 for a total live storage volume of 168,966 cubic feet. Therefore, the pond provides 27,412 cubic-feet of surplus live storage volume which may be utilized by future project and property modifications. Storm Drarnage Repor! For King Exlrusion - Page l3 I