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be constructed according to approved plans and provides 126 cubic yards of live storage below <br />Otter Lake's HWL. <br />SCHWARTZ/MELTON SITE DRAINAGE <br />The recent survey of the swale running from the low area on the northeast corner of the <br />Schwartz's property to the Melton pond shows a slightly negative flow gradient. The swale high <br />point appears to be approximately 0.5' above the lowest spot on Melton's property. According to <br />Bob Adamson's November 10, 1999 letter, the Melton's have agreed to regrade the swale to <br />provide adequate drainage. <br />SUMMARY <br />Approximately 650 cubic yards of live storage was constructed in the form of the two water <br />quality ponds. This volume is in excess of the required 640 cubic yards of compensatory <br />floodplain storage. Live storage created in the ponds should qualify as compensatory floodplain <br />storage because 1) the live storage in both ponds is directly connected to Otter Lake's floodplain, <br />2) as -built live storage between pond runout elevation and Otter Lake's HWL of 912.9 was <br />calculated correctly, and 3) rate control was not required for this permit (which eliminates the <br />possibility of "double counting" live storage needed for both rate control and compensatory <br />storage). <br />The Melton swale is insufficiently graded to provide adequate drainage from the northeast <br />• portion of the Schwartz's property. <br />RECOMMENDATIONS <br />I recommend the following: <br />• The compensatory storage created in the two ponds suffices as compensatory floodplain <br />storage as required by the RCWD permit. <br />• The Melton swale is regraded to provide adequate drainage from the Schwartz property to <br />the pond. <br />Please distribute this memorandum to all interested parties. Feel free to refer questions to me at <br />(612) 595-5261. <br />-2- <br />