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Page 3 <br /> RE: Bridges Technology Center <br /> Mounds View, MN <br /> Clark Comm. No. C95104 <br /> CL_ B. Water Quantity <br /> ENGINEERING As mentioned above, the Proposed Pond and Future Pond are for <br /> CORPORATION water quality only. It is proposed that a portion of Outlot A be used <br /> to provide for the live storage or what can be said to be the <br /> difference of the storm water runoff of a 24 hour duration storm <br /> with a 100-year-reoccurrence-for-the-existing-conditions versus the <br /> proposed conditions on Lots 1, 2, 3 and Outlot A. <br /> With the use of computer modeling, estimates of storm water runoff <br /> flows from Lots 1, 2, 3 and Outlot A were determined for a 1 year, <br /> 10 year and 100 year storm event. <br /> Discharge from Outlot A is limited to the 100 year storm event for <br /> the existing site conditions. Assumptions were required to determine <br /> the conditions after development to the three lots. "C" values were <br /> given the following, wetlands 75, pond areas (water) 99, building <br /> and pavement 98, and grass area 60. <br /> Through modeling the results of a 100 year storm event having a 24 <br /> hour duration on Lots 1, 2, 3 and Outlot A would produce <br /> approximately 21 CFS of storm water runoff into Outlot A. <br /> Using this information in our model, restricting the discharge rate <br /> from Outlot A to approximately 21 CFS, the high water elevation in <br /> Outlot A after Lots 1, 2 and 3 are developed, would be 902. This <br /> is 2 feet above the estimated normal water level elevation in Outlot <br /> A of 900. This can be reviewed by looking at the model of existing <br /> conditions. <br /> This would require minimal berming at several locations indicated on <br /> Sheet Cl of the Item 3 Calculations. <br /> Please refer to the attached sheets for computations. <br />