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Attachment 2 <br />West Vadnais Outlet HydroCAD Model Summary <br />Type II, 24 -hour, 100 -year Rainfall = 5.90 inches <br />TKDA run 2/19/04 <br />At Jiggs Pond <br />Existing <br />Proposed* <br />*Includes 4 cfs base flow <br />from West Vadnais outlet at <br />time of storm event <br />(no additional area) <br />Drainage Area — ac <br />35.3 <br />42.1 <br />Peak Inflow - cfs <br />50.63 <br />55.09 <br />Peak Outflow — cfs <br />50.9 <br />35.84 <br />Normal Water Level <br />873.50 (invert elevation <br />twin 36 inch CMP) <br />873.50 <br />100 -Year High Water Level <br />876.3 <br />875.8 <br />Volume inflow — acre-ft <br />10.316 <br />23.828 <br />(West Vadnais outlet <br />portion — 7.9) <br />> The drainage area to Jiggs Pond (excluding the area tributary to West Vadnais <br />Lake) is increased by 6.8 acres. <br />> Peak inflow to Jiggs Pond is increased from 50.63 cfs to 55.09 cfs. <br />> Peak discharge from Jiggs Pond is decreased from 50.9 cfs to 35.84 cfs. <br />> The Normal Water Level of Jiggs Pond is unchanged. <br />> The 100 -Year High Water Level of Jiggs Pond is decreased from 867.3 to 875.8. <br />> The total volume of water reaching Jiggs Pond increases from 10.316 acre -feet to <br />15.928 due to the "Unweave the Weave" project alone (without the West Vadnais <br />outlet being constructed). Adding the conservative condition of the West Vadnais <br />outlet pipe flowing full in the Proposed condition, an additional 7.9 acre -feet of <br />water reaches Jiggs Pond and is directed to Gervais Lake. <br />-17- <br />