Page | 7 <br /> <br />Figure 4 - Extensive wetlands serve a critical role in stormwater flow control <br /> <br /> <br />3. Grossly Underestimated Detention Capacity: Figure 5 [1] illustrates the alarming discrepancy between <br />the proposed detention capacity and the scientifically calculated need [5]. The plan proposes a mere 1047 <br />cubic feet of capacity, while calculations based on data from the 2003 Hydrologic Analysis and the 2001 <br />ORWAP report, indicate a need for up to 81,806 cubic feet —a difference of over 75 times! This massive <br />shortfall poses a direct threat of increased flooding downstream. The plan severely underestimates <br />detention capacity required to limit peak flows. The plan is limited to a single 24” diameter detention pipe <br />which only provides 1,047 cubic feet of capacity. Oddly, the capacity calculations in the plan are based <br />on a 60” diameter pipe(?). If the plan was revised to use this bigger pipe it would provide 6,538 cubic <br />feet. Goebel Engineering estimated that 17,791 cubic feet of detention should be required, assuming <br />much of the wetlands would remain intact. If wetlands are removed as proposed, 81,806 cubic feet of <br />storage would be required to replace existing capacity [5]. <br />Appeal Testimony (PDT 24-01 & ST 24-03) - Batch #1 Page 33 of 43