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The following is an additional response under Section 2.05.3 (2) as found <br />in Appendix E. <br />An additional 30-inch culvert will be installed along side the existing <br />culvert No. 8. The following calculations result when an additional 30- <br />inch culvert is added: <br />T = 0.34 hours <br />c <br />Drainage = 93.4 acres = 0.15 square miles <br />Runoff = 0.52 inches (1.8 inches rainfall, CN of 82). <br />Peak flow (from Figures 5.2, Reference No. 2) = 650 csm/in. <br />650 cfs/sq. mi. x 0.15 sq. mi. x 0.52 in. i 2 (culverts) = 25.35 cfs <br />inches <br />=Q <br />From the upstream invert elevation to the edge of the road, 5.2 feet of <br />head is available. <br />.~ *Assuming that maximum tail water is at crown of pipe, the following <br />calculations result: <br />Upstream Control Situation <br />W.S. = 7396.6' + 3' = 7399.6' <br />Freeboard = 2.2' <br />Downstream Control Situation <br />W.S. = 7398.0 + 1.6' = 7399.6 <br />Freeboard = 2.2' <br /> <br />M287 <br /> <br />