Laserfiche WebLink
• structure of 50' x 50' at the top and 46' x 46' nt the bottom. Thie design <br />includes an emergency spillway but does not anticipate the need for a principal <br />spillway. It is planned to pump out water to leave significant storage to <br />accommodate run-off from a 30 yeas, twenty four hour storm event. This emer- <br />gency spillway provides a non-clogging conduit avenue to remove water storage <br />resulting from inflow. This conduit will be located on the West end of the <br />sediment pond and will be located at a higher level than the maximum sediment <br />storage level. As recommended by PETER O'CONNOR, a staff gauge will be'instal- <br />led to determine the 60Y sediment cleanout level. <br />SEDIMENT POND SIZE <br />The pond is 50 feet wide, 50 feet long, and has a normal depth of <br />about 4 feet. See attached letter from ANNE BALDRIGE. <br />CALCULATION OF SURFACE RUN-OFF <br />PEAK WATER RUN-OFF AND SEDIMENT POND SIZE: <br />By regulation, the ponds must handle precipitation from an expected ]0 <br />yeas, twenty four hour storm event. <br />Referencing: NationalOceanic and Atmospheric Precipitation <br />Atlas and Soil Conservation Service's Technical Release Peak Flows in <br />Precipitation data is listed. 2.5 inches is the predicted precipitat <br />Converting inches to acre feet <br />2.25 inches water <br />Disturbed acreage <br />= 0.]9 acre ft. water <br />= 3.0 acres excluding road <br />I <br />surfaces not in disturbed <br />area <br />0.79 x 5.36 <br />to be contained in sediment pond. <br />57 acre ft. water <br />