Laserfiche WebLink
• <br /> <br />Elevation (8/27/86) Design <br />Capacity Cum. Capacity <br />(Ac-ft) (Ac-ft) (1986 Survev) <br />Capacity Cum. Capacity <br />(Ac-f t) (Ac-f t) (1987 <br />Capacity <br />(Ac-ft) Survey) <br />Cum. Capacity <br />(Ac-ft) <br />6566.0 0 0 0 0 0 0 <br />6568.0 0 0 0.27 0.27 0.03 0.03 <br />6570.0 0.59 0.59 0.68 0.95 C.50 0.53 <br />6572.0 0.94 1.53 0.94 1.89 0.93 1.46 <br />6574,0 1.20 2.73 1.20 3.09 1.18 2.64 <br />6576.0 1.46 4.19 1.46 4.55 1.46 4.10 <br />6577.1 0.94 5.13 0.94 5.49 0.98 5.08 <br />6578.0 0.84 5.97 0.84 6.33 0.92 6.00 <br />6580.0 2.02 7.99 2.02 8.35 1.85 7.85 <br />At the principal spillway elevation of 6577.10, the design sediment storage was 5.13 <br />ac-ft; whereas, the 1986 and 1987 annual sediment survey indicates a sediment storage <br />volume of 5.49 and 5.08 ac-ft, respectively. The design and the 1987 sediment survey are <br />very similar. <br />• Based on the design: <br />(1) 10-year, 24-hour precipitation event generated a MUSLE sediment volume equal to <br />0.05 ac-f t. <br />Based on the 1987 annual sediment survey, the equivalent sediment generated from <br />approximately 102 10-year, 24-hour precipitation events could be stored beneath the <br />principal spillway elevation. This is a conservative amount of sediment storage; <br />therefore, at this time, no remedial sediment clean-out work is scheduled for the <br />five-year permit term. <br />Sediment Pond 004. Design information and calculations for this pond were submitted in <br />the Seneca II Permit Renewal Application (8/27/86), and subsequently approved by CMLRD. <br />In 1986 and 1987, Sedimentation Pond 004 was resurveyed as part of Seneca's annual <br />sediment survey. The survey information was utilized to develop a contour map. This data <br />was used to calculate the remaining sediment storage beneath the principal spillway. <br />• Following is a comparison of the design, the 1966 and the 1987 annual survey volume <br />calculations: <br />7-11A-7 <br />