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As shown on Map C -2, Pond #2 is 1.15 acres in surface area, therefore, its required depth is 2.9 feet <br />to hold 3.34 acre feet. It will be constructed to 3.3 feet deep and 2H:1 V sideslopes. All other ponds <br />will use similar slopes. <br />Runoff from the initial gold mining area and the prep plant area will be directed to Pond 4. Although <br />Pond 4 generally contains water, it is never allowed to be within 3 feet of the top of the dam. There- <br />fore, storage volume is available for storm runoff. <br />Since only 1.0 acre feet of storage is needed and the pond contains 1.65 acres x 3.0' height = 4.95 <br />acre feet available, the pond is more than adequate to contain the runoff from the 100 year storm for <br />the drainage area designated. Pond A will also handle the runoff from the sand and gravel mining <br />operation. The large pond area combined with the porous pond bottom will ensure that the water <br />seeps into the ground to replenish the water from the pit pumping and to ensure that no discharge <br />occurs from the site. <br />The design parameters for each of the South ponds are given below: <br />Pond <br />Name <br />Sideslope <br />Depth <br />Surface area <br />at top <br />Volume in <br />ac -ft <br />Pond <br />Purpose <br /># 1 <br />2H:1 V <br />3.25 <br />0.25 ac <br />0.8 <br />runoff sediment detention <br />#2 <br />2H:1 V <br />4.25 <br />1.0 ac <br />4.0 <br />runoff storage and seepage <br />#3 <br />2H:1 V <br />3.25 <br />0.25 ac <br />0.8 <br />pit pumping detention <br />#4 <br />2H:1 V <br />3.5 <br />1.2 <br />4.0 <br />Pit pumping seepage /recycle <br />All of these ponds are shown on Maps C -2 and C -4. <br />Alma Placer 1115 23 <br />