SU0013451 - Laserfiche WebLink

Home Browse Search

SO. It is possible that during these short periods of high flog: (1-5 days) , enough water could be pumped from the river to completely fill the lakes . To obtain water from the Mokelumne River a pump station would be located at Point "A" . The existing drainage channel to the river would serve as the supply channel to the pump station. Pumped ground water, ulthough expensive , is probably the most reliable source of water available and would serve as a supplement to the other sources . Ground water would be supplied from pumps located near Points "C" and "D" . The pump locations are intended to supply water to the upper ends or arms of the lakes so as to provide better circulation and better water quality. Water Containment The water storage capacity of both lakes would be increased by excavation of approximately 10 feet of bottom material from the main bodies of the lakes . This will also help reduce the potential for excessive growth of aquatic vegetation. Approximately 450 , 000 cubic yards of material will be excavated from North lake and approximately 900 , 000 yards from South Lake . In order to decrease the potential for seepage losses the bottoms of the lakes will be sealed with compacted native clay. Some shore line modification will be dobe to create islands for waterfowl and to create additional shore line habitat and storage volume. A portion of the channel connecting the two lakes will be filled and a culvert and control gate installed at j point "B" so that the water levels in the two lakes can be maintained independently of one another. The water level in North Lake would be maintained at a constant level of approximately 20 feet in elevation in order to allow a more permanent shore line and aquatic environment to become established. This would be accomplished by a controlled release of water from South Lake to replenish water lost from North Lake due to evaporation, seepage and irrigation. If the water level in South Lake becomes lower than that of North Lake, the water level in North Lake would be maintained by pumping from South Lake or from ground water pumping. After excavation, the capacity of North Lake corresponding to the 20 foot water level would be approximately_ 640 acre feet with a surface area of approximately 40 acres . South Lake will serve as the primary water storage location. Runoff from Jahant Slough and any available water from the Mokelumne River will be stored in South Lake up to a maximum water surface elevation of approximately 25 feet. If necessary, groundwater pumping would be utilized on a limited basis to maintain a minimum acceptable water surface elevation. In order to prevent flooding of a large portion of the riparian forest and the western portions of the property when South Lake is filled an embankment will be constructed at Point "E" . A culvert will be installed to allow for water to be supplied to North Lake. After excavation, the capacity of South Lake corresponding to the 25 foot elevation will be approximately 2, 250 acre feet with a surface area of approximately 265 acres . A stage 4