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I I I I I I I I I I I I I I I I I I I unknown and there has been no precedent set for placement of this type of plug at other dams. In addition, use of this plug would require that water be pumped over the spillway to meet downstream water demands. (b) use of a fabricated steel plug which would weigh 1,700 pounds and would be designed with a new seal to reduce leakage while in place. Also an 8-inch butterfly valve would be installed in the plug to allow releases of 11 cfs or more into the e~isting outlet pipe for downstream demands without pumping. Because of the location of the intake structure, option (a) would require divers to dislodge and place the concrete plug. In order to move a plug of this weight and size, the reservoir levels would have to be lowered considerably to allow use of a winch on a barge, but the safety and reliability of moving the plug would still be questionable. This process 'HQuld have both negative economic and environmental impacts. The lowering of the water levels would virtually destroy the kokanee salmon and rainbow trout populations in Lemon Reservoir. The CDOW would prefer to avoid this if at all possible. In addition, as a result of the very low levels in the reservoir, water releases downstream would have to be maintained by an elaborate and expensive pump system. Option (b) could be implemented with minimal impacts to the fishery in the reservoir and downstream, as (I) reservoir levels CQuld be maintained near the 14-year average for October and (2) the 8-inch valve would maintain flows in the river with no addi- tional pumping and equipment costs. It was determined, with the assistance of the CDOW, that option (b) would be the preferred approach for this project. Once emergency sary, and the outlet is closed, gates, replace the seats, reassemble the gates. The a crew will disassemble the repair other parts as neces- regulating gates will be 4.0-4