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<br />I <br />1 <br />1 <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />1 <br />1 <br />I <br />I <br />I <br />I <br />1 <br />I <br /> <br />This option would allow normal operations with hydraulically controlled inlet and <br />outlet valves. Discharge through the fixed cone valve would be vibration and <br />cavitation free reducing wear on the tower and outlet tunnel. The hydraulic system <br />could be converted to any type of remote control in the future. <br /> <br />4. Abolish the existing gate tower and replace with a new outlet structure: <br /> <br />This alternative would involve draining Sanchez Reservoir or constructing a coffer <br />dam while the new outlet works were constructed. This alternative is economically <br />unfeasible, <br /> <br />The Company's engineer provided technical engineering assistance in the evaluation of the above <br />alternatives, particularly concerning the type and configuration of valves and operators to be used <br />in the gate tower. The Sanchez Reservoir and gate tower were designed in 1910 to handle 104,000 <br />acre feet of water. Although the original gate tower design allowed for the release of up to 1500 <br />cubic feet per second of water, one of the original 48-inch diameter valves was never put into <br />operation, reducing the maximum release to approximately 1000 cfs. Associated downstream <br />structures have not been developed to handle this volume of water. To date, the reservoir has had <br />a maximum of 67,236 acre feet of storage utilized. Damage to downstream structures and <br />properties has occurred with releases of less than 200 cfs. Appendix B lists Sanchez Reservoir <br />Storage Capacities at gauge height elevations and Appendix C <br /> <br />The biggest obstacle in selecting viable repair and replacement alternatives is being able to achieve <br />emergency drawdown requirements as set forth by the State Engineer's Office. These regulations <br />state that there must be a means of lowering the water level in the reservoir a minimum of one <br />foot per day for five consecutive days, At the historic high level of 67,236 acre-feet, the required <br />discharge is approximately 1000 cubic feet per second. With only two 48-inch valves at the base <br />of the gate tower, it is questionable whether the valve configuration at Sanchez Reservoir has ever <br />been able to meet the drawdown requirements. <br /> <br />THE SELECTED PROJECT <br /> <br />The company has chosen to replace three of the existing 30-inch diameter wedge gate valves with <br />new 30-inch diameter knife gate valves that are hydraulically operated. The remaining three <br />functional 30-inch wedge gate valves will be checked to ensure that they are operable and repaired <br />where necessary. The two lower 48-inch valves will be repaired and the mechanical operators <br />replaced with hydraulic operators. A new 30-inch fixed cone valve will be located in the existing <br />outlet conduit and connected by steel pipe to the opening of the upper 48-inch valve, which has <br />never been operable, A hydraulic operating system capable of being powered by 1201240V AC <br />power or 12V DC power will be constructed to operate the new gates. The hydraulic operating <br />system shall be designed and built to accommodate three future knife gate valves and shall be <br />readily adaptable to future remote control capabilities. <br /> <br />5 <br /> <br />- <br />