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I I I I I I I I I I I I I I I I I I I due to overtopping during a storm larger than the spillway could handle. The spillway, as designed, uses very little concrete and all of the material removed from the spillway channel is usable as embankment. Therefore, even if the State Engineer allowed a smaller spillway capacity, the overall cost of the project would not decrease significantly. 5.4 OUTLET WORKS DESIGN The design parameters for the outlet works are as follows: 1. Provide sufficient size to drain the top five feet of reservoir in five days. 2. Provide sufficient size to pass the average stream flow and the owners demands with a minimum head of ten feet. This is estimated to be 61.5 cfs. 3. Provide a guard gate or other positive means at the upstream end of the conduit for shutting off inflow. 4. Make provisions to bypass inflow to the reservoir to meet downs~ream water rights of approximately 46.5 cfs. 5. Design the outlet works to accommodate diversion of the stream during construction. The capacity should be determined during final design. 6. Select the invert elevation of the outlet works to take into account the dead storage requirements of 75 acre-feet for the project. The outlet works configuration was discussed with the State Engineer's office. Normally the State requires the downstream one-half of the outlet works conduit to be nonpressurized. Since a pipeline would connect directly to the outlet works conduit, an exception may be granted. For the purposes of this report, the outlet works is designed as pressurized for the entire length. Flow is controlled by two high pressure slide gates located at the toe of the dam. The main conduit is a 30-inch diameter steel pipe encased in 12-inches of concrete with an 18-inch diameter bypass 5-4