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bypass or collection facility and some type of fish handling or disposal. All of these factors eliminate the downstream location as a feasible option. Physical facilities designed for in-reservoir control include both high velocity and low velocity screens. Both the high and low velocity screens constructed in the reservoir would have to be designed to operate for the full range of flow conditions. High velocity screens include Eicher and Modular Inclined Screens. Both of these screen types are intended for use within a reservoir outlet or penstock and both require fish bypass. To meet the criteria set for this study, the reservoir outlets would have to be reconstructed to a size that would pass all flow up to the 100 year event and include the screen. The fish bypass would require a fish collection facility that could retain any bypassed fish for either disposal or transport back to the reservoir. This would require additional operation and maintenance funds for the life of the project. This additional cost in excess of the capitol cost for reconstruction of the outlet works and - requirement for fish handling makes these screen types lower priority for selection than types that have no fish bypass or fish handling. Low velocity screens include traveling and fixed screen types. The traveling screens all require considerable operation and maintenance costs. In addition, there is a possibility that escapement can occur as screen seals wear. The gap between the screen and the seal could exceed the 3/32 inch opening for the criteria for this project. This would not meet the exclusion criteria for the project. The traveling low velocity screens would require a large screen face relative to the flow rate ratio and do not work in a submerged location. The large size would require considerable capitol cost for construction of the civil works associated with these types of screen and high annual operation and maintenance costs. Therefore, traveling screens were not selected for further evaluation in this project. Fixed screens are generally designed for low approach velocities to eliminate fish impingement. Most fixed low velocity screens have a traveling brush to clean the screen face of debris. Any such mechanical device requires additional maintenance over an non-mechanical system. Therefore, fixed screens that can be installed in a submerged location without mechanical gleaning were rated as the best potential device for this project. The two objectives for this project require two different screen evaluations, one that prevents escapement of all life stages and the second that protects to the current industry standard. In this project, impingement was deemed an acceptable consequence of in-reservoir protection. This allowed the evaluation of higher velocity (2 feet/second) fixed screens in this project for both objectives. In addition, for the protection to current industry standards option, a secondary protection mechanism was evaluated in each reservoir in addition to the fixed screens to protect at high flow events. 1 Control Structure Feasibility Evaluation Miller Ecological Consultants, Inc., February 18, 1997 1-34