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fishway. A portable or semi-permanent, experimental facility could be constructed and installed at a low-head structure to test if fish would use a fish passageway. An experimental facility would cost far less at a low-head structure than at a medium-height structure such as the one proposed at Redlands. 4. Biological problems using a fish passageway: 1) It is not recommended that fish passage be provided in reaches that may be on the fringe of the squawfish's historic range, if there is uncertainty if successful spawning did or would occur there. Additionally, fish passage should not be used if it is soley to add habitat that is not currently limiting. If sub-adult and adult habitat is not limiting in reaches currently occupied, simply adding more habitat in other reaches cannot be considered beneficial to the population. Cited as an example is the river reach above the Grand Valley Diversion. This low-head irrigation diversion is the first in a series of three irrigation diversions in river reaches that may be on the fringe of current as well as historic range of the squawfish. Fish that move upstream of the Grand Valley Diversion would encounter another medium-size barrier, the Price Stub Dam. The three-mile river reach between these two barriers has been used recently by one radio-tagged squawfish. This fish was observed at the base of the Price Stub Dam in both the summer of 1986 and 1987. In both years, this fish originated below the Grand Valley Diversion, and successfully negotiated up- and downstream passage of the diversion. The extent of use by other adult squawfish in this reach is unknown. Assuming that adult squawfish habitat is not limiting downstream of the Grand Valley Diversion, providing more adult habitat in other river reaches, such as that upstream of the Grand Valley Diversion, may not be beneficial to the population, unless fish successfully spawn there, thus enhancing the population. Barrier Type: Medium 1. Consequences: Obstruction of upstream movement during all flows 2. Solution: 1) Until information is known about the ability of the squawfish to use a passive fishway, less costly methods, such as trapping and trucking is recommended. Once information is obtained that indicate squawfish will use a passive fishway, (e.g., from one built at a low-head structure), then consideration could be given to expand and incorporate that facility to a medium-size structure. 3. Biological benefits using a fish passageway: 1) Population "maintenance". This is considered maintaining the population at status quo. Allow and maintain undisrupted movement to priority areas presently occupied, either to enable upstream movement of adults to known spawning areas, or to allow fish downstream access to known spawning areas and upstream return after spawning. 12