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23 and power generation (U.S. Fish and Wildlife Service 1981), 128 km of river channel whooping crane habitat have been lost. In the remaining 120 km of the Platte River channel that crosses the breadth of the migration path, there has been a 58 to. 87 percent reduction in channel area due to encroachment of woody vegetation and a 70 percent loss in the average annual flow since 1930. As much as 97 percent of suitable crane roosting habitat has been lost in some river segments. Over 73 percent of native grasslands and wetlands adjacent to the river channel have been lost due to declines in river flows, construction of drainage systems, and conversion to cropland (Currier et. al. 1985). Considering the significant loss of river channel and adjacent wetland habitat, the need to prevent further deterioration of habitat was identified by the U.S. Fish and Wildlife Service 0 981). The findings of the Platte River Ecology Study suggest that a long term goal should be to establish management areas under public ownership or otherwise managed specifically for cranes. These areas would be managed to prevent further channel shrinkage and encroachment by woody vegetation. Along the Platte River, roosting habitat suitability criteria (Ward and Anderson 1987, Armbruster 1990) combined with hydraulic simulations of Instream Flow Incremental Methodology (IFIM) have been used to identify the relationship between river discharge and roosting habitat (Platte River Management Joint Study 1990, Ziewitz 1992). The IFIM consists of a collection of computer models including the Physical Habitat Simulation Model and analytical procedures designed to predict incremental changes of habitat resulting from incremental changes in river discharge. The models that have been developed with this methodology are based solely on physical features of Platte River roosting habitat. The purpose of this application is to characterize the relationship between river discharge and the quantity and quality of whooping crane roosting habitat based on physical habitat parameters within the channel. The models are designed to be used as a tool for evaluating water management alternatives for roosting habitat on the Platte River and in selecting a river discharge that will provide the necessary quantity and quality of roosting habitat. A river management plan prepared by the Biology Workgroup of the Platte River Management Joint Study (a group of representatives from the U.S. Fish and Wildlife Service, Bureau of Reclamation, Corps of Engineers, States of Wyoming, Colorado, and Nebraska, water development interests, and environmental groups) identified management alternatives that could be implemented in the Platte River basin as an aid to future management direction (Platte River Management Joint Study 1990). Currier et al. (1985) and Strom 0 987) describe management programs to preserve, rehabilitate and restore river habitat. Other research conducted along the Platte River (Hurr 1983, Henszey and Wesche 1993, Wesche_Zl. 1990) indicates river discharge and stage is a dominant factor affecting groundwater levels in wet meadow grasslands. This information has implications to river flows required to maintain the wet meadows used by cranes. The Platte River Whooping Crane Habitat Maintenance Trust (Trust) began implementing their habitat restoration program in the early 1980's. The Trust is acquiring land through fee title acquisition and conservation easements. Restoration activities include clearing and maintaining river roost sites free of trees and shrubs and restoring and rehabilitating wetland meadows and marshes adjacent to the river channel. Human activity near river roosts and wetland meadows is restricted during the migration periods.