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numerous water surface elevations throughout the runoff season to develop stage/discharge relationships and assess the floodability of each bottomland. • Identify existing bankfull discharge and flooding discharges for all the bottomland sites. • Perform topographic surveys in order to create mapping, estimate the area of potential flooded bottomland inundation, and identify levee removal strategies to enhance floodability. • Develop area of inundation as a function of flow relationships for each site. • Relate the historical flow magnitudes, frequency and duration to the bankfull discharge and flooded bottomland inundation. • Design restoration alternatives to enhance the floodability of the bottomlands to mimic historic frequencies and durations while avoiding the overwintering of non-native fishes. Site Descriptions The Green River is the major tributary of the Colorado River with a basin draining approximately 45,700 square miles of western Colorado, southwestern Wyoming and eastern Utah. Flows in the Green River have been regulated by Flaming Gorge Reservoir since October, 1962. The major tributaries to the Green River upstream of the ten BLM and ONWR Sites include the Yampa and Little Snake Rivers (Figure 1). Flows in the Green River are primarily snowmelt from the western slope of the Rocky Mountains and annually peak in late May or early June. The base flow period extends from about September to March. The hydrology of the Green River has been altered by water resource development throughou# the basin. Changes which have occurred in the magnitude and duration of discharge are discussed in the hydrology section of this report. Ten Green River flooded bottomland sites were selected for floodability assessment in 1996. One of the main reasons these sites were chosen was because of land ownership. The first five sites were all located on Bureau of Land Management Land (Figure 2), therefore, access was not a problem, and cooperation with the agency facilitated the data collection effort and will permit restoration activities. Similarly, the next five sites, located on the Ouray National Wildlife Refuge (Figure 3), were also easily accessible. Cooperation with the refuge staff enhanced the data collection efforts. In addition to the ease of access, all ten sites provided a wide array of bottomland characteristics, which will allow different levee removal strategies and provide research opportunities to study how native and non-native fish utilize different types of bottomlands and hydraulic connections. The ten bottomland sites are also in proximity of the razorback spawning habitat near the Jensen gage. Under existing conditions, all ten sites act as depressions which are inundated by high runoff flows and retain water after peak flows recede. Currently, most of these sites completely dry after runoff season or drop to less than a foot of depth. The one exception is the Above Brennan bottomland. The bottomland sites were originally defined as depression or terrace sites by the recovery program. By the Recovery Program definition, a depression site retains water in the bottomland after flood flows recede. All ten sites studied act as depressions under existing conditions. A terrace, by the program's definition, drains with the river as flood flows recede. Bureau of Land Management Sites Bonanza Bridge Bottomland -The furthest upstream site, Bonanza Bridge (BB) Bottomland, is located at river mile 290 (290 miles upstream of the confluence with the Colorado River). The Bonanza Bridge itself is located approximately 3/4 of a mile upstream of the bottomland. A dirt road provides access up to the site just off of Highway 45. The Bonanza Bridge Bottomland provides approximately 38 acres of floodable • 2