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1 1 1 1 1 1 Conclusions The installation of the Canyonland staff gages and level logger provides a tool for researchers and river engineers to estimate the Green River discharge while working in the canyon. Following two years of discharge data collection, the calibration for the Bonita Bend staff gage is excellent and will provide reliable estimates of the discharge by using either the rating curve or the equation presented in this report. The level logger operated through the high flow season and was subject to some vertical shifting resulting from loose mounting bolts. A stage shift was made to accommodate the stage variation where possible. The Canyonland level logger discharge correlated well with the upstream level loggers and USGS gaging station discharge. The plotted hydrograph results indicated that the USGS Green River gage was apparently subject to frequent stage shifting. The Green River peak discharge exceeded both the Canyonlands level logger discharge downstream and the Desolation level logger discharge upstream. During the recessional limb the Green River gage reported discharge was less than the both the Desolation and Canyonlands discharges. Maintaining the Canyonlands level logger and staff gage accuracy from year to year ' requires occasional flow measurements over a wide range of discharges. Changes in channel geometry near the gaging site involving sediment deposition or scour can effect the stage- discharge relationship and cause a shift in the rating curve. It is suggested that discharge measurements at the site are periodically collected to recalibrate the rating curve. t The level logger data records the high flow discharge hydrographs which create the critical nursery habitat for larval razorback sucker, in the Canyonlands backwater habitat reach. In the future, the level logger data will be used to analyze the effects of Flaming Gorge releases on the timing, duration, and magnitude of flows in the lower Green River system. The information is important to predict timing and duration of flows that open backwater nursery habitat. The level logger data collection program is critical to the habitat restoration and channel monitoring programs of the Recovery Implementation Program for Endangered Colorado River Fishes. This discharge data will enhance our capability to understand and predict water and sediment movement throughout the Green River system. 18