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in transport through the narrower downstream reaches and little <br />no deposition would occur. Sand deposition is possible at downstream locations where the river <br />channel becomes significantly wider or when there are significant losses of riverflow to <br />groundwater, canal diversion, or attenuation of flood peaks. <br />In general, the clearing and leveling of river islands would create a wider river channel and <br />provide more sand to the river to offset ongoing channel degradation. Monitoring of the managed <br />channel area, and downstream locations, would ensure that continued river island clearing and <br />leveling does not cause excessive sand deposition at downstream locations, because the island <br />sand would be added to the river in several stages. <br />Conclusions for the short- and long-term impacts can be derived from the 13-year and 61-year <br />data, respectively. Changes to channel width in the short term are primarily a reflection of the <br />mechanical impacts of the land plan for each alternative. <br />INSERT Not continuous text <br />IMPACTS ANALYSIS <br />The five action alternatives are compared to the Present Condition with respect to the <br />indicators: flow; sand transport, deposition, and erosion; grain size; sandbar-building <br />potential; and channe] width. <br />FLOw <br />Values were calculated for the mean annual flow, the peak flood with a recurrence interval <br />of 1.5 years, and the differences with respect to the Present Condition by percentage. The <br />mean annual riverflows, the 1.5-year flow, and percent differences for the last 48 years of <br />each alternative are summarized in table 5-27. <br />Values for mean annua] flow give an indication of the volume of flow for each alternative <br />with respect to the Present Condition. The Cozad U.S. Geological Survey (USGS) discharge <br />gauge is located approximately 14 miles upstream of Lexington, the approximate upstream <br />border of the Central Platte Habitat Area. The Overton gauge is 12 miles downstream of <br />Lexington, and the Grand Island gauge is near the downstream boundary of the Central Platte <br />Habitat Area. At these gauges, the mean annual flow is greatest for Water Leasing with 5 to