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6 z. Ground water studies by Carpenter, et. a1. (1995) have shown that the volume of water stored in the beaches, river stage fluctuation, and downramp rates are controlling the dynamics of the ground water return flow and seepage erosion. 3. Rill erosion studies performed by the National Park Service (Werre11, et. a1, 1993) have shown that the rate of decline in river stage induces water trapped in the sediment to cut away at beach faces. 4. The Smith and Wiele (1994) model showed that the higher upramp wave would be attenuated by lower Marble Canyon and therefore no impact would be found downstream. Therefore, it was concluded that as long as the down ramp rate is maintained at 1,500 cfs/hr and the daily fluctuation is limited to between 5,000 cfs and 8,000 cfs per day, the upramp rate could be changed with no anticipated impact on the sediment resources. Increases in the release rate and corresponding increase in river stage tend to increase available habitat for fish. The rate of increase is likely to have no effect on the aquatic ecosystem. There should be no impacts to the biological resources below lower Marble Canyon as a result of the increase in ramping rates because the effects will be largely attenuated prior to reaching lower Marble Canyon. All size classes of trout and native fish should be able to accommodate the increase. Since upramp rates are not related to beach erosion, no impacts are anticipated to occur to riparian areas or terrestrial populations associated with the near shore environment. Cultural resources depend on the sediment resource. Since the increase in the upramp rate would not negatively effect the sediment resource, it would not impact the cultural resources contained within the sediment deposits. The impacts of increasing the upramp rate on recreation resources below Glen Canyon Dam are also expected to be minimal. Effects on boating operations have not been linked to upramp rates. Boating operations are still linked to changes in river stage and minimum flows. Based on Table Z, the safety effects on wading anglers should be minimal. As shown, increasing the upramp rate from 2,500 cfs/hr to 4,000 cfs/hr results in a stage change of 0.66 .feet (8 inches) more per hour. While this additional change in stage will be noticeable, it is unlikely to result in a difference in the rate of wading mishaps.It is important, however, that anglers be well informed about ramping rates to reduce any potential safety related impacts.