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-, J, Pg. 138, C. 2, P. 2. The advent of stable flows has reduced the risks and allowed recreation use of the river riparian corridors to increase dramatically including such uses as hiking, camping and rafting. The DEIS should provide a discussion of these reduced risks. ; Pg. 139, C. 1, P. 3. The DEIS should explain that blue-ribbon fisheries have developed below dams in the Colorado River drainage even with hydropower releases which raise and lower flows. ,. Pg. 139, C. 2, P. 3. Loss of individual trout may occur as a result of stranding from hydropower releases during spawning when some fish move into shallow areas and this may detract from the angling experience for some people. Trout pOPulations in the tail waters are probably not sufficiently affected by hydropower releases to impact the numbers of fish available to sustain angler enjoyment. The DEIS should explain these differences. Pg. 140, C. 2, P. 3. Trout populations in a dam tailwater may be affected by a maturing reservoir until it reaches an equilibrium. This may occur possibly decades after creation, because released water is likely to decrease in its potential to sustain high productivity due to changing nutrient conditions in the reservoir and its watershed. The DEIS should mention this expectation. ", l ~ . " ~: !-. Pg. 143, C. 1, P. 1. Under hydropower releases, commercial rafting below Glen Canyon Dam has blossomed to a multi-million dollar industry with over 50,000 users per year from less than 600 immediately pre-dam. This industry is occasionally inconvenienced by hydropower releases when rafts are left dry by an overnight drop in stage, refloated by an increase or required to negotiate rapids under differing conditions. The DEIS should explain the actual problem and put it in some perspective relative to other issues. " :'~ I ~ <. , Pg. 143, C. 1, P. 3. Rafters camp on sand beaches created during high, flood flow events and a change in beach availability would require some parties to crowd onto remaining beaches. The DEIS should explain why this is expected to be a problem. >. ! " '.. CHAPTER IV ~i, .~ ~ ~ Pg. 173, C. 2, P. 6. Sediment - Glen Canyon Dam effectively halted sediment movement into the Grand Canyon from the Colorado River. Water leaving the Dam is free of sediment and will remain so regardless of changes in release patterns. A lack of sediment to replenish beaches results in a gradual loss. Water Temoerature - Glen Canyon Dam draws water from the deep, cold water levels of Lake Powell. Temperature of water leaving the Dam averages about 500F and will remain so regardless of release patterns. Cold water is needed to maintain the trout fishery but creates a significant impact to chub and other native fishes. . ~. ":: 29