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~ ., , , Attainment of more historic beach and sandbar conditions below Glen Canyon Dam with high flow releases is an unrealistic and impractical way to recover endangered fish, and enhance riparian habitats and beaches. There are several problems with this approach which demonstrate direct conflicts: * Release of water from the dam in excess of power plant capacity violates existing laws. * Habitat Building Flows are a high risk, low return venture and probably unnecessary for long-term sustainment of beach sand deposits. periodic large flood events similar to the floods of 1983-84 create such massive changes in sand volume and deposition that creating small, artificial floods may be a futile exercise. !<< '. :? +. * Proposed steady flows coupled with Habitat Building Flows would eliminate new riparian conditions created after dam construction. ~~ ~. i, ;~~ ';:: * Proposed steady flows would encourage riparian and wetland vegetation below the present New High Water zone (NHWZ)i but periodic HBF would inundate these new growths with water and sediment, destroying newly created habitat for riparian species of animals as well as vegetation used by all species for food and shelter. Vegetation capable of withstanding this onslaught would likely be less woody, less perennial and more herbaceous and annual, typical of the types present pre-dam. * The lowered maximum flow will reduce water to present riparian vegetation thereby reducing their chance of survival and the periodic high flows will remove new vegetation encroaching below the old high flow elevation. ". II:~ , i:~. ., (.. * Riparian plants in the existing New High Water Zone would be desiccated by the lowered maximum flow and replaced with less dense, xeric forms. This has not been assessed .;' ...~ * Fish researchers think young Humpback chub and other young native fish would be lost by being transported' downstream during flows of 45,000 cfs and this has Dot been assessed. * The projected impact to algae production during the extended period when high Habitat Maintenance Flows or Habitat Building Flows increases turbidity and reduce light to the algae has not been assessed and could be significant. "<.' ~'"J.. ~ .;~ , * The impact to the trout population of a change in quantity of algae could be significant including a die-off comparable to that seen when the onset of test flows hampered algae production and this has not been assessed. 10