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717 50. Comment: Response: 51. Comment: Response: 52. Comment: Response: 53. Comment: Response: 54. Comment: Response: they occur. In addition. Reclamation will implement certain plans to lessen any impact to the trout fishery, especially below Citizen's Ditch. Please reference Response No. 41 for more specific infonnation related to monitoring and fisheries. The low-flow test will not reveal the full extent of impacts of reoperation...: chronic problems will not be apparent and the reduction in sediment transport will not be evaluated during the short test. The primary reason the test will be of short duration is to avoid having a long-lasting impact to resources associated with river flow. During the test, physical changes to the river will be monitored and measured. in turn, this infonnation will be used to more accurately predict the effects of a longer duration reduced summer flow and incorporated into the Navajo Operations EIS. The self-sustaining brown trout population downstream from Citizen's Ditch will require many years to recover. This population would be more difficult to recover than the upstream fishery which is supported by stocking, primarily with rainbow trout. See response to Comment # 41describing Reclamation's proposed plan for fisheries. Statements such as "the test may stress fish" or "float fishing may be affected" are inaccurate. Clarify that these resources will be affected. The text within the EA has been changed to incorporate your comment. The aquatic food base will be adversely affected during the test; will this be monitored -by monitoring changes in drift and emergence? Reclamation does not plan to specifically study the effects to macro invertebrate populations during the proposed test. Reclamation does not believe that aquatic food base, principally macro invertebrates, is a limiting factor to the trout fishery. This is based on studies conducted in 1996-97 which showed no appreciable loss of the ratio of weight to length in trout (condition factor} during the 4 month winter low flow test. While a minimal loss to macro invertebrates will occur. it will recover soon after the test is over. If a longer summer low flow occurs in the future, pending the selection of a preferred alternative in the Final E1S, the corresponding effect to trout would be assessed. Depending on the stratification in Navajo Reservoir at the time of the test, low dissolved oxygen conditions may exacerbate the stress that the trout experience. Releasesfrom Navajo Dam are well below any developing thennocline in 25