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<br />'- <br /> <br />77 :; <br /> <br />American tribes have ancestral and traditional ties to the San Juan Basin. The test is of a short- <br />term duration and will occur exclusively within the channel of the San Juan River. The nature of <br />the proposed undertaking is such that is has no potential to cause effects to historic properties. <br /> <br />As indicated previously, the test flows will provide data to assist in preparing an EIS on the <br />operation of Navajo Dam and Reservoir to implement flows recommended by the SJRBRIP. <br />These changes are expected to have significant impacts on several resources; the test flow period <br />will help determine this. Impacts of the test itself are not anticipated to be significant because of <br />its short duration and because the test does not represent any long-term decision. In addition, the <br />test will not significantly impact San Juan River flows below the confluence of the Animas <br />River. Data gained may also develop information that can reduce the impacts of long-term <br />changes. <br /> <br />Overall the test should not have a significant effect on the quality of the human environment <br />because of its short duration. Public health and safety are not expected to be adversely affected; <br />however, provisions are included to terminate the test early if such problems occur. Releases <br />from the dam should be adequate to meet actual downstream senior water rights; however, the <br />complex interaction of physical layout of diversion structures, level of river administration, <br />return flows, water demand at the time, and other factors make it difficult to predict whether <br />shortages will occur. <br /> <br />Because of the short-term duration, the reduced flows are not expected to impact wetlands and <br />riparian areas associated with the river. <br /> <br />The tail water trout fishery may be stressed by the lower flows, reduced useable habitat, and <br />perhaps by higher water temperatures. The short duration of the test should prevent significant <br />impacts from occurring although the test will be cut short if significant long-term effects begin to <br />occur. This will be determined in consultation with the New Mexico Department of Game and <br />Fish. A reduction in wetted perimeter should cause a temporary reduction in aquatic insects <br />although the extent of this loss is difficult to quantify. Warm water fisheries occur downstream <br />from the tailwater and extremely low flows may occur in this area downstream from diversions. <br />For the short duration, fish should find adequate habitat in pools and other more permanent <br />habitat. Fish resorting to such pools may be more susceptible to predation and fishing harvest. <br /> <br />Endangered species, including river fish, are not expected to be affected; the test flow regime <br />will be similar to flows recommended by the SJRBRIP for the fishes. Temporary lower flows <br />are not expected to affect habitat of the southwestern willow flycatcher which is a potential <br />nesting species along the San Juan. If adverse effects are determined to be occurring on <br />endangered species by the New Mexico State Office of the Fish and Wildlife Service the test will <br />be terminated. <br /> <br />6 <br />