WSP04963

• File Number: 8220.105.I
• Description: Colorado River-Water Projects-Navajo-Environmental Studies
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 4/1/2002
• Author: BOR
• Title: Navajo Dam EIS-Summer Low Flow Test Report-San Juan River New Mexico and Utah
• Water Supply Pro - Doc Type: Report/Study

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Initial Summary of Findings

Following the July 9-15,2001, Summer Low Flow Test
(Test) on the San Juan River, the Bureau of Reclamation
(Reclamation) found that, over the period of the Test, few
major negative impacts occurred to the fishery, recreation,
diversion structures, or other resources that Reclamation
monitored, However, for a number of reasons, these
findings may not hold entirely true over the long term for
some resources. Accordingly, a full analysis of impacts
will be presented in the Navajo Reservoir Operations
Environmental Impact Statement (EIS), which will use the
Test results as well as other data.

This report presents major findings for the various resources
studied and was prepared as a response to public concerns
about the effects of low releases (250 cubic feet per second
(cfs]) from Navajo Dam, as outlined in the Flow
Recommendationsfor the San Juan River (Holden, 1999)1
(Flow Recommendations).

I Under the direction of the San Juan River Basin Recovery Implementation
Program's Biology Committee, test releases from Navajo Dam were conducted and
evaluated from J 992-98. At the completion of the research period, the committee
completed a repon, Flow Recommendations for rhe San Juan River (Holden, 1999),
which provides recommended flows for the endangered fish in the San Juan River
below Farmington and for water development. The recommendations define the
conditions for mimicking a natural hydro graph in tenns of magnitude, duration, and
frequency of flows in the ri veT below Farmington. It is these recommendations that
Reclamation is proposing to meet by modifying the operations of Navajo Dam.

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