9582

• UCREFRP Catalog Number: 9582
• Author: U.S. Bureau of Reclamation.
• Title: Final Environmental Impact Statement - Navajo Reservoir Operations Volume III Comments and Responses.
• USFW Year: 2006.
• USFW - Doc Type: Grand Junction - Durango, CO.
• Copyright Material: NO

Volume III - Comments and Responses
FEIS - Navajo Reservoir Operations
General Comment 15: Several comments addressed the monitoring of the base flows
(targeted at 500-1,000 cfs downstream from Farmington). The method needs to be
clarified-will base flows be met under the proposed monitoring methods?
Response: The goal of the Flow Recommendations is to maintain San Juan River base
flows downstream from the Animas River confluence at Farmington between 500 and
1,000 cfs. Because of variable inflows from the Animas River; occasional high inflow from
intermittent tributaries, diversions, and return flow; and water travel time from Navajo
Dam, this goal is difficult to consistently meet.
The Flow Recommendations call for using a moving average of two of the four downstream
gages to monitor whether flows are kept between 500 and 1,000 cfs. This monitoring plan
was presented in the DEIS. There can be significant variability in these gage readings, and
the selective use of any two gages could give results above or below the intent of the Flow
Recommendations. Because of this, in 2002, the Biology Committee of the SJRBRIP
suggested that flows be monitored by the following: "Use the lesser of the average of Bluff,
Four Corners, and Shiprock (gages) and the average of Farmington, Shiprock, and Four
Corners (gages)...extreme conditions (low or high flows) identified by ... Reclamation win
be handled on a case-by-case basis with recommendations of the Biology Committee." The
Service has provided written support of this approach to monitoring.
Reclamation's intent, which is documented in the FEIS, will be to maintain the
recommended base flows in the critical habitat reaches by using the best available gage
information. In practice, Reclamation and the Service will discuss flows routinely during
the irrigation season and as needed the remainder of the year to determine the operations
needed to meet the base flows. Reclamation, in consultation with the Service, will use the
lesser of the weekly moving average of the Bluff, Four Corners, and Shiprock gages and the
average of the Farmington, Shiprock, and Four Corners gages as the guide in meeting this
intent. In periods of severe drought, Reclamation will work with the Service to arrive at
operating criteria to respond to these conditions.
General Comment 16: The DEIS should recognize that Reclamation has the right to
operate the dam in such a way as to minimize negative impacts, even if operations may
not be in strict accord with Flow Recommendations. Flow Recommendations should be
applied with some common sense to mitigate devastating impacts on the economy and
environment.
Response: Reclamation not only has an obligation to protect endangered species but also
an obligation to try to minimize adverse impacts on other resources while doing so. During
the planning process for the EIS, Reclamation looked at various minimum releases between
250 and 500 cfs in an effort to minimize negative impacts. It was determined that only the
250/5000 Alternative (Preferred Alternative) met the Flow Recommendations. However,
within the Flow Recommendations there exists some flexibility in reservoir releases until
full development of NIIP and the ALP Project occurs because water committed for present
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