Navajo Dam Operations
Navajo Dam is a water storage unit of the Colorado River Storage Project (CRSP). The CRSP was authorized on April 11, 1956 to regulate the flow of the Colorado River; provide for flood control: provide for storage and delivery of water for irrigation, municipal, industrial, and other beneficial purposes; and generate electrical power. The CRSP also provides for recreation and improves conditions for fish and wildlife. Construction of the CRSP water storage facilities including, Navajo Dam, was critical to the development of the Upper Colorado River Basin’s water resources.
Navajo Dam was constructed by the Bureau of Reclamation and was dedicated on September 15, 1962. The authorization did not provide for construction of a powerplant at Navajo Dam. However, a powerplant was constructed and is owned and operated by the city of Farmington, New Mexico, under a license issued October 15, 1985 by the Federal Energy Regulatory Commission. Operation and maintenance of the dam are performed by employees of the Western Colorado Area Office and are funded from revenues received from the sale of CRSP power.
Operation of Navajo Dam under its original operating criteria focused primarily on meeting irrigation needs and providing flood control. However, the storage and use of water altered natural flow patterns, water temperatures, and water quality of the San Juan River. While non-native fish (trout) populations downstream of the dam flourished, native fish populations and their habitat were modified or adversely affected in part by the construction and subsequent operation of the dam. Over the last decade, the criteria and associated pattern for releasing water from the dam has been modified to accommodate endangered fish research and recovery efforts in the San Juan River through Endangered Species Act consultations under section 7 with the Fish and Wildlife Service (Service). Section 7 consultations are intended to ensure federal agency actions are not likely to jeopardize the continued existence of a listed species.
The catalyst for changing the operating criteria for Navajo Dam began with consultation with the Service on the proposed construction of the Animas-La Plata (ALP) Project. On May 7, 1990, the Service issued a draft biological opinion concluding that the ALP Project would jeopardize the continued existence of the Colorado pikeminnow. During this time, new hydrologic investigations suggested that additional flexibility existed in the operation of Navajo Dam which could help offset the negative impacts of the ALP Project’s construction and operation. For example, reducing late fall and winter releases could make water available to increase spring peak flows, returning the San Juan River downstream of Farmington to more natural flow conditions by mimicking pre-dam historic flow patterns. This flexibility in flow patterns would assist in the development of a reasonable and prudent alternative (RPA) to the jeopardy biological opinion and allow initial ALP Project construction efforts to move forward. The RPA that was developed required Navajo Dam operations to more closely resemble natural flow conditions for the life of the dam. Because no natural flow patterns were defined or developed for the San Juan River, the RPA also included a commitment to fund approximately seven years of research to determine the flow requirements for the Colorado pikeminnow and razorback sucker.
This seven-year study was completed in 1997 under the San Juan River Basin Recovery Implementation Program (SJRBRIP). In May 1999, the SJRBRIP Biology Committee provided year-round flow recommendations for the San Juan River necessary for the recovery of the two endangered fishes. Reclamation’s implementation of the flow recommendations through modification of the operations decision criteria of Navajo Dam will provide sufficient releases of water at times, quantities, and durations necessary to protect the endangered fish and their designated critical habitat while maintaining the other authorized purposes of the Navajo Unit.
Because the modified operating decision criteria resulting from implementing the flow recommendations differs from historic operations, Reclamation decided to complete an environmental impact statement (EIS) covering the flow recommendations implementation. Reclamation initiated the process by filing a notice of intent in the Federal Register on October 1, 1999. The final EIS was released in April 2006 and the Record of Decision (ROD) was signed July 31, 2006. The ROD provides for potential refinement of the flow recommendations based on relevant new information that may be gained over time through an adaptive management process.
Through the adaptive management process and periodic public meetings to discuss operations, consideration is given to a broader range of uses’ including the trout fishery, endangered fish, water quality, irrigation, and flood control.