Glen Canyon Dam
Glen Canyon Dam is on the main stem of the Colorado River near the Arizona-Utah state line. It is approximately 15 miles upstream from Lee’s Ferry which is the measuring point for the Colorado River Compact between the Upper Basin states (Utah, Colorado, New Mexico, and Wyoming) and the Lower Basin states (Arizona, Nevada, and California). The dam backs up water forming Lake Powell, which contains approximately 27 million acre-feet of water at the normal water surface elevation. The power plant consists of eight units which can generate approximately 162.5 MW each, for a total output of approximately 1300 MW. The Colorado River Compact requires that 7.5 million acre feet must be released in each rolling ten-year period. The addition of Mexican Treaty water brings this to an average annual release of 8.23 million acre feet per year. Part of the power generated by the dam is used for irrigation pumping and other project uses. The remaining “marketable resource” is sold first to preference customers. Each year the Bureau of Reclamation develops an annual operating plan defining the monthly releases from each of the projects for the upcoming year. Historically, the Western Area Power Administration has been allowed to vary the releases on a daily and hourly basis to meet power demands within the monthly water release constraints.
In 1978 the Bureau of Reclamation began evaluating the possibility of upgrading the eight generating units at Glen Canyon. This was possible primarily due to design characteristics of the generators and improved insulating materials. This upgrade was completed in 1984, and the generation was increased from about 1000 MW to 1300 MW. To fully utilize the unit upgrades would require the maximum release of Glen Canyon to be increased from 31,500 CFS to about 33,200 CFS. The possibility of increasing maximum releases from Glen Canyon raised concerns with downstream users. After discussion with stakeholders, the Secretary of Interior initiated the first phase of the Glen Canyon Environmental Studies.
In 1982, the Bureau of Reclamation, at the direction of the Secretary of Interior, began Phase 1 of the Glen Canyon Environmental Studies. These studies were primarily to analyze the impacts of raising the maximum release form 31,500 CFS to 33,200 CFS on the transport of sediment downstream from the dam, recreation (including fishing and rafting), endangered species (including the humpback chub in the Lower Colorado River), and the riparian habitat along the river banks. The studies proceeded during the early 80s and were concluded in 1987. The general conclusion of the Glen Canyon Environmental Studies Phase 1 was that the dam had blocked much of the sediment coming down the Colorado River and therefore beaches were not being replenished with sand. The Glen Canyon Environmental Studies Phase 1 process did not necessarily follow sound science in that the impact on power and water economics had not been fully explored.
After reviewing the Glen Canyon Environmental Studies Phase 1 and the review by the National Academy of Science, the Secretary of Interior determined the Glen Canyon Environmental Studies should be continued to address the economic impacts, particularly as they relate to power, and also to collect additional data to substantiate some of the conclusions in the Phase 1 report. The Glen Canyon Environmental Studies Phase 2 was initiated in 1989. The Bureau of Reclamation and the Senior Scientist developed Phase 2 studies, which included a series of test flows to evaluate the impact of different operating conditions and to develop response curves for various conditions. Many interested parties, including water, power, recreation, environment, and Native American interests participated in the process.
In July 1989, the Secretary of Interior announced the start of an EIS on the operation of the Glen Canyon Dam. No specific recommended action was identified. Meetings were held during 1990 to seek input into alternatives that should be considered, and the Bureau of Reclamation determined the alternatives which were to be studied. The EIS was completed and the Record of Decision signed in October, 1996. The result was that Glen Canyon operations were changed to reflect a revised flow regime; approximately one-third of the generating capacity was lost due to changed operations. The cost of the Glen Canyon EIS was approximately $104 million, and was funded by power revenues collected from the CRSP customers.
CREDA participates on the Federal Advisory Committee charged with making recommendations to the Secretary of the Interior as to operations of Glen Canyon Dam pursuant to the Record of Decision and underlying laws. Funding for the program (Adaptive Management Program) is through power revenues. On October 27, 2000, President Clinton signed the Interior Energy and Water Appropriations bill, which includes language (section 204) capping the amount of CRSP power revenues that can be used for the Adaptive Management Program, at $7,850,000, subject to inflation. CREDA supports other sources of funding for this program, and has continuing concern about the budget growth.
In April of 2000, it was determined that due to hydrologic conditions and resulting from a 1994 USFW biological opinion, a low flow summer experiment would be undertaken. The experiment included high spike flows in May and September, with low flat flows (8,000 cfs) all summer. The purpose was to gain information regarding humpback chub conditions. The low, flat flows had a severe impact on power generation, requiring Western Area Power Administration to purchase replacement power on the open market in order to meet contractual obligations to the CRSP customers. The cost of this replacement power was over $32 million! The cost of the experiment was over $3 million, also funded by CRSP power revenues.
On March 31, 2004, the Grand Canyon Trust filed litigation in Arizona District Court alleging the humpback chub recovery goals are too low and asking the Court to require the USF&W to revise the goals. The Court ruled, requiring USF&W to update the goals as to schedule and cost elements. In February, 2006, the Center for Biological Diversity and other organizations filed suit against the United States, asking the Federal Court to interpret the Grand Canyon Protection Act and to require the USBR to re-consult with USFW on a new biological opinion. In August, 2006, the United States settled with the Plaintiffs, which settlement required an environmental documentation process to begin not later than January 31, 2007. In December 2008, the Grand Canyon Trust again filed litigation against the United States. CREDA, 7 Basin States and water interests intervened. On March 29, 2011, the case was finished, the Judge ruling on all counts for the United States. Final Court Order The Trust has appealed to the 9th Circuit Court of Appeals, and on August 13, 2012, the 9th Circuit ruled in favor of the United States on all claims.(Final Order)