As the level of Lake Powell rises, so does the interest in what the Bureau of Reclamation is doing with Glen Canyon Dam. The Canyon Club of Page hosted a presentation by Gus Levy, Deputy Field Manager of the Glen Canyon Dam, entitled “Colorado River Operations/ Glen Canyon Field Division Update” on June 16, 2023. Levy talked about the history of the dam and what the Bureau has been up to in response to the drought.
From left to right, photos by Phil Clark:
Glen Canyon Dam as seen from the “Dam Overlook” in Page.
Gus Levy answers questions from the audience during his presentation about Glen Canyon Dam operations.
The Colorado River, flowing through 11 units of the National Park Service and seven National Wildlife Refuges, provides water to over 40 million people in the Upper and Lower Basin states and to Mexico. The water irrigates around five million acres of farmland and produces around 4200 megawatts of electricity. The Colorado River Storage Project (CRSP) was established in 1956 to “allow for the comprehensive development of water resources in the Upper Colorado Basin” for water storage, distribution, power generation, flood control and “reclamation of arid lands.” The CRSP includes Glen Canyon (Arizona), Navajo (New Mexico), Flaming Gorge (Utah) and Aspinal which includes Blue Mesa, Crystal and Morrow dams in Colorado.
The total capacity of the CRSP is about 30 million acre-feet (maf). An acre-foot is about the size of a football field, without the end zones, one foot deep. Of the total, Glen Canyon Dam has 25 maf at maximum storage. Of the total power capacity of the CRSP, Glen Canyon produces 75 percent of the total.
Levy shared some recent statistics of the snowpack for 2023. The expected unregulated inflow to the system from the mountains, as of May 16, 2023, for April to July 2023 is around 11.00 maf and is about 172 percent of average. The predicted total for the entire 2023 water year is 148 percent of average, or some 14.17 maf. According to Levy, the reservoir has been recently rising about a foot per day. The lowest reservoir elevation last winter was 3519.92 ft., with an expected peak elevation of 3590 ft., resulting in an increase of around 70 feet since the winter low. According to Patty Koppenol, a member of the audience, “The Cut” is expected to open with an elevation of 3583 ft. As of June 18, 2023, the lake elevation was 3576.82 ft. according to https://lakepowell. water-data.com/
As a result of the high runoff this year, the Bureau plans to increase releases from the dam from 7 maf to 9.5 maf. The simulated ‘Spring Flow” this year released around 38,000 cubic feet per second (cfs) (equivalent to 38,000 basketballs flowing by in one second.) Levy said the releases would continue at this level until September when water demand drops. The total annual outflow for Glen Canyon Dam is unchanged. The difference is the Bureau was holding water back in the winter to continue generating electricity. Because of the higher reservoir levels, the dam is expected to generate some 3.6-megawatt hours (MWH) of power, up from an all-time low of some 2.6 MWH in 2022.
Levy cautioned the crowd that this year’s wet winter does not mean that the megadrought is over. The last 23 years have been the driest on record, comparable to the drought that occurred in the mid-12th century, when the Ancestral Puebloans started migrating away from the Colorado Plateau. Of the last 23 years, the reservoir has only received above average runoff for five of the 23 years. It is not unusual to have a few years of higher runoff during an extended drought.
The water supply for the town of Page has been a concern for both the City of Page and the Bureau of Reclamation. As a result, the Bureau has re-plumbed the outlet works, where the water is discharged back into Glen Canyon, to include an alternate, lower elevation, inlet to supply water to Page. The original ‘Page Straw’ draws water from Lake Powell at elevation 3465ft. The Bureau added a new connection at elevation 3362 ft., or some 102 ft. lower than the original. According to Levy the water supply pipe from the dam to the City is original from the 1950s. Levy said he understood that it is a steel pipe with a mortar lining, around a foot in diameter at the dam and around 18 inches when it reaches the city system. He recommends that the City inspect the pipe with a camera to determine the current condition and repair needs.
The Bureau is addressing a variety of maintenance and repair projects to prepare for the future. The “River Outlet Works/Bypass Tube” have been maintained throughout their 60- year life so far and are used for the simulated flood event. The tubes were not originally designed for a constant flow of water. If the reservoir level drops below 3490 ft., the generators would no longer generate power. The outlet works would have to be opened and water would flow constantly down the Colorado River. The Bureau’s Technical Service Center and Glen Canyon High Scaling Crew have inspected the outlet works and tubes and are accelerating repairs and maintenance. A contract will be awarded later this year to re-coat the interior of the tubes with a “polymer/epoxy” coating. Should the reservoir reach “dead pool” at 3370 ft., Levy says there will still be water flowing in the Colorado River from the jet tubes.
The fixed wheel gates have also been repaired and cleaned. The gates had heavy coatings of quagga mussels, around eight inches thick, approaching the limit of the cranes used to lift the gates. The gates have been cleaned with high pressure washers. Levy said that the good news about the Quagga Mussels is that they have coated the steel and reduced corrosion.
Because of the mussels, the mechanical strainers at the inlet to the cooling system had been cleaned every three months. The Bureau is now cleaning them monthly. Future plans are to use ultraviolet (UV) light to control the growth of the mussels in incoming water which is used for transformer and bearing cooling. The UV technology has long been used in potable water plants and has been used at Hoover and Parker Dams to kill the shellfish.
The elevation of the Colorado River below the dam is 3132 ft., according to the Bureau. Currently the Bureau is expecting the 2024 water year to be a “good” year. For more information about Glen Canyon Dams, visit usbr.gov/uc/rm/crsp/gc.
According to the Canyon Club of Page website, “the purpose of the Canyon Club is to actively pursue improvements to the community in which we live. Through our involvement in our community we will create an atmosphere where local citizens can participate in activities that will enrich their lives and the lives of those living in this community.” The Canyon Club is a non-profit organization. Those interested in joining or attending the monthly presentations should contact the Canyon Club at YourFriends@PageCanyonClub.org.