#ColoradoRiver: Inside the Glen Canyon Dam during a high-flow experiment #COriver — #Arizona Daily Sun

The generator building of Glen Canyon hydro power plant in Arizona via Wikimedia.
The generator building of Glen Canyon hydro power plant in Arizona via Wikimedia.

From The Arizona Daily Sun (Taylor Hartman):

In an attempt to restore some natural flow to the Colorado River, high flow experiments are conducted from Glen Canyon Dam. Taking tips from Mother Nature, these experiments mimic natural floods that occurred before the construction of the dam. On Monday, November 7, one such experiment began, freeing a large quantity of water from Lake Powell reservoir over the span of five days.

During the controlled flood, the view from the steel bridge changes: the awakened Colorado River thrashes in the canyon below. Water flows through the hydroelectric generators and erupts from four river outlet tubes, with its roar reverberating off the canyon walls and mist sparkling under the warm November sun. Dazzling white due to immense pressure, 36,000 cubic feet of water bursts from the dam every second. This peak flow is four to six times greater than usual discharge, and lasted for 92 hours.

While the bridge offers an incredible view of the dam, canyon, river and reservoir, tours bring visitors inside the dam daily. From within the cold walls of the dam, the sound of rushing water is accompanied by the rhythm of generators turning at 150 rounds per minute. During the experiment, these generators still produce hydroelectric power, but less than usual. The Bureau of Reclamation says that all power demands will still be met.

The ground floor of the dam tour is at river level, and the 710-foot dam is even more impressive when viewed from the bottom. At this level, the sound of water overpowers all other noise, and wild emerald waves crash against concrete and sandstone. As floodwaters leave the dam and travel through Grand Canyon, sediment is picked up from tributary rivers and suspended in the tumultuous flow. The experiment is timed to follow an influx of sand from the Paria River, enabling the flood to redistribute it throughout the river corridor.

Downstream, the river corridor is cleansed: low vegetation is ripped from riverbanks, beaches are submerged, and sand is suspended and deposited. The flood affects campers and rafters through Grand Canyon. People recreating near or on the Colorado River were encouraged to be on alert, camp on high, stable beaches, and practice leave-no-trace ethics. On the other side of the dam, water level at Lake Powell has dropped more than three feet.

This flood is the latest release in a series of high flow experiments since 1996. Controlled floods have the potential to enlarge sandbars and beaches downstream of Glen Canyon Dam, which could provide ecological and recreational benefits. These benefits include: improving the habitat of native fish such as the endangered humpback chub, reducing erosion of archaeological sites, restoring vegetation, and increasing the size of beaches.

As the flood ramps down, the river returns to its usual controlled flow condition. The promising white blast from the outlet tubes subsides, and the buzzing of the generators recaptures the soundscape at Glen Canyon Dam. Scientists will continue to monitor Colorado River conditions in order to understand how this flow affects downstream ecosystem and resources, and to plan future floods. The Bureau of Reclamation says that the occurrence and intensity of future high flow experiments will depend on weather, sediment influx from tributaries, and other resource conditions.

November 2012 High Flow Experiment via Protect the Flows
November 2012 High Flow Experiment via Protect the Flows

#ColoradoRiver Compact Commission in Santa Fe, November 24, 1922 — @USBR #COriver

On this day in 1922, Federal and State representatives met for the Colorado River Compact Commission in Santa Fe, New Mexico. Among the attendees were Arthur P. Davis, Director of Reclamation Service, and Herbert Hoover, who at the time, was the Secretary of Commerce. Photo taken November 24, 1922. USBR photo.
On this day in 1922, Federal and State representatives met for the Colorado River Compact Commission in Santa Fe, New Mexico. Among the attendees were Arthur P. Davis, Director of Reclamation Service, and Herbert Hoover, who at the time, was the Secretary of Commerce. Photo taken November 24, 1922. USBR photo.

From Wikipedia:


The compact was the fruit of several years of negotiations among the states. The seven states had previously formed the League of the Southwest in 1917 to promote development along the river. In 1921, Congress authorized the states to enter into a compact for allocation of the river resources. The agreement was approved by Congress in 1922, the same year it was signed. Colorado River Compact was signed by the delegates from the seven Colorado River Basin states: Wyoming, Colorado, Utah and New Mexico were designated Upper Basin states and California, Arizona and Nevada as the Lower Basin states. This compact determined that the water would be shared equally among the upper and lower basin states. Prior to the compact, the name of the river was standardized along its length. Previously the portion of the river upstream from its confluence with the Green River had been known locally as the “Grand River”. The change was opposed by many local residents in Utah and Colorado, and the new name was enforced locally by acts of the state legislatures in both states in the early 1920s. One of the major concerns both today and back in the 1920’s was the expanding population, and this increased the demand for water, particularly in California. In more recent years, mainly because of Las Vegas, Nevada has been looking for more use of the Colorado River.

Arizona Navy photo via California State University
Arizona Navy photo via California State University

In 1934, Arizona, unhappy with California’s decision to dam and divert the river, called out the National Guard and even commissioned a two boat “navy.” The matter was eventually settled in court.

The agreement was controversial even at the time, however. Arizona, for example, was dissatisfied with the lower basin allotment and refused to ratify the agreement until 1944.[7] The specific allotments were disputed by Arizona until the United States Supreme Court upheld the amount in the 1963 decision in Arizona v. California. The agreement ended many years of dispute, clearing the way for the Central Arizona Project, authorized by Congress in 1968.

Delph Carpenter's 1922 Colorado River Basin map with Lake Mead and Lake Powell
Delph Carpenter’s 1922 Colorado River Basin map with Lake Mead and Lake Powell

The @USBR Releases Two WaterSMART Grants Funding Opportunities for Water Conservation and Energy Efficiency Projects

Photo via the State of Idaho.
Photo via the State of Idaho.

Here’s the release from the US Bureau of Reclamation (Peter Soeth):

Today, the Bureau of Reclamation released two WaterSMART Grants funding opportunities including the water and energy efficiency grants funding opportunity and the new small-scale water efficiency projects funding opportunity. These two funding opportunities will help move the West towards resilience in the face of drought and ongoing imbalances between water supply and demand.

The new small-scale water efficiency projects funding opportunity is for small improvements that have been identified through previous planning efforts. Projects eligible for funding include installation of flow measurement or automation in a specific part of a water delivery system, lining of a section of a canal to address seepage, small rebate programs that result in reduced residential water use, or other similar projects that are limited in scope. These projects are eligible to receive up to $75,000 in federal funding. For this funding opportunity, Reclamation has developed a streamlined selection and review process to reflect the small-scale nature of these projects.

Previously, small-scale water efficiency projects were funded through Reclamation’s Water Conservation Field Services Program, which beginning this year will focus on planning and design activities to help lay the groundwork for future improvements. Proposals for this new category of WaterSMART Grants will be accepted, evaluated and selected on a rolling basis with the final application submission deadline on April 27, 2017, at 4:00 p.m. MDT. This funding opportunity is available at http://www.grants.gov by searching for funding opportunity BOR-DO-17-F011.

Water and energy efficiency grants focus on larger scale projects that result in quantifiable and sustained water savings and that may have several components intended to address a significant water management concern. Projects include canal lining and piping, more comprehensive installation of irrigation flow measurement or canal automation improvements, installation of water meters and other similar projects. Projects may also include components that increase renewable energy use and improve energy efficiency, and projects that result in instream flows for endangered species and other fish and wildlife or support water sustainability in other ways.

Applications may be submitted to one of two funding groups:

  • Funding Group I: Up to $300,000 will be available for smaller projects that may take up to two years to complete.
  • Funding Group II: Up to $1,000,000 will be available for larger, phased projects that will take up to three years to complete. No more than $500,000 in federal funds will be provided within a given year to complete each phase.
  • Proposals must be submitted by January 18, 2017, at 4:00 p.m. MST. The funding opportunity is available at http://www.grants.gov by searching for funding opportunity number BOR-DO-17-F012.

    Those eligible to apply for both grants are states, tribes, irrigation districts, water districts or other organizations with water or power delivery authority located in the western United States or United States territories as identified in the Reclamation Act of June 17, 1902. Another WaterSMART Grants funding opportunity, for water marketing activities, is expected to be released this winter.

    WaterSMART aims to improve water conservation and sustainability, helping water resource managers make sound decisions about water use. The program identifies strategies to ensure this generation and future ones will have sufficient amounts of clean water for drinking, economic activities, recreation and ecosystem health. The program also identifies adaptive measures to address climate change and its impact on future water demands. To learn more, please visit http://www.usbr.gov/watersmart.

    @USBR Releases Funding Opportunities for #Drought Contingency Planning and Drought Resiliency Projects

    US Drought Monitor November 8, 2016.
    US Drought Monitor November 8, 2016.

    Here’s the release from the US Bureau of Reclamation:

    Two funding opportunities are now available from the Bureau of Reclamation for entities to develop drought contingency plans and build long-term solutions to drought. These two funding opportunities are part of Reclamation’s Drought Response Program.

    The drought contingency planning funding opportunity is for applicants to request up to $200,000 to develop a new drought plan or to update an existing drought plan. Applicants may also request technical assistance from Reclamation for the development of elements of the Drought Contingency Plan. States, Indian tribes, irrigation districts, water districts, and other organizations with water or power delivery authority located in the 17 Western United States and Hawaii are eligible for this funding opportunity. It is available at http://www.grants.gov by searching for funding opportunity number BOR-DO-17-F009.

    The drought resiliency projects funding opportunity is for projects that will increase the reliability of water supply; improve water management; implement systems to facilitate the voluntary sale, transfer, or exchange of water; and provide benefits for fish, wildlife, and the environment to mitigate impacts caused by drought.

    Applications may be submitted under one of two funding groups for resiliency projects:

  • Funding Group I: up to $300,000 for projects that can be completed within two years
  • Funding Group II: up to $750,000 for larger projects that can be completed within three years.
  • For drought resiliency projects, states, tribes, irrigation districts, water districts, and other organizations with water or power delivery authority in the 17 Western United States or United States Territories as identified in the Reclamation Act of June 17, 1902, are invited to leverage their resources by cost sharing with Reclamation. Applicants must also provide a 50 percent non-Federal cost-share. It is available at http://www.grants.gov by searching for funding opportunity number BOR-DO-17-F010.

    The fiscal year 2017 budget request includes $4 million for the Drought Response Program. Applications are due on February 14, 2017, by 4 p.m. MST as indicated in the funding opportunities.

    For more than 100 years, Reclamation and its partners have worked to develop a sustainable water and power future for the West. This program is part of the Department of the Interior’s WaterSMART Program, which focuses on improving water conservation and sustainability, while helping water resource managers make sound decisions about water use.

    To find out more information about Reclamation’s WaterSMART program, visit http://www.usbr.gov/watersmart, or visit the Drought Response Program at http://www.usbr.gov/drought.

    Flatiron Reservoir, Marys Lake and Lake Estes drawn down for work — Loveland Reporter-Herald

    Colorado-Big Thompson Project east slope facilities
    Colorado-Big Thompson Project east slope facilities

    From The Loveland Reporter-Herald:

    Starting Oct. 27, officials from the Bureau of Reclamation turned off the water diversion tunnel from the West Slope to the Colorado-Big Thompson Project that feeds many of the lakes and reservoirs in Larimer County. The reservoir levels have also been lowered through the release of water to storage downstream.

    According to a news release from the agency, the shutdown has allowed for the inspection of dams at Marys Lake and Lake Estes near Estes Park, and Flatiron Reservoir west of Loveland.

    While the reservoirs are at low levels, crews are also looking at the power generation facilities at the Marys and Pole Hill power plants and the Charles Hansen Feeder Canal.

    According to agency officials, the work will continue on the reservoirs and facilities throughout November, with water diversions through the Adams Tunnel from the Western Slope slated to resume in mid-December.

    #ColoradoRiver: Beauty, “It’s not a concept that lends itself very well to science” — Esther Vincent #COriver

    Grand Lake via Cornell University
    Grand Lake via Cornell University

    From Aspen Journalism (Allen Best) via The Aspen Daily News:

    Nobody disputes that the Colorado-Big Thompson project has changed Grand Lake, the state’s largest, deepest natural lake. How could it not?

    In the 1940s, Grand Lake was integrated into the giant C-BT, what the late historian David Lavender called a “massive violation of geography.” It’s Colorado’s largest transmountain diversion project. By one tally in the 1990s, it delivers an average 231,060 acre-feet annually from the headwaters of the Colorado River to cities and farms east of the Continental Divide. This compares to the 105,024 acre-feet from three tunnels through the Sawatch Range east of Aspen.

    Almost immediately after the C-BT was completed in 1953, locals began to complain that the project shoehorned into the lake had sullied the lake’s clarity by introducing algae and sediments. This is, they insist, a violation of federal law.

    The controversy pivots on Senate Document 80, a part of the Congressional authorization for project funding in 1937. The document describes the needs of irrigation, industrial and power production but also warns against impacts to nearby Rocky Mountain National Park.

    The lake, if outside the park, has one of Colorado’s most memorable backdrops. The document specifies the need “to preserve the fishing and recreational facilities and the scenic attractions of Grand Lake…”

    On that, say many locals, the C-BT has failed, and they say that until recently they got little response from the U.S. Bureau of Reclamation, the agency that built the C-BT.

    But now, in a reversal, the bureau is working with 18 other stakeholders in an effort to solve the problem. Parties include Northern Colorado Water, the agency that manages the diversions for cities and farmers of northeastern Colorado, Grand County and other state and local organizations.

    Grand Lake’s story fits into a broad theme of changed sensibilities in Colorado about 20th century river alterations. Restoration and remediation projects are starting or underway on the San Miguel River in Telluride, on the Eagle River at Camp Hale and on the Fraser River near Winter Park.

    “It’s possible that at one time, the impacts of the CBT Project on Grand Lake clarity were thought to be just part of the price we pay for valuable water projects,” said Anne Castle, a fellow at the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at the University of Colorado-Boulder. “Now, we are more inclined to believe that the environmental values have significance, including economic significance, and that operations can and should be adjusted to better accommodate these values.”

    The work at Grand Lake also illustrates the power of persistence and spunk by advocates of environmental protection. And it involves a collaborative process called adaptive management that emphasizes consensus-based decision-making in solving stubborn issues involving water diversions.

    Nobody thinks solving this problem will be easy, though. In April, after several years of working together, the Grand Lake stakeholders submitted a plan to the Colorado Water Quality Control Commission. The plan approved by the commission sets an interim clarity goal for summer pumping during the next five years.

    During that time, the Bureau of Reclamation is to develop a plan for long-term solutions. Alternatives include expensive new tunnels, possibly bypassing Grand Lake altogether. A preview of the alternatives may emerge at a meeting of stakeholders in late November.

    Not everybody in Grand Lake thinks that reduced clarity is a problem. “There are people who think there’s a problem, but there is no problem,” says Jim Gasner, a member of the Grand Lake Board of Trustees, the town’s elected body, and a fishing “teacher” at Rocky Mountain Outfitters.

    But Elwin Crabtree, a real estate agent and former Grand County commissioner, sees something different. “It’s adverse to its natural being,” he said in early August in an interview at his office along the town’s main street of knotty-pined stores and lodges. “I think we look at it as a moral issue,” he added. “I think we believe in having responsibility to be good stewards of our environment.”

    The C-BT is an effort to address what one historian in the 1950s called “nature’s error.” Even as Aspen was putting on its silver-lined britches in the 1880s, farmers along the South Platte River and its tributaries were struggling with inadequate water in late summer to finish their corn and other crops.

    Grand River Ditch July 2016. Photo credit Greg Hobbs.
    Grand River Ditch July 2016. Photo credit Greg Hobbs.

    Irrigators set out to remedy this. The first large-scale transmountain diversion from the headwaters of the Colorado River began in 1890. Called the Grand River Ditch, it’s beveled into the side of the Never Summer Range in what is now Rocky Mountain National Park, collecting water like a rain gutter from a roof.

    Then came the 1930s, the decade of the Dust Bowl, the Great Depression and the New Deal. Farmers in northeastern Colorado had long been agitating for added infusions of water from the Colorado River headwaters. But they couldn’t get it done themselves. They needed federal funding.

    Map of the Colorado-Big Thompson Project via Northern Water
    Map of the Colorado-Big Thompson Project via Northern Water

    The flawed design

    But the work along the Continental Divide from 1939 to 1953 created a wound at Grand Lake. In retrospect, the design was flawed.

    The C-BT at the Colorado River headwaters consists of three main bodies of interconnected water. Only one, Grand Lake, is natural.

    Farthest downstream is Granby Reservoir, which is Colorado’s third largest, capable of holding 539,758 acre-feet of water during runoff of spring and early summer. This compares to Ruedi Reservoir’s 102,373 acre-feet and Dillon’s 257,304 acre-feet.

    From Granby, water is pumped upstream as needed by Eastern Slope diverters to Shadow Mountain Reservoir. Shallow, no more than nine feet deep, Shadow Mountain is directly connected through a short canal to Grand Lake.

    In 2011, reservoirs east of the divide were full, so water was allowed to continue down the Colorado River without diversion. This photo shows what the lake looked like on Aug. 30, without pumping. Photo courtesy of Byron Metzler and pilot Steve Paul
    In 2011, reservoirs east of the divide were full, so water was allowed to continue down the Colorado River without diversion. This photo shows what the lake looked like on Aug. 30, without pumping. Photo courtesy of Byron Metzler and pilot Steve Paul

    The canal occupies the original path of the Colorado River emerging from Grand Lake. From the interconnected Grand Lake and Shadow Mountain Reservoir, water is then pumped through the 13.1-mile Alva Adams Tunnel underneath the national park to the Estes Park area for storage in reservoirs there and along the northern Front Range.

    Shadow Mountain is a problem, though. Its shallowness allows water to be easily warmed in summer, producing algae that can float into Grand Lake. The shallowness also allows lake-bottom sediments to be disturbed more easily and dispersed into Grand Lake.

    Evidence for the historic, pre-construction clarity of Grand Lake is scant: Just one measurement, taken in 1941, of 9.2 meters (30 feet).

    Detailed observations during the last decade show clarity down to 6 meters (19.6 feet), but no more.

    The standard adopted in April by the state agency specifies a minimum of 2.5 meters and an average of 3.8 meters (8.2 feet to 12.4 feet) during summer diversion season.

    “I think the clarity standard has really elevated the discussion,” says Lane Wyatt, co-director of the water quality/quantity committee in the Northwest Council of Governments. “This is the only clarity standard in Colorado. It’s the first one we’ve ever done.”

    Clarity is not the only issue, though. Water must be delivered to farms and cities. As it is flows downhill toward the Great Plains, it generates electricity distributed by the Western Area Power Authority. Purchasers of this low-cost power include Aspen Electric and Holy Cross Energy.

    Canton “Scally” O’Donnell, president of the Three Lakes Watershed Association, remembers a more pristine past.

    As a boy, his family summered at Grand Lake. That was in the 1930s and 1940s. “We drank the water right out of the lake, and many families did that,” O’Donnell said.

    The first complaint about the sullied water was filed in 1954, the year after the project’s formal completion. In 1956, Grand Lake trustees adopted a resolution that informed Colorado’s congressional delegation of problems. The resolution was aimed at the Bureau of Reclamation.

    “I think it’s fair to say that up until seven or eight years ago, the bureau pretty much stonewalled,” O’Donnell said. “They just did not want to recognize the problem, and Northern Colorado Water, the same.”

    Movement has occurred during the last decade. One avenue for local protest was a proposed expansion of an existing diversion of the Colorado River at Windy Gap, about 15 miles downstream. Completed in 1985, the Windy Gap dam uses the C-BT infrastructure to deliver additional water to the Rawhide power plant north of Fort Collins, Greeley, Boulder and other cities.

    The Windy Gap Firming, or expansion, plan was formally introduced after the drought of 2002. It proposes diversion of remaining water rights owned by a string of northern Front Range cities.

    The effect of persistence

    O’Donnell, of the Three Lakes Watershed Association, thinks the changed attitudes is explained by the persistence of individual public officials.

    He singles out Lurline Underbrink Curran, then the Grand County manager. “She’s smart and she’s tough,” he said. “She just kept on beating on everybody to make it happen.”

    He also points to the influence of Anne Castle, a long-time Denver water lawyer who served from 2009 to 20014 as assistant secretary for water and science in the Interior Department. Her responsibilities included oversight of the Bureau of Reclamation.

    “I think part of the reason it has attention now is the fact that the Windy Gap Firming Project required the federal government to pay attention to Senate Document 80 and both C-BT and Windy Gap Firming Project do have an impact on Grand Lake’s recreation and scenic attraction. Calling attention to that issue, as both Lurline and I did, with prodding from Scally, had an impact,” Castle said.

    But again, agreeing there is a problem is not the same thing as finding a solution.

    “There is a lot of uncertainty about how our operations affect clarity,” said Victor Lee, an engineer for the Bureau of Reclamation.

    The precise circumstances that cause algae and sediments to degrade clarity are poorly understood. Northern has been altering its diversion regimes, to see if that will improve clarity.

    This year, from July until late August, pumping was conducted about 15 hours a day at 250 cubic feet per second. Clarity degraded, though. Algae growth was suspected. So the pumping was accelerated to about 20 hours a day with two pumps. Results were mixed.

    It was a success, said Lee, in that they learned something. Clarity readings exceeded the minimum but did not meet the average standard. “I would say the experiment was successful, but we did not meet our objective,” he said.

    Esther Vincent, water quality manager for Northern Water, said the effort to address Grand Lake’s muddled clarity is attracting attention across Colorado by water professionals. Spurring their interest, she said, is the possibility of other bodies of water being assigned clarity standards.

    There’s also interest in the adaptive management process created for Grand Lake. It’s similar to but separate from Learning By Doing, which was created in response to expanded water diversions from both Windy Gap and by Denver Water’s Moffat Tunnel collection system.

    Vincent also points out a deeply philosophical question. In 1937, when adopting S.D. 80, did Congress have the same notion about what constitutes “scenic attraction” as we do today?

    “I am an engineer,” she said. “Asking an engineer to define what beauty is, is an interesting dilemma. It’s not a concept that lends itself very well to science.”

    Editor’s note: Aspen Journalism and the Aspen Daily News are collaborating on coverage of Colorado’s rivers and water. More at http://www.aspenjournalism.org.

    Center for #ColoradoRiver Studies: Fill Mead first — A Technical Assessment #COriver


    Click here to the Denver for Colorado River Studies at Utah State University for all the inside skinny on the report. Here’s the executive summary:

    The Fill Mead First (FMF) plan would establish Lake Mead reservoir as the primary water storage facility of the main-stem Colorado River and would relegate Lake Powell reservoir to a secondary water storage facility to be used only when Lake Mead is full. The objectives of the FMF plan are to re-expose some of Glen Canyon’s sandstone walls that are now inundated, begin the process of re-creating a riverine ecosystem in Glen Canyon, restore a more natural streamflow, temperature, and sediment-supply regime of the Colorado River in the Grand Canyon ecosystem, and reduce system-wide water losses caused by evaporation and movement of reservoir water into ground-water storage. The FMF plan would be implemented in three phases. Phase I would involve lowering Lake Powell to the minimum elevation at which hydroelectricity can still be produced (called minimum power pool elevation): 3490 ft asl (feet above sea level). At this elevation, the water surface area of Lake Powell is approximately 77 mi2, which is 31% of the surface area when the reservoir is full. Phase II of the FMF plan would involve lowering Lake Powell to dead pool elevation (3370 ft asl), abandoning hydroelectricity generation, and releasing water only through the river outlets. The water surface area of Lake Powell at dead pool is approximately 32 mi2 and is 13% of the reservoir surface area when it is full. Implementation of Phase III would necessitate drilling new diversion tunnels around Glen Canyon Dam in order to eliminate all water storage at Lake Powell. In this paper, we summarize the FMF plan and identify critical details about the plan’s implementation that are presently unknown. We estimate changes in evaporation losses and groundwater storage that would occur if the FMF plan was implemented, based on review of existing data and published reports. We also discuss significant river-ecosystem issues that would arise if the plan was implemented.

    From The Grand Junction Daily Sentinel (Gary Harmon):

    Making Lake Mead the primary water storage facility on the Colorado River isn’t as simple as it might seem and would require more study than it’s been given so far, says a study released Thursday.

    Backers of the Fill Mead First idea said the study underscores the need to move ahead with studies and a spokesman for the Colorado River Water Conservation District said the discussion ignores a significant element: the need for Colorado and other states to save water in Powell.

    The Center for Colorado River Studies at Utah State University said more study of evaporation from Lake Powell is needed, as well as a study of groundwater into the reservoir and of the fine sediment that would be released should Lake Powell be drained.

    That would be a good start, said Eric Balken, executive director of the Glen Canyon Institute, which drafted the idea of filling Lake Mead instead of storing water in Powell so as to reduce water lost to evaporation.

    The Interior Department has so far “written off” the idea, Balken said.

    “Now is the time to initiate new measurement programs of (evaporation) losses at Lake Powell and Lake Mead so that future policy discussions have access to less uncertain data regarding evaporation and groundwater storage,” Balken said in an email.

    The idea ignores Lake Powell’s “primary purpose,” which is to serve as a savings account for the upper Colorado River Basin states to deliver an average 7.5 million acre-feet of water per year to the lower basin, said Chris Treese of the River District.

    The amount is set in the 1922 compact that governs the use of the river, which provides water to millions of people in the arid Southwest.

    Advocates of draining Lake Powell tend to write off the upper basin concerns by saying it’s “with a wave of the hand that you’d have to ‘make a few changes’,” to the compact, Treese said, “As if it’s simple and desirable to open up the Colorado River Compact.”

    The Fill Mead First idea proposes draining Lake Powell in a three-stage process and storing the water in Lake Mead, 300 miles downstream.

    “It is surprising how much uncertainty there is in estimating losses associated with reservoir storage,” said Jack Schmidt of the Center for Colorado River Studies, who served as chief of the U.S. Geological Survey’s Grand Canyon Research and Monitoring Center from 2011 to 2014.

    Evaporation losses at Lake Mead are measured by the U.S. Geological Survey in a state-of-the-science program, but there have been no efforts to measure evaporation at Lake Powell since the mid-1970s, Schmidt said.

    Using the most recent data, researchers showed the Fill Mead First plan might reduce evaporation losses slightly, but noted that such a prediction is uncertain.

    The Interior Department should conduct a thorough scientific investigation of evaporation and seepage losses at lakes Powell and Mead, as the Utah State study suggests, Balken said.

    Delph Carpenter's 1922 Colorado River Basin map with Lake Mead and Lake Powell
    Delph Carpenter’s 1922 Colorado River Basin map with Lake Mead and Lake Powell