Less urgency for the #Drought plan for the Lower #ColoradoRiver Basin states #COriver

The Colorado River Basin. The Upper Colorado River Basin is outlined in black.

From The Arizona Daily Star (Tony Davis):

For many months, water agencies including Tucson Water have discussed a plan to save 1.2 million acre-feet of river water over three years to delay the threat of shortages to the Central Arizona Project, which brings drinking water to Tucson and Phoenix and irrigation water to Central Arizona farmers.

But the snowy winter appears to mean that the river and lake will be flush enough this year to significantly reduce the odds of short-term water cuts even without a conservation plan. The abrupt weather shift has intensified an already major split among water officials about what to do next.

CAP officials say the earlier proposal is “no longer viable” and that it’s time for a new approach.

“The improved hydrology has changed the landscape and given us a reprieve,” said Suzanne Ticknor, CAP’s water-policy director. “We have the opportunity to get it right, to sit back and find out what we want to do to find consensus in the state. We don’t need to do huge volumes of conservation right now.”

Other water users disagree with this position, including the Arizona Department of Water Resources (DWR), the Tucson and Phoenix water utilities and the Gila River Indian Community, which controls the largest share of CAP water.

“I do not believe one year of good hydrology is enough to stop us from seeking to conserve water in the lake,” Arizona DWR Director Tom Buschatzke said, referring to Lake Mead, a reservoir of Colorado River water.

He and other officials said recent weather doesn’t substitute for a long-term policy during a 17-year drought, the longest in the historical record dating to 1906.

WATER FEAST OR FAMINE
At stake is an Arizona version of the Drought Contingency Plan, an effort by this state, California and Nevada to negotiate a long-term, water-use reduction agreement. The goal is to reduce the risks of Lake Mead dropping below 1,025 feet, compared to the 1,070s to 1,080s it has been at recently.

At the lower lake level, water deliveries to Tucson and Phoenix would be jeopardized and Hoover Dam’s power output would be dramatically curtailed. The risk is due to what authorities say is a structural deficit, in which people in the Lower Colorado River Basin use more water each year than the over-allocated river provides, even when it’s not in a drought.

The Arizona plan, called DCP Plus, seeks to delay for three years or longer the first CAP shortage, which would happen if the lake drops below 1,075 feet at year’s end. Last December, the U.S. Bureau of Reclamation predicted that the chance of a shortage for 2018 through 2020 was around 50 percent and warned the river was “on the brink”.

But at a March 2 CAP board meeting, project officials were rejoicing over the heavy snowfalls that had fallen in the river’s Upper Basin, which supplies crucial spring runoff to Lake Powell, another Colorado River reservoir.

“The Green River has a tremendous snowpack situation. Flooding will occur in that watershed this spring. Not that we’re wishing it on our Wyoming friends, but quite frankly I’m for it,” said CAP Colorado River program manager Chuck Cullom.

There’s so much snow that a major Wyoming cloud-seeding program has been suspended to reduce the risk of flood damage, Cullom added.

As of March 1, Upper Basin snowpack was 154 percent of normal. Annual spring runoff into Powell was predicted to be 10.4 million acre-feet, or 145 percent of average, said Brenda Alcorn, a federal Colorado Basin River Forecast Center hydrologist.

The reclamation agency now sees a greater chance of above-average water releases from Powell to Mead for three years than it does of shortages.

So instead of a fixed, three-year conservation plan, CAP official Ticknor said that while the agency remains committed to reducing the river’s structural deficit over the long term, the best solution now is to plan annually.

“It has to be more of an adaptive approach and look at things in real time and understand the hydrology, what the inflow to Powell is and what Mead’s elevation is each year,” she said.

Setting hard, three-year targets can create an “overconserving” risk, Ticknor said.

That’s possible due to the complex, seven-state guidelines covering management of Lake Mead at the Arizona-Nevada border and Lake Powell at the Arizona-Utah border, she said. Worrying about “overconserving” is a shift in emphasis among CAP officials, who have a “Protect Lake Mead” message on their home page and produced videos and other material saying the same.

While remaining concerned about Mead’s long-term risks, CAP officials say that under certain circumstances, the guidelines mean that too much conservation can reduce how much water Powell releases to Mead. That deprives the three Lower Colorado River Basin states, including Arizona, of additional water.

Phoenix Water Director Kathryn Sorensen counters, “The ‘risk’ of overconserving is a Colorado River that is less vulnerable to shortages and more resilient over the long run, a river that is more protective of our economy and our quality of life.”

Under guidelines approved in 2007 by the seven basin states, Lake Mead gets an extra surge of water from Powell in a year in which forecasters predict that Powell will stay above 3,575 feet while Mead falls below 1,075 feet on a given date.

This year, conditions are good enough that the lake is expected to get at least 9 million acre-feet, nearly 700,000 acre-feet above average. But if conservation pushes Mead’s forecast above 1,075 at the end of 2017, that extra water goes away.

“You could have an unintended consequence,” Ticknor said. “You have a narrow band of operating space with the reservoirs. You have to be careful about what you do.”

Old Time Poker Players. Photo credit: the 19th Century on Pinterest.

“NOT A GAME OF POKER”
Phoenix’s Sorensen replied that playing the probabilities of shortage year-by-year is a short-sighted strategy that fosters uncertainty and keeps Arizona’s economy closer to the razor’s edge.

“This is not a game of poker. Arizona has weathered the last 17 years of drought precisely because generations ago, we planned methodically for the long run. We must continue this legacy,” Sorensen said.

State Water Resources Director Buschatzke said he prefers the risk of overconserving “because if you underconserve there isn’t much you can do about it” if a shortage occurs. Tucson Water Director Tim Thomure said authorities should err on the side of conservation and focus on the longer term.

“We have to be nimble enough to manage year by year, but decisions need to be made with the long-term in mind,” Thomure said.

Plus, Mother Nature can make unanticipated weather shifts, Buschatzke said. Just since March 1, hot, dry weather has caused federal river-basin forecasters to lower projections for runoff into Powell by half a million acre-feet. That’s enough to serve Tucson Water’s 700,000-plus customers for five years.

The April runoff forecast is still expected to be high enough for an above-average release from Powell. But if the region experiences the flip side of the “Miracle May” rains that pounded the Rockies in May 2015 — saving the river from an almost certain shortage — that wouldn’t leave authorities much time to forestall a 2018 shortage, Buschatzke said.

“These are hard issues — harsh decisions. I want to err on the side of more certainty,” he said.

The bottom line is that the water agency now can’t meet its goal of getting a water-saving plan to this year’s legislative session for approval, he said.

Senate confirms Zinke as Interior Secretary

Arizona Water News

The new Zinke team, including appointments to Bureau of Reclamation, will need to learn quickly about the complexities of Colorado River water law and the drought-induced woes facing Lake Mead

zinke-confirmation-photo

By a comfortable 68-31 margin, the U.S. Senate today confirmed President Trump’s nominee for Secretary of the Interior, Ryan Zinke.

The former Montana member of Congress will head a department that manages around 500 million acres of land and waterways in the United States.

Zinke’s department also includes the federal Bureau of Reclamation, the agency responsible for the system of dams and reservoirs on the Colorado River, the waterway that is integral to the livelihood of 40 million U.S. citizens living in the Southwest.

In a statement declaring his approval of the appointment, Arizona Sen. Jeff Flake said he looked forward to working with Zinke’s department, notably on behalf of Arizona’s Colorado River allotment.

“I was pleased to vote to…

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@wradv report: Arizona’s Water Future: Colorado River Shortage, Innovative Solutions, Living Well With Less

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Here’s the release from Western Resource Advocates:

Western Resources Advocates (WRA) released a new analysis today that shows Central Arizona’s cities, suburban growth in significant areas, and agriculture face substantial cuts in Colorado River water supplies if Lake Mead levels continue to fall. Analysis of data from the Arizona Department of Water Resources (ADWR) and Central Arizona Project (CAP) identifies who could face a reduction of Colorado River supplies, and at what level, within Arizona as Lake Mead levels continue to drop.

The report, Arizona’s Water Future: Colorado River Shortage, Innovative Solutions, Living Well with Less, finds:

  • Phoenix and Tucson suburban growth that uses the Central Arizona Groundwater Replenishment District to prove there is renewable water to cover development will be cut first in a shortage declaration under existing agreements;
  • Four important Central Arizona Irrigation Districts could also lose a substantial portion of their CAP water, including Maricopa Stanfield, Central Arizona, Hohokam, and Harquahala; and
  • Major cities, including Phoenix and Tucson, could face a reduction of Colorado River supplies within this decade if Lake Mead drops below the 1,025’ level.
  • These cuts are looming because Arizona’s ”bank” for 40% of its water supply, Lake Mead, is being drained faster than it can be filled. The U.S. Bureau of Reclamation estimates there is a nearly 50% chance of a federal shortage declaration, that would cut 320,000 acre-feet of Colorado River water deliveries to Arizona, happening as soon as 2018 under business as usual. This level of cuts could harm agriculture, lead to over-drafting of nonrenewable groundwater, reduce hydroelectric power, and provide a lot less water for Arizona cities and the environment.

    “Arizona is facing perhaps its greatest challenge since the settlement of the region and development of modern cities, agriculture, and industry,” said Drew Beckwith, Water Policy Manager, Western Resource Advocates. “The time is now for ADWR and CAP to put in place longer-term solutions that prevent significant water shortages and stand the test of time. One cannot put Band-Aids on an ill patient, while failing to address the underlying illness.”

    Arizona has already taken important action by implementing interim measures to keep more water in Lake Mead to help stave off federally mandated cutbacks of Colorado River water. The Arizona Department of Water Resources has also been working with California, Nevada, and key water users within Arizona on plans to keep Lake Mead from falling to critically low levels.

    Western Resource Advocates and conservation partners at American Rivers and Environmental Defense Fund have developed seven policies and actions to protect groundwater and help Arizona’s agriculture, cities, Indian tribes, economy, and environment thrive in a future with less Colorado River water supplies.

    Three of the seven proposed policies and actions are:

  • Water providers and farmers, with support from ADWR, should adopt next-generation water conservation and efficiencyfor our homes, business and agriculture.
  • The Central Arizona Project should expand its support of system conservation programs allowing municipalities and other water users to dedicate conserved water to stay in Lake Mead to prevent water levels from dropping farther.
  • Water providers, cities and agriculture, with support from CAP and ADWR, should increase the number of innovative water sharing arrangements between themselves,like the Phoenix-Tucson water sharing agreement.
  • “System Conservation Programs have proven to be a great success along the Colorado River, putting more water into Lake Mead and keeping the lake from falling to drastically low levels,” said Jeff Odefey, Director, Clean Water Supply, American Rivers. “Innovative water sharing agreements, like that between Phoenix and Tucson, are an ideal example other water interests should adopt, demonstrating the collaboration and flexibility we will need to stabilize Lake Mead levels for the long term.”

    “We are all in this together in the Colorado River basin. ADWR is on the right track with increasing the level of collaboration and proactive actions with all Arizona water stakeholders. Now ADWR and stakeholders need to also adopt longer-term solutions,” said Kevin Moran, Senior Director, Colorado River Program, Environmental Defense Fund. “In the end, the strategy which has served Arizona and the Lower Basin states the most is to focus on collaboration and ongoing water management innovation that benefit both current and future generations.”

    The two-page Arizona’s Water Future Executive Summary is downloadable here and the thirty-page full report is downloadable here.

    High Demand, Low Supply: Colorado River Water Crisis Hits Across The West — @NewsCPR

    Colorado River Basin including out of basin demands -- Graphic/USBR
    Colorado River Basin including out of basin demands — Graphic/USBR

    From Colorado Public Radio (Grace Hood):

    For decades, the [Colorado River] has fed growing cities from Denver to Los Angeles. A lot of the produce in supermarkets across the country was grown with Colorado River water. But with climate change, and severe drought, the river is reaching a crisis point, and communities at each end of it are reacting very differently…

    The problem is that Colorado’s population will nearly double by 2050. Future residents will need more water. Denver Water CEO Jim Lochhead says more storage is part of the solution. It’s also an insurance policy against future drought.

    “From Denver Water’s perspective, if we can’t provide clean, reliable, sustainable water 100 years from now to our customers, we’re not doing our job,” Lochhead says.

    Demand for Colorado River water is already stretched thin. So it may sound crazy that places like Colorado and Wyoming want to develop more water projects. Legally, that’s something they are entitled to do.

    Wyoming is studying whether to store more water from a Colorado River tributary. “We feel we have some room to grow, but we understand that growth comes with risk,” says Pat Tyrrell, who oversees Wyoming’s water rights.

    Risk because in 10 or 20 years there may not be enough water to fill up expanded reservoirs. A 16-year drought has dramatically decreased water supply even as demand keeps growing. And climate change could make this picture worse.

    It makes Tyrrell’s job feel impossible.

    “You understand the reality today of a low water supply,” he says. “You also know that you’re going to have permit applications coming in to develop more water. What do you do?”

    Tyrrell says that as long as water is available, Wyoming will very likely keep finding new ways to store it. But a future with less water is coming.

    In California, that future of cutbacks has already arrived. The water that started in Colorado flows more than 1,000 miles to greater Los Angeles.

    So even in the sixth year of California’s drought, some lawns are still green.

    “Slowly but surely, the entire supply on Colorado River has become less reliable,” says Jeffrey Kightlinger, who manages the Metropolitan Water District in Southern California. He notes that the water level in Lake Mead, the biggest reservoir on the river, has been plummeting.

    An official shortage could be declared next winter. “And that’ll be a historic moment,” Kightlinger says.

    It’s never happened before. Arizona and Nevada would be forced to cut back on how much water they draw from the river. California would be spared that fate, because it has senior water rights. So you wouldn’t expect to hear what Kightlinger says next.

    “We are having voluntary discussions with Arizona and Nevada about what we would do proactively to help,” he says.

    California could help by giving up water before it has to, between 5 percent and 8 percent of its supply. Kightlinger isn’t offering this out of the goodness of his heart; if Lake Mead drops too low, the federal government could step in and reallocate all the water, including California’s.

    “We all realize if we model the future and we build in climate change, we could be in a world of hurt if we do nothing,” Kightlinger says.

    This idea of cooperation is somewhat revolutionary after years of lawsuits and bad blood.

    Recently, farmer Steve Benson was checking on one of his alfalfa fields near the Mexican border. “We know there’s a target on our back in the Imperial Valley for the amount of water we use,” he says.

    This valley produces two-thirds of the country’s vegetables in the winter — with water from the Colorado River.

    In fact, for decades, California used more than its legal share of the river and had to cut back in 2003. This area, the Imperial Irrigation District, took the painful step of transferring some of its water to cities like San Diego.

    Bruce Kuhn voted on that water transfer as a board member of the district. “It was the single hardest decision I have ever made in my life,” he says.

    Kuhn ended up casting the deciding vote to share water, which meant some farmers have had to fallow their land.

    “It cost me some friends,” he says. “I mean, we still talk but it isn’t the same.”

    Soon, Kuhn may have to make another painful decision about whether California should give up water to Arizona and Nevada. With an emergency shortage looming, Kuhn may have no choice.

    Colorado River Water Users Association Annual Conference recap

    Lake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona. Lake Havasu City sits on the lake's eastern shore. Photo credit MyGola.com
    Lake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona. Lake Havasu City sits on the lake’s eastern shore. Photo credit MyGola.com

    From HavasuNews.com (Brandon Messick):

    Lake Mead’s water levels this year fell to a near all-time low in the midst of a 16-year drought throughout the Southwestern U.S., prompting discussion at a national conference last week.

    The Colorado River Water Users Association met [December 14-16, 2017] in Las Vegas for an annual conference, where guests — including Arizona Gov. Doug Ducey and Colorado Gov. John Hickenlooper — discussed the need for conservation efforts and governance of the Colorado River’s water supply. Ducey and Hickenlooper hosted a question-and-answer session with the U.S. Chamber of Commerce last Monday, in which both agreed that water is an issue that “transcends partisan politics.”

    According to the Arizona Department of Water Resources, Arizona and California are negotiating the terms of a contingency plan to protect Lake Mead, a final agreement is still pending.

    “This plan is a way to delay and maybe thwart shortage declarations with the most important aspect of California agreeing to take shortages after Lake Mead reaches particular elevations,” said Lake Havasu City’s Water Resources Coordinator Doyle Wilson. “Since the plan has not yet been approved by all parties, details are uncertain.”

    Havasu receives an allocation of about 28,000 acre-feet of water per year from the Colorado River. Havasu uses about half that amount. If a water shortage were declared, the city would be required to use 20 percent less than its currently-allocated amount. According to Lake Havasu City officials, the city would be in no immediate danger in the event of a shortage. Havasu’s pending effluent water project is will provide reused water to city parks, further progressing the city’s conservation efforts.

    “A combination of projects and programs have helped to educate the community on conserving water and have resulted in real water use efficiency at both the personal and citywide levels,” Wilson said. Havasu residents have used low water-use faucet and shower heads, geyser stop devices for irrigation systems, and have received rebates for water conservation.

    “Over the years, the combined activities, along with the acknowledgment that the winter water averaging strategy for setting monthly sewer rates has lowered the city’s overall water consumption,” Wilson said.

    In Havasu, total water consumption has more than halved in the past thirty years. In 1985, water consumption peaked at more than 450 gallons daily per capita. As of 2015, Havasu’s total water consumption was recorded at about 175 gallons per capita, daily, and trending even lower. Residential water consumption in Havasu was recorded at about 130 gallons per capita, daily.

    Conservation efforts continue statewide, according to Arizona Department of Water Resources spokeswoman Michelle Moreno.

    “As a state, we’re more efficient in water conservation,” Moreno said. “We use less than we did in the 1950s, despite a 600-percent population increase, in part because of our conservation efforts.”

    Arizona regulates water use on an industrial level, maintaining mandatory conservation while allowing providers to educate customers in conservation efforts. Some water providers offer rebates to customers for efforts to conserve water at home.

    The Central Arizona Project is continuing to lead conservation programs to prevent a shortage in 2018, according to the Department of Water Resources, but the risks of another shortage are expected to increase from 2019-21.

    Stakeholders in the Lower-Basin Colorado River expected this year’s conference to focus on agreements associated with the Drought Contingency Plan, which would revise water conservation efforts and restrictions in the event of a water shortage. Stakeholders also expected announcements involving an agreement on water rights and restrictions between the U.S. and Mexico. No such announcements came, which could hold consequences for Lake Havasu City, as well as the American Southwest.

    The situation in Lake Mead is only projected to become worse, according to the U.S. Bureau of Reclamation. Lake Mead’s surface now rests at about 1,077 feet above sea level, and Bureau of Reclamation officials say there is a 54 percent chance that the lake will fall below 1,075 feet in 2017.

    Lake Mead’s water levels are measured every August, and the results of that month’s measurement will determine if cuts will need to be made, according to the Arizona Department of Water Resources. If Mead’s water level falls below 1,075 feet above sea level in August 2017, Arizona water providers will be forced to reduce their water usage by 192,000 acre-feet until August 2018, according to new proposed guidelines. Nevada would similarly have to reduce water usage by 8,000 acre-feet per year, while California would not be required to make reductions at all.

    Arizona, California and Nevada each have an interest in maintaining Lake Mead’s water levels. Mead represents one of the two largest reservoirs in the Colorado River system, and directly affects the supply of river water to all three states. Federal agencies measure Lake Mead’s water levels to determine whether a shortage should be declared on the Colorado River. If such a shortage were declared, California would be asked to make significant cuts to its water usage.

    Arizona, California and Nevada are negotiating the terms for their proposed “Lower Colorado River Basin Drought Contingency Plan,” which would revise 2007 water restriction guidelines among the three states. According to the 2007 guidelines, Arizona would make the bulk of reductions in the event of a shortage, despite consuming less than either of its neighboring states. California, however, would never face water restrictions, no matter how low the water levels become at Lake Mead.

    The Colorado River provides water to 13 percent of America’s population. More than 40 million people rely on the river, but water shortages have exposed a need for changes in water use and policy. According to this month’s Arizona Department of Water Resources Drought Index, Southwestern Arizona continues to undergo severe drought conditions and the Havasu region is beginning to experience an “abnormally dry” season.

    As negotiations continue between Arizona, Nevada and California, the Department of Water Resources says the next steps for its “Lower Colorado River Basin Drought Contingency Plan” discussions will include continuing to assess potential impacts on the southwest.

    #ColoradoRiver: Sharing Water: A Special Presentation from Author John Fleck Wednesday, November 30 #COriver

    Young girl enjoying the river restored temporarily by the pulse flow March 2014 via National Geographic
    Young girl enjoying the river restored temporarily by the pulse flow March 2014 via National Geographic

    Register here. From the website:

    When the governments of the United States and Mexico released water from Morelos Dam on the Colorado River in the spring of 2014, it marked the culmination of one of the most important environmental restoration experiments in arid western North America. In the midst of deep drought, water returned to the river’s desiccated delta, and with it birds, riparian plant communities, and even beavers. But while all nature is ultimately local, bringing water and wildlife back to that landscape required linking those local environmental concerns to water management in the entire Colorado River Basin, spread across seven U.S. states and two in Mexico. John Fleck will talk about his new book “Water is for Fighting Over: and Other Myths about Water in the West,” which chronicles the environmental success in the delta and the broader problem solving that made it possible.

    waterisforfightingoverandothermythsaboutwaterinthewestjohnfleckcover

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

    fillmeadfirstatechnicalassessment

    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