In 1922, the Colorado River Compact was signed by the federal government and the seven states in the Colorado Basin. The Compact allocated water rights between the states of the upper (New Mexico, Utah, Wyoming, and Colorado) and lower (Arizona, California, and Nevada) Colorado River Basin. This paved the way for Hoover and Glen Canyon dams, which impound Lake Mead and Lake Powell, as well as the entire Colorado River water management system.

Today, the Colorado River Basin is facing a water supply crisis. We now know that the Colorado River Compact was based on flawed projections that seriously overestimated actual river flow and seriously underestimated future water demand. As a result, growing demand, relentless shortage, and climate change are creating an average water deficit of almost 1 million acre-feet a year in the Colorado River system. Both Lake Powell and Lake Mead reservoirs are half empty, and scientists predict that they will probably never fill again. The water supply of more than 22 million people in the three Lower Basin states is in jeopardy.

The region is also facing an environmental crisis. The ecological health of the Southwest is tied to the fate of the Colorado River. A century ago, the Colorado was one of the world’s wildest rivers. Its extraordinary variations in water flow, temperature, and sedimentation created a unique ecosystem that was once home to 16 endemic fish species — the largest percentage of any river system in North America.

The construction of more than a dozen dams during the last century has critically damaged the integrity of the Colorado River. Hundreds of miles of canyon and countless archaeological sites have been flooded, and dozens of wildlife species have been endangered. Glen Canyon Dam is one of the largest contributors to these problems, with major impacts that stretch from above Glen Canyon, through the Grand Canyon, all the way to the Colorado Delta in Mexico. In 1992, Congress passed the Grand Canyon Protection Act, which sought to modify Glen Canyon Dam operations to “protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established.” Unfortunately, efforts to implement the act have been only partially successful.

GCI believes the time has come to change Colorado River management to address today’s new realities. This is the goal of our Fill Lake Mead First proposal. Since Glen Canyon Dam was completed in 1963, the goal of water managers has been to capture “excess” water and keep both Lake Powell and Lake Mead full. Now, with two half-empty reservoirs, this policy no longer makes sense. Through our Fill Mead First, GCI is advocating a new approach that consolidates most of the water from both reservoirs in Lake Mead, with Lake Powell used as a backup in flood years.

The Fill Mead First strategy could seriously benefit the people and ecosystems of the Colorado River Basin and beyond. This approach would help to maintain a reliable water supply for millions of people who depend on Lake Mead, in major cities such as Las Vegas, Phoenix, Los Angeles, and San Diego, as well as on farms across the region. It would also help to restore Colorado River ecosystems. Water would be permitted to flow more naturally through Glen Canyon Dam, helping to heal the damage done by the dam to the Grand Canyon. A lowered Lake Powell would expose many more portions of Glen Canyon that have been flooded under the reservoir, allowing them to recover their natural beauty and integrity. If executed cooperatively between all basin states, FMF could be implemented in a way that shares benefits between the upper basin and lower basin.

In 2013, GCI commissioned a study that analyzed water lost to ground seepage in Lake Powell. The study, “Loss Rates from Lake Powell and their Impact on Management of the Colorado River”, which was published in the Journal of the American Water Resources Association, showed that Lake Powell had lost significant amounts of water that soaked into the porous sandstone walls of Glen Canyon. Some of this water can return to the river system, while some of it remains trapped in the walls for decades or more.

The hydrologist who conducted the study estimated up to 300,000 acre feet of water could be saved each year in the Colorado Basin if the Fill Mead First proposal were implemented. That’s the same amount of water allocated to the entire state of Nevada.

In 2016, Utah State University’s Center for Colorado River Studies conducted an assessment of Fill Mead First, and estimated that water savings under the proposal would be closer to 50,000 acre feet. While the two studies project different savings, both lead scientists agree that much more research is needed on evaporation and seepage.

The Fill Lake Mead First proposal is an expansion on an idea that has been proposed before by the likes of David Brower, who helped to found Glen Canyon Institute. In the past, this strategy was considered “politically unrealistic.” Now, in the face of unprecedented water supply and environmental challenges, the various people and institutions involved in Colorado River water policy are increasingly open to new ideas they never would have considered before. GCI is optimistic that this will lead to exceptional, positive change in the years to come, for the benefit of the people and ecosystems of the Colorado River Basin.

The idea behind the Fill Mead First proposal is to move water stored in Lake Powell downstream to Lake Mead. Currently, there is not enough water between both reservoirs to keep even one full. This process would take place through three stages, ultimately leading to the restoration of a free-flowing Colorado River through Glen Canyon and Grand Canyon.

The first stage is where Lake Powell would near 3,490 feet, or minimum power pool. At this stage, there would still be little to no power generation at the dam and some reservoir recreation. At 70 feet below the level of Lake Powell as of spring 2021, this stage of Fill Mead First would allow much of Glen Canyon’s world-renowned landscape to reemerge and be restored.

In the second stage of Fill Mead First, the reservoir’s level would near 3,374 feet, near the river outlet works. At this stage a significant amount of Glen Canyon would be exposed, allowing remarkable opportunities for restoration. No power would be generated at this stage, and much less water would be able to move through the dam because of reduced outlet capacity.

The third stage of the Fill Mead First would entail drilling new diversion tunnels around Glen Canyon Dam, and allowing the Colorado River to flow freely through it. This would allow for optimum restoration of Glen Canyon, and for normalized sediment flows to take place in the Grand Canyon, which has been starved of sediment for the last 50 years. Hydropower generation turbines could be installed in the tunnels to produce electricity.

Glen Canyon Institute submitted the Fill Mead First proposal to the Glen Canyon Dam Long Term Experimental Management Plan EIS, as well as the Bureau of Reclamation Supply and Demand Study. Neither process considered the proposal for further study. GCI will continue to facilitate research that supports the Fill Mead First proposal, and push policy makers to take it into consideration. With Lake Mead nearing shortage levels, and total storage between Powell and Mead reaching record lows, the proposal to Fill Mead First becomes more realistic and pragmatic everyday.

Please see more detail about each of these stages below. 

With Lake Mead nearing shortage levels, and total storage between Powell and Mead reaching record lows, the proposal to Fill Mead First becomes more realistic and pragmatic everyday.

The Fill Lake Mead First proposal is an expansion on an idea that has been proposed before by the likes of David Brower, who helped to found Glen Canyon Institute. In the past, this strategy was considered “politically unrealistic.” Now, in the face of unprecedented water supply and environmental challenges, the various people and institutions involved in Colorado River water policy are increasingly open to new ideas they never would have considered before. GCI is optimistic that this will lead to exceptional, positive change in the years to come, for the benefit of the people and ecosystems of the Colorado River Basin.

The idea behind the Fill Mead First proposal is to move water stored in Lake Powell downstream to Lake Mead. Currently, there is not enough water between both reservoirs to keep even one full. This process would take place through three stages, ultimately leading to the restoration of a free-flowing Colorado River through Glen Canyon and Grand Canyon.

Phases I and II

Phase I: Lake Powell at or near minimum power pool ~3,490 ft

  • Some reservoir recreation
  • Some hydropower generation
  • Water still released through  hydropower penstocks
  • 45,000 cfs release capacity in Grand Canyon
  • Recreation in Grand Canyon largely stays the same
  • More normalized water temperature in Grand Canyon
  • ~100 newly flowing river miles (Colorado, San Juan, Escalante, Dirty Devil)
  • 175 sq. miles of newly-emerged land in Glen Canyon

 

Phase II: Lake Powell is below minimum power pool, and above dead pool, 3,490 ft – 3,374 ft

  • Water released through river outlet works
  • Maximum release of 15,000 CFS
  • No hydropower generation
  • Limited release options into Grand Canyon
  • Would affect rafting in the Grand Canyon

–No flows higher than 15,000 cfs

–Largest recreational impact likely motorized boating

  • ~150 newly flowing river miles (main stem and tributary)
  • 222 sq. miles of newly-emerged land in Glen Canyon

Phase III: Run of the River

While we are going to go through Phases I and II as the reservoir drops, it will be imperative to get to Phase III as soon as possible.

  • Requires construction of new bypass tunnels
  • Best chance at re-naturalized flows in grand canyon
  • Allows for sediment flow into Grand Canyon
  • Opportunity for maximum restoration of Glen Canyon and Grand Canyon
  • Some hydropower possible if turbines installed in new bypass tunnels
  • Recreation in Grand Canyon would resemble pre-dam conditions

–Seasonal motorized recreation

–Low flows in winter months (~4,000 CFS)

  • All 254 sq. miles of Glen Canyon emerge
  • Newly-flowing river miles:

–Colorado River: 186 Miles

–San Juan: 71 miles

–Escalante: 22 Miles

–Dirty Devil: 13 Miles

The Case for Phase III (full drawdown of Lake Powell)

Phase I – at/near minimum power pool:

-Due to natural fluctuations of runoff, it’s conceivable that Powell dips below power pool into Phase II territory

Phase II – between power pool and dead pool:

-Phase II could have significant negative impacts to the Grand Canyon and would create headaches for managing the reservoir

–   Modeling each one of these scenarios requires significant resources

–   The best use of resources would be to analyze Phase III in addition to Phase I

Considerations for Full Drawdown of Lake Powell (Phase III)

  1. Law of the River

2. Basin Water Rights

3. Hydropower

4. Water Savings

5. Engineering: cost and technology

6. Glen Canyon restoration

7. Grand Canyon restoration

8. Implications for Tribes

9. Protection from mega-floods

10. Recreation

 

Fill Mead First Proposal

GCI will continue to facilitate research that supports the Fill Mead First proposal, and push policy makers to take it into consideration.

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