The 27-year-long drought gripping the Southwestern United States—now officially recognized as the longest dry period in the region over the past 1,200 years—is taking a severe and escalating toll on the flow of the Colorado River. Driven by the compounding effects of climate change, the vital snowpack in Colorado’s Rocky Mountains, which accounts for roughly 80 percent of the river’s annual flow, is steadily shrinking. Higher atmospheric temperatures are causing this snowpack to melt much earlier in the year, effectively sapping vital runoff during the late summer and fall months when water demands are highest.
At the same time, warmer weather is dramatically accelerating evaporation rates across the river’s vast network of 40 reservoirs, most notably its two largest and most critical storage facilities: Lake Powell and Lake Mead.
Last month, Lake Powell, situated squarely on the Utah-Arizona border, plummeted to a record low. Water levels dropped to less than 150 feet above the "dead pool" threshold—the critical point at which water can no longer flow naturally through the Glen Canyon Dam’s bypass tubes to reach Lake Mead, held back by the Hoover Dam some 300 miles downstream. This unprecedented drop has severely compromised hydropower generation at both major reservoirs, complicated the delicate management of fragile riverine ecosystems, and forced sharp cuts in water deliveries to the Lower Basin states of Arizona, California, and Nevada.
The cascading impacts of the water crisis are now visible across the regional economy. Farmers throughout the basin have been forced to fallow productive agricultural fields, while real estate developers in several booming municipalities have paused new housing construction due to a lack of guaranteed, long-term water supplies. Meanwhile, the U.S. Bureau of Reclamation has curtailed its vital "environmental flows"—scheduled releases of cold water from Lake Powell designed to protect endangered native fish species and rebuild downstream sandbars that provide essential wildlife habitat in the Grand Canyon. According to regional observers, regardless of how the river is managed in the future, ecosystems both upstream and downstream will undergo profound and lasting transformations.
A Legacy Born of Controversy
Faced with the alarming prospect of even lower water levels on the Colorado River, federal and state governments have scrambled to devise solutions to reconcile the competing demands of the disparate interests relying on the basin. Proposed remedies range widely: topping off Lake Powell with water emergency-diverted from upstream reservoirs, slashing downstream water deliveries by up to 40 percent, and paying agricultural producers substantial subsidies to keep their allocated water in the river system. The severity of the crisis has even pushed stakeholders to consider a radical fix that was once deemed entirely unthinkable: draining Lake Powell entirely.
When the Glen Canyon Dam was constructed in the 1960s, its proponents heavily promoted its anticipated benefits: cheap and reliable hydroelectric power, heavily subsidized water for cotton and alfalfa growers, lucrative real estate along the newly formed shoreline, and a sprawling recreational playground for boaters and tourists. However, conservationists and detractors strongly bemoaned the drowning of Glen Canyon itself—a magnificent labyrinth of red rock gorges, soaring spires, secluded cliffs, and hidden grottoes that many early environmentalists described as even more breathtaking than the Grand Canyon.
Over the ensuing decades, a dedicated faction of environmental advocates consistently argued for the complete removal of the Glen Canyon Dam to restore the buried canyon to its natural state. For a long time, the proposition was universally dismissed as prohibitively expensive and wildly impractical, primarily because it would completely wipe out a major regional source of electricity generation.
Now, however, a more tempered and pragmatic approach is gaining traction among policy experts and conservation groups. Organizations like the Glen Canyon Institute are no longer advocating for the physical demolition of the massive dam structure. Instead, they are championing a plan to drain Lake Powell through new, lower diversion tunnels that would be drilled well beneath the existing bypass tubes, positioned closely to the natural riverbed.
Advocates argue that the potential upsides of this strategy would be manifold. The redirected water would immediately boost dwindling hydropower production downstream at Lake Mead. Furthermore, the stunning geological formations of Glen Canyon, along with countless cultural sites sacred to regional Indigenous communities, would gradually remerge from beneath the receding waters. Native wildlife would return, and riparian habitats both above and below the dam site would eventually be restored. The comprehensive proposal is formally known as "Fill Mead First."
Structural Vulnerabilities and Infrastructure Limits
For more than four decades, the Glen Canyon Dam was viewed as an unmitigated asset to the entire Colorado River Basin, according to Eric Balken, executive director of the Glen Canyon Institute. Today, however, that perspective has fundamentally shifted.
"It’s becoming a liability because it might actually prevent water from flowing downstream," Balken said. "All of the core assumptions around the dam have been turned on their head."
This vulnerability stems directly from the dam’s rigid structural limitations. If the surface elevation of Lake Powell drops below the minimum power pool, its penstocks—the massive pipes that feed water directly into the dam’s eight power-generating turbines—will be left entirely stranded, high and dry. When this occurs, lake water must instead be forced through the dam’s bypass tubes. While these tubes sit at a lower elevation than the penstocks, they possess less than half the water-discharging capacity.
Crucially, these bypass tubes were never engineered for sustained, long-term operational use. Forcing high volumes of water through them over extended periods can induce severe structural vibrations, scouring, and other mechanical stresses that risk irreparable damage to the dam itself. Although the Bureau of Reclamation has long issued warnings against relying exclusively on the bypass tubes to sustain river flows, agency officials noted after inspecting and relining the tubes in 2025 that they could function if absolutely necessary.
Yet a daunting logistical challenge remains: relying entirely on these narrow tubes would severely impair the ability of Upper Basin states—Colorado, New Mexico, Utah, and Wyoming—to meet their mandated water delivery obligations to Lower Basin states and, by international treaty, to Mexico.
Reevaluating Old Taboos
Allowing water to flow more freely through the Glen Canyon Dam infrastructure by draining the reservoir through existing bypass tubes and newly drilled riverbed-level tunnels is no longer dismissed out of hand by water authorities.
"That conversation has evolved," noted Kathryn Sorensen, director of research at the Kyl Center for Water Policy at Arizona State University.
Jack Schmidt, director of the Center for Colorado River Studies at Utah State University, concurred, describing lower release structures as "an utterly reasonable idea" that firmly warrants a place in current policy discussions. Regarding the potential loss of Lake Powell’s hydroelectric capacity, proponents of the drainage strategy point out that those lost megawatts could be readily replaced by utility-scale solar installations. For comparison, the newly operational Gemini solar project near Las Vegas boasts a generation capacity of 690 megawatts, closely approaching the Glen Canyon Dam’s current output capacity of roughly 730 megawatts.
Meanwhile, Lower Basin states, which rely primarily on Lake Mead for their supplies and have seen their water allotments repeatedly withheld to artificially prop up Lake Powell upstream, have actively urged the federal government to consider modifying the dam with lower outlets rather than forcing continuous, drastic cuts to downstream deliveries, as the Biden administration ordered in 2024.
"Addressing the infrastructure limitations may be the one long-term measure that would best achieve operation and management improvements to the Glen Canyon Dam," representatives of the Lower Basin states wrote in a joint letter to Interior Secretary Doug Burgum last year.
Draining Lake Powell completely could also yield critical water-conservation dividends. According to Sorensen, such a move could eliminate evaporative losses amounting to "a couple hundred thousand acre-feet" annually, given that experts estimate roughly 11 percent of the reservoir’s total volume is lost to evaporation each year.
"On a river that is much smaller than anyone expected, that water really matters," Sorensen said. Nevertheless, she cautioned that while the Glen Canyon Institute’s proposal is gaining incremental traction, "it faces a lot of obstacles."
Obstacles and Ecosystem Trade-Offs
Among the most significant hurdles is the stance of the federal government, which notably omitted the possibility of draining Lake Powell from its comprehensive environmental impact statement finalized in August. That document focused strictly on alternative strategies for managing the Colorado River over the upcoming decade.
Local political resistance is also evident. Officials in Page, Arizona, whose local economy relies heavily on a thriving water-based recreation and tourism industry, have strongly opposed any efforts to drain the lake. Leading the formal opposition is the BlueRibbon Coalition, an organization representing motorized and off-road outdoor recreation. The coalition has advanced a model legislative proposal called the Colorado River Abundance Act. This $40 billion plan aims to supply treated water to Lower Basin states through nuclear-powered seawater and brackish water desalination alongside advanced water reuse technologies, allowing more freshwater to be retained inside Lake Powell.
Time represents yet another formidable obstacle. Constructing new diversion tunnels would likely require an entire decade dedicated solely to rigorous scientific study, engineering design, and physical construction, with a price tag running into the billions of dollars.
Meanwhile, the diminished flows of the Colorado River continue to exact a heavy toll on riverine ecosystems, which aquatic scientists describe as "novel" because they have been radically reshaped by seven decades of heavy human intervention, most notably the permanent elimination of natural seasonal flooding. Due to critically low lake levels and administrative constraints, the Bureau of Reclamation has canceled numerous scheduled environmental flows from the Glen Canyon Dam in recent years. This deprivation denies the river system the large pulses of sediment vital to its natural ecology—sediment that traditionally rebuilds sandbars and beaches utilized by boaters in the Grand Canyon while creating crucial shallow-water habitats for threatened and endangered native fish.
The Bureau has also historically relied on targeted releases of cold water from the dam to lower river temperatures and deter invasive, warm-water-loving bass from establishing permanent populations in the Grand Canyon stretch, where they threaten native fish species. However, the prolonged drought, which has simultaneously crippled hydroelectric generation, has forced the curtailment of these protective cold-water releases as well.
Conversely, supporters of draining the reservoir emphasize that a complete drawdown of Lake Powell would allow Glen Canyon to naturally recover as the river eventually flushes out accumulated sediment. Native flora, including cottonwoods and willows, would rapidly take root, helping to crowd out invasive species like tamarisk. Regional wildlife populations, such as river otters, beavers, native birds, and amphibians, would be expected to return to the restored canyon landscape. Furthermore, the long-drowned red rock arches, natural rock bridges, hidden amphitheaters, and cascading waterfalls would gradually emerge from the mud, alongside thousands of cultural sites deeply sacred to Native American tribes.
At the same time, a fundamental shift in the regional hydrological regime would trigger profound and complex ecological effects across hundreds of miles of river habitats downstream, including within the Grand Canyon.
"It would change in ways that are only partially predictable," Schmidt warned. "Suddenly the river would have great fluctuations. The river would have much more sediment. The river would be much more turbid."
Furthermore, the Grand Canyon—currently serving as an essential refugium for native fish—would likely be inundated with non-native fish species originally introduced into Lake Powell for recreational sport fishing.
"It just keeps getting more complicated," Schmidt acknowledged. "It’s all a trade-off in this screwy manmade world."
For the time being, the "Fill Mead First" proposal remains an ambitious concept, though one garnering serious attention as regional water levels continue their downward trajectory and global temperatures rise. While the federal government holds ultimate authority over the long-term future of the Glen Canyon Dam, advocates like Eric Balken believe that a radical departure from current management practices is long overdue.
Propping up Lake Powell, Balken warned, is simply "kicking the can down the road. But they are running out of road."