Introduction
Lake Powell is the second-largest reservoir in the United States by water capacity, stretching 299 kilometers through the desert canyonlands of southern Utah and northern Arizona. Created by the completion of Glen Canyon Dam on the Colorado River in 1963, the reservoir was named after John Wesley Powell, the one-armed Civil War veteran who led the first recorded expeditions through the Grand Canyon in 1869. At full capacity, the lake has nearly 3,200 kilometers of shoreline — more than the entire Pacific coast of the United States.
Lake Powell is one of America's most controversial water projects. Environmentalists have mourned the loss of Glen Canyon, often called the place no one knew — a landscape of soaring sandstone walls, natural bridges, and hidden grottos that rivaled the Grand Canyon in beauty but was seen by few before it was submerged. The reservoir, meanwhile, has become both a beloved recreation destination drawing millions of visitors and a symbol of the unsustainable water management of the American West.
Geography & Formation
- Surface Area: ~658 km² (at full pool)
- Max Depth: 171 m (at dam, full pool)
- Length: 299 km
- Shoreline: 3,200 km (at full pool)
Lake Powell fills the deep, narrow canyons carved by the Colorado River and its tributaries over millions of years through the Navajo Sandstone and other colorful rock layers of the Colorado Plateau. The result is an extraordinary labyrinth of flooded side canyons, many of which are barely wider than a boat, creating an intimate and dramatic landscape. The reservoir inundated 96 side canyons in Glen Canyon alone.
Glen Canyon Dam stands 216 meters tall and was built between 1956 and 1966 as part of the Colorado River Storage Project. The dam was designed to store water for the upper Colorado River basin states (Wyoming, Colorado, Utah, and New Mexico) and generate hydroelectric power. The reservoir took 17 years to fill to capacity, finally reaching its high water mark in 1980. Since then, prolonged drought and increasing water demand have caused dramatic declines in water level.
Water & Hydrology
- Capacity: 30 km³ (at full pool)
- Current Level: Approximately 30-40% of capacity (variable)
- Water Source: Colorado River and tributaries
- Evaporation Loss: ~760 million m³/year
Lake Powell has been in a state of persistent decline since 2000, driven by a megadrought that has gripped the Colorado River basin for over two decades. At its lowest point in 2022, the reservoir dropped to just 24 percent of capacity, the lowest level since it was first being filled in the 1960s. The declining water level has revealed features of the original Glen Canyon not seen in over 50 years, including the Cathedral in the Desert, a massive natural amphitheater.
Evaporation is a major issue for Lake Powell. The desert reservoir loses approximately 760 million cubic meters of water per year to evaporation — roughly 6 percent of the Colorado River's average annual flow. This has fueled arguments that the reservoir is an inefficient way to store water in an arid environment. Some environmental groups and policy analysts have called for draining Lake Powell and storing water in Lake Mead downstream instead, arguing that Glen Canyon's narrow, deep canyons are particularly poor at retaining water in a hot desert climate.
Ecology & Biodiversity
- Fish Species: Introduced bass, walleye, catfish, striped bass
- Invasive Species: Quagga mussels (arrived ~2012)
- Emerging Canyon Ecology: Recovery of Glen Canyon as water recedes
As a man-made reservoir, Lake Powell's ecology is dominated by introduced fish species including largemouth bass, smallmouth bass, striped bass, walleye, and channel catfish. These species support an important sport fishery that is central to the local tourism economy. However, the reservoir has been detrimental to native Colorado River fish, including the endangered humpback chub and razorback sucker, by altering water temperatures and flow patterns downstream.
The arrival of quagga mussels around 2012 poses a significant threat to both the reservoir's ecology and its infrastructure. The invasive mussels clog water intake pipes at Glen Canyon Dam and coat submerged surfaces. Boat inspection stations at reservoir access points aim to prevent further spread. Meanwhile, as the water level has dropped, the re-emerging canyon walls and newly exposed side canyons have begun to revegetate, offering a preview of what Glen Canyon's recovery might look like if the reservoir were eventually drained.
Cultural Significance
- Environmental Movement: Glen Canyon Dam controversy sparked modern environmental debate
- Recreation: ~2-3 million visitors per year
- Book: "The Monkey Wrench Gang" by Edward Abbey (1975)
The construction of Glen Canyon Dam is one of the most contentious chapters in American environmental history. David Brower, then executive director of the Sierra Club, later called his failure to prevent the dam "the greatest sin I have ever committed." The flooding of Glen Canyon galvanized a generation of environmentalists and directly influenced the passage of the National Environmental Policy Act and the creation of laws requiring environmental impact assessments for major federal projects.
Edward Abbey's 1975 novel "The Monkey Wrench Gang," which fantasized about blowing up Glen Canyon Dam, became a foundational text of the radical environmental movement. The novel inspired the founding of Earth First! and remains one of the most influential works of environmental literature. The debate over Lake Powell's future — whether to maintain the dam, drain the reservoir, or find some middle ground — continues to be one of the most passionate environmental discussions in the American West.
Visitor Experience
- Best Season: May to October
- Key Destinations: Rainbow Bridge, Antelope Canyon, Wahweap Marina
- Activities: Houseboating, kayaking, jet skiing, swimming, hiking
Despite the controversy, Lake Powell offers a recreational experience unlike any other in the United States. Houseboating on the reservoir — navigating narrow side canyons with towering red sandstone walls rising on either side — is the signature experience. Hundreds of side canyons provide secluded anchorages, natural waterslides, and hidden beaches. The contrast between the deep blue water and the red, orange, and white striped sandstone creates an almost psychedelic color palette.
Rainbow Bridge, the world's largest natural bridge, is accessible by boat from the reservoir and is sacred to the Navajo Nation. Antelope Canyon, a famous slot canyon near Page, Arizona, is not part of the reservoir but is typically visited in conjunction with a Lake Powell trip. As water levels have fluctuated, previously submerged features have emerged, creating new opportunities for exploration — paradoxically, the reservoir's decline has revealed the beauty of the landscape it destroyed.
Key Facts
- Lake Powell is the second-largest reservoir in the United States
- The reservoir has 3,200 km of shoreline at full pool — more than the US Pacific coast
- Glen Canyon Dam drowned a landscape many considered as beautiful as the Grand Canyon
- The reservoir has been at historically low levels since 2000 due to megadrought
- Lake Powell loses approximately 760 million m³ of water per year to evaporation
Fun Facts
- The reservoir took 17 years to fill to capacity after the dam was completed
- As water levels dropped, a perfectly preserved 49-foot boat from the 1960s emerged from the depths
- Rainbow Bridge, accessible by boat from the lake, has a span of 84 meters — tall enough for the Statue of Liberty to fit beneath it
- Edward Abbey's novel about destroying the dam is sold in the Glen Canyon Dam visitor center gift shop
Final Thoughts
Lake Powell is the American West's most beautiful paradox — a stunning recreational playground created by drowning an even more stunning natural landscape. The ongoing megadrought that is draining the reservoir has reignited the decades-old debate about whether the dam should have been built at all. As the original Glen Canyon slowly re-emerges from beneath the receding waters, a new generation is catching its first glimpse of the place no one knew, and the conversation about its future grows more urgent and more complicated with every passing year.
