Lake Powell is an artificial reservoir on the Colorado River in Utah and Arizona, United
States.
It is a major vacation spot visited by approximately two million people every year.
It is the second-largest artificial reservoir by maximum water capacity in the United States
behind Lake Mead, storing 25,166,000 acre-feet of water when full.
However, Lake Mead has fallen below Lake Powell in size several times during the 21st century
in terms of volume of water, depth, and surface area.
Lake Powell was created by the flooding of Glen Canyon by the Glen Canyon Dam, which
also led to the 1972 creation of Glen Canyon National Recreation Area, a popular summer
destination of public land managed by the National Park Service.
The reservoir is named for John Wesley Powell, a civil war veteran who explored the river
via three wooden boats in 1869.
It primarily lies in parts of Garfield, Kane, and San Juan counties in southern Utah, with
a small portion in Coconino County in northern Arizona.
The northern limits of the lake extend at least as far as the Hite Crossing Bridge.
Lake Powell is a water storage facility for the Upper Basin states of the Colorado River
Compact (Colorado, Utah, Wyoming, and New Mexico).
The Compact specifies that the Upper Basin states are to provide a minimum annual flow
of 7,500,000 acre-feet to the Lower Basin states (Arizona, Nevada, and California).
In the 1940s and early 1950s, the United States Bureau of Reclamation planned to construct
a series of Colorado River dams in the rugged Colorado Plateau province of Colorado, Utah,
and Arizona.
Glen Canyon Dam was born of a controversial damsite the Bureau selected in Echo Park,
in what is now Dinosaur National Monument in Colorado.
A small but politically effective group of objectors, led by David Brower of the Sierra
Club, succeeded in defeating the Bureau's bid, citing Echo Park's natural and scenic
qualities as too valuable to submerge.
By agreeing to a relocated damsite near Lee's Ferry between Glen and Grand Canyons, however,
Brower did not realize what he had traded away.
At the time, Brower had not actually been to Glen Canyon.
When he later saw Glen Canyon on a river trip, Brower discovered that it had the kind of
scenic, cultural, and wilderness qualities often associated with America's national parks.
Over 80 side canyons in the colorful Navajo Sandstone contained clear streams, abundant
wildlife, arches, natural bridges, and numerous Native American archeological sites.
By then, however, it was too late to stop the Bureau and its commissioner Floyd Dominy
from building Glen Canyon Dam.
Brower believed the river should remain free, and would forever after consider the loss
of Glen Canyon his life's ultimate disappointment.
Glen Canyon Dam was built to solve the downstream delivery obligations of the Upper Basin states.
Lake Powell is an "aquatic bank" built to fulfill the terms of the "Compact Calls" of
Lower Basin.
If the Compact had required the Upper Basin to deliver half the flow of Colorado in low
water years, rather than a fixed amount, the burden of drought would have been spread equally
between the basins and there would have been no need to build the dam.
It is ironic that the lake is named after John Wesley Powell, who planned to settle
the West based on the facts of hydrology, not politics.[Construction on Glen Canyon
Dam began with a demolition blast keyed by the push of a button by President Dwight D.
Eisenhower at his desk in the Oval Office on October 1, 1956.
The first blast started clearing tunnels for water diversion.
On February 11, 1959, water was diverted through the tunnels so dam construction could begin.
Later that year, the bridge was completed, allowing trucks to deliver equipment and materials
for the dam, and also for the new town of Page, Arizona.
Concrete placement started around the clock on June 17, 1960.
The last bucket of concrete was poured on September 13, 1963.
Over 5 million cubic yards of concrete make up Glen Canyon Dam.
The dam is 710 feet high and the surface elevation of the water at a full pool is approximately
3700 feet.
Construction of the dam cost $155 million, and 18 lives were lost in the process.
From 1970 to 1980, turbines and generators were installed for hydroelectricity.
On September 22, 1966, Glen Canyon Dam was dedicated by Lady Bird Johnson.
Upon completion of Glen Canyon Dam on September 13, 1963, the Colorado River began to back
up, no longer being diverted through the tunnels.
The newly flooded Glen Canyon formed Lake Powell.
Sixteen years elapsed before the lake filled to the 3,700 feet level, on June 22, 1980.
The lake level fluctuates considerably depending on the seasonal snow runoff from the Rocky
Mountains.
The all-time highest water level was reached on July 14, 1983, during one of the heaviest
Colorado River floods in recorded history, in part influenced by a strong El Niño event.
The lake rose to 3,708.34 feet above sea level, with a water content of 25,757,086 acre-feet.
Colorado River flows have been below average since 2000 as a result of the southwestern
North American megadrought, leading to lower lake levels.
In winter 2005 (before the spring run-off) the lake reached its then-lowest level since
filling, an elevation of 3,555.10 feet above sea level, which was approximately 150 feet
below the full pool.
After 2005, the lake level slowly rebounded, although it has not filled completely since
then.
Summer 2011 saw the third-largest June and the second-largest July runoff since the closure
of Glen Canyon Dam, and the water level peaked at nearly 3,661 feet, 77 percent of capacity,
on July 30.
However, water years 2012 and 2013 were, respectively, the third and fourth-lowest runoff years recorded
on the Colorado River.
By April 9, 2014, the lake level had fallen to 3,574.31 feet, largely erasing the gains
made in 2011.
Colorado River levels returned to normal during water years 2014 and 2015 (pushing the lake
to 3,606 feet by the end of the water year 2015.
The Bureau of Reclamation 2014 reduced the Lake Powell release from 8.23 to 7.48 million
acre-feet, for the first time since the lake filled in 1980.
This was done due to the "equalization" guideline which stipulates that an approximately equal
amount of water must be retained in both Lake Powell and Lake Mead, in order to preserve
hydropower generation capacity at both lakes.
This resulted in Lake Mead declining to the lowest level on record since the 1930s.
The long-term water-level decline continued, forcing an even Canyon National Recreation
Area draws more than two million visitors annually.
Recreational activities include boating, fishing, waterskiing, jet-skiing, and hiking.
Prepared campgrounds can be found at each marina, but many visitors choose to rent a
houseboat or bring their own camping equipment, find a secluded spot somewhere in the canyons,
and make their own camp (there are no restrictions on where visitors can stay).
The Castle Rock Cut is one of the most important navigational channels in the lake; it was
blasted as early as the 1970s to allow boaters to bypass the winding canyons between the
Glen Canyon Dam and reaches of Lake Powell further upstream – saving, on average, one
hour of travel time.
The cut has been deepened several times since then, to allow the use of the channel during
droughts.
During the protracted 21st-century drought, however, the lake has dropped so quickly on
several occasions that the cut dried up during the summer tourist season, most recently in
2013.
Continued deepening of the Castle Rock cut has been criticized for its high cost, but
boaters and the National Park Service argue that it improves safety, saves millions of
dollars in fuel, and improves emergency response time.
In September 2021 the level of Lake Powell was 45 feet below the bottom of the Castle
Rock cut.
Currently, most Marinas on the lake don't have Automatic Identification System monitoring
stations that transmit boat positions to the AIS websites for the boating community.
A substantial number of vessels on the lake do not have AIS transponders as there currently
are no mandatory requirements for AIS usage for this body of water.
Extra precautions must be taken with respect to boating safety, as the fractal nature of
the lake's hydrologic surface area can allow vessels with limited charting equipment to
become easily lost.
The burying of human (and pet) waste in Glen Canyon National Recreation Area is prohibited.
Anyone who camps farther than a quarter of a mile from a marina must bring a portable
toilet.
Pet waste must also be packed out.
The southwestern end of Lake Powell in Arizona can be accessed via U.S. Route 89 and State
Route 98.
State Route 95 and State Route 276 lead to the northeastern end of the lake in Utah.
emergency release of water from the Flaming Gorge Reservoir in July 2021.
and by April 22, 2022, Lake Powell was at 3,522.24 feet in elevation – just 22.88%
of capacity.
This marks the lowest water level for Lake Powell since it was filled in 1963.
Glen Canyon National Recreation Area draws more than two million visitors annually.
The southwestern end of Lake Powell in Arizona can be accessed via U.S. Route 89 and State
Route 98.
State Route 95 and State Route 276 lead to the northeastern end of the lake in Utah.