Hoover Dam
Frequently Asked Questions - Lake Mead
Recreation, although a by-product, constitutes a major use of the lake. Lake
Mead is one of America's most popular recreation areas, with a 12-month season
that attracts more than 9 million visitors each year for swimming, boating,
skiing, and fishing. The lake and surrounding area are administered by the
National Park Service as part of the Lake Mead National Recreation Area, which
also includes Lake Mohave downstream from Hoover Dam.
What is the lake's elevation at high-water?
The high-water line is at 1,229 feet above sea level. At this elevation,
the water would be more than 7 1/2 feet over the top of the raised spillway
gates, which are at elevation 1,221.4 feet. All lands below elevation 1,250
have been retained for reservoir purposes.
What is the reservoir's area?
At elevation 1,221.4 feet the reservoir covers about 157,900 acres or 247
square miles.
How long and wide is the reservoir?
At elevation 1,221.4, Lake Mead extends approximately 110 miles upstream
toward the Grand Canyon. It also extends about 35 miles up the Virgin River.
The width varies from several hundred feet in the canyons to a maximum of
eight miles.
How much water will Lake Mead hold?
At elevation 1,221.4, it would contain 28,537,000 acre feet. An acre-foot
is the amount of water required to cover one acre to a depth of one foot, or
approximately 326,000 gallons. The reservoir will store the entire average
flow of the river for two years. That is enough water to cover the State of
Pennsylvania to a depth of one foot.
How is the reservoir capacity allotted?
Below elevation 1,229, about 1,500,000 acre-feet of storage capacity is
reserved exclusively for flood control; about 2,378,000 acre-feet of
sedimentation control; about 15,853,000 acre-feet for joint use (flood
control, municipal and industrial water supply, irrigation and power); and
10,024,000 acre-feet for inactive storage.
Who operates the dam and reservoir?
The Bureau of Reclamation operates and maintains the dam, powerplant and
reservoir. The National Park Service administers Lake Mead as part of the Lake
Mead National Recreation Area.
How much sediment will be deposited in the reservoir?
Between 1935 and 1963, about 91,000 acre-feet of sediment was deposited in
Lake Mead each year. With the installation of Glen Canyon Dam, about 370 miles
upstream, the life of Lake Mead is indefinite.
Source - U.S. Department of the Interior - Bureau of Reclamation