Water shortage threatens Lake Mead
Experts talk solutions with Mexico
By Robert Coulter, November 2009
Staff Writer
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Photo by AP
The white "bathtub ring" shows where the water level at Lake Mead used to be. This photo from July 2006 shows the lake 32 feet higher than it is today. |
Lake Mead, the largest man-made reservoir in the United States and a key component to Arizona water delivery, is at its lowest level in over 40 years—a sign that water shortages may be on the horizon.
The lake, which was formed by the construction of the Depression-era Hoover Dam, stores Colorado River water for the lower basin states: Nevada, Arizona and California. The dam also creates hydroelectric power that is purchased by all three states.
In 2000, the water level at Lake Mead was 1,214 feet above sea level; but after 10 years of drought, it now stands at 1,093 feet—around 42 percent of total capacity.
The Colorado River, which flows into Lake Mead, is fueled by spring snowmelt in the Rocky Mountains—another phenomenon on the decline.
John Douglass, Physical Geography Instructor at PVCC, cites a decrease in average snowfall as well as a rise in sublimation rates for causing the decreased inflow. Sublimation in particular is a problem, since according to Douglas, “Snow, instead of melting into water, literally evaporates into water vapor.”
Other factors more logistical in nature may be contributing to Lake Mead’s decline.
Arizona, which receives roughly 37 percent of the Colorado River water allocated to the lower basin, brings most of that liquid to the state’s interior via the Central Arizona Project, a canal system originating at Lake Havasu.
Bob Barrett, a spokesman for CAP, says that the low level at Lake Mead is in part due to its connection with another Colorado River reservoir: Lake Powell.
Lake Powell, which lies east of Lake Mead on the Utah-Arizona border, was allowed to fill to a higher level last year causing Lake Mead to receive less water.
“It’s a balancing act and a juggling act,” says Barrett of the Lake Powell and Lake Mead relationship.
Lake Powell, which had also been dangerously low, was permitted to withhold water from Lake Mead; but Barrett says that starting in October, water will be released again in order to raise the level at Lake Mead.
This will undoubtedly benefit lower basin water distribution, but also power generation since according to Robert Walsh of the United States Bureau of Reclamation: Hoover Dam’s power generating capacity “…has dropped from 2,078 megawatts to about 1,656 megawatts,” due to the reduced water level.
But even if Lake Mead recovers over the next year, its future is still uncertain.
According to Douglass, if the lake drops so low that water delivery to the lower basin becomes problematic, Arizona’s share will be cut first. Douglass says that when the CAP canal was built by the federal government, a concession was made that gave priority to California water distribution. If Arizona’s portion is reduced, less water will be pumped into underground water banks leaving residents in a potential tight spot.
“Arizona's groundwater is our drought buffer, but we’re using it at an alarming rate,” says Douglass.
As Arizona’s population increases along with a demand for potable water, a somewhat unusual solution may be necessary if Colorado River shortages become a reality.
Bob Barrett of CAP says that talks have begun between Mexico and the United States regarding the building of a possible desalination plant that would pipe water out of the Sea of Cortez. This water would then be de-salted and piped back to states in the American Southwest. Any concrete plans are still a ways off, but in Barrett’s words, “It has begun.”
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