For generations the Colorado River has supplied water to homes, farms, and industry in Arizona, California, Colorado, Utah, Nevada, New Mexico, and Texas. Now a 14-year drought, climate change, a growing population, and overuse are drying up the Colorado. The water levels in Lake Powell, the reservoir behind the Glen Canyon dam on the upper Colorado, and Lake Mead, the reservoir behind Hoover dam on the lower Colorado, have dropped to all time lows.
In California, the snowpack in the Sierra Nevada was 10% of normal in the winter of 2013-14. Water deliveries to farmers in the San Joaquin Valley, where 65% of the nation’s fruits and nuts are grown, were drastically reduced. Ground water supplies are also declining due to over-pumping. Water shortages are threatening to curtail the region’s $44 billion annual agricultural production.
Water use restrictions have been imposed throughout the region, but even the strictest rationing can’t make up for the enormous loss of basic water supply. A number of ideas have been proposed for supplying additional water to the parched Southwest. Some appear less practical than others, but all are receiving new consideration.
Alaska to California Pipeline. In the 1990s, the then-governor of Alaska proposed construction of a 2,000 mile (3,218km) undersea pipeline from river sources in southern Alaska to the Shasta reservoir in Northern California. The congressional Office of Technical Assessment estimated the cost of construction at $150 billion in 1990 dollars. Most experts consider the plan unfeasible due to cost and engineering challenges.
Missouri River Pipeline. A proposal to run a 600 mile (965km) pipeline from the Missouri River to Denver has been considered by Interior’s Bureau of Reclamation. Interior Secretary Ken Salazar at the time of the proposal opposed the idea due to high construction cost, to keeping water levels on the Missouri and Mississippi high enough for navigation, and because of political opposition from environmental groups.
Converted Oil Tankers. Single-hulled oil tankers were mothballed when new laws mandated double-hulled vessels for transporting oil in 1993. A proposal to sanitize the tanks on the single-hulled tankers and use them for transporting water from Alaska to California has been floated, so to speak. The expense of bringing the ships out of mothballs, sandblasting the tanks; and fuel, crew, and maintenance costs would make it impractical to deliver fresh water by this method at an affordable price, according to those who have studied the idea.
Giant waterbags. A California company is building flexible fabric barges designed to carry more than a million US gallons of fresh water. Since fresh water is lighter than salt water, these huge waterbags will float when full, and a train of 4 or 5 of them can be towed by a vessel the size of a tug. They are built to withstand almost any weather. A train of such bags can deliver 4 to 5 million gallons of water at a cost lower than water delivered by pipeline or aqueduct, according to the builders. The bags have been used for delivering water successfully from Turkey to points in the Mediterranean, but have not yet been used on the US west coast.
Desalination. This process uses large amounts of fuel to pump seawater through filters to extract the salt. However, several of the US national labs have been researching ways to make desalination more efficient and cost effective. Fresh water supplied by the Israeli-designed plant under construction near San Diego will cost about twice as much as water from the California Aqueduct, but supplies of aqueduct water are being cut back.
The three most practical approaches at this time seem to be more efficient desalination, towing waterbags from surplus-water areas to places that need the water, or living with water rationing. People living in drought areas will have to decide.