Serious Water Losses Identified in Colorado Basin

The Colorado River basin is drying up. According to data recently released by NASA, the basin has lost nearly 53 million acre feet of freshwater since 2004, taking away far more water than the region can hope to refill. 

Based on data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission, researchers have determined that more than 75 percent of all this water loss if coming straight out of underground resources, meaning that the region's overall long-term water supply might be in big trouble.

"We don't know exactly how much groundwater we have left, so we don't know when we're going to run out," explained Stephanie Castle, a water resources specialist at the University of California, Irvine.

Castle recently led the study that came up with these findings, which have since been accepted for publication in the journal Geophysical Research Letters.

"This is a lot of water to lose," she added in a statement. "We thought that the picture could be pretty bad, but this was shocking."

The Colorado River Basin has been stricken with drought-like conditions since the early 2000s, and Castle and her colleagues had set out to use GRACE data to assess the damages.

Study senior author Jay Famiglietti said that understanding groundwater levels could prove very important in determining what kind of action needs to be taken in the future, as Nevada's Lake Mead - the largest reservoir in the United States - is reporting record low levels.

"The Colorado River Basin is the water lifeline of the western United States," Famiglietti said. "With Lake Mead at its lowest level ever, we wanted to explore whether the basin, like most other regions around the world, was relying on groundwater to make up for the limited surface-water supply. We found a surprisingly high and long-term reliance on groundwater to bridge the gap between supply and demand."

And this is very bad news for the 40 million people and four million acres of farmland that are serviced by the river. By drawing on groundwater to supplement a lacking reservoir, things will only get worse in the long run.

The entire country of Iran is similarly suffering from this kind of problem, where they are using natural groundwater tables faster than they can refill them, exacerbating water scarcity conditions year-by-year.