That Ol' Man River just don't keep rollin' along!
Here in the Northeast major river systems are so common that the principal infrastructure concern they raise is the bridges that cross them. Within a relatively small geographic area, for example, lie the Ohio, Susquehanna, Delaware and Hudson river watersheds.
In the vast Southwest, in contrast, just one beleaguered river system, the Colorado, provides drinking water for 40 million people in seven states while irrigating about 4 million acres of farmland.
It's well known that surface water supplies related to the Colorado River are dwindling throughout the system. Water marks on reservoir walls now are scores of feet above the current water levels.
But a new NASA analysis of the Colorado watershed is even more alarming. The Gravity Recovery and Climate Experiment satellite is able to measure the mass of the entire watershed, rather than simply the volume of surface water. That mass includes subterranean water in the underlying aquifers. And according to NASA, about 75 percent of the water loss in the region has been from underground sources, meaning that the system is even more stressed than surface supplies indicate.
"We don't know exactly how much groundwater we have left, so we don't know when we're going to run out," said Stephanie Castle, a water resources specialist at the University of California, Irvine. She called the data "shocking."
Researchers noted that the surface water sources are managed and carefully measured by the U.S. Bureau of Reclamation, but that pumping from underground sources is controlled by individual states.
The unfolding water emergency in the Southwest is important beyond that region because of the economic implications. Congress should mandate the creation of a regional water authority to better manage the dwindling resource, and ensure that NASA retains the capacity for its enlightening research.