"A new study finds more than 75 percent of the water loss in the drought-stricken Colorado River Basin since late 2004 came from underground resources. The extent of groundwater loss may pose a greater threat to the water supply of the western United States than previously thought."
Science Daily had the story July 24, 2014.
SEE ALSO:
"Study: Colorado River Basin Drying Up Faster Than Previously Thought" (Washington Post)
Source: Science Daily, 07/25/2014