Scientists looking at the impacts of climate change on Western water have mostly focused on the surface, like streams and reservoirs. But a new study looked at what’s going on underground with possible implications for the Colorado River.
Scientists are trying to explain the gap between water forecasts and the amount that actually ends up in rivers each year. Hydrology researcher Rosemary Carroll says water supplies may be dropping even more than previously believed, when you account for the water stored in aquifers and soil.
"We predict maybe 13% reduction in stream flow with warming. But with groundwater that nearly doubles to 35% reduction in annual streamflow," Carooll says.
The new findings could help water managers make more accurate predictions of how much water will end up in big reservoirs such as Lake Powell, and the rest of a system that supplies 40 million people across the Southwest.