A recent study finds the Colorado River Basin has lost a tremendous amount of water in the last two decades, in part from thirsty farms pumping water from deep aquifers much faster than it can be replenished. Lead author Jay Famiglietti, a Global Futures Professor at Arizona State University, spoke with Living on Earth’s Paloma Beltran about the “Wild West” of unregulated groundwater, potential solutions and why the rapid depletion of ancient groundwater threatens the water supply for future generations.

Recharging is more or less what it sounds like: “Reclaimed water soaks into the aquifer, it mills around down there, and you get a credit,” Kathryn Sorensen, director of research for the Kyl Center for Water Policy and former director of Phoenix Water Services, explained. “That credit becomes a right to pump a well.”

“As long as groundwater is treated as an open resource in these rural parts of Arizona, they’re susceptible to new industries coming in and using the groundwater for that industry,” said Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University’s Morrison Institute.

To get a better idea of how much groundwater is being extracted, Jay Famiglietti, director of science for the Arizona Water Innovation Initiative at Arizona State University, and his colleagues turned to data from NASA's Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On satellite missions.

The researchers estimate that since 2003, pumping from wells has drained about 28 million acre feet (34 cubic kilometers) of groundwater from the Colorado River Basin. This is akin to the capacity of Lake Mead, the largest U.S. reservoir, which sits behind the Hoover Dam on the Colorado River. The study was published May 27 in the journal Geophysical Research Letters.

Community-based action can often lead to big impacts. This is especially applicable in addressing the state’s water issues, which is why Arizona State University is rolling out four new community-driven projects to advance water resilience in unique and meaningful ways.

“We’re excited to support these new projects through Impact Water – Arizona. This was a competitive application cycle, and we ultimately selected four strong proposals that align closely with the program’s goals — to support actionable, collaborative work that addresses statewide water priorities and delivers real, on-the-ground impact,” said Susan Craig, director of Impact Water – Arizona.

“This and previous studies have clearly demonstrated that (Colorado River Basin) groundwater is disappearing much faster than Colorado River streamflow and surface water storage in Lakes Powell and Mead,” the study reads. “However, CRB groundwater receives scant policy attention relative to surface water.”

James Famiglietti, a professor at ASU’s School of Sustainability who led the research, said the study is about “raising awareness that this is happening. We already use more groundwater than we use surface water. People don't really realize that.”

Industries that need ultra-pure water — including semiconductor, battery, pharmaceutical, food and beverage companies — are expanding in Arizona. One of the most overlooked challenges for these businesses is what gets left behind in the pursuit of clean water: brine, the salty byproduct of processes like reverse osmosis.

“The Phoenix area is a salt concentrator,” said Paul Westerhoff, Regents Professor at ASU and director of the Global Center for Water Technology. However, for Shahnawaz Sinha, an associate research professor in civil and environmental engineering at Arizona State University, brine isn’t just waste, it’s an opportunity. 

In March, Saiter was one of 26 La Paz County residents who joined water experts and facilitators for a two-day Rural Groundwater Resilience Workshop. The workshop was led by Impact Water - Arizona, part of the Arizona Water Innovation Initiative at Arizona State University.

The event was the second of several planned workshops around the state. In them, residents and community leaders work with science and policy experts to discuss their concerns and priorities and come up with strategies that work for their individual communities.

During today’s Opening General Session, keynote speaker Kathryn Sorensen, director of research at the Kyl Center for Water Policy at Arizona State University and former director of Phoenix Water Services and Mesa Water Resources, addressed attendees. Her remarks focused on the complexities of water service delivery and the unwavering dedication of water professionals who continually rise to meet the sector’s challenges.

“Working through chaos is not new,” Sorensen said. “Our duties, our jobs, our responsibilities do not change in times of unrest and uncertainty. If anything, we step up to the plate and do more, because water is that important. Be constant.”

Jay Famiglietti, a longtime contributor to Ten Across, specializes in the use of satellite data to monitor the world’s groundwater mass. His team’s new findings focus on the U.S. Southwest—a region at the forefront of the nation’s water supply challenges and the complex balances between resource limitations and economic growth.