For more than 20 years, satellites orbiting Earth have quietly monitored the planet’s water—tracking glaciers, ice sheets, lakes, rivers, soil moisture, and underground aquifers. Now, an extensive analysis of this data paints a stark picture: freshwater is vanishing at an alarming rate, fueling a dangerous trend of global “mega-drying.”
Expanding Dry Zones
Scientists report vast regions of drying stretching from the western United States through Mexico and Central America, and from Morocco across the Middle East to northern China. The culprits are twofold: rising global temperatures caused by fossil fuel consumption and heavy extraction of ancient groundwater reserves.
Hydrologist Jay Famiglietti, professor at Arizona State University, underscores the urgency:
“In the past decade, the water cycle has shifted rapidly, increasing drying rates. The impact of climate change on water resources is undeniable.”
The View from Space
Since 2002, satellites have measured changes in Earth’s gravity field to detect shifts in frozen and liquid water. The findings are sobering:
- 6 billion people in 101 countries live in areas experiencing water loss.
- Each year, drying zones expand by an area twice the size of California.
- Regions losing the most freshwater include Canada, Russia, the U.S., Iran, and India.
Melting ice and permafrost drive losses in colder countries, while rising heat and relentless groundwater pumping plague others. Agriculture is a major driver—water drawn from aquifers evaporates and eventually returns to the ocean, accelerating sea level rise.
A study in Science Advances found that groundwater depletion now contributes more to rising seas than melting glaciers or polar ice sheets.
Groundwater on the Brink
The numbers are staggering. Drying regions are losing 368 billion metric tons of water every year—twice the volume of Lake Tahoe or ten times Lake Mead’s capacity. Researchers estimate that 68% of continental water losses (excluding glaciers) stem from groundwater pumping, mostly for crop irrigation.
As aquifer levels plunge:
- Wells dry up, forcing deeper drilling.
- Land subsides as underground voids collapse.
- Losses may become irreversible, leaving future generations without vital reserves.
Co-author Hrishikesh Chandanpurkar likens it to draining a savings account:
“Our bank balance is consistently decreasing. This is inherently unsustainable. Water bankruptcy is imminent once reserves are gone.”
Hot Spots of Depletion
The world’s fastest-depleting groundwater region is California’s Central Valley, followed closely by aquifers in Russia, India, and Pakistan. In the western U.S., the past 25 years may have been the driest stretch in more than 1,200 years. The Colorado River Basin, the Ogallala Aquifer, and agricultural belts across Central America have also become epicenters of crisis.
Satellite data shows many of these regions are already consuming more water than nature can replace.
Local Struggles, Global Stakes
In California, overpumping has left thousands of rural households without water while sinking land damages roads and canals. Although a 2014 state law mandates reduced groundwater use by 2040, aquifer levels continue to fall.
Elsewhere:
- Arizona enforces groundwater conservation in cities, but many rural areas lack restrictions. Large-scale farms—some owned by out-of-state companies—are accelerating extraction.
- Authorities are experimenting with stormwater capture and aquifer recharge projects, but progress is slow.
Globally, most regions have no limits on well drilling or water pumping, and usage often goes untracked.
A Call to Action
Famiglietti, formerly NASA’s senior water scientist, warns that governments are unprepared for what’s coming. Without urgent reform, the world faces reduced agricultural output, economic upheaval, water conflicts, and even destabilized governments.
“Groundwater will become the most important natural resource in the world’s drying regions. We need to carefully protect it,” he stresses.
As the evidence mounts, one truth grows clearer: the world’s hidden water savings account is draining fast, and the time to act is running out.