OPINION: New Mexico’s water use is not sustainable. That places our future at great risk.

Most water used by farmers and cities along the Rio Grande is unsustainable. These communities are using more water than nature can replenish — and there’s no plan for paying that debt back. That needs to change soon, because New Mexico’s economy, communities and way of life depend on it.

For nearly 25 years, communities that depend on the Rio Grande have been taking more water from the river and its connected aquifers than the system can sustainably restore. To make up the deficit, they’re drawing down what was stored in reservoirs and underground, much like draining a savings account to cover an overdrawn checking account.

The numbers tell the story. Since 2002, the six major reservoirs along the Rio Grande and its tributaries in New Mexico have lost more than a million acre-feet (for context, one acre-foot equals about 326,000 gallons — enough to supply two or three households for a year). Frighteningly, the reservoirs have dropped to 13% of their capacity, placing New Mexicans in danger of losing all their reserve supplies in just one or two more dry years.

The overdraft is much worse underground. Many New Mexicans living or farming along the Rio Grande depend on aquifers whose levels have been dropping for decades. Using state-of-the-science measurements from NASA satellites, we estimate that groundwater depletion has been more than a half-million acre-feet per year, nearly 25 times the volume depleted from reservoirs.

Then there’s the legal side of New Mexico’s overdraft. Under the Rio Grande Compact of 1938, New Mexico is legally required to share some of the Rio Grande’s water with its downstream neighbor, Texas. Over the past decade, New Mexico has fallen behind on those deliveries, creating a “water debt” of about 124,000 acre-feet, as of December 2024. The states have reached a settlement agreement subject to the Supreme Court’s approval that has heavy implications for farmers in southern New Mexico.

When you add that legal debt to the physical depletion of New Mexico’s reservoirs and aquifers, the math is stark: more than three-quarters of the state’s water use along the Rio Grande is unsustainable.

Fortunately, there are a lot of very smart and dedicated people in New Mexico working hard to rebalance the state’s water budget. During 2000-2020, the Albuquerque-Bernalillo County Water Utility Authority reduced its total water use by 17%, even as its population grew by 40%. That is a phenomenal water conservation achievement. And in its effort to reduce farm water use, the Middle Rio Grande Water Conservancy District has been compensating farmers — up to $700 per acre — for voluntarily reducing their irrigation. These local innovations show New Mexicans are willing to adapt to water shortages.

But much more still needs to be done. New Mexico urgently needs a comprehensive, statewide plan to bring water use back into sustainable balance across all Rio Grande water users — farmers, cities and industries alike. With New Mexico’s water savings running dry, the state must stop living on borrowed water and start living within its means.

Brian Richter is a global expert on water scarcity and its solutions, and a senior freshwater fellow with the World Wildlife Fund. Enrique Prunes is the Rio Grande manager and freshwater lead specialist for freshwater at the World Wildlife Fund.