By John — Desalination News
The Rio Grande, the 1,900-mile river that supplies drinking water to roughly 15 million people across Colorado, New Mexico and Texas, has lost about 85% of its historic flows, according to the World Wildlife Fund — a decline severe enough that water managers along its length are now openly discussing desalination as one of the few remaining paths to a reliable supply.
New Mexico’s flows this water year ran at about 31% of the historical median, with August readings falling to just 14% of median, Newsweek reported October 10. More than 112 miles of the river dried up entirely over the summer. Elephant Butte Reservoir, the basin’s largest storage reservoir and a critical buffer for both states, was measured at under 1.5% of capacity on August 31 — its lowest level on record for that date, and consistent with New Mexico water-monitoring site Western Water’s independent tracking, which put the reservoir at roughly 1.4% full, its lowest point since 1971, in readings taken in July and August.
Against that backdrop, water officials interviewed for the report pointed to desalination as a long-term fix, even as they acknowledged its costs keep it a last resort for most utilities. Brian E. Macmanus of the East Rio Hondo Water Supply Corporation, which serves communities in the lower basin, called brackish and seawater desalination the “true long-term solutions” to the region’s supply problem. Hydrologist Timothy Parker said New Mexico is separately weighing brackish groundwater treatment — a less energy-intensive cousin of seawater desalination that treats naturally salty groundwater rather than ocean water — as a way to add new supply without relying on the river itself.
The region already has a working example of that approach. El Paso’s Kay Bailey Hutchison Desalination Plant, which has run since 2007 and produces more than 27.5 million gallons of fresh water a day from brackish groundwater, is the largest inland desalination facility of its kind in the country and supplies both the city and the Fort Bliss military base. Its existence is often cited in the broader debate as proof that desalination can work at scale on the Rio Grande’s margins, even as the much larger fight over seawater desalination for the Gulf Coast — including the long-running, repeatedly stalled push for an Inner Harbor plant in Corpus Christi — continues on a separate track entirely, drawing on seawater rather than the river.
The numbers underpinning the current crisis are stark on their own terms, independent of any single technology’s role in addressing them. Texas state projections cited in the report put the shortfall at about 3.6 million acre-feet a year by 2030, growing to 5.8 million acre-feet by 2080, if a drought on the scale of the state’s historical “drought of record” recurs without new supply coming online — a gap large enough to exceed the full storage capacity of Toledo Bend, Texas’s largest reservoir. Irrigated agriculture accounts for 87% of direct water consumption in the basin, according to a November 2025 study cited in the report, which warned that New Mexico’s remaining reservoir storage could be exhausted within one or two additional low-runoff years. The state’s Office of the State Engineer separately projects about 25% less water in the Rio Grande by 2070 as snowmelt runoff — which has already averaged 17% below 20th-century levels since 2000 — continues to decline.
Legal pressure is compounding the physical shortage. A May 2026 U.S. Supreme Court decree in Texas v. New Mexico requires New Mexico to substantially cut groundwater use over the next decade, tightening the options available to exactly the kind of local utilities now weighing desalination as an alternative. Macmanus noted that the population of the region he serves could double within 20 to 25 years, adding demand pressure on top of a shrinking supply.
None of this suggests an imminent desalination plant on the Rio Grande itself — the officials quoted were explicit that cost remains the central barrier, and no specific brackish-water project beyond El Paso’s existing plant has been announced. But the fact that desalination is now part of the explicit policy conversation in both states, rather than a niche idea raised only in coastal contexts, marks a shift in how the Southwest’s water managers are framing their options as the drought drags on with no clear end in sight.
(Source: Newsweek, Western Water)