New Mexico's Largest Reservoir Falls to Just 1.4% Capacity

New Mexico's Elephant Butte Reservoir, the state's largest, held just 1.4% of its capacity in a NASA satellite image taken July 27, 2026, its lowest level since 1971. NASA said the drop resulted from a combination of prolonged drought across the Rio Grande basin and the earliest snowmelt on record at the river's headwaters in the southern Rocky Mountains, which reduced the water available later in the season.

The reservoir was nearly full on June 2, 1994, and water levels stayed relatively high through much of the period from 1985 to 2000. During an earlier major drought, it reached an annual low of 2.9% capacity on July 8, 2013 — still far above this year's level. Water volume records kept by the Texas Water Development Board trace the reservoir's level back to its creation in 1915.

The exceptionally low water in 2026 exposed debris that had been hidden along the shoreline and left boat ramps at Elephant Butte Lake State Park coated with sediment. According to state officials, water releases for agriculture ended after July 28, allowing the reservoir to begin slowly gaining water again after reaching its lowest point of the year in late July.

Water from Elephant Butte and other reservoirs along the Rio Grande supports irrigation for crops including alfalfa, cotton, onions, pecans and Hatch green chiles in an otherwise dry region — the same green, irrigated valley northwest of El Paso, Texas, that astronaut John Glenn noted while orbiting Earth in 1962. Water users in both New Mexico and Texas draw on surface water and groundwater throughout the valley, and managers must carefully plan how the shrinking supply is stored, allocated and shared.

Several projects supported by NASA's Western Water Action Office combine satellite observations with other measurements to give water managers a clearer picture of changing conditions. One project built a near-real-time tool using satellite data on soil moisture and evapotranspiration — the movement of water from land into the atmosphere through evaporation and plant activity — to supplement the Elephant Butte Irrigation District's water allocation system. Another combined satellite measurements of water surface height with drone and ground observations to study how groundwater pumping affects the Rio Grande's flow, information the office says can help administer water rights.