Hurricane season doesn’t usually do New Mexico any favors. The state sits a long way from either coast, and by the time a Pacific storm’s leftovers drift that far inland they’re good for a wet weekend and a few flooded arroyos. But the remnants of Hurricane Polo did something in late September that the Rocky Mountain snowpack couldn’t manage all spring: they put water back in Elephant Butte, the biggest reservoir in the state, and a lot of it in a hurry.<\/p>\n
How much is a lot?<\/p>\n
On September 18 the lake held 29,241 acre-feet, according to the daily table the Texas Water Development Board<\/a> keeps on it. On October 17 it held 94,986. That’s more than triple in a month, and the surface came up about 20 feet. It’s also still 4.8 percent full, which tells you how empty it got.<\/p>\n Elephant Butte Dam’s a 301-foot concrete wall across the Rio Grande about 125 miles north of El Paso, finished in 1916, and the Bureau of Reclamation<\/a> says the reservoir behind it can store a little over 2 million acre-feet. An acre-foot is a foot of water spread over an acre, about 326,000 gallons. That water goes to farms in the Rincon and Mesilla valleys, to a share of El Paso’s drinking supply, and, under a treaty, to Mexico. Hatch green chile grows on it. So do a lot of pecans and alfalfa.<\/p>\n NASA’s Earth Observatory<\/a> put out a Landsat picture of the lake in August, shot on July 27, and the caption carried the number everybody’s quoted since: 1.4 percent of capacity, the lowest the reservoir’s been since 1971. For scale, you’d have found the lake nearly full in June 1994, and the 2013 drought, which felt like the bottom at the time, only took it down to 2.9 percent.<\/p>\n By August 20 the lake held 27,369 acre-feet, against 74,334 on the same day a year earlier, and it was still parked at 1.4 percent nearly a month after the satellite pass. In mid-September the surface sat at about 4,276 feet above sea level. Reclamation puts the riverbed at the dam at 4,210 feet, so by my math there were roughly 66 feet of water against a wall designed to work with 197. The rest of that depth was holding back air.<\/p>\n Two things did this. The Rio Grande basin has been in a drought for years, and 2026 added the earliest snowmelt on record at the river’s headwaters in the southern Rockies, according to the federal drought monitor NASA cites. Snow that melts in March instead of May runs down the river before the farms need it, and a reservoir this low doesn’t have a cushion to catch it. Reclamation kept releasing irrigation water through July 28, state parks officials said, then shut the releases off, and NASA figures the lake bottomed out for the year within a few days of that.<\/p>\n New Mexico State Parks closed the main boat ramp at Elephant Butte Lake State Park on August 3 and had a long-reach excavator scooping silt and debris off the Marina del Sur ramp through the summer. Falling water also uncovered junk that had been underwater for 50 years, which made local TV and didn’t do the ramps any good.<\/p>\n Polo didn’t get anywhere near New Mexico as a hurricane. What arrived in the last week of September was its leftover moisture, wrung out by a low-pressure system coming in from the West Coast, and there’s a small flood-control dam in the Hatch Valley that nearly didn’t make it through the rain that followed.<\/p>\n That dam’s the McLead, a 25-foot earthen structure near Garfield that state records say failed once before, in 1987, and was rebuilt in 1993. On the night of September 29 Do\u00f1a Ana County sent crews out to pump water downstream and take pressure off it, after what the county described as a pipe failure that kept water from draining through. The county told Garfield, Salem, Rincon, Hatch and Placitas to get out. About 100 people checked into shelters in Radium Springs and Las Cruces, and most of them were back home late that night. A 2023 state inspection had already rated the McLead’s condition as poor, with a spillway too small for a 100-year storm. “We’re very pleased that this wasn’t much worse than it is,” Amanda Bowen, the county’s emergency manager, told the Albuquerque Journal.<\/p>\n I don’t want to oversell this one. The dam held and nobody got hurt. But holding because a county crew spent the night pumping is, in my book, a different thing from holding on its own.<\/p>\n Downstream of the big dam, the Elephant Butte Irrigation District<\/a>, which runs the canals that feed the farms, turned the storm into a water supply. Its gauges flagged arroyo runoff coming into the river channel, and it diverted what it could into its canals: 6,791 acre-feet through October 7, which it works out to about 2.2 billion gallons, most of it going straight onto fields instead of being pumped out of the aquifer.<\/p>\n None of that water went into the lake, mind you, since it was all caught below the dam. What put the reservoir up 20 feet was the rain that fell above it and ran down the river and the arroyos, and that happened during those same days, which is why the lake’s chart turns almost straight up in the last week of September.<\/p>\n There’s one, a three-turbine hydro plant at the base of the dam that federal power-plant data rates at 27.9 megawatts, and it’s been there since 1940. Reclamation’s older project page lists it at 24,300 kilowatts, so I assume the gap comes from upgrades over the years, but either way it’s a small plant. Hoover, which we wrote about yesterday<\/a>, runs 17 turbines and 1,191 megawatts, so nobody in Las Cruces is about to lose their lights over this.<\/p>\n So does it still run?<\/p>\n As far as I can tell, not since the end of July. The plant generates on the water Reclamation releases for irrigation, which gets caught again at Caballo Dam about 22 miles downstream and parceled out to the farms from there. No releases, no generation. Reclamation also lists what it calls the top of the inactive pool at 4,282.2 feet, which basically means the line below which the agency doesn’t normally draw water at all, and the lake spent mid-July into late September under it. What I can’t give you is a 2026 generation number. Reclamation’s public monthly series for the plant stops at January, so whether it made a single kilowatt-hour after the July 28 shutoff is a question I couldn’t answer from the published data.<\/p>\nSo how low did it get?<\/h2>\n
Then a hurricane showed up<\/h2>\n
What about the power plant?<\/h2>\n