Asier Artaechevarria's grandfather farmed potatoes in Colorado's San Luis Valley when spring runoff turned fields into shallow lakes. Water pooled a foot deep across the land, sometimes deeper. Farmers had to wait for neighbors to start irrigating just to lower the water table enough to plant.

Artaechevarria farms that same land now. This October, he's running numbers on whether he can pump any groundwater next season. The aquifer that once flooded his grandfather's fields sits at its lowest recorded level in history. He holds legal water rights designed for his grandfather's climate. The water itself is disappearing.

That world is gone. The San Luis Valley gets less than nine inches of precipitation annually. The unconfined aquifer has collapsed after two decades of drought intensified by climate change. The legal framework governing Artaechevarria's water use—the 1939 Rio Grande Compact—was written for the climate his grandfather knew, not the one Artaechevarria is trying to survive in.

"When the apportionment was made in 1939, there wasn't as much groundwater pumping as there is now," explains Harvard Law Professor Andrew Mergen. "The baseline from when this compact was enacted in 1939 has undoubtedly changed, but we're locked in."

His water rights are legally guaranteed based on 1939 conditions when snowmelt was reliable and aquifers were full. His legal right to water has become a right to something that no longer physically exists.

Last year, Artaechevarria pumped groundwater at $150 per acre-foot to grow potatoes, nearly filling his storage building that holds 16 million pounds. That fee was already double what it cost a few years earlier. This fall, under a new management plan from the area's largest irrigation district, the fee jumps to $500 per acre-foot.

He's not exaggerating. Potato farming operates on thin margins. At $500 per acre-foot, the water costs more than the crop can earn. The fee isn't designed to be affordable. It's designed to force farmers to stop pumping from an aquifer that's collapsing despite tens of millions of dollars spent trying to save it.

Cleave Simpson manages the Rio Grande Water Conservation District. He's also a farmer and rancher working this same land, watching the same aquifer fail. "The aquifer has not recovered, and we have spent tens of millions of dollars on programs to reduce groundwater withdrawals," says Amber Pacheco, the district's deputy general manager. After two decades of paying farmers to fallow fields, retiring pumping rights, imposing conservation measures, the aquifer has recovered only one-third of what it needs.

Simpson has been experimenting with hemp and other drought-resistant crops on his own operation, trying to find something that survives on less water. But there's no crop that replaces the San Luis Valley's $370 million agricultural economy, built on potatoes, barley, oats, and hay. This is the nation's second-largest potato economy. State officials describe what's coming plainly: farmers face "quickly approaching deadlines to reduce their water use to avoid mandatory curtailment of groundwater pumping on a scale that could devastate these agricultural communities."

State Engineer Jason Ullmann warned in February that if the aquifer doesn't show progress "in the next couple of years," mandatory well shutdowns could come before the 2031 deadline. There are 3,614 wells in Subdistrict 1 alone. The state shutting down thousands of wells because farmers can't recharge an aquifer depleted by climate change they didn't cause—that's the threat everyone farms under now.

Former Congressman John Salazar, a farmer and rancher from nearby Antonito, is blunter about the desperation: "We just don't have enough water here. We're very, very, very, very limited on the water."

In August, New Mexico, Texas, Colorado and the United States filed a settlement package in the decade-long Texas v. New Mexico Supreme Court case. The settlement attempts to introduce "new metrics" addressing changed circumstances since 1939: increased groundwater pumping, severe drought worsened by climate change.

For Artaechevarria, the settlement changes nothing about his immediate reality. He still faces the $500 per acre-foot fee that makes pumping economically impossible. He still faces the new requirement to replace one-for-one any water he pumps—an absurd standard when there's no water to replace it with. And in January 2026, a five-week water court trial will determine whether the management plan that prices him out of farming gets approved.

He's supposed to plan next year's crop around all of this. The legal framework says he has water rights. The aquifer says those rights are meaningless. The state says solve it by 2031, maybe sooner. The settlement says we're working on new metrics.

Artaechevarria is trying to grow potatoes in the gap between what the law promises and what the ground can actually deliver.

His grandfather waited for fields to drain before planting. Now Artaechevarria calculates whether he can afford to use water he legally has a right to but economically cannot access, under a compact designed for a climate that no longer exists. The law promises water based on conditions from 1939. The aquifer is at its lowest level in recorded history. Farmers hold rights to water that has physically disappeared, facing mandatory shutdowns for failing to recharge what climate change depleted.

The water that made his grandfather wait to plant has become water his grandson can't afford to pump—assuming it still exists at all.