“We kind of just grew and grew together to realize we are neighbors” — Ralph Curtis

San Luis Valley Groundwater
San Luis Valley Groundwater

From The Pueblo Chieftain (Matt Hildner):

When State Engineer Dick Wolfe turned in a set of proposed groundwater rules and regulations to the division water court on Sept. 23, he channeled Yogi Berra.
“When you come to the fork in the road, take it,” he said, quoting the Hall of Fame Yankees catcher who passed away the day before.

But for nearly four decades, the San Luis Valley’s water users avoided any path that involved giving the state engineer the authority to shut down or limit pumping by the valley’s roughly 4,500 irrigation wells.

Two aquifers supply the water for those wells and help farmers irrigate valley staples such as potatoes, barley and alfalfa.

The shallower of the two, the unconfined aquifer, is fed by streams, seepage from irrigation canals and return flows from fields, and some upward leakage from a deeper aquifer.

The deeper aquifer, known as the confined aquifer, is fed by streams at the rim of the valley and is under artesian pressure.

Both aquifers are hydrologically connected to the valley’s surface streams to varying degrees, a fact that underlies complaints from surface-water users that their rights are injured by groundwater pumping.

Wolfe’s predecessor had proposed rules in 1975 only to see them shelved as the valley’s water users looked for another way to mitigate the impacts of well pumping on surfacewater users. And while this version still will have to gain approval from water court, enough had changed in the intervening decades to prompt a second stab at rules and regulations.

To begin, the federal Closed Basin Project, which pumps groundwater from the eastern edge of the valley for delivery to the Rio Grande, has been ineffective.

The valley’s water user groups signed an agreement in 1985 that divvied up how the project’s water would apply toward Colorado’s obligations to the Rio Grande Compact.

The move was regarded as an olive branch to surface-water users on the Conejos and Rio Grande rivers, since they alone carried the burden of complying with compact obligations.

Without the policing powers rules could give the state engineer, groundwater users faced no such burden.

The pact, commonly known as the 60-40 Agreement, also included a provision that kept valley surface-water users from going to court to shut down groundwater wells.

But since 2000, the amount of water produced by the project has never exceeded 20,000 acre-feet — far below envisioned amounts of up to 100,000 acre-feet when it was authorized by Congress in 1972.

Another change since the last rule proposals involved a pair of unsuccessful efforts in the 1990s to ship large amounts of the valley’s groundwater to the Front Range.

The proposals from American Water Development and later the Stockmen’s Water Company put all of the valley’s water users in the same boat, said Ralph Curtis, who managed the Rio Grande Water Conservation District for 25 years.

“We kind of just grew and grew together to realize we are neighbors,” he said.

Moreover, less was known in the 1970s about the two major groundwater bodies that sit beneath the valley floor. When the 1975 rules were proposed, a monitoring network that could measure levels in the unconfined aquifer in the north-central part of the valley still was a year away.

Exactly how much was pumped from the aquifers was not known either until 2006 when the engineer’s office implemented well-metering requirements.

Mac McFadden, who was the division engineer for the valley in 1975, and Steve Vandiver, who later would serve 24 years in the same post, both pointed to the development of the state’s groundwater computer model as an important advancement.

While that model could be a point of contention in court hearings for the current version of rules, it provides the basis for estimating how much instream losses are caused from well pumping Lastly, both Curtis and Vandiver point to the drought that began in 2002 as a pivotal point in the valley’s water politics and one that would pave the way to a new version of state rules.

“The drought of 2002 just tipped over the bucket of worms,” Vandiver said. “It was obvious then what the impacts of wells were on the (Rio Grande) — river just went away.”

The lowest flows ever recorded on the Conejos and the Rio Grande rivers where they enter the valley floor came in 2002.

And much of those meager flows were lost to aquifers that were being drawn on heavily by irrigators that had no surface supplies.

The division engineer’s annual report for that year estimated stream losses on the Rio Grande were as high as 40 percent at times, while on the Conejos they peaked as high as 60 percent.

“That provided the impetus for the surface-water users to say we’ve had enough,” Vandiver said.

Vandiver credited Manassa rancher Kelly Sowards and other surface-water users for creating the subsequent push to regulate wells.

Two years later, state lawmakers would pass a bill that created the framework for the current version of the rules and groundwater management subdistricts.

The first such subdistrict, which buys water to return to the Rio Grande and also pays ditch companies for losses caused by pumping, went into operation four years ago in the north-central part of the valley.

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