As a kid, Casey Darr would hop in the truck with his father for the drive up the narrow canyon to LaPrele Dam to check outflow gauges and the water level behind the hulking concrete structure.
His family’s ranch relied on that storage water, and these excursions were a welcomed break from tending to livestock on the open prairie a few miles away.
During spring runoff, when water gushed from the overflow tunnel near the top of the structure and shot out of the dam’s lower outlet, the spray cast richly colored rainbows between the canyon walls and over lush, green flora below. The mist combined with the roar of moving water tamed by early 20th-century ingenuity created a weirdly tranquil atmosphere. It was an exclusive experience: The reservoir, dam and stretch of canyon leading to them are private property, accessible only to the landowners and irrigators who hold title to the dam.
“It was almost like going into Jurassic Park,” Darr said, noting the oddity of such a space hidden in what appears, from a distance, to be dull foothills of the Laramie Range. “It was just mind-blowing. It was just really, really beautiful to see, and you felt honored to be one of the few individuals that got to see it.”
But in January, when Darr, who serves as treasurer on the LaPrele Irrigation District Board, and District Vice President Philip Dziardziel drove up the canyon with two journalists, they had to stop at a temporary, mobile office to ask permission to approach the dam. It’s now a condemned structure because it poses a catastrophic risk to humans and everything below it — including, according to engineers, Ayres Natural Bridge Park, several ranch homes and other structures, two bridges on Interstate 25 and, potentially, anything or anyone along the North Platte River banks all the way through Douglas, a town with 6,400 people 20 miles to the east.
In fact, it’s a wonder the dam has stood this long, engineers who have studied it say. Completed in 1909, it’s the last standing Ambursen-style flat-slab and fin-buttress dam in the U.S. — a design that was determined to be a bad idea decades later. With so many individual concrete slabs, there’s more potential for flaws and erosion, and there’s little redundancy to hold if there’s a failure in one piece. If any of the multiple concrete slabs fail while holding back a full reservoir, it wouldn’t merely leak, according to engineers. It would immediately crumble like a house of cards.
Under a full reservoir scenario, the torrent of water would rip through about 1.5 miles of narrow canyon before it overcomes Ayres Natural Bridge while shredding old stands of cottonwood and boxelder trees and filling the natural bowl with flotsam before boiling over to continue its path of destruction.
‘Got to suck it up’
Darr and thousands of others who have relied on the LaPrele Dam for their livelihoods for more than a century have always carried with them a sense of nausea understanding their concrete savior that bestowed an unusually prolific agricultural economy to otherwise high-and-dry plains wouldn’t last forever. Now, with crews setting up to breach, then take down Darr’s Jurassic Park concrete wall, he and others are preparing for what will feel like a “funeral.”
“It’s been a part of our lives and these communities for over 100 years,” Dziardziel said, hands in his pockets, while standing next to Darr just below the dam.
“It’s been very emotional for a lot of people — ourselves included,” Darr agreed. “But at the same time, you’ve got to take your own personal feelings, thoughts, opinions aside and do what’s right for the safety of others.”
Not all irrigators reliant on the dam share the sentiment. Some suppose that engineers’ warnings and estimations of worst-case failure and destruction models amount to hyperbole, and insist the dam will hold until a replacement is constructed in about five years.
“It’s not necessary at all to destroy the old one and to open up all those people, all that land and everything else, to destruction [from potential flooding],” said Leonard Chamberlain, who grew up in the irrigation district and whose family business still has a stake in it. “I would like to see it in place to make sure all the funding, permitting and lawsuits are done, and it’s up before you take out the structure that’s protecting everybody.”
Dziardziel said he’d felt the same way and, for a long time, was dead set against taking the dam down before a replacement was built.
“But once I was up there with the engineers and actually put my hands on the surface of that dam, and they showed me the cracks, it was obvious that, just for safety reasons, we could not store water in that dam,” he said. “It would just put people at risk. There was absolutely no way we could do that.”
Though design plans are in the works for a new dam — estimated at $182 million — not all of the funding pieces have fallen into place. Nor is there unanimous support for how much or whether the state and federal government should pitch in.
There is one thing for certain: The dam will be mechanically breached before spring runoff — enough to ensure that LaPrele Creek free-flows through the structure without any water backing up behind it, according to state officials. Until a replacement is completed, LaPrele irrigators will be entirely at the whims of Mother Nature, which rarely provides enough natural flow for late-season irrigation. With the dam cracked open to the point of free flow, Mother Nature might also serve up floods in an agricultural community that, for the past 116 years, has built up an infrastructure without much consideration for a deluge.
“We just got to suck it up and deal with it for a few years in exchange for the safety of the community,” Darr said. “It’s been a hard decision. None of us are happy about this. But at the same time, the right decision isn’t always the easy one.”
Patchwork, boulder fall and a change of plans
Construction of the original dam was funded via the federal Carey Act of 1894, a measure pushed by Wyoming’s U.S. Sens. Francis E. Warren and Joseph M. Carey to help arid western states develop more water for irrigation. Completed in 1909 with an expected lifespan of about 50 years, the dam enabled a prosperous little agricultural community of 104 different family businesses that, in turn, became an integral part of the economy for the broader region.
Irrigators were aware of concerns surrounding the dam’s Ambursen buttress-style design, but held a sort of cross-that-bridge-when hope for its longevity, which was first tested in 1970s when it was first determined to have reached the end of its safely useful life. Cost estimates for a replacement then seemed insurmountable for members of the LaPrele Irrigation District.
But the district received an offer from a private company that it couldn’t refuse.
The Panhandle Eastern Pipeline Co. was gunning to develop a coal-gasification project nearby, and it needed water. In return for a slice of storage water rights, the company agreed to finance major patching and concrete refurbishing. The work was completed, but Panhandle’s coal-gasification project never came to fruition. LaPrele irrigators retained all their storage rights — and a gussied-up dam, to boot — and carried on with their operations that continued to inject dollars into the economies of Glenrock, Douglas and beyond.
Until somebody noticed a boulder that had apparently tumbled — in 2016 — from the western side of the limestone-walled canyon just below the dam. It struck a dirt mound on the way down and, by luck, rolled away from the dam’s concrete fins instead of toward them, according to engineers’ accounts. Had it landed on the other side of the mound, it would have rolled toward the dam.
The boulder aroused curiosity about the state of the dam.
Migrating cracks, observed from usual vantage points, were apparent. Engineers took a closer look by rappelling down the structure. Crack measurement devices were installed, and in November 2019 the data led to a state order to maintain the reservoir behind the dam at a lower level — to ease pressure on the structure — resulting in a 45% squeeze on available storage water for irrigation.
The dam continued to crumble and crack, and in August 2021 a tour was organized to begin underscoring the dam’s inevitable demise, setting into motion plans for a replacement and how to fund it. The plan, until recently, was to maintain the aging dam while constructing a new one just below, allowing for mostly uninterrupted irrigation. But cracks continued to widen, alarming state officials, and in November, State Engineer Brandon Gebhart issued a breach order, declaring the dam at risk of “catastrophic failure.”
“This dam has significant structural deficiencies and has exceeded its useful life,” Gebhart said in issuing the order.
Funding, legislation and criticism
When Darr and Dziardziel guided a pair of journalists to the dam on a recent, breezy January day, they had to remain at a distance from the structure. Cold water gurgled under a bridge and beneath crusts of ice at the creek’s edges.
“I’ve been coming here for 50 years, and every time I come around that bend [and the dam comes into view],” Dziardziel said, “it always reminds me of what they accomplished back in the early 1900s. I mean it was just amazing, and it makes you proud to be an American, really.”
Self-described “hermits” who prefer the solitude of ditch riding and tending to their ranches (WyoFile had to twist their arms for an in-person interview), Darr and Dziardziel lamented their forced entrance into the bureaucracy and politics of government needed to negotiate a tangle of demolition and reconstruction matters.
“We were all petrified of having to go deal with all this stuff that we’re not experienced with,” Darr said. “But it’s been remarkable how members from both sides of the table see a problem and have come together with us to help work through it. It’s taken a lot of fear out of politics for me, to be honest.”
But the work isn’t over.
As LaPrele irrigators prepare for a spring of free-flowing water and a late season without storage, lawmakers are in Cheyenne debating how much money to provide, which pots of money to dip into and whether the state ought to demand public access for fishing and recreation in return for the investment or even, potentially, assume state ownership of the new structure.
The estimate for the dam’s replacement ranges from $116 million to about $182 million, according to state-level discussions. The Wyoming Legislature, in 2022, set aside $30 million and is now considering adding another $60 million.
“It’s been very emotional for a lot of people — ourselves included. But at the same time, you’ve got to take your own personal feelings, thoughts, opinions aside and do what’s right for the safety of others.”
Casey Darr, LaPrele irrigator
So far, the state has secured a total $63 million in federal grants for the project via the Infrastructure Investment and Jobs Act to help cover both demolition and replacement costs.
With Wyoming potentially kicking in a total $90 million — which faces some opposition — lawmakers have said they’re hopeful the federal government will kick in an additional $34 million. Though LaPrele irrigators and state officials have received assurances of supplemental federal funding for the project in recent years, the picture has become less clear under the Trump administration.
The primary funding proposal for Wyoming’s potential $60 million appropriation lies within House Bill 117, “Omnibus water bill-construction.” The majority of that funding comes from redirecting $50 million away from the Alkali Reservoir. A prudent move, proponents say, because that project doesn’t have the easements needed to start construction.
A “backup” measure, of sorts, House Bill 143, “LaPrele dam rebuilding,” would provide the same level of funding without shifting dollars from the Alkali project.
Meantime, HB 117 has been amended to include a $1 million grant to the LaPrele Irrigation District to assess the feasibility of drilling one or more water wells to supplement water supplies during the expected five-year period between demolition and replacement. The amendments would also provide a loan of $19 million to construct the wells.
The funding proposals — like many water infrastructure construction projects — face criticism from many who see them as spending taxpayer money for the benefit of a limited number of irrigation operations. Such appropriations amount to “picking winners and losers,” Lander Republican Rep. Lloyd Larsen of Lander said during a recent committee discussion regarding one portion of the funding proposals. “Government can’t just step in and take care of things for everybody,” he added.
Regarding such criticism, Darr said, yes, the LaPrele Irrigation District and the family businesses it supports would be prime beneficiaries of the investment. But, he pointed out, this would be the first major state investment in an irrigation district that provides economic support to the broader communities in the area, including businesses in Glenrock, Douglas and beyond.
“This district took a dam that had a lifespan of 50 years, and we got 116 years out of it with no state help,” Darr said. “The economic impact that this dam has provided for this community far exceeds the amount of money that we’re getting from the state. And we are extremely grateful for their help, because we honestly can’t do it without them.”
If the LaPrele Irrigation District were to lose the old dam without replacing it, the economic repercussions would be felt far beyond the tiny irrigation community, Dziardziel said.
“I buy equipment from Torrington clear to Riverton,” he said. “I buy fertilizer from Rock Springs. I even buy equipment from Cody. So, I mean, this affects the whole state.”
Not only would the state and federal investment help keep younger generations in the business of irrigated agriculture at LaPrele, Dziardziel added, it will help maintain a broader agricultural community in the state.
“When oil and gas play out, we’ll still have agriculture,” he said. “It’s a great long-term investment for the state.”
This article was originally published by WyoFile and is republished here with permission. WyoFile is an independent nonprofit news organization focused on Wyoming people, places and policy.
