There has been much discussion regarding LaPrele Dam and its future in recent years. Unfortunately, there has also been some conflicting information circulating locally on this important topic. Therefore, I believe it is time to lay out where we have been and where we are going regarding the need to finally replace this extremely old piece of critical infrastructure.
I have been very concerned about the increasingly questionable state of our water infrastructure as much of it exceeds the 100-year mark. Some of this aging infrastructure has failed catastrophically, most notably twice in the past few years in Goshen County. I am proud of the work the Wyoming Water Development Commission has done to begin to assess the scope of this challenge which threatens important parts of our economy. In the case of LaPrele, we were lucky to catch the problem before a catastrophic failure.
While it is frustrating to spend so much time and resources just to maintain what we already have, the need to do so is beyond question. The dam is over 110 years old, with just one upgrade 40 years ago. Since that time the dam has deteriorated significantly. For example, while buttress 17 has had a large crack since at least the late 1970s, additional fissures have been developed on buttresses 2 and 7 since then. These fissures were not addressed in the overhaul the dam received in the early 1980s and have developed in such a way that suggests the entire east side of the dam is “sheering”. Even worse, the integrity of the concrete has deteriorated to unacceptable levels. This type of dam is expected to have a compressive strength of 3,000 to 4,000 psi. The concrete on buttress 17 was measured at 1,720 and 2,210 psi.
That the dam is in such a dire condition should not come as a surprise. LaPrele is one of the only “Ambursen” style dams left in the country. These dams were popular in the early 1900s as they didn’t require much concrete and were cheap to build. Unfortunately, that means they aren't as structurally sound as a more traditional gravity concrete dam. It also means that when there is a failure, it happens suddenly and catastrophically. Such a failure would likely result in loss of life for anybody along LaPrele Creek at the time of the failure, as well as the destruction of Natural Bridge and I-25 between Douglas and Glenrock. The costs to both state and local government as well as to our economy of such a failure would be enormous.
The dam also has a significant economic impact as well. Maintaining this infrastructure is vital to ensure our agricultural industry can thrive for the next 100 years. The LaPrele irrigation district services 100 users and well over 11,000 acres of irrigated land in southern Converse County. Without the dam, that irrigated acreage would shrink to only benefit the landowners directly on LaPrele Creek. Ultimately, failure to replace the dam will result in our water being used by other downstream states.
The State of Wyoming has been diligently working to ensure the safety of the LaPrele Dam as it reaches the end of its useful life. The Wyoming Water Development Commission is on schedule to expend $5.2 million by June 30, 2024. This includes work to assess the geology of the new site for the dam, design the structure and work to ensure regulatory compliance. The state is also likely to receive a significant amount of federal funds through the bipartisan infrastructure law passed a few years ago. It is only fitting that federal government helps to replace this infrastructure that it built in the first place.
The process for funding through the Bureau of Reclamation funding is not easy, but we are making progress. I have been working with the Director of the Wyoming Bureau of Reclamation in my capacity as chairman of the last Select Federal Natural Resource Management Committee. I am also keeping a keen eye out for any unusual strings attached to this funding, since that is a definite concern with this administration. So far there is nothing out of the ordinary - though the need to go through all the red tape, such complying with the National Historic Preservation Act, is mildly annoying.
This is a pivotal time for LaPrele dam and our ag industry in Converse County. All the funding sources are lining up to replace this structure – an opportunity we probably won’t likely have again. Put another way, this is a once in a century opportunity we would be foolish to pass up. By staying course on this project, we can ensure another 100+ years of Wyoming irrigators have the same opportunities of those that came before them.