Attempts to save a small reservoir in a remote part of Southwest Colorado inched closer to completion after a bid recently went out calling for a final design to improve the existing dam structure.
Jordan Dimick, a senior engineer with SGM, the firm helping to draft construction plans, said a final feasibility study on what’s known as Red Mesa Reservoir was completed this summer.
Now, after securing state and local grant funding, a “request for proposals” recently went out to get an engineer to start the final design of the project, hopefully in early 2021.
“Now we can sit down and have another engineer firm look at what we did,” Dimick said. “And we can figure out how much it’ll cost for the final design.”
Red Mesa Reservoir is a small 1,175-acre-foot storage body (nearby Long Hollow Dam, for reference, is about 5,400 acre-feet) that provides water to about 50 people in the notoriously arid western part of La Plata County.
The dam, historically known as Mormon Reservoir, was built in the early 1900s by members of the Church of Jesus Christ of Latter-day Saints, which used a “Fresno scrape,” a machine pulled by horses for building canals and ditches.
In 1911, a flood washed out the earthen dam, and it wasn’t until 1945 that the structure was rebuilt. Aside from minor improvements over the years, Red Mesa Reservoir, which sits about 20 miles southwest of Durango off La Plata Highway (Colorado Highway 140), has remained mostly unchanged.
Since at least the 1980s, however, Colorado’s Division of Water Resources has deemed the dam’s spillway (the structure used for overflows) inadequate to handle the waters of major floods.
Calls to the Division of Water Resources were not returned.
In January 2018, the issue came to a head when the Division of Water Resources ordered Red Mesa Reservoir managers to complete improvements to the structure by 2024 or face demolition, while at the same time prohibiting any water to be stored there until it was deemed safe.
In an effort to buy time, Red Mesa Reservoir managers spent $25,000 to expand the spillway, and in exchange, were allowed to keep water in the reservoir.
Red Mesa Reservoir, however, is still being held to a tight timeline to make permanent fixes.
The hope, those involved with the project said previously, is to start construction in 2022 and complete the project in 2024.
Ideally, Dimick said the dam would be enlarged to hold double the capacity it currently does. And, water managers would like for Red Mesa and Long Hollow to operate in tandem to meet water compacts with New Mexico.
For the past few years, Red Mesa Reservoir managers have been selling the idea of enlarging the dam in an attempt to generate more interest, more stakeholders and therefore, more money toward the project.
Calls to Trent Taylor, operator of Red Mesa Reservoir and a board member of the Red Mesa Reservoir and Ditch Co., were not returned.
Colorado Parks and Wildlife has shown interest in keeping water in the La Plata River for native fish when water isn’t flowing out of Long Hollow Dam during the non-compact season, which typically runs from December to February.
Previously, Taylor estimated it could take about $9 million to bring the dam structure up to standards. But it remains unclear how much it might cost to double the capacity of the reservoir, Dimick said.
Dimick said SGM included several alternatives in the final feasibility study. It’ll be up to all those involved in the project to select the “leanest cost” that will provide the “biggest benefit” in improving Red Mesa Reservoir, he said.
“We’d like to double the reservoir, but the question now is, are there enough funds?” Dimick said.