Stillwater Reservoir west of Yampa in need of expensive repairs

Stillwater Reservoir west of Yampa in need of expensive repairs
Stillwater Reservoir was drained in August 2021 for inspections to establish upgrades required to the growing old infrastructure.
Colorado Division of H2o Resources/Courtesy photograph

When the 75-foot dam for Stillwater Reservoir was constructed in 1939 by the Civilian Conservation Corps for the former Yampa Reservoirs Public Irrigation District, it was effectively constructed to meet engineering standards at the time.

But by today’s requirements, the dam’s abutments would be addressed in a different way, stated Dana Miller, dam basic safety engineer with the Colorado Division of Drinking water Sources in Steamboat Springs. As a end result, the getting old dam infrastructure wants expensive updates to convey the framework up to existing safety benchmarks, Miller stated.

Given that it was produced, the dam at about 10,300 toes elevation has seasoned consistent seepage concerns in which the sides of the dam abut the hillsides. If not dealt with, the seepage could inevitably guide to a failure of the dam, Miller described.

Although the seepage has been worked on via the decades with nominal success, lasting improvements could value thousands and thousands, according to the proprietor Bear River Reservoir Co. The reservoir h2o is owned by 18 agricultural shareholders and the city of Yampa, and those southern Routt County hay growers have been affected monetarily due to lower drinking water storage allowances, additionally several years of drought.

The Stillwater Reservoir was placed on a fill restriction by the point out in June 2019 and at this time is constrained to roughly 80{64d42ef84185fe650eef13e078a399812999bbd8b8ee84343ab535e62a252847} capacity, which the h2o storage degree might reach throughout wetter decades. The construction is labeled as a high-hazard dam, which is not primarily based on its situation but due to the fact “loss of daily life and sizeable injury is envisioned downstream if the dam were to fall short,” Miller explained.

The 129-acre reservoir, which is also recognised for the trailhead to well known Devil’s Causeway hike, was drained to a modest dead pool in August 2021 for inspections of the upstream aspect of the reservoir outlet gates. The reservoir was drained yet again in Oct for do the job on the hydraulic operating system, explained Andi Schaffner, secretary for Bear River Reservoir Co. 

Yampa resident Schaffner explained the entrepreneurs of the personal, nonprofit reservoir organization have contributed additional than $100,000 to aid with dam concerns in the previous 11 a long time, and complete updates to the hydraulics are predicted to charge $300,000.

Workers with Marine Diving Solutions inspect the outlet to Stillwater Reservoir when it was drained in August 2021.
Colorado Division of Water Assets/Courtesy image

This yr, the reservoir corporation received grants towards the updates like $139,500 from the Yampa-White-Green Basin Roundtable, $125,000 from Colorado River District and $50,000 from Upper Yampa H2o Conservancy District, Schaffner claimed.

Perform commenced in Oct and November to up grade the hydraulics technique and will be completed by W.W. Wheeler & Associates drinking water sources engineers in Englewood soon after the reservoir is drained again following the irrigation season in 2023, Schaffner reported.

Workers examine the inner hydraulics of Stillwater Reservoir dam in August 2021.
Colorado Division of H2o Means/Courtesy picture

With tens of millions of bucks most likely wanted to deal with the seepage difficulties, the timeline for that perform is optimistically believed for 2025, in accordance to the reservoir company.

Dams and reservoir storage are essential to agriculture and the Routt County group, but they also produce an inherent possibility to people residing downstream, Miller mentioned. So giving money methods to support dam entrepreneurs repair and maintain the structures is essential. The 20 recommendations in the Yampa Integrated H2o Administration Program released in September included the advice to “identify repairs for current reservoirs and safe infrastructure funding to total them” and “support owners of 6 substantial reservoirs with important infrastructure maintenance demands.”

The engineer stated if the Stillwater Reservoir ended up allowed to fill to full potential and did breach, some of the downstream reservoir dams “could not accept that form of move, and the dams would fall short as well.” Having said that, the reservoir organization observed engineering research show the dam is not in hazard of failing. Relatively, the difficulty is getting ready to fill to capacity.

“We’ve finished important reports and investigative engineering get the job done. We are content for the grants that we have been ready to procure so significantly, but we will be looking for numerous extra for the ultimate venture,” Schaffner said. “We would just like to be ready to see it return to complete storage. You just cannot swap the reservoir storage with other water which is why it’s so important to keep it operational.”

One more high-hazard dam in the location is Sheriff Reservoir, and town leaders in Oak Creek are at this time hunting for funding to finish required repairs. Four other smaller sized private dams in just the water division are under point out-requested fill limitations, which include Rams Horn south of Yamcolo Reservoir in the Flattops, Drescher southeast of Craig, Nofstger southeast of Hayden and Sullivan south of Craig close to Pagoda, Miller explained.  

The engineer claimed the h2o division commonly has 6 different reservoirs per yr less than fill restrictions right up until repairs are built, including one particular scaled-down dam that has been on a fill restriction considering that 1988.

Stillwater Reservoir situated 15 miles west of the Town of Yampa was drained in August 2021 for inspection work and then drained yet again for the start of upgrade do the job in Oct 2022.
Colorado Division of Drinking water Means/Courtesy photo