Construction work to repair the Goose Pasture Tarn Dam is set to begin this month.

While the dam is located in Blue River, the rehabilitation project is being led by Breckenridge, which owns and operates the dam. Water from the Goose Pasture Tarn goes to the Gary Roberts Water Treatment Plant, which serves the residents of Breckenridge.

According to a press release from the town, rehabilitation of the dam includes the replacement of two existing spillways with a single, larger spillway that is intended to improve the safety of the dam. Officials expect the project to be completed in the fall of 2023. The dam repair project is expected to cost a total of $20 million, which is being paid for by Breckenridge, Colorado and the Federal Emergency Management Agency.

Moving forward with the project is a sigh of relief for Breckenridge residents because the dam, which was constructed in 1965, was classified as a “high hazard” in the U.S. Army Corps of Engineers’ 2018 National Inventory of Dams. The press release noted that the dam wasn’t classified as a high hazard because of its condition. Instead, the designation was based on the estimated consequences if the dam were to fail. However, safety issues during high flows were identified in 2016, and as a result, reservoir-storage restrictions were put in place that reduced flows.

The project was set to begin in spring of 2020, but last April, Public Works Director James Phelps recommended that the Breckenridge Town Council postpone the project until 2021 because of concerns about the lack of proposals received from contractors for the project. At the time, he said there were risks associated with waiting to repair the dam, but said it wasn’t a major cause for concern because of recent improvements made to the dam and a relatively nonaggressive spring runoff compared to previous years. The town selected Moltz Constructors, Inc. as the contractor for the project.

In a call with the Summit Daily News last Thursday, Phelps explained that the overall goal of the project is to repair and strengthen the dam.

“The dam has a weakness in it now that’s been identified over the years, and so now we have a plan to basically rebuild it,” Phelps said, noting the spillway replacement. “We’ll build up some of the material that’s underneath the spillway, and that’s really where it’s been compromised. There’s water that’s going underneath the current spillway, which is starting to erode some of that material which is causing the (dam) to slowly fail.”

Phelps said that unless people are very close to the dam, they likely won’t see or hear much construction during the three-year build. However, people living nearby may have to deal with some truck traffic.

“The construction activities this year are mainly excavation and construction, so there will be probably a lot of trucks,” Phelps said. “… There will be heavy equipment in there. It’s going to be noisy, but the noise will be localized to that area around the dam itself.”

Phelps said the Goose Pasture Tarn’s water level will be lowered for about a month near the end of July. The water will be lowered for a longer period of time next summer. During the project, recreational use of the tarn is prohibited and the lowering of water levels may impact nearby residential wells. The release said that the town has installed monitoring wells to track fluctuations in groundwater levels near the reservoir and will “enact additional measures” to reduce impacts.

Phelps explained that construction work is planned to happen within three time frames: April 2021 through September 2021, April 2022 through September 2022, and May 2023 through the fall of 2023. Work could be done as early as the end of August 2023. Phelps noted that the heavy construction work will be completed in 2022, and a lot of the work that will be done in the final phase of the project will be to revegetate the area around the dam.

For more information on the project, visit TownOfBreckenridgeGPTD.com. Specific questions can be emailed to BreckenridgeGPTD@TownOfBreckenridge.com.