Exploratory Drilling to begin at Vallecito Dam

DURANGO, Colo.  - Exploratory work will soon be conducted at Vallecito Dam, located on the Pine River 18 miles northeast of Durango, to help evaluate and guide future rehabilitation efforts to be completed under the Bureau of Reclamation's Safety of Dams Program.

Beginning July 27, crews will begin exploratory drilling efforts. This work will mark the first phase of field explorations to gather geotechnical data at the dam's crest and spillway. A small portion of Forest Road 603, which provides access to a parking area, vault toilet and Dam Park, will be closed to vehicles for approximately 4-5 months while this work is completed. The road and amenities will remain open to pedestrians. Drilling will continue along the spillway into 2027.

In 2018, Reclamation first identified changes in seepage underneath the spillway at Vallecito Dam and began a rigorous monitoring effort that included investigations to understand if dam safety risks were present. Based on this analysis, Reclamation initiated a Corrective Action Study in March 2025 to develop alternatives for addressing the seepage issue in the spillway. The project will aim to address concerns with the foundation material under the spillway and increase operability of the three spillway radial gates. Data collected during drilling will be used to inform the next phase of design, where repair alternatives will be evaluated.

"The exploratory drilling at Vallecito Dam represents a critical step in ensuring the long-term safety and reliability of this important infrastructure," said Western Colorado Area Office Manager Bart Deming. "By gathering detailed data, we're laying the groundwork for informed decisions on future repairs and rehabilitation. This effort is not only about addressing current concerns, but also about safeguarding the dam for the communities and resources it serves."

Updates to the project will be posted on the Western Colorado Area Office website when available.

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The Bureau of Reclamation is a federal agency under the U.S. Department of the Interior and is the nation's largest wholesale water supplier and second largest producer of hydroelectric power. Our facilities also provide substantial flood control, recreation opportunities, and environmental benefits.