Barr Engineering updates Mitchell Lake project on dredging and dam reconstruction plans

During the July 7, 2025, City Council meeting in Mitchell, South Dakota, significant updates were provided on the Lake Mitchell project, which aims to enhance the lake's infrastructure and water management capabilities. Eric Lund from Barr Engineering presented a detailed overview of the project's current status, focusing on the drawdown and dredging initiatives.

Lund reported that the project has made substantial progress over the past year, including monthly coordination meetings with city officials to discuss milestones and upcoming deliverables. Key developments include the completion of a coring investigation of the existing spillway, which is crucial for assessing the structure's integrity. This investigation revealed varying depths of concrete, leading to the decision to initiate the dam breach on the south side of the spillway, where the concrete is thicker and more stable.

The drawdown process is designed to be gradual to maintain the structural integrity of the shoreline and to protect local wildlife, particularly the Topeka shiner, a protected species in the area. The plan includes installing sedimentation controls to prevent dirty water from flowing into Firesteel Creek during the drawdown.

Lund also discussed the design of a new permanent drawdown structure that will allow the city to manage the lake's water levels more effectively in the future. This structure will include an intake system that can lower the lake level by approximately 8 to 10 feet, facilitating maintenance and other city needs without requiring a full drawdown.

In addition to the drawdown and dredging updates, the council addressed the irrigation supply needs for local facilities, including the soccer complex, golf course, and Cadwell Park. A hydraulic model has been developed to estimate how much water will remain in the lake during the partial drawdown, ensuring that these facilities continue to receive adequate water supply.

The meeting concluded with a commitment to keep the community informed about the project's progress and its implications for local water management and infrastructure. As the Lake Mitchell project moves forward, it aims to enhance both the ecological health of the area and the recreational opportunities for residents.