Upper Mill Creek Dam Temporary Fish Ladder Extension Project

The Upper Mill Creek Dam Temporary Fish Ladder Extension Project aims to restore critical passage for special status salmonids by constructing a temporary extension to an existing fish ladder that has been compromised by undermining. The solution involves installing three new fish ladder cells using a custom-fabricated steel tubing frame wrapped with chain-link fencing, designed to conform to the natural contours of the streambed. This structure will be stabilized by ballasting it with native rock sourced from onsite stockpiles relocated after the 2024/2025 high flow events. Once filled with rock, a steel plate will be secured over the top to form a unified, flood-resistant base, upon which wooden fish ladder panels will be mounted. These wooden components are engineered to detach during high flow events to prevent structural damage and will be reinstalled once water levels recede, ensuring the system remains functional and adaptable to dynamic stream conditions. The project is being managed by the Regional Water Quality Control Board, Region 5 - Redding, under the oversight of Senior Environmental Scientists Lynn Coster and Adam McKannay. All work will be performed manually to minimize disturbance to the surrounding environment, and the temporary nature of the structure reflects a designed balance between immediate ecological needs and long-term resilience. The use of locally sourced materials and a detachable wooden panel system reduces environmental impact while allowing for seasonal maintenance and flood recovery. The project is forecasted with a posted date of June 18, 2026, and will be implemented in California, specifically in the vicinity of Upper Mill Creek.