The Army Corps of Engineers has implemented emergency operations at two hydropower dams on the Skagit River, significantly mitigating flooding concerns. These measures highlight the dual nature of large dams, which provide both benefits and drawbacks. While they generate climate-friendly electricity, they also pose risks to local ecosystems and communities.
Skagit Dams in Action: Reducing Flood Waters
During a recent flood alert, the Army Corps took control of the Ross Dam, a 540-foot concrete structure owned by Seattle City Light, and the Upper Baker Dam, which stands at 300 feet and is managed by Puget Sound Energy. The primary objective was to manage reservoir levels effectively and prevent severe flooding downstream.
Key Actions and Impact on Flooding
As water levels in the Skagit River surged, the Army Corps ceased operations at the Ross Dam, preventing 99% of the inflow into Ross Lake. Despite these actions, flooding downstream still approached record levels. Preliminary estimates indicate that dam operations successfully lowered the river’s peak height by 4 to 5 feet, which reached approximately 37 feet. According to the Army Corps, this strategic reduction played a critical role in minimizing flood damage in communities like Concrete and Mount Vernon.
Statistics and Flood Management
- Skagit River Flow: 60% of the flow remains undammed.
- Ross Dam Height: 540 feet.
- Upper Baker Dam Height: 300 feet.
- Flood Peak Height: Approximately 37 feet.
- Water Flow Reduction: Estimated reduction of 4 to 5 feet.
Seattle City Light’s representative, Jenn Strang, confirmed that Ross Dam did not generate hydropower during the emergency period. Meanwhile, other dams from the same utility continued electricity production.
Next Steps in Flood Control
After the immediate flood risk decreased, the Army Corps began releasing stored water from the reservoirs. This process is essential for preparing for potential future flood events. As forecasts indicated increased river flows approaching 90,000 cubic feet per second, control of Ross Dam was reassumed by the Army Corps for proactive management.
The Skagit River basin, primarily characterized by wild waters, includes several undammed tributaries such as the Cascade, Sauk, Suiattle, and White Chuck rivers in the North Cascades. These natural systems contribute to the overall dynamic management strategy of the Skagit River.
In summary, the emergency operations at the Skagit dams showcase the important role these infrastructures play in flood management while simultaneously stressing the need for careful ecological consideration.
