Navy Intervention Reduces Flood Ranges at Skagit Dams

The Military Corps of Engineers was in a position to cut back flooding on the Skagit River with emergency operations of two hydropower dams upstream.

Massive dams have large downsides, together with killing salmon and drowning complete valleys underneath reservoirs.

However in addition they have main upsides, together with climate-friendly electrical energy and, as grew to become obvious final week, flood management.

Because the Skagit’s flood waters have been constructing, the Military Corps took over Ross Dam, a 540-foot tall concrete dam owned by Seattle Metropolis Mild, and Higher Baker Dam, a 300-foot excessive concrete dam, owned by Puget Sound Vitality.

The objective: holding again water to scale back flooding downstream.

As flows surged into the reservoir often called Ross Lake, engineers turned off Ross Dam spigot.

The dam held again 99% of water flowing into the reservoir, in line with Military Corps officers.

Even that wasn’t sufficient to maintain downstream flooding from breaking data.

However dam operations have been in a position to shave 4 to five ft off the river’s peak top of about 37 ft, in line with the Military Corps’ preliminary estimates.

“With out this strategic discount, peak [river] phases in Concrete and Mount Vernon may have been a lot greater, resulting in extra extreme flooding,” in line with an Military Corps press launch.

The waters of the Skagit basin are principally wild, with 60% of the Skagit River’s move by no means passing by way of a dam. Undammed tributaries embody the Cascade, Sauk, Suiattle, and White Chuck rivers excessive within the North Cascades.

Seattle Metropolis Mild spokesperson Jenn Strang stated Ross Dam generated no hydropower throughout the Military Corps’ takeover. Two different Metropolis Mild dams on the Skagit saved producing energy.

After the flooding danger dropped on Friday, engineers began releasing water once more to create space within the reservoirs for the subsequent spherical of flooding.

The Military Corps returned management of Ross Dam to Seattle Metropolis Mild over the weekend however took over the dam once more as forecasters predicted river flows on the city of Concrete would rise previous 90,000 cubic ft per second once more.