Early Snowpack Near Normal for Seattle City Light Hydroelectric Dams

While snowpack levels in the watershed that collects Seattle's drinking water is below normal at the start of 2015, snowpack levels in the watersheds that feed Seattle City Light's hydroelectric dams are near normal. Even so, it's early in the season and a lot can change before the end of winter.

A story in this morning’s Seattle Times about snowpack conditions in the Cascades generated several questions about the amount of snow that will eventually support Seattle City Light’s hydroelectric dams once it melts.

The key to the answer is location, location, location.

Our friends at Seattle Public Utilities collect our area’s drinking water from the Cedar River watershed east of Seattle. Snowpack levels there are significantly below normal.

Seattle City Light’s large hydroelectric dams are located on the Pend Oreille River in Northeast Washington and the Skagit River northeast of Seattle. Those dams depend on snowpack in the Rocky Mountains of Montana and the North Cascades where conditions are close to normal for this time of year.

The water year starts in October, so it is still early in the measurements. A lot can change between now and May. Remember that conditions were very dry a year ago until March brought heavy snows. Our staff monitors those conditions so we can adjust our operations as needed based on how much power we expect to be able to generate.

Here’s a look at the snowpack levels measured across the region. 

 

Map of the Pacific Northwest showing snowpack levels at monitoring stations.

Pacific Northwest snowpack levels.