Cold spring means slow runoff into Lake Chelan

CHELAN/MANSON – Every year is unique for Lake Chelan Basin runoff and refill, and this spring started with a healthy snowpack that’s slow to melt. That means the annual runoff that refills the Lake Chelan this time of year is delayed.

It’s been colder than normal these past several weeks. Temperatures in April averaged 6.3 degrees below normal, as recorded at Pangborn Airport. So far, May temperatures have averaged 6.2 degrees below normal.

Snowpack in the Lake Chelan Basin was about 90 percent of average during the April 1 snow survey, and it’s staying put. Forecasts indicate about 22 feet of refill water remains in snowpack, and there is 9 feet of room in the lake. Any excess water will either be run through the dam for power generation or spilled into the Chelan River.

Lake Chelan is the reservoir for the Lake Chelan Hydro Project. Managing the level of popular Lake Chelan requires balancing several objectives within its federal operating license that together provide recreation, protect fish, provide flood control, reduce erosion and restore year-round flows to the Chelan River.

In order to speed up lake refill, Chelan PUD began to curtail energy generation on April 24, and shut down generation on May 13 as lake levels gradually rise closer to target elevation. Lake levels are nearly 1,091 feet as of May 23. The goal is to reach the 1,094-foot target elevation by June 1.

Managing the level of the lake is not an exact science. It involves a series of forecasts and calculations, with the added uncertainty of weather. Check lake levels any time at chelanpud.org.

Chelan PUD also offers a free app – Current – which includes real-time data for local rivers and lakes. Features include: Lake Chelan levels, boat launch water depth and real-time water flow.  The Current app is available for iOS and Android platforms. You can find the download link and a 30-second video at chelanpud.org/app.