[4/12/18] Lake Chelan Lake Level Continues To Rise Ahead Of May 1st Target Elevation

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You may have noticed the Lake Chelan lake level starting to creep up.

As of this morning- the Chelan PUD website indicates 1086.3 feet asl (above sea level). That’s up about 8 inches in the last 10 days, but still 13 feet below 1100 feet asl which is considered full pool.

Chelan County PUD manages the draw down and refill of Lake Chelan every year by scheduling and operating hydro power generation and spill. Lake elevation target curves were developed by Chelan PUD staff by modeling the many years of historical inflows into the lake. Lake levels are managed to reach a balance between seven operating objectives and minimum target elevations contained in the operating license issued by FERC- the Federal Energy Regulatory Commission.

Since the first licenses was issued in 1926, the lake has been requited to operate at a maximum surface elevation of 1100 feet asl and a minimum surface elevation of 1079 ft asl

The second license, issued in 1981 included a provision that Chelan County PUD make every reasonable effort to maintain the reservoir at or above elevation 1098 from June 30 through September 30 each year.

That provision changed with the issuance of the third license, issued in 2006- which requires Chelan County PUD to make every reasonable effort to comply with the seven operating objectives, that together provide recreation, protect fish, reduce erosion and restore year round water flows to the Chelan River.

Once the lake level is drafted down to the target curve and minimum tail race water flow obligations for fish in the river are being met, the timing of runoff, or daily inflows into the lake play the largest role in spring lake levels.

Maintaining minimum flows in the Chelan River has priority over lake levels.

The most current survey indicates that snow pack that feeds Lake Chelan is at or above normal levels, meaning we will have plenty of runoff, but the timing of runoff is dictated simply by weather.

Not quite midway through April, we are very close to our target elevation for May 1st, which is 1087.6 asl. Target elevation for June 1st is 1094 feet asl, it’s 1098 feet by the 1st of July and 1099 feet on the 1st of August. All recreationally acceptable lake levels.

If you would like to learn more about Lake Chelan lake level, visit chelanpud.org– open the Parks and Recreation tab and click on Chelan Lake Levels.

There you will find a comprehensive history of managing lake levels including what to expect in the summer and fall of 2018. Again, that website chelanpud.org.