Lake Chelan annual operating range and lake level history
The summer of 2015 has been unusual for Lake Chelan. Lake levels were kept somewhat higher than in most years because of the low snowpack and limited runoff that occurred. As we move into the fall, the PUD expects to be at the Federal license minimum of 1,098.7’ by Sept. 7. This allows the PUD to be in a position to manage any rainfall that could occur later in the season. Click here for the Northwest River Forecast Center water supply forecast for Lake Chelan.
Graph lines can be turned "on" and "off" by clicking on the legend names above.
Zoom function is enabled by clicking and dragging the mouse pointer over a section of the graph
Lake levels are expected to be within the forecasted operating range most of the time.
Actual lake levels may be higher or lower than the forecasted operating range.
Future Operation (updated Oct. 1):
The graph above represents the Chelan Lake Levels for the water year just completed (October 2014 – September 2015).
The final April 1 to July 31 water supply was approximately 66 percent-of-average. This is the sixth lowest year in the last 60 years. Temperatures in the Chelan Basin were above average for the summer season, while precipitation was below average.
During the later part of July, the lake level was reduced about .5 foot prior to start of one of the two Chelan Hydro project’s generating units being taken out of service for planned maintenance work on Aug. 4. With only half the project’s generating capability available, there is half the ability to generate inflows and further reduce the lake level, as usual this time of year. Should inflows be higher than forecast during this outage period, this allows some room in the lake to catch unexpected water while keeping spill risk low. The unit’s scheduled return has been extended from Sept. 25 to Oct. 16. The one available unit is expected to generate around the clock through the extended outage period.
All License minimum target elevations for 2015 were met. A forecasted Operating Range for the new water year (October 2015 – September 2016) will be available soon.
For Those on the Go
A direct link to current lake level readings is available using smart phones and tablets by scanning a QR (Quick Response) code. The code is available on posters at boat launches and marinas and rack cards distributed throughout the Chelan-Manson-Chelan Falls community.
Lake Level Management
Lake Chelan is the reservoir for the Lake Chelan Hydro Project. Managing the level of popular Lake Chelan requires balancing seven objectives in the operating license that together provide recreation, protect fish, reduce erosion and restore year-round flows to the Chelan River.
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. However, updated tools and additional data will help us provide information that is more useful for residents and visitors.
Targeting a Range
Chelan PUD estimates that Lake Chelan can be operated within the above Current Operating Range most of the time, and meet the District’s seven license operating objectives and target elevations in most years.
We are committed to letting you know about any changes in expected lake levels as soon as we can so residents and visitors know what to expect. We welcome your comments or questions about Lake Chelan levels.
The District expects to maintain the lake level within a range of 1,084 to 1,100 feet above sea level during most years. In extremely wet years, the lake level could be lowered to 1,083 feet above sea level, or lower (the license minimum is 1,079 feet above sea level), as more room is needed to capture increased runoff. Factors that can affect lake level management include:
We are sensitive to the needs of the many users of Lake Chelan. Below are the elevations at the bottom of each concrete boat ramp. As lake levels fluctuate, boaters are asked to take these elevations into consideration before launching a boat.
|Elevation at |
End of Boat Ramp
|Chelan Riverwalk Park||Chelan PUD||Chelan||2 concrete ramps||1080.5 feet|
|Lake Chelan State Park||WA State Parks||Chelan||1 concrete ramp||1090.0 feet|
|City of Chelan||Chelan||2 concrete ramps||1090.0 feet|
|Manson Bay Park||Manson Parks||Manson||1 concrete ramp||1077.9 feet|
|Old Mill Park||Manson Parks||Manson||4 concrete ramps||1082.9 feet|
|25-Mile Creek State Park||WA State Parks||Chelan||2 concrete ramps||1093.0 feet|