The long-term sustainability of the clear, blue water that characterizes Lake Chelan is key to the economic viability of this region.
Over recent decades, Lake Chelan has experienced significant changes including substantial development in the lower part of the Chelan Valley. Increasing population, tourism growth, changing land use, and invasive species threaten this sensitive aquatic ecosystem.

In open water, Lake Chelan exhibits remarkable long-term stability in water clarity, nutrient concentrations, and growth of algae. This stability reflects the large, mostly pristine nature of the lake’s watershed. The nearshore environment of Lake Chelan is less stable, undergoing a transition in which algae along the shoreline have increased and Aquatic Invasive Species (AIS) have expanded over the last few decades.

Increases in algae and AIS along the shoreline are likely sentinels for long-term changes that could impact the entire lake.
This situation underscores the importance of continuing systematic, long-term water quality monitoring to further our understanding of the year-to-year changes occurring within the lake.

Continued monitoring is vital to assess the impact of environmental events and allow early detection of water quality trends. Results will provide crucial information to management and conservation efforts, focusing local actions to control undesirable changes in Lake Chelan.

To read the full report of the State of the Lake 2021 click on the “read full report” button