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Lake services and information
King County provides an array of services and information to facilitate lake management, monitoring, and enjoyment.
Water quality
Major lakes monitoring
Monthly data for lakes Washington, Union, and Sammamish, as well as sites in the Ship Canal and Montlake Cut.
Major lakes buoy data
Data collected on an ongoing basis by buoys stationed in lakes Sammamish and Washington.
Small lakes monitoring and information
Information about the many small lakes throughout King County, as well as data collected as part of our Lake Stewardship volunteer lake monitoring program.
Swimming beach monitoring
Swimming beaches throughout King County are monitored for bacteria and temperature. Toxic algae samples are collected and tested when blooms are observed.
Recreation
Small lakes recreation guide
This guide lists many of the smaller lakes in western King County with public access points, boat launches, swimming beaches, and/or parks.
Boating regulation information
Learn about boating restrictions, equipment requirements, safety, aquatic weed, and other related information in the Washington State Boating Handbook.
Projects and programs
Lake stewardship program
King County's volunteer-based water-quality monitoring program.
Combined sewer overflow monitoring and real-time map
Get current information on recent Combined Sewer Overflows so you can make informed decisions about using our local waters.
Shoreline master program
Learn how we work to protect shoreline natural resources, promote public access, and encourage water-dependent uses.
Streams monitoring
Learn about our monitoring sites and see data and analysis for individual streams and watersheds.
Toxic algae monitoring
See toxin data related to cyanobacteria blooms in Washington lakes, ponds, and streams.
Phytoplankton and zooplankton
We monitor the amounts and type (community composition) of phytoplankton and zooplankton in the Puget Sound Central Basin, as they are indicators of ecosystem health.
References and resources
King County iMap
Zoom in to your area of interest. In the layers list, click "Hydrography" and the layers you need such as "Lakes and large rivers."
Lakes FAQ
Find answers to frequently asked questions about King County lakes.
Glossary of lake terms
From aerobic to zooplankton, learn all the lake terminology.