Lake water quality monitoring & protection

We offer a clearinghouse for information associated with lake monitoring and protection across the state. Most lake monitoring for water quality is currently conducted by counties, local health departments, lake associations, and volunteers, aside from a few specific surveys, as noted below.

All known data, including some photographs and lake-bottom maps (bathymetry), is captured and compiled into the lakes module of the Coastal Atlas database.

While funding for regular lake monitoring stopped in 2000, our staff and volunteers conducted a full decade of lake monitoring from 1989-1999 across Washington to identify water quality concerns, including dissolved oxygen, water clarity, temperature, and contaminants. We still monitor some lakes each year for toxic metals and other chemicals.

We also participate in EPA's National Lakes Assessment every five years. Data are collected on a random sampling of lakes representing different regions of the state. In the summer and fall of 2017, scientists are collecting data from a representative sample of lakes for analysis over the next year or so. We also partnered with the EPA on this project in 2007 and 2012.

Lakes Environmental Data - Click for full database with map.

A number of resources, websites, and historical documents provide additional information on lake monitoring in Washington, ranging from the state toxic algae database to the freshwater fish contaminant monitoring program.