In 2007, EPA and the States conducted a survey of the nation's lakes, ponds and reservoirs. This National Lakes Assessment is designed to help us to provide statistically valid regional and national estimates of the condition of lakes. It uses a probability-based sampling design to represent the condition of all lakes in similar regions sharing similar ecological characteristics. Consistent sampling and analytical procedures ensure that the results can be compared across the country. The National Lakes Assessment will also help build state and tribal capacity for monitoring and assessment and promote collaboration across jurisdictional boundaries in the assessment of water quality. A report on the findings is available below. In 2012, EPA, the States and Tribes will begin a second national assessment of Lakes.
Ecological Condition of Lakes in Idaho, Oregon, and Washington (PDF) (74 pp, 1.3MB) - March 2011