Cowlitz County Lake Quality

Cowlitz County holds 6 monitored lakes. With a sample that small the county-level summary describes those specific waters, not necessarily every water body in the county. The 6 monitored lakes in Cowlitz County carry whatever clarity, phosphorus, and chlorophyll-a readings Washington Ecology has published, shown as reported.

Many of the county's lakes are deep glacial basins, over 50 feet at their deepest point, which gives them thermal stratification and a buffer against summer warming.