The Cedar Watershed (HUC 12030107) covers approximately 71 square miles in western Washington. It is characterized by a humid, temperate climate with moderate rainfall throughout the year. The hydrology of the watershed is dominated by the Cedar River, which is fed by snowmelt and precipitation from the surrounding mountains. The watershed contains several reservoirs, including the Cedar Lake and Chester Morse Lake, which provide drinking water for the Seattle metropolitan area. The snowpack in the watershed is an important source of water for the reservoirs, with peak snow accumulation usually occurring in February. Surface water quality in the watershed is monitored closely, and efforts are underway to reduce pollution from urban and agricultural runoff. Climate change is expected to have significant impacts on the Cedar Watershed, with increasing temperatures and changes in precipitation patterns potentially affecting the timing and volume of streamflow.