Publication Summary

Clark County, the fastest growing county in the state, faces water quality challenges in the Salmon Creek watershed. The creek and its tributaries are located northeast of Vancouver and entirely within Clark County. Salmon Creek flows from the foothills of the Cascade Mountains through a mixture of small towns, small and large farms, pasture, and homes. Near the end of its journey, it meanders through a highly urbanized, developed area of Clark County and then west to Lake River, which flows into the Columbia River.

Clark County, the fastest growing county in the state, faces water quality challenges in the Salmon Creek watershed. The creek and its tributaries are located northeast of Vancouver and entirely within Clark County. Salmon Creek flows from the foothills of the Cascade Mountains through a mixture of small towns, small and large farms, pasture, and homes. Near the end of its journey, it meanders through a highly urbanized, developed area of Clark County and then west to Lake River, which flows into the Columbia River.

Under the Clean Water Act, every state has its own water quality standards designed to protect, restore, and preserve water quality. Water quality standards consist of designated uses, such as cold water biota and drinking water supply, and criteria, usually numeric criteria, to achieve those uses. When a lake, river or stream fails to meet water quality standards the Clean Water Act requires that the state place the water body on a list of "impaired" water bodies. When a water body is listed, the state is required to prepare an analysis called a Total Maximum Daily Load (TMDL). The U.S. Environmental Protection Agency (EPA) has established regulations (40 CFR 130) and developed guidance (EPA, 1991) for establishing TMDLs.