The State of Washington's Shoreline Management Act (SMA), codified as RCW 90.58, was passed by the state legislature in 1971 and adopted by the voters in a 1972 referendum. The goal of the SMA is to prevent the inherent harm in an uncoordinated and piecemeal development of the state's shorelines. The Act establishes a broad policy of giving preference to uses that:

• Protect the quality of water and the natural environment;
• Depend on proximity to the shoreline (water-dependent uses); and,
• Preserve and enhance public access or increase recreational opportunities for the public along shorelines.

Under the SMA, each city or county adopts a Shoreline Master Program (SMP) that, while based on State guidelines, is tailored to the specific geographic, economic, and environmental needs of the local area. More than 200 cities and all counties in the state are required to develop and adopt SMPs. In 1977, Cowlitz County adopted the Shoreline Master Program and associated Shoreline Designation Map, authority given under Cowlitz County Code 19.20.

The County's Master Program overall goals are to:

• Assure healthy, orderly, economic growth in the shorelines of the county.

• Maintain a high quality environment along the shorelines of Cowlitz County.

• Establish criteria for safe, orderly residential growth within the shorelines of Cowlitz county.

• Preserve and protect those fragile and natural resources, and culturally significant features along the shorelines of Cowlitz County.

• Provide safe and reasonable access for the public in the shorelines of Cowlitz County.

• Preserve the rights of private ownership and property uses of the shorelines of Cowlitz County.

The Cowlitz County Department of Building and Planning is the lead agency for local shoreline permits along the bodies of water within the jurisdiction of the State of Washington's Shoreline Management Act (SMA). Requests for development permits are reviewed under the criteria established by the Shoreline Management Act through the County's SMP and WAC 173-27.

Cowlitz County has a number of rivers, streams, and lakes that are considered Shorelines of Statewide Significance or Shorelines of the State. These bodies of water, and the jurisdictional boundaries, are identified in the WAC 173-18-120, WAC 173-20-180 and WAC 173-20-190.