Wetland regulation & permitting resources

We protect and manage wetlands through multiple state laws, which define our regulatory authority. Two state laws, the state Water Pollution Control Act and the Shoreline Management Act, give us the authority to regulate wetlands. We also use the State Environmental Policy Act (SEPA) process to identify potential wetland-related concerns early in the permitting process.

In addition, we provide technical assistance to local governments under the Growth Management Act. This includes assistance in developing comprehensive plan policies and development regulations, and in implementing local wetland regulations.

Will your project impact a wetland?

Our regional wetlands staff review applications for projects that have the potential to impact wetlands and other "waters of the state." Applicants who propose altering aquatic resources must go through mitigation sequencing to avoid and minimize impacts before determining whether compensatory mitigation is appropriate and a permit is required.

We regulate wetlands regardless of federal jurisdiction

Applicants and consultants should coordinate with our staff on projects that will have potential impacts to wetlands. When a proposed project will have potential impacts to wetlands, applicants should also work with the U.S Army Corps of Engineers to determine if the wetlands are regulated under federal law. Based on the Corps' determination, activities in wetlands in Washington may be authorized by Ecology through one of the following processes:

  • For federally regulated wetlands, applicants must submit a request for a Section 401 Water Quality Certification under the federal Clean Water Act.
  • For non-federally regulated wetlands, applicants must submit a request for an Administrative Order (to comply with Chapter 90.48 RCW).

Regardless of the authorization process, the necessary application information and standards of review are the same.


Section 401 water quality certifications

Section 401 of the federal Clean Water Act provides the state authority to approve, condition, or deny proposed projects in "waters of the U.S.," including wetlands, to ensure they meet state water quality standards. When an individual section 401 water quality certification is needed, any actions necessary to protect water quality are included as conditions in the 401 certification and incorporated into the federal permit.

State Administrative Orders (Non-Federally Regulated Wetlands)

We issue Administrative Orders under the state Water Pollution Control Act, Chapter 90.48 RCW, for impacts to wetlands that are not jurisdictional under the federal regulations (i.e., non-federally regulated wetlands or NFRs). These wetlands remain protected under state and local laws and rules. 

State laws that protect wetlands are broader than current federal regulations. The state can establish protocols for managing wetlands falling outside federal jurisdiction. For example, impacts to wetlands outside federal jurisdiction are authorized through administrative orders under the state Water Pollution Control Act.

In general, the state emphasizes a local approach to wetland protection and regulation. The state Growth Management Act (GMA) authorizes and requires cities and counties to regulate wetlands within their jurisdictions. This is typically accomplished by adopting a Critical Areas Ordinance (CAO). We play an advisory role by providing comments during CAO updates and offering technical assistance.