Wetlands

Overview

Wetlands are fragile ecosystems that serve important functions, including reducing erosion, siltation, flooding, ground and surface water pollution, as well as providing wildlife, plant, and fisheries habitats. Wetlands include swamps, marshes, bogs, and similar areas. Wetlands are identified as critical areas in the Washington State Growth Management Act (GMA) (RCW 36.70A.030(5) and RCW 36.70A.060). This page provides information of use to local governments in their wetlands regulation and permitting functions.

In Washington, the Department of Ecology is charged with protecting, restoring, and regulating wetland resources. Two state laws, the Water Pollution Control Act and the Shoreline Management Act, give Ecology the authority to regulate wetlands. Ecology also uses the State Environmental Policy Act (SEPA) process to identify potential wetland-related concerns early in the permitting process.

Wetlands are rated according to a system that organizes wetlands into four categories based on wetland functions, sensitivity to disturbance, rarity, and replacement potential. Wetland delineation involves determining the edge of a wetland based on three parameters: water, plants, and soil.

Strategies for saving wetlands and other critical areas include limiting uses and avoiding development in some areas, transferring development density to other sites or non-sensitive portions of larger sites, and publicly purchasing valuable or unique wetlands. Buffer areas around wetlands and along streams are also used to protect the functions of these critical areas. Mitigating impacts on wetlands and other critical areas involves reducing the adverse impacts of projects to acceptable levels. In addition to critical areas regulations, nonregulatory and incentive programs are also used to protect wetlands.

Many local governments hire wetland experts to prepare and update wetlands ordinances. Local governments also require developers to perform special studies of wetlands located on proposed development sites. Some jurisdictions have prepared lists of preferred wetlands consultants.

Statutes and Administrative Regulations

Statutes

• Growth Management Act
  • RCW 36.70A.030(48) – Definitions
  • RCW 36.70A.060 – Natural resource lands and critical areas - Development regulations
  • RCW 36.70A.172 – Critical areas - Designation and protection - Best available science to be used
  • RCW 36.70A.175 – Wetlands to be delineated in accordance with manual
• Chapter 90.58 RCW – Shoreline Management Act
  • RCW 90.58.380 – Adoption of wetland manual
• Chapter 90.84 RCW – Wetlands Mitigation Banking

Administrative Regulations

• Chapter 173-22 WAC – Adoption of Designations of Shorelands and Wetlands Associated with Shorelines of the State
• WAC 173-26-221(2)(c)(I) – General master program provisions, Wetlands
• WAC 173-158-080 – Wetlands management; provides information about floods
• WAC 173-183-700 – Vulnerability of freshwater wetland environments to oil spills
• WAC 173-183-710 – Wetlands vulnerability classification
• Chapter 173-201A WAC – Water Quality Standards for Surface Waters of the State of Washington
• Chapter 197-700 WAC – Wetland Mitigation Banks
• WAC 365-190-080 – Critical areas
• WAC 365-196-485 – Critical areas
• Chapter 365-195 WAC – Growth Management Act - Best Available Science

Federal Resources

This section includes information on wetlands regulations and protection from federal agencies that is relevant to local governments.

U.S. Environmental Protection Agency (EPA)

• Wetlands Protection and Restoration – General information about wetlands and federal regulations
• Background About Compensatory Mitigation Requirements – Includes information on Final Compensatory Mitigation Rule regarding compensatory mitigation for authorized impacts to wetlands, streams, and other waters under Section 404 of the Clean Water Act
• Wetland Program Development Grants and EPA Wetlands Grant Coordinators – Financial assistance for wetland protection and enhancement for state, tribal and local governments
• Estuaries and the National Estuary Program – Network of voluntary community-based programs to protect fragile coastal estuaries

U.S. Fish & Wildlife Service

• National Wetlands Inventory – Provides detailed information on the abundance, characteristics, and distribution of US wetlands

Washington State Resources

Washington departments, especially the Department of Ecology, offer information on wetlands protection and resources. Under the Growth Management Act, local governments are required to use the best available science when reviewing and revising their policies and regulations on wetlands.

Washington Department of Ecology

• Wetlands – Overview of federal, state, and local regulations, mitigation resources, and additional tools
• Local Wetland Regulations: Growth Management Act Technical Assistance – Guidance for local governments
• Interagency Wetland Mitigation Guidance – Two-part interagency document providing guidance on wetland mitigation. Pt. 1 and 2 are linked below:
  • Part 1: Agency Policies and Guidance (2021) – See Chapter 2, "Primer on the Wetland Regulatory Process," and Chapter 5, "Methods of Compensatory Mitigation"
  • Part 2: Developing Mitigation Plans (2006)
• Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington) (2009)
• Selecting Wetland Mitigation Sites Using a Watershed Approach (Eastern Washington) (2010)
• Best Available Science for Wetlands – Under the GMA, local governments are required to use the best available science in their policies and regulations on wetlands. This page provides documents on the science currently available about wetlands, their functions, and management.
• Wetland Rating Systems – Department of Ecology describes how to rate wetlands in Eastern and Western Washington. 
• Wetland Mitigation Banking – Document explains how mitigation banking benefits wetlands. 

Governor's Office for Regulatory Innovation and Assistance (ORIA)

• Wetland Permits – Environmental Permit Handbook (Scroll to bottom to view)

Local Ordinances and Informational Handouts

This section includes selected local ordinances from Washington jurisdictions and development assistance handouts on wetlands.

Codes and Ordinances

• Clark County Code Ch. 40.450 – Wetland Protection
• Mukilteo Municipal Code Ch. 17.52B – Wetland Regulations - Recommended as an example for other cities
• Redmond Zoning Code Sec. 21.64.030 – Wetlands
• Spokane Municipal Code Ch. 17E.70 – Wetlands Protection
• Sumner Ordinance No. 2212 (2007)
• Woodinville Municipal Code Sec. 21.51.340 – Wetlands - Mitigation

Development Assistance Handouts on Wetlands

• Kent Development Assistance Brochures:
  • Wetland Delineation Reports (2015)
  • Conceptual Mitigation Plans for Wetlands, Streams, and Associated Buffers
  • Final Conceptual Mitigation Plans for Wetlands, Streams, and Associated Buffers
• King County Wetlands:
  • Wetland Delineation and Rating Criteria (2020)
  • Critical Areas Ordinance Users Manual (2004)
• Kitsap County: Brochure # 27 - Wetlands

Recommended Resources

The following are general websites and webpages that provide guidance on wetlands protection.

• Center for Watershed Protection – Provides guidance to communities on how to integrate wetlands into larger watershed protection efforts. Includes articles, slide shows, bibliographies, links, and events.
• MRSC: Critical Areas
• MRSC: Flexibility in Environmental Regulation