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Flood Hazard Management Planning

This page provides basic information about flood hazard management for local governments in Washington State, including relevant statutes and agencies, local examples, and useful resources. Detailed information should be obtained from the regulatory agencies.

It is part of MRSC's series on Emergency Management and Disaster Planning.


In the federal regulations (CFR 44 § 59.1), floodplain management means the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plans, flood control works, and floodplain management regulations. Participation in the National Flood Insurance program requires the adoption of floodplain management regulations that comply with federal requirements.

Washington State regulates flood control management projects on the state's streams and requires a comprehensive flood control management plan to qualify for flood assistance account funds.

Natural hazard mitigation plans that include floods are required for certain Federal Emergency Management Agency (FEMA) funds. Hazard mitigation planning is the ongoing effort to lessen the impact disasters have on people's lives and property through damage prevention and flood insurance.

Federal and State Agencies

In Washington, the state coordinating agency for floodplain management is the Department of Ecology, which works with the Federal Emergency Management Agency and local governments to address flood hazard challenges statewide. 


Federal Emergency Management Agency (FEMA) — Administers a comprehensive, risk-based, emergency management program of mitigation, preparedness, response and recovery

  • FEMA Region 10 - Administers the federal emergency preparedness, damage prevention, and response and recovery programs to Alaska, Idaho, Oregon and Washington State


Department of Ecology (DOE) — The primary state agency responsible for administration and enforcement of all laws related to flood control and floodplain management regulation. DOE provides grants and technical assistance to local communities to reduce losses to life and property and protect the environmental functions of flood hazard areas or floodplains, and assists FEMA and the Washington State Military Department's Emergency Management Division by evaluating community floodplain management programs, reviewing local floodplain ordinances, and participating in statewide flood hazard mitigation planning.

Emergency Management Division (EMD) — Works in partnership with federal, state, and local agencies, volunteers, and private organizations to reduce the potential effects of natural hazards. EMD coordinates emergency management programs with local governments, public agencies, private organizations, businesses, communities, and individuals to prepare for, respond to, and recover from emergencies. The EMD manages emergency management funds, workers, organizations, services and plans, and procedures for disaster recovery.

Statutes and Regulations

This is a list of the principal statutes and regulations relating to flood control and floodplain management.

General Provisions

  • RCW 36.70A.170 and .172 — Jurisdictions planning under the Growth Management Act are required to designate and protect frequently flooded areas as part of the requirements for critical areas
  • Ch. 86.12 RCW — Provides for the collection of a flood control fee and provides additional authority for county flood control and the development of comprehensive flood control management plans; a county may act to control flooding under the authority of this statute without forming a special purpose district
  • Ch. 86.13 RCW — Provides authority and procedures for joint flood control by two counties where a river forms a boundary between the counties or where the river waters alternate between counties with potential for flood damage in both counties
  • Ch.86.16 RCW — A Floodplain Management Ordinance, approved by the DOE, is required for a community to qualify for the National Flood Insurance Program
  • Ch. 86.24 RCW — Addresses flood control by the state in cooperation with federal agencies
  • Ch. 86.26 RCW — Addresses state participation in flood control maintenance
  • RCW 86.26.050 — Requires DOE approve the floodplain management activities of the county, city, or town having planning jurisdiction for funding of any flood control maintenance projects through the state's Flood Control Assistance Account
  • Ch. 173-145 WAC — Addresses the administration of the Flood Control Assistance Account Program
  • WAC 173-145-040 — Lists contents of the Comprehensive Flood Control Management Plan (CFCMP)
  • Ch. 173-158 WAC — Addresses flood plain management; adopted pursuant to chapter 86.16 RCW

Flood Control District Statutes

Following catastrophic floods in Washington in 1933 the federal government provided emergency relief to the state. Later, the state passed the Flood Control District Act of 1935 (Ch. 86.05 RCW), which authorized the formation of flood control districts to build permanent flood control works. This act was repealed in 1965, but existing districts were allowed to continue. There are now no known districts operating under the 1935 Act.

The Flood Control District Act of 1937, Ch. 86.09 RCW, provided for the creation of flood control districts for the protection of life and property, the preservation of the public health, and the conservation and development of the natural resources.

Flood Control Zone Districts legislation, Ch. 86.15 RCW, which was passed in 1961, enabled "flood control zone districts," for the purpose of undertaking, operating, or maintaining flood control projects or storm water control projects or groups of projects that are of special benefit to specified areas of the state.

Floodplain Management and the National Flood Insurance Program

The DOE is the state agency in Washington responsible for coordinating the floodplain management regulation elements aspects of the National Flood Insurance Program (NFIP), which is managed by FEMA. Statewide floodplain management regulation is exercised through:

  • local governments' administration of the national flood insurance program regulation requirements;
  • the establishment of minimum state requirements for floodplain management that equal the minimum federal requirements for the national flood insurance program; and
  • the issuance of regulatory orders governing the planning, construction, operation and maintenance of any works, structures and improvements, private or public, which might, if improperly planned, constructed, operated and maintained, adversely influence the regimen of a stream or body of water or might adversely affect the security of life, health and property against damage by flood water.

To qualify for flood insurance under the NFIP, local communities must adopt floodplain management regulations at least as stringent as the federal minimum standards established by FEMA (see RCW 86.16.041). RCW 86.16.031 offers a list of the DOE’s duties regarding local government floodplain management.

Floodplain Management Resources


Local Government Planning, Regulations, and Public Information

The following citations are illustrations of planning information, local regulations, flood control districts, and examples of public information about floodplain management and flooding.

Flood Control Districts/Authorities

Cities and Towns


Recommended Resources

  • Association of State Floodplain Managers — National professional association of floodplain management professionals
  • Floods: Be Prepared, Be Safe — Offered by the Washington State Department of Health Public Health, this webpage has downloadable resources for state residents related to flood management and post-flood clean up and health-based priorities like safe drinking water
  • USGS Streamgaging Network — Coordinated by the U.S. Geological Survey, this program provides streamflow information and the understanding required to meet local, tribal, State, regional, and national needs
  • US Army Corps of Engineers — Builds and maintain America’s infrastructure and provides military facilities where US servicemembers train, work, and live

Last Modified: January 03, 2023