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Flood Hazard Management Planning

This page provides information about flood hazard management for local governments in Washington State, including relevant statutes and agencies, local examples, and useful resources.


Comprehensive flood hazard management is the most effective way to address flood control issues. It incorporates a variety of engineering, environmental protection and planning measures. It includes floodplain management, flood control maintenance activities, stormwater management, shoreline management, protection of frequently flooded areas under Growth Management, watershed management, other flood hazard mitigation activities, and preparation for flood disasters where mitigation activities cannot prevent flooding. This page is part of a series in Emergency Management and Disaster Planning and is intended to provide basic references to federal and state information sources and examples of local programs. Detailed information should be obtained from the regulatory agencies.

The concept of flood hazard management includes flood control management and floodplain management. Traditional flood control measures have generally referred to various engineering type projects aimed at controlling flood waters, such as building of levies and traditional floodplain management which was aimed at controlling building in the floodplain. Current efforts are directed toward comprehensive flood hazard mitigation planning.

In the federal regulations 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. CFR 44 Part 59.1 See also FEMA's What is Floodplain Management? Participation in the National Flood Insurance program requires the adoption of floodplain management regulations that comply with federal requirements.

The 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 FEMA funds. Hazard mitigation is the ongoing effort to lessen the impact disasters have on people's lives and property through damage prevention and flood insurance. See FEMA's What is Mitigation? page and MRSC's Hazard Mitigation Planning in Washington State.

Principal Agencies

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

  • Department of Ecology (DOE) - The primary state agency responsible for administration and enforcement of all laws related to flood control and floodplain management regulation. Floodplain Management includes technical assistance, flooding in Washington State, planning and grants, mapping assistance, and RiskMAP.
  • 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.
  • 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

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 - GMA Critical Areas Designation - 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 - Flood Control by Counties (River Improvement Fund) - 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 - Joint Flood Control - 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 - Floodplain Management - A Floodplain Management Ordinance approved by the Department of Ecology is required of a community to qualify for the National Flood Insurance Program
  • Ch. 86.24 RCW - Flood Control by State in Cooperation with Federal Agencies, Etc.
  • Ch. 86.26 RCW - State Participation in Flood Control Maintenance
  • RCW 86.26.050 - Projects in which state will participate -- Allocation of funds - Requires Department of Ecology approved 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 - Administration of the Flood Control Assistance Account Program
  • WAC 173-145-040 - Comprehensive Flood Control Management Plan (CFCMP) - Lists contents of the Comprehensive Flood Control Management Plan
  • Ch. 173-158 WAC - Flood Plain Management - Adopted pursuant to chapter 86.16 RCW

Flood Control Districts

  • Flood Control District Act of 1935, Ch. 86.05 RCW (Repealed) - Following catastrophic floods in 1933 in which emergency relief was received from the federal government, the state passed the Flood Control District Act of 1935 authorizing 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 - Provides 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, Ch. 86.15 RCW - Passed in 1961, the law 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 county.

Floodplain Management and the National Flood Insurance Program

The Washington State Department of Ecology is the state agency in Washington responsible for coordinating the floodplain management regulation elements aspects of the national flood insurance program. 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 the Federal Emergency Management Agency (FEMA). See RCW 86.16.041. See RCW 86.16.031 for a list of the Department of Ecology's duties with regard to local government floodplain management.


Local Government Planning, Regulations, and Public Information

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

Flood Hazard Management and Endangered Species Act

Recommended Resources

Last Modified: May 23, 2018