The Growth Management Act (GMA) requires that certain counties, and the cities within those counties, engage in planning for future population growth.  Counties that have a population of 50,000 or more and, prior to May 16, 1995, had its population grow by 10 percent or more in the prior 10 years, or, after May 16, 1995, by 17 percent or more in the prior 10 years, are covered by the GMA.  So too is any county that experiences population growth of 20 percent over a 10-year period.  Counties with populations under 50,000, that would otherwise be required to plan, can remove themselves from the GMA's comprehensive planning requirements.  Conversely, counties that do not meet the standards for automatic inclusion in the GMA may choose to plan.  

Currently, 18 counties are required to plan, 10 have chosen to plan, and 11 are not subject to the full GMA planning requirements.

Whether a county is automatically required to plan under the GMA or voluntarily chooses to, the planning requirements are largely the same.  The county must develop a countywide planning policy to provide a framework in which the county, and the cities within the county, can develop consistent comprehensive plans.  The county and cities must adopt development regulations to conserve agricultural lands, forestlands, and mineral resource lands.  The county and cities must also adopt urban growth area regulations.  Finally, the county and cities must adopt a comprehensive land use plan and adopt development regulations consistent with the plan.

The comprehensive plan is the central part of the whole planning process.  The Legislature has established 14 goals to act as the basis of all comprehensive plans.  Examples of goals include reducing sprawl, providing for affordable housing, and protecting property rights.  The comprehensive plan must address these goals and set out the policies and standards that are meant to guide the city or county's actions and decisions in the future.  Comprehensive plans must contain certain elements, such as a land use element, a housing element, and a capital facilities plan element.  These elements must satisfy the requirements for each individual element while fitting within the overall comprehensive plan.

Every eight years, a county or city that is planning under the GMA must review and revise its comprehensive plan and development regulations to ensure that the plan and regulations comply with the requirements of the GMA.  This review and revision requires legislative action from the county or city.  The county and cities must establish a public participation program that provides notice to various interested or impacted individuals and organizations who can become involved in the process.  The county and cities may generally only consider updates to the comprehensive plan once per year.  

The eight-year review and revision deadlines are staggered for different counties.  Currently, King, Kitsap, Pierce, and Snohomish counties, and the cities within those counties, have a deadline of June 30, 2024.  Clallam, Clark, Island, Jefferson, Lewis, Mason, San Juan, Skagit, Thurston, and Whatcom, and the cities within those counties, have a deadline of June 30, 2025.  Benton, Chelan, Cowlitz, Douglas, Franklin, Kittitas, Skamania, Spokane, Walla Walla, and Yakima, and the cities within those counties, have a deadline of June 30, 2026.  Finally, Adams, Asotin, Columbia, Ferry, Garfield, Grant, Grays Harbor, Klickitat, Lincoln, Okanogan, Pacific, Pend Oreille, Stevens, Wahkiakum, and Whitman, and the cities within those counties, have a deadline of June 30, 2027.  Each of these counties, and the cities within those counties, must again update their comprehensive plans every eight years after the current deadline.

Comprehensive plans must be reviewed and revised every 10 years.  The next deadline for the review and, if necessary, revision of the comprehensive plans of King, Kitsap, Pierce, and Snohomish counties, and the cities within those counties, is December 31, 2024.

Counties planning under the GMA that have:  (a) a population of 200,000 and a population density of at least 100 people per square mile on or after April 1, 2021; and/or (b) have grown by an annual rate of 1.75 percent or more and have a population density of at least 75 people per square mile on or after April 1, 2021; as well as cities with more than 6,000 people on April 1, 2021, within counties that satisfy either or both of these criteria, must provide the Department of Commerce with an implementation progress report five years after the adoption of a comprehensive plan.  Once a county has satisfied either of the criteria, the implementation progress report requirement will remain for that county and its covered cities, even if the county later does not satisfy either or both of the criteria.  The Department of Commerce must develop guidelines for the criteria and measures for counties and cities to use in the report covering:

• the implementation of previously adopted changes to the housing element of the comprehensive plan and the effect of those changes on housing affordability and availability within the jurisdiction;
• permit processing timelines; and
• progress toward implementing actions required to achieve reductions to meet greenhouse gas and vehicle miles traveled requirements as provided for in any element of the comprehensive plan.

If a county or city that is required to provide an implementation progress report has yet to implement any changes that were included in the most recent update to its comprehensive plan, or has not yet taken the legislative or administrative actions necessary to implement the changes by the due date for the implementation progress report, then the county or city must identify the need for such changes or action in the report.  The county or city must adopt a work plan to implement the changes, and must complete all work necessary for implementation within two years of the submission of the implementation progress report.