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 their population grow by 10 percent or more in the proceeding 10 years, or, after May 16, 1995, by 17 percent or more in a 10-year period are covered by the GMA. So too is any county that experiences population growth of 20 percent or more over 10 years. Counties with populations under 50,000, that would otherwise be required to plan because of population growth, 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 be included. 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 central part of the planning process is the comprehensive plan. 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's or county's actions and decisions in the future. Comprehensive plans must contain certain elements, which must satisfy the requirements for each individual element while also fitting within the overall comprehensive plan.
One such element is a capital facilities plan element. This element consists of an inventory of existing capital facilities owned by public entities, a forecast for the future needs for capital facilities and the proposed locations and capacities of new facilities, a plan going out at least six years for financing the capital facilities, and a plan to reassess the land use element if funding falls short of meeting existing needs and to ensure that the land use element, capital facilities plan element, and financing plan are coordinated and consistent.
Another element is a transportation element. This element must implement, and be consistent with, the land use element of the comprehensive plan. It also must include a variety of subelements, including estimated traffic impacts, facilities and service needs, financing, demand-management strategies, and pedestrian and bicycle components. Counties and cities must also adopt ordinances to prohibit development if the development would cause the level of service on locally-owned transportation facilities to decline below transportation element standards, unless improvements are made concurrent with the development.
Comprehensive plans are required to be reviewed and, if necessary, revised every 10 years. The review deadlines are staggered for different groups of counties. The next review deadline is December 31, 2024, for King, Kitsap, Pierce, and Snohomish counties and the cities within those counties.
All counties and cities are required to designate natural resources lands and adopt development regulations that protect critical areas, and to update these regulations by the comprehensive plan update deadline.
Critical areas are wetlands, areas with a critical recharging effect on aquifers used for potable water, fish and wildlife habitat conservation areas, frequently flooded areas, and geologically hazardous areas.
When designating and adopting development regulations to protect the functions and values of critical areas, counties and cities must use the best available science. The Department of Commerce (Department) has adopted guidelines for determining the best available science, including that the information used should be derived using a scientifically valid process.
Cities and towns within counties planning under the GMA may opt out of the full comprehensive plan review and revision requirements if the city or town:
The Department must review the population growth rates of cities and towns that have opted out of the full comprehensive plan requirements at least three years before the deadline for the city's or town's next comprehensive plan update, and must notify cities of their eligibility.
A city or town that opts out of the full comprehensive plan requirements must still review and revise its critical area regulations, capital facilities plan element, and transportation element.