Growth Management Act. The Growth Management Act (GMA) is the comprehensive land use planning framework for counties and cities in Washington. The GMA establishes land-use designation and environmental protection requirements for all Washington counties and cities. The GMA also establishes a significantly wider array of planning duties for 28 counties, and the cities within those counties, that are obligated to satisfy all planning requirements of the GMA. These jurisdictions are sometimes said to be fully planning under the GMA.
The GMA also directs fully planning jurisdictions to adopt internally consistent comprehensive land use plans. Comprehensive plans are implemented through locally adopted development regulations, and both the plans and the local regulations are subject to review and revision requirements prescribed in the GMA. Comprehensive plans must be reviewed and, if necessary, revised every ten years to ensure that it complies with the GMA. When developing their comprehensive plans, counties and cities must consider various goals set forth in statute.
Each comprehensive plan must include a plan, scheme, or design for certain enumerated elements, including mandatory land use and housing elements. The housing element must ensure the vitality and character of established residential neighborhoods and among other requirements consider the role of accessory dwelling units in meeting housing needs.
Increased Residential Building Capacity. Cities planning fully under the GMA are encouraged to take two or more of the following actions to increase residential building capacity:
Cities fully planning under the GMA must adopt or amend their development regulations, zoning regulations, or other official controls prior to allow for the splitting of residential lots under certain conditions. These regulations must take effect six months after the jurisdiction's next periodic comprehensive plan update. When regulating lot splitting, cities may not:
Any construction on the resulting lots is subject to all existing state and local laws regarding stormwater runoff, critical areas, shorelines, and conservation areas.
The requirements of this act apply and take effect in any city that has not adopted or amended their development regulations, regulations, or other official controls and supersede, preempt, and invalidate any conflicting local development regulations within six months after the jurisdiction's next periodic comprehensive plan update.