City Council Adopts GMA Compliance Ordinances

On July 21, 2026, the Mercer Island City Council held its final meeting regarding GMA compliance efforts in advance of the set July 31, 2026, deadline. At this meeting, three ordinances were adopted as follows:

Ordinance No. 26-09 – Amended the Comprehensive Plan to address land capacity, adequate provisions, and establish a new Station Subarea Plan.
Ordinance No. 26C-10 – Amended Title 19 Mercer Island City Code (MICC) to implement the updated comprehensive plan, including implementation of Phase 1 of the Station Subarea Plan.
Ordinance No. 26C-11 – Amended Title 15 MICC to implement the updated Utilities Element.

Combined with Ordinance No. 26C-07 which was adopted in June 2026 and amended Title 5 MICC to establish anti-displacement measures, these ordinances serve as Mercer Island’s work related to GMA compliance. More background information about the Growth Management Hearings Board (GMHB) Order can be read about on Understanding the Growth Management Hearings Board Order and Appeal Outcome.

ADDRESSING THE GROWTH MANAGEMENT HEARINGS BOARD ORDER

The GMHB Order requires the City to address four issues:

Land Capacity Analysis: Identify residential land capacity at each housing affordability level and close any identified gaps.
Adequate Provisions: Adopt incentives, mandatory provisions, and planned actions (“aka adequate provisions”) that will increase the supply of affordable housing.
Station Area Subarea Plan: Adopt a subarea plan for the area around the transit station.
Anti-Displacement Measures: Adopt anti-displacement measures to address the potential displacement that can occur with changes in zoning.

To address these four issues, the City has updated the comprehensive plan, development regulations, business regulations, and fee schedule.

Issue #1: Land Capacity

Issue 1 from the GMHB Order requires the City to analyze development and demonstrate that there is adequate capacity available for housing at each affordability level. More information about the Mercer Island Housing Goals can be read about on Planning for Housing Across Income Levels: Affordable and STEP Housing.

Table 1. Mercer Island Housing Needs by Housing Affordability Level.Source: King County Ordinance 19660 approved 8/22/2023.

Notes:

PSH = Permanent Supportive Housing
Emergency Housing is its own metric and not part of the housing need or housing growth target.

The City has prepared the 2026 Land Capacity Analysis Update to evaluate current housing capacity at each affordability level. The 2026 Land Capacity Analysis Update included analysis of the development capacity added by the zoning changes made during Phase 1 of the Station Subarea Plan. Below, Map 1 illustrates the proposed zoning changes under Phase 1 of the Station Subarea Plan. The Town Center boundary has been expanded to include the adjacent MF-2 and MF-2L zones and the subareas within the Town Center have been reconfigured. Town Center subarea TC-8A and TC8-B allow buildings heights up to 8 stories while subarea TCMF-6 allows building heights up to 6 stories.

Map 1. Phase I Town Center Zoning Update.

The updated Land Capacity Analysis indicated the Phase 1 Station Subarea Plan upzone proposed for Town Center provides enough development capacity to address its housing needs for households earning 50% AMI or above. The analysis identified the market would be unable to produce housing serving households earning under 30% AMI regardless of capacity. A gap of 510 units serving households earning 0-30% AMI must be addressed through other City actions in addition to the proposed zoning changes. Adequate provisions are required to be included in the Comprehensive Plan to address Issue 2.

Issue #2: Adequate Provisions

Issue 2 from the GMHB Order required the City to adopt mandatory provisions, incentives and planned actions, known as “adequate provisions.” The adequate provisions focus on addressing the remaining affordable housing needs below 50% AMI. The adequate provisions address the barriers to housing production identified in the Barriers Analysis. The Comprehensive Plan and development code have been updated to make adequate provisions, including but not limited to:

Inclusionary zoning in the Station Subarea Plan Phase 1 – New development in the Town Center zone must include at least 10% of units affordable at 50% of the area median income (AMI) for rental units and 80% AMI for ownership units.
Fee in lieu – A fee in lieu of constructing the units required by the inclusionary requirement that can help fund the affordable housing units needed below 50% of the AMI.
Opportunity sites – surplus public property within the station area is identified as opportunity sites in the Station Subarea Plan

Issue #3: Station Subarea Plan

The City of Mercer Island is required to adopt a Station Subarea Plan to address Issue 3 of the GMHB Order. The updated Comprehensive Plan includes a Station Subarea Plan that adopts goals and policies for the area around the light rail station. Many of the policies included in the adopted Station Subarea Plan were relocated from other elements of the Comprehensive Plan.

The Station Subarea Plan is divided into two Phases. Phase 1 has been adopted concurrently with the Comprehensive Plan update and includes zoning changes to increase capacity in the Town Center and adjacent multifamily zones. No zoning changes have been adopted in the larger Phase 2 area. Map 2 shows the Station Subarea and the Phase 1 and 2 areas.

Map 2. Station Subarea and Phase Areas.

Source: Station Subarea Plan Figure 2.Phase 2 of the subarea plan will provide more time to engage the community in the larger Phase 2 area. Phase 2, anticipated to be completed by 2029, will focus on planning for the broader Station Area. This effort will include additional planning and development regulation updates to comply with the statewide TOD planning requirements.

Issue #4: Anti-Displacement Measures

To address Issue #4 from the GMHB Order, the City adopted the following anti-displacement measures:

Advance notice of rent increase – tenants must be notified at least 120 days prior to rent increases greater than 3%.
Relocation Assistance – Low-income tenants must be provided with relocation assistance prior to redevelopment of an apartment building.

The anti-displacement measures were adopted by Ordinance No. 26C-07. This ordinance established a new chapter in Title 5 of the Mercer Island City Code (MICC) – Business License and Regulations.

Next Steps

The City was required to take action and adopt necessary amendments contained within Ordinance Nos. 26C-07, 26-09, 26C-10, and 26C-11 to comply with the GMHB Order by July 31, 2026. Next, the GMHB will hold a compliance hearing on September 15, 2026, to consider the adopted amendments and determine whether they satisfy the GMHB Order. The GMHB is expected to issue a decision sometime in October, 2026.