Regional Growth Planning

The Puget Sound region is beginning the process to update the regional, county, and city plans for growth. The current focus of this process is being conducted by the Puget Sound Regional Council (PSRC), which will inform growth plans developed by King County, and eventually Mercer Island.

PSRC is updating the regional plan for managing growth, known as VISION 2050. Forecasts show the region needs to plan for 1.8 million additional people and 1.2 million new jobs by 2050. VISION 2050 will inform countywide growth targets and city comprehensive plans. PSRC has identified three growth alternatives, and has analyzed the environmental effects of each alternative in a draft Supplemental Environmental Impact Statement (SEIS). More information on the update process and the three alternatives is provided below.

The City of Mercer Island sent a comment letter to PSRC on April 29, 2019. The comment letter was drafted based on the guidance contained in the City's adopted Comprehensive Plan.

City staff will update this page as the regional growth planning process progresses.


The Puget Sound region is beginning the process to update the regional, county, and city plans for growth. The current focus of this process is being conducted by the Puget Sound Regional Council (PSRC), which will inform growth plans developed by King County, and eventually Mercer Island.

PSRC is updating the regional plan for managing growth, known as VISION 2050. Forecasts show the region needs to plan for 1.8 million additional people and 1.2 million new jobs by 2050. VISION 2050 will inform countywide growth targets and city comprehensive plans. PSRC has identified three growth alternatives, and has analyzed the environmental effects of each alternative in a draft Supplemental Environmental Impact Statement (SEIS). More information on the update process and the three alternatives is provided below.

The City of Mercer Island sent a comment letter to PSRC on April 29, 2019. The comment letter was drafted based on the guidance contained in the City's adopted Comprehensive Plan.

City staff will update this page as the regional growth planning process progresses.


  • Regional Growth Planning Timeline

    2 months ago
    Vision 2050 timeline 04012019

    This timeline is meant to illustrate how state, regional, county and city planning processes come together to plan for regional growth. Currently, the City of Mercer Island is focused on commenting on the Draft SEIS for VISION 2050. Later this summer, the Puget Sound Regional Council will release the draft VISION 2050 plan for review and comment. In addition, city staff are providing data to King County to assist in the Urban Growth Capacity Analysis. This effort will assess the zoning capacity for additional development in communities across King County. This information will inform the development of growth targets for each community beginning in 2020.


    This timeline is meant to illustrate how state, regional, county and city planning processes come together to plan for regional growth. Currently, the City of Mercer Island is focused on commenting on the Draft SEIS for VISION 2050. Later this summer, the Puget Sound Regional Council will release the draft VISION 2050 plan for review and comment. In addition, city staff are providing data to King County to assist in the Urban Growth Capacity Analysis. This effort will assess the zoning capacity for additional development in communities across King County. This information will inform the development of growth targets for each community beginning in 2020.


  • Updating the Regional Growth Strategy

    3 months ago
    Regional growth



    VISION 2040 is the region’s current plan for managing growth forecasted through the year 2040. The plan includes overarching goals, an environmental framework, a strategy to sustainably guide growth in the region, and multicounty planning policies as required by the state Growth Management Act (GMA). The plan also includes implementation actions at the regional, county, and local levels. VISION 2040 was adopted in 2008, and the Puget Sound Regional Council (PSRC) is now in the process of updating the plan.


    The updated plan will be known as VISION 2050. The update will consider the best approach to managing growth with...



    VISION 2040 is the region’s current plan for managing growth forecasted through the year 2040. The plan includes overarching goals, an environmental framework, a strategy to sustainably guide growth in the region, and multicounty planning policies as required by the state Growth Management Act (GMA). The plan also includes implementation actions at the regional, county, and local levels. VISION 2040 was adopted in 2008, and the Puget Sound Regional Council (PSRC) is now in the process of updating the plan.


    The updated plan will be known as VISION 2050. The update will consider the best approach to managing growth with a projected 1.8 million additional people and 1.2 million new jobs by 2050. The update process will continue through the coming year, with adoption planned for May, 2020.


    The process of developing VISION 2050 includes considering three distinct regional growth alternatives:
    • Stay the Course
    • Transit Focused Growth
    • Reset Urban Growth

    Each of these three alternatives distributes growth in unique patterns that have different trade-offs. PSRC recently released the Draft Supplemental Environmental Impact Statement (SEIS) for review. This is the environmental review of the draft VISION 2050 plan, and it analyzes the environmental effects of the three alternatives. The Draft SEIS shows a range of land use, transportation, environmental, and other impacts that would likely occur with each of these alternatives and identifies opportunities to mitigate them.

    The City of Mercer Island is seeking feedback from the community on the SEIS to inform the City's formal comments on the draft. Please use the comment form to submit your comments. Comments can also be submitted directly to PSRC: https://www.psrc.org/vision-2050-draft-seis-comment-form. Comments are due April 29, 2019.
  • SEIS Alternatives Analysis

    3 months ago
    Seis alternatives

    At the heart of VISION 2040 is a shared vision of how and where the region should grow. The Regional Growth Strategy provides a description of a planned physical development pattern that the central Puget Sound region will evolve into over time. The draft SEIS analyzes three distinct alternative patterns of future growth that were developed after a public comment and scoping process, extensive review by PSRC’s Growth Management Policy Board, and input from regional staff and other stakeholders. These three alternatives allow the environmental analysis to consider the effects of extending the current growth strategy to 2050 and the...

    At the heart of VISION 2040 is a shared vision of how and where the region should grow. The Regional Growth Strategy provides a description of a planned physical development pattern that the central Puget Sound region will evolve into over time. The draft SEIS analyzes three distinct alternative patterns of future growth that were developed after a public comment and scoping process, extensive review by PSRC’s Growth Management Policy Board, and input from regional staff and other stakeholders. These three alternatives allow the environmental analysis to consider the effects of extending the current growth strategy to 2050 and the potential effects of changes to that strategy.


    Stay the Course (No Action) Alternative

    The Stay the Course alternative is a direct extension of the VISION 2040 Regional Growth Strategy and assumes a compact growth pattern, focused in the largest and most transit-connected cities in the region within the region’s 29 designated regional growth centers. This alternative serves as the required no action alternative that must be evaluated in accordance with SEPA.

    This alternative continues to direct the largest share of future growth to the region’s five major Metropolitan Cities: Seattle, Bellevue, Everett, Bremerton, and Tacoma. Growth is also focused in the region’s Core Cities—those other cities with regional growth centers that are concentrations of growth and serve as economic and transportation hubs for the region.

    Compared to historical trends, this alternative allocates less growth in urban unincorporated and rural areas and more growth in cities. Growth in urban unincorporated growth areas is envisioned as occurring in areas affiliated with cities for annexation, and growth in rural areas is minimized when compared to past trends.

    This alternative maintains the current Regional Growth Strategy allocation of shares of growth. For this analysis, Stay the Course and subsequent data measures use the revised regional geographies. PSRC developed model inputs for Stay the Course using the existing VISION 2040 regional geographies and then calculated inputs and results based on the revised system of regional geographies.

    Transit Focused Growth Alternative

    The Transit Focused Growth alternative considers a compact growth pattern based on the VISION 2040 Regional Growth Strategy that assumes accelerated growth near the region’s existing and planned transit investments.

    The Transit Focused Growth alternative assumes an explicit goal for 75 percent of the region’s population and employment growth to occur within a quarter- to a half-mile from current and planned high-capacity transit station areas, including light rail, bus rapid transit, commuter rail, ferries, and streetcar. This would result in the largest shares of growth to Metropolitan Cities, Core Cities, and HCT Communities.

    The alternative also assumes a greater role in accommodating future growth for areas served by high-capacity transit outside of Metropolitan and Core Cities. Growth in unincorporated urban growth areas with existing or planned high-capacity transit and planned for annexation or incorporation would be similar to cities with high-capacity transit. The remaining share of population and employment growth would be distributed largely within the urban growth area among areas not served by high-capacity transit based on the broad objectives for the Regional Growth Strategy. Growth in rural areas and unincorporated areas without access to high-capacity transit and unaffiliated unincorporated areas is the lowest in this alternative

    Reset Urban Growth Alternative

    The Reset Urban Growth alternative shares similarities with actual growth patterns that occurred from 2000 to 2016 and assumes a more dispersed growth pattern throughout the urban area.

    The Reset Urban Growth alternative assumes a more distributed pattern throughout the urban area. This alternative would continue to allocate the largest shares of growth to Metropolitan Cities and Core Cities, although the overall growth to these geographies and HCT Communities would be less compared to Stay the Course or Transit Focused Growth.

    Growth allocations for Cities & Towns and Urban Unincorporated areas are based on land use capacities identified in currently adopted comprehensive plans. Growth in urban unincorporated areas without access to high-capacity transit and unaffiliated urban unincorporated areas is the highest in this alternative. Growth in rural areas would be slightly higher than Stay the Course.

    Comparison of the Alternatives

    All alternatives assume the same amount of regional growth in population and employment from 2017 to 2050—1.8 million additional people and 1.2 million additional jobs. As described above, the difference between alternatives is how the growth is allocated among the regional geographies—Metropolitan Cities, Core Cities, HCT Communities, Cities & Towns, Urban Unincorporated, and Rural areas—and among the region’s four counties. This distribution of additional growth throughout the region results in environmental impacts. Some impacts are similar across all alternatives, and some impacts show differences between alternatives. For example, below is a comparison of the impacts of each alternative on transportation. Additional comparison charts are available in the Executive Summary.

    More information on the alternatives is available in Chapter 3 of the Draft SEIS.