Critical Areas Ordinance and Shoreline Master Program Update

Logo for the Critical Areas Ordinance and Shoreline Master Program Update



In 2018-2019, the City of Mercer Island will be updating its Critical Areas code and Shoreline Master Program. The Critical Areas code is the portion of the City's code that sets standards and requirements for areas like wetlands, landslide hazard areas, watercourses. The Shoreline Master Program contains regulations pertaining to parts of Mercer Island within 200 feet of Lake Washington.



In 2018-2019, the City of Mercer Island will be updating its Critical Areas code and Shoreline Master Program. The Critical Areas code is the portion of the City's code that sets standards and requirements for areas like wetlands, landslide hazard areas, watercourses. The Shoreline Master Program contains regulations pertaining to parts of Mercer Island within 200 feet of Lake Washington.

  • SMP Status Update – March 2020

    8 days ago
    As noted in the previous (February 2020) update, the Department of Ecology has indicated that revised SMP language regarding the repair of docks is required. Revised, draft Shoreline Master Program (SMP) language and the supporting Cumulative Impact Analysis, which incorporate past Department of Ecology (DOE) feedback, has been completed. The revised SMP language is tentatively scheduled for City Council review in late April or early May of 2020. These documents represent several months of review between DOE and the City of Mercer Island to ensure: 1) that the changes adopted by the City Council are consistent with state law; 2)...

    As noted in the previous (February 2020) update, the Department of Ecology has indicated that revised SMP language regarding the repair of docks is required. Revised, draft Shoreline Master Program (SMP) language and the supporting Cumulative Impact Analysis, which incorporate past Department of Ecology (DOE) feedback, has been completed. The revised SMP language is tentatively scheduled for City Council review in late April or early May of 2020. These documents represent several months of review between DOE and the City of Mercer Island to ensure: 1) that the changes adopted by the City Council are consistent with state law; 2) the original intent of the amendments related to dock repair is retained; and 3) that this consistency is clearly documented. For the revised SMP language to become effective, both the City Council and DOE will need to approve it.

    Both the draft, revised SMP language (“City Council-approved draft SMP w-draft revisions) and Cumulative Impact Analysis are available in the Resource Library.

  • SMP Status Update - February 2020

    about 1 month ago
    The City Council approved SMP amendments in mid-June of 2019, which were transmitted to the Department of Ecology (DOE) in July of 2019. The amendments to the SMP included both an update to critical area protections, and amended language around dock repairs in the SMP (in response to public comment). Following adoption of the SMP amendments, the Department of Ecology is required to either approve, approve with conditions, or deny the amended SMP.

    Initially DOE was cautious about adopting the proposed changes to the dock repair standards, because the amendments may result in an increased environmental impact and/or would establish...

    The City Council approved SMP amendments in mid-June of 2019, which were transmitted to the Department of Ecology (DOE) in July of 2019. The amendments to the SMP included both an update to critical area protections, and amended language around dock repairs in the SMP (in response to public comment). Following adoption of the SMP amendments, the Department of Ecology is required to either approve, approve with conditions, or deny the amended SMP.

    Initially DOE was cautious about adopting the proposed changes to the dock repair standards, because the amendments may result in an increased environmental impact and/or would establish a precedent on Lake Washington. The City has been working with DOE and the City’s consultant to confirm that no adverse environmental impact will result from the proposed amendment and we are now updating our Cumulative Impact Analysis (CIA) documentation accordingly. This process has been iterative with three or four interactions between DOE and the City of Mercer Island around the scientific content of the CIA documents and the specific language of the SMP.

    There has been some delay – both because the DOE has been reviewing SMP amendments for multiple jurisdictions, and because the City has amended its scope with the City’s consultant to complete the additional technical work to support the proposed SMP amendment. City staff have been working with DOE to expedite the review as much as possible. The City anticipates that DOE will approve SMP amendment with conditions in the near future – tentatively by mid-March. Staff anticipate that DOE will support the overall concept around dock repair articulated by the City Council, but will require additional clarifying language; the City Council is tentatively scheduled to review this revised language in April with adoption anticipated in late April or early May.

  • Critical Areas Ordinance and Shoreline Master Program Updates Adopted

    9 months ago

    The City Council approved the Critical Areas Ordinance and Shoreline Master Program at its June 18, 2019 meeting. For the full text of the new code, please review the following documents:

    The Critical Areas Ordinance is scheduled to take effect July 29, 2019. The Shoreline Master Program follows a different process: It must be reviewed and approved by the Washington Dept. of Ecology before it can take effect. This is expected to be a 1-2 month process, but for the time being, the effective date is uncertain. Let’s Talk will be updated when an effective date is known. Until then, the existing SMP, adopted in 2015, contains the effective standards.

    The City Council approved the Critical Areas Ordinance and Shoreline Master Program at its June 18, 2019 meeting. For the full text of the new code, please review the following documents:

    The Critical Areas Ordinance is scheduled to take effect July 29, 2019. The Shoreline Master Program follows a different process: It must be reviewed and approved by the Washington Dept. of Ecology before it can take effect. This is expected to be a 1-2 month process, but for the time being, the effective date is uncertain. Let’s Talk will be updated when an effective date is known. Until then, the existing SMP, adopted in 2015, contains the effective standards.

  • Planning Commission Recommendation Now Available

    11 months ago
    The Planning Commission’s Recommendation to the City Council for the Critical Areas Code and Shoreline Master Program is now available. The Planning Commission’s recommendation was developed after review and consideration of comments made by the public on the Public Hearing Draft.

    The Planning Commission’s Recommendation to the City Council for the Critical Areas Code and Shoreline Master Program is now available. The Planning Commission’s recommendation was developed after review and consideration of comments made by the public on the Public Hearing Draft.

  • Public Hearing Draft of code available

    about 1 year ago

    Thanks to countless hours spent by the Planning Commission and community, a public hearing draft of the Critical Areas Ordinance and Shoreline Master Program are now complete and ready for review. Please see the "Resource Library" on this page to access the draft code documents!

    Thanks to countless hours spent by the Planning Commission and community, a public hearing draft of the Critical Areas Ordinance and Shoreline Master Program are now complete and ready for review. Please see the "Resource Library" on this page to access the draft code documents!

  • What are Critical Areas? Watch the Video!

    over 1 year ago

    The City has created a brief 6-minute video to inform the community about the Critical Areas and Shoreline Master Program update. Watch the video to learn more about critical areas and shorelines and why the city is updating the regulations.

    Watch it here!

    The City has created a brief 6-minute video to inform the community about the Critical Areas and Shoreline Master Program update. Watch the video to learn more about critical areas and shorelines and why the city is updating the regulations.

    Watch it here!

  • Best Available Science

    over 1 year ago
    Critical areas

    The Growth Management Act (RCW 36.70A) requires Washington’s counties and cities to review, evaluate, and update comprehensive land use plans, as well as updating development regulations using Best Available Science (BAS) to identify, designate and protect critical areas.

    Mercer Island last updated its Critical Area regulations in 2005, and an update is due by summer, 2019. The City hired a consultant, ESA, to conduct an analysis of the Best Available Science as it pertains to the critical areas located in Mercer Island. ESA's findings are available in two reports here and here.

    Mercer Island is home to 5 types of critical areas:

    1. Wetlands
    2. Watercourses
    3. Fish and wildlife habitat conservation areas
    4. Geologically hazardous areas
    5. Critical aquifer recharge areas
    ESA analyzed scientific research pertaining to the protection of these 5 types of critical areas and performed a gap analysis of the BAS findings and Mercer Island's current critical area regulations. At a high level, the BAS shows that the City should expand buffers around critical areas (buffers are a setback area around the critical area where development activities are restricted). The Planning Commission has been briefed on these findings and is considering the BAS as they develop draft code language.


    The Growth Management Act (RCW 36.70A) requires Washington’s counties and cities to review, evaluate, and update comprehensive land use plans, as well as updating development regulations using Best Available Science (BAS) to identify, designate and protect critical areas.

    Mercer Island last updated its Critical Area regulations in 2005, and an update is due by summer, 2019. The City hired a consultant, ESA, to conduct an analysis of the Best Available Science as it pertains to the critical areas located in Mercer Island. ESA's findings are available in two reports here and here.

    Mercer Island is home to 5 types of critical areas:

    1. Wetlands
    2. Watercourses
    3. Fish and wildlife habitat conservation areas
    4. Geologically hazardous areas
    5. Critical aquifer recharge areas
    ESA analyzed scientific research pertaining to the protection of these 5 types of critical areas and performed a gap analysis of the BAS findings and Mercer Island's current critical area regulations. At a high level, the BAS shows that the City should expand buffers around critical areas (buffers are a setback area around the critical area where development activities are restricted). The Planning Commission has been briefed on these findings and is considering the BAS as they develop draft code language.


  • Why are we updating critical areas and shorelines regulations?

    over 1 year ago

    The City is required by state law to periodically update its Critical Areas Ordinance (CAO) and Shoreline Master Program (SMP). In addition to being a legal requirement, the periodic update provides an opportunity for the community to ensure its critical areas and shoreline codes are up to date with the latest science and in line with the City's current land use policies.

    The process began with the City Council setting a scope of work, providing a framework for what will be covered over the course of this project. The City's Planning Commission has started on that scope of work, first reviewing the state laws pertaining to CAO and SMP updates, and next by reviewing the latest science on managing development in and around critical areas. Through review of scientific information, the City's comprehensive plan and public input, the Planning Commission will draft new code language for review and approval by the City Council.

    The City is required by state law to periodically update its Critical Areas Ordinance (CAO) and Shoreline Master Program (SMP). In addition to being a legal requirement, the periodic update provides an opportunity for the community to ensure its critical areas and shoreline codes are up to date with the latest science and in line with the City's current land use policies.

    The process began with the City Council setting a scope of work, providing a framework for what will be covered over the course of this project. The City's Planning Commission has started on that scope of work, first reviewing the state laws pertaining to CAO and SMP updates, and next by reviewing the latest science on managing development in and around critical areas. Through review of scientific information, the City's comprehensive plan and public input, the Planning Commission will draft new code language for review and approval by the City Council.