Planning commission recommends park‑zone code updates, adopts lighting and temporary‑structure exemptions

The Mercer Island Planning Commission voted June 10 to recommend the City Council adopt a package of amendments establishing a Park Zone development chapter and related code changes, and approved several specific drafting changes including new lighting standards and an exemption for temporary structures from impervious-surface limits.

The commission also asked the City Council to write to the Washington State Department of Transportation (WSDOT) seeking clarification about whether Aubrey Davis Park — where WSDOT holds certain interests — can be included in the new Park Zone without regulatory conflict.

Why it matters: The Park Zone chapter creates a clearer regulatory framework for parks and recreation facilities on Mercer Island, including rules on permitted uses, trail design and lighting that will guide park projects, permit decisions and capital planning.

Key votes and actions

- Motion recommending Council adoption: Commissioners moved to recommend the City Council adopt the proposed new section MICC 19.05.060 (Park Zone) and related amendments to definitions and zone-establishment code sections. The final roll call on the overall recommendation was recorded as: Commissioner Perez — Aye; Chair Thompson — Aye; Commissioner Cuse — Aye; Vice Chair Gibson — Aye.

- Purpose statement and permitted uses: The commission approved revised purpose language that emphasizes recreation, conservation and social gathering spaces. Commissioners also agreed to reposition “multipurpose facilities” in the permitted-uses list so those facilities are explicitly treated as park uses.

- Setbacks and parking: The commission removed an amendment that would have required new parking areas adjacent to certain residential zones to have a 20-foot setback; staff noted that several existing park parking areas (Groveland Beach, Slater, and others) already sit within that distance and would become nonconforming.

- Trail-width debate: Commissioners debated a Parks & Recreation Commission recommendation that trail widths “not exceed 12 feet” and additional staff text proposing minimums and shoulders for paved shared-use trails. Several commissioners argued the 12-foot cap preserves character and acknowledges budget constraints for shoulders; others raised safety and commuter-bike concerns for Aubrey Davis segments that are wider. Motions to add an Aubrey Davis exception or adopt a widened shared-use standard failed. The commission left the trail language to the version reflecting the Parks & Recreation Commission recommendation (12-foot guidance), noting staff should clarify application across existing trails.

- Impervious-surface exemption for temporary structures: The commission voted 3–1 to exempt temporary uses/structures from the park-zone impervious-surface calculation, which staff said would allow temporary stages, coverings or short-term event surfaces to avoid triggering permanent-coverage limits. That motion passed with Vice Chair Gibson, Commissioner Acuse and Commissioner Perez voting Aye; Chair Thompson recorded a Nay.

- Lighting and design: Commissioners adopted staff-crafted lighting language that combines earlier amendments emphasizing “dark-sky” and salmon‑friendly practices, with fixture-level caps and exemptions for certain city-managed lighting. The adopted language also incorporates Crime Prevention Through Environmental Design (CPTED) principles for park lighting review.

- WSDOT/Aubrey Davis and arts coordination requests: The commission voted to ask the City Council to contact WSDOT about including Aubrey Davis Park in the Park Zone (motion passed 3–1), and separately endorsed a Parks & Recreation Commission recommendation to coordinate park siting and scale of public art installations with the Arts Council (also passed 3–1).

Statements and context

- “There are existing parking lots that are within 20 feet of a residential zone,” staff said, noting that imposing a new 20-foot setback would create nonconforming conditions for existing facilities including Groveland and Slater parks.

- Commissioners emphasized balancing park character and pedestrian/bicycle safety. Commissioner Gibson said he supported returning to the Parks & Recreation Commission’s 12-foot trail guidance, citing maintenance and budget considerations; other commissioners asked staff to provide clear application rules for existing, legally established trail segments.

Next steps

The Planning Commission’s recommendation — as amended — will be transmitted to the City Council for public hearing and final decision. Staff will prepare final ordinance text and a staff report for the Council packet; commissioners asked staff to coordinate with WSDOT where state-owned or -leased parcels may be affected and to clarify trail-width application in the draft code.