Mercer Island Parks commission narrows park-zone rules on signs, scoreboards, impervious surface and building size

Mercer Island Parks and Recreation Commission members reviewed and largely endorsed a package of draft park‑zone development regulations on March 6, 2025, after staff presented follow‑up recommendations and examples for signs, scoreboards, impervious surface exemptions and new building‑size standards.

The discussion, held during the commission’s regular meeting at the Mercer Island Community and Events Center and on Zoom, focused on balancing long‑term park stewardship with practical needs for restrooms, maintenance storage and recreation support structures. Carson Hornsby, management analyst for the city, told commissioners the staff recommendation was “a limit of 16 square feet” for general park signs and that the one outlier at Mercerdale would be treated as nonconforming and reduced if replaced.

Commissioners heard staff proposals for scoreboards, including a 250‑square‑foot size limit designed to encompass the Island Crest Park scoreboard and lettering, and for permitting electronic and externally lit scoreboards. Commissioner Markson asked about caps on the number of scoreboards per park; Hornsby said the current draft does not set a per‑park scoreboard count.

Why this matters: the draft park zone is intended to protect open space character while allowing routine park operations and upgrades. Commissioners repeatedly raised the challenge of writing rules that keep parks from becoming over‑built yet still allow functional facilities such as restrooms, storage and small support buildings.

Key decisions and consensus points

- Signs: commissioners gave staff a thumbs‑up for a 16‑square‑foot maximum for standard park signs; the larger Mercerdale…