Mill Creek planning commission reviews South Town Center redevelopment plan with new park, stormwater 'sponge' and reconfigured streets

The Mill Creek Planning Commission on Tuesday reviewed a draft South Town Center redevelopment plan that envisions a walkable, mixed‑use extension of the city’s town center with a new Central Park, a nearby "Sponge Park" for regional stormwater management and a reconfigured street grid to improve pedestrian, bicycle and retail access.

The study session, led by the project presenter, explained that the master plan includes three main chapters — an introductory community profile, the redevelopment plan and forthcoming design guidelines — and builds on earlier work including the 2022 Mill Creek Boulevard study and the 2024 comprehensive‑plan rezone of the subarea.

The presenter summarized the plan’s central goal: to create “a vibrant, walkable, mixed use extension of Mill Creek Town Center,” with a compact, activated public realm and connections to the North Creek Trail. The plan lays out five neighborhood parts, including a Main Street commercial corridor and a Central Core intended to host the new Central Park and surrounding ground‑floor retail.

On open‑space design, staff described two major park features: a Central Park conceived as a civic gathering space for events, markets and concerts, and a Sponge Park intended primarily as a regional stormwater detention and treatment facility that would also serve as passive public space when not inundated. The presenter said the Sponge Park is expected to hold water during larger storms and that detailed vault and sizing work is still at the design stage. “For a typical annual storm, we expect it fills up about halfway,” the presenter said; “for a 10‑ to 25‑year event it would fill, and a 100‑year event would route excess into the stream.”

The transportation framework would break up existing superblocks, add a new Main Street corridor and include a two‑way cycle track on Mill Creek Boulevard, broader sidewalks and roughly 260 on‑street parking stalls. Commissioners asked about bike connectivity to existing lanes and whether the plan’s bicycle facilities would use green striping; staff said the design envisions green striping and that the two‑way track could be extended onto Village Green Drive with some median changes.

On fiscal impacts, staff presented a build‑out comparison between the current zoning and the proposed master‑plan scenario. The presenter said the master‑plan buildout produces a projected roughly $140,000 annual increase in sales tax revenue and projects property tax revenue rising to between about $782,000 and $844,000 compared with roughly $600,000 under the status‑quo scenario; staff emphasized these are build‑out projections and do not account for all fiscal streams or the city’s recently adopted utility tax.

Commissioners also pressed staff on transit and right‑of‑way coordination. Staff said Community Transit declined to add a new intermediate stop because it prefers current stop spacing, and any changes that affect the highway would require coordination with WSDOT. Staff noted some intersection work — including a proposed signal at 61st and the state highway — will require WSDOT collaboration and that roundabouts remain a possible WSDOT option at some highway connections.

Staff closed by describing next steps: a council study session on the plan, a July design‑review board session, a planning commission public hearing at the commission’s next meeting and a target council adoption in September after the Department of Commerce review period.

The commission did not take final action on the plan at the study session; staff asked commissioners to send any plan corrections by email and to expect additional review opportunities. The meeting adjourned after routine business.