Mercer Island council reviews schematic plans for combined public safety and maintenance facility; staff estimate $105–110 million

City Manager Jessie Baum and the project team presented schematic designs on Feb. 4 for a new Public Safety and Maintenance (PSM) facility that would combine the police department, public works operations, the emergency operations center (EOC), IT/GIS and a customer-service storefront on the City Hall/Public Works campus.

At a planning-session presentation, Baum said the design effort follows the council’s October 2023 decision to permanently close the old City Hall after an asbestos discovery and seismic concerns. Architects from Northwest Studios showed site plans that place public access and parking on the north side of the campus, the main two-story PSM building in the midblock, and large covered and high-bay operations and storage yards to the south.

Why it matters: the city has been operating without a storefront and with staff dispersed after City Hall closed. The proposed PSM would centralize many essential services and be built to high seismic and resiliency standards (described in materials as a “risk category 4” / level 4 facility), so it can continue operating during major emergencies.

Design and program highlights

Northwest Studios presented an organization of the site into a public-facing north edge, a central PSM building and a two-part lower and upper yard. The PSM building is shown as roughly 36,000 gross square feet across two floors. The western/second-floor zones are primarily office and collaboration space for public works and shared staff areas; the eastern and ground-floor areas include the EOC, customer counter and police functions with separate secure circulation for in-custody processing, evidence storage and secure vehicle parking.

Public-safety specifics shown in the plans include a sally port and short-term holding/processing cells, dedicated secure storage for evidence and marine patrol gear, separated locker-room strategies (shared locker footprint with individual privacy/shower rooms) and sleeping rooms for staff during extended emergency response. Public works program elements shown include a high-bay operations building (mezzanine for storage and building systems), covered oversized-vehicle storage, a wash/decant facility, and separate zones for raw materials, organics and recycling.

Site constraints and circulation

Consultants walked council through site conditions: the campus totals about 13.5 acres (roughly a 4-acre front parcel and a 9.4-acre back parcel), mapped trees and small wetlands in the wooded south end of the property, and identified steep slopes and existing impervious areas that will constrain placement of buildings and yards. The team emphasized that much of the existing yard used by public works is uncovered and congested, and proposed moving to one-way circulation loops in the yards to reduce vehicle conflict points and speed ingress/egress for crews.

Shared spaces and resilience features

Designers emphasized shared support spaces — laundry, laundry/mud rooms, locker rooms, large kitchens, conference rooms and storage — where appropriate, while keeping secure police areas separated. The project team also showed options to provision the site and building for future electrification (conduit for EV charging), rooftop solar potential, and rainwater harvesting for nonpotable uses. A preliminary solar assessment suggested the combined roofs and covered yards could produce substantial energy; the team flagged that solar sizing, battery backup and cost/benefit must be studied in more detail.

Cost and schedule (preliminary)

Project staff provided an early, high-level cost estimate for the full project (buildings and yard work) of about $105 million to $110 million. That estimate is preliminary and includes construction, soft costs, escalation and taxes; staff said they will update it as schematic design advances. Baum told council staff expect monthly design briefings through late spring/early summer, community outreach in March–April, and zoning code work (rezoning the back parcel from residential to public institutional) in the March–May timeframe.

Council questions and follow-ups

Council members pressed on future expandability, vehicle and boat storage, whether locker rooms would accommodate changing staff mixes over time, vehicle heights and clearance (vacuum trucks and trailers), wash-bay drainage and capture, and how solar, rainwater capture and rooftop potable storage would affect structural design and life-cycle costs. Staff and Northwest Studios repeatedly said the presentation was schematic and that detailed engineering, geotechnical work, wetlands delineation and cost/benefit analyses (including life-cycle costs for solar, batteries and rooftop tanks) are next steps.

Next steps and community engagement

Staff said the schematic design will be refined in March–July with monthly council check-ins, a community road show in March–April and a forthcoming funding plan for council review in spring. The project team recommended continuing field verification of wetlands, detailed geotechnical surveys, further coordination on EV infrastructure conduit, and follow-up cost analyses for major trade decisions (structural system, covered parking vs. canopy, and rooftop vs. underground potable storage).

Ending note

Council members expressed broad interest in moving the design forward while asking staff to return with more detailed cost/benefit analyses, including tradeoffs for roof coverage, potential parking canopies with solar, structural materials (mass timber/steel/concrete), and options to reduce long-term operations costs. Staff emphasized that the design is not final and will change as the team resolves technical issues and council preferences.