Sonoma County Civic Center | Santa Rosa, CA

Situation:
Sonoma County needed to expand and reorganize its County Administration Center (CAC) in Santa Rosa to address overcrowded and dispersed staff, aging buildings, inefficient site circulation, and insufficient parking. The County was also considering consolidation of government functions at CAC and changes due to court facilities potentially transferring to the State.

Existing Conditions and Context

The CAC site encompassed roughly 82 acres, bounded by Highway 101 to the east, Mendocino Avenue to the west, and adjacent to residential and commercial uses. At the time, the site comprised multiple aging buildings mostly 1-2 stories tall, including the Main Adult Detention Facility (MADF) and Sheriff’s building, which were to remain. Key challenges included fragmented departmental offices scattered onsite, limited parking (approximately 2,700 spaces), inefficient vehicular and pedestrian circulation, and constraints from neighboring residential areas, utility capacities, and zoning codes. The site was well connected by vehicle and public transit but had poor internal pedestrian linkages. Sonoma County’s growing demographic trends and strategic service delivery changes were expected to influence future space needs.

County Planning Goals

• Improved site utilization by increasing usable floor area and relocating non-core functions offsite;

• Enhancing internal functionality, including flexible space to accommodate growth and promote interdepartmental collaboration;

• Improving external functionality such as access, wayfinding, public convenience, and sufficient parking;

• Integrating sustainability through energy and water conservation, greenhouse gas reduction, and encouraging transit and bike access;

• Ensuring security for continuity of government operations, employee/public safety, and minimizing impacts to neighbors;

• Establishing a strong identity that reflects Sonoma’s cultural and natural heritage with a welcoming civic environment; and

• Leveraging the site as a real estate asset to generate revenue through joint development.

Development Principles and Strategies

• Concentrating core county government functions near the highway, with non-core agencies moved offsite;

• Preserving critical justice facilities adjacency (Courts and Jail);

• Designing flexible building layouts for phased growth and adaptability over decades;

• Reserving the southeast portion of the site along Mendocino Avenue for joint public-private development (commercial, residential, retail);

• Developing mid-rise buildings exceeding local zoning height limits to maximize land use efficiency while mitigating impacts on adjacent neighborhoods, including strategies like land acquisition or negotiated buffering;

• Minimizing surface parking by employing parking structures distributed to serve specific facilities, supported by policies to reduce auto dependency;

• Creating clear, safe vehicular and pedestrian circulation with enhanced gateways and landmarks;

• Expanding open space adjacent to Paulin Creek as a natural amenity and buffer zone.

Phasing Considerations

The study emphasized that development phasing depended on complex factors such as space demand timing, court replacement schedules, funding availability, and market conditions for joint development. A likely first step was relocating and demolishing Fleet Operations to enable construction of initial consolidation buildings. Joint development could start immediately on underutilized parking areas. Special phasing considerations included relocating the Data Center offsite, potential Central Mechanical Plant replacement, and careful timing aligned with Courts replacement and daycare facilities. Construction-related parking displacement and traffic impacts required thorough planning.

Task:
The consultant team was tasked to conduct a site evaluation and opportunities analysis to identify development opportunities, constraints, and planning options for CAC's long-range facility plan, looking ahead 50 years. The goal was to determine the best and highest use of the site to meet functional, operational, sustainability, security, and identity goals.

Actions:

• Collected and analyzed relevant data on site conditions, context, infrastructure, zoning, demographics, and regional market.

• Identified key County facility planning goals including improved site utilization, internal/external functionality, sustainability, security, identity, and revenue generation.

• Evaluated existing conditions and summarized site opportunities (good access, public transit proximity, views) and constraints (lack of freeway ramps, limited developable area, need to retain jail and sheriff buildings).

• Developed and analyzed three conceptual development options:

Option A: Taller mid-rise towers with mixed-use "town square" and no land acquisition required for courts.

Option B: Low-rise campus with a "green mall" and some land acquisition needed adjacent to jail.

Option C: Emphasis on visibility from highway with a “winding parkway” and mid-rise tower, requiring land acquisition at main entry.

• Analyzed development phasing considerations, highlighting the timing and relocation needs for functions like Fleet Operations and Courts.

• Provided advantages and obstacles for each option.

• Recommended next steps including market analysis, city coordination, relocation planning, land acquisition exploration, public engagement, joint development solicitation, parking and transit policy programs, and coordination with State on courts plan.

Result:
The report offered a foundation for Sonoma County to plan for future development with flexible, sustainable, and functional site organization options that align with strategic goals. It identified viable pathways to improve facility efficiency and public service delivery while leveraging joint development opportunities and accommodating necessary infrastructure upgrades. It provided actionable steps to progress from conceptual options to implementation planning.