Skip to Content

Sonoma Developmental Center Specific Plan

Sonoma Developmental Center Specific Plan, Our Valley Our Future

The Sonoma Developmental Center (SDC) provided services to persons with developmental disabilities for over 120 years in the heart of Sonoma Valley. At 945 acres, the property includes a large historic campus, agricultural lands to the east, and vast ecological and open space resources. The SDC was the County’s largest employer at its peak. In 2018 the State of California officially closed the facility and relocated clients to smaller, community-based care facilities. The State of California which owns the site forged a unique partnership with Sonoma County that allows the County, together with the community, to chart the future role of the SDC. The culmination of that process occurred on December 16, 2022, when the Board of Supervisors passed the Sonoma Developmental Center Specific Plan and certified an environmental impact report that charts the future of the site.

Board of Supervisors Resolutions

Resolutions of the Sonoma County Board of Supervisors certifying the Environmental Impact Report for the SDC Specific Plan Project.

Environmental Impact Reports

Specific Plan

Past Meetings

Meeting Date
Board of Supervisors Hearing  December 16, 2022
Planning Commission Public Hearing
on SDC Plan and Final EIR
November 3, 2022
Planning Agency In-Person Special Meeting September 29, 2022
Planning Commission Meeting September 15, 2022
Sonoma County Landmarks Commission September 6, 2022
Joint Meeting with Sonoma Valley Citizens Advisory Commission, North Sonoma Valley Municipal Advisory Council, and Springs Municipal Advisory Council August 24, 2022
Sonoma Developmental Center Specific Plan Policy Input #1 March 22, 2022
Sonoma Developmental Center Specific Plan Policy Input #2 March 26, 2022
CEQA Scoping Meeting February 17, 2022
Board of Supervisors Meeting January 25, 2022
Joint SMAC/NSVMAC/SVCAC Meeting November 17, 2021
Reunión del Ayuntamiento de SDC en español November 16, 2021
Alternatives Community Meeting November 13, 2021
Reunión comunitaria en español September 8, 2021
Board of Supervisors Meeting: Project Update January 26, 2021
Community Workshop November 14, 2020

Specific Plan Vision

The former SDC site has emerged as a culturally and ecologically vibrant and resilient community. A core 180-acre developed area is surrounded by a vast protected open space of oak woodlands, native grasslands, wetlands, forests, creeks, and lakes that provide habitats and wildlife movement corridors; agricultural land; and recreational open space integrated with the surrounding park systems.

The developed core area comprises a complementary mix of housing, commercial, and institutional uses. The SDC site is financially independent and supporting infrastructure is up to date and well maintained. A variety of housing—including affordable, workforce, mid-income, and market-rate housing; senior housing; housing for people with developmental disabilities; and in new and adaptively re-used buildings—will foster a diverse and inclusive community. New development complements the adjacent communities of Glen Ellen and Eldridge. Residents enjoy pedestrian access to essential services and parks, and seamless connections to surrounding open spaces. Employment opportunities reflect the site’s legacy of care and emphasize innovation, research, education, environment, and ecology, together with supporting commercial and visitor-serving uses. Sonoma Valley’s former largest employment hub is reinvigorated as a regional model for sustainable development.

The reinvigorated community builds upon the site’s rich historic legacy while embracing the future. Key historic resources—including the Sonoma House and the Main Building—have been repurposed for contemporary uses, and elements of the historic landscape preserved. Site design patterns—streets layout, building/street relationship, streetscape character—maintain east-west views to the Sonoma and Mayacamas mountains and foster a harmonious sense of place. Contemporary buildings are intermixed with repurposed historic structures, creating a rich and visually cohesive development fabric.

A comprehensive network of pedestrian and bicycle paths connects residents to local and regional destinations, and to transit. Well-designed bus stops, crosswalks, and protected bike lanes create an inviting sense of safety for those of all ages and abilities and provide better walking and biking access to Glen Ellen and Eldridge, and to the regional bicycle network.

New land uses contribute positively to the site’s financial feasibility, enabling efficient and sustainable construction of necessary infrastructure. Water is conserved and reused, and safety and fire protection built into the landscape, with defensible design, new fire-resistant buildings, and well-planned evacuation routes. Reuse of historic buildings has saved resources needed for new construction, and building designs reflect sustainable practices and wildfire resiliency. The surrounding open spaces, preserved in perpetuity, are home to countless local species that use SDC’s habitat corridors. Sightings of wildlife throughout the site and along Sonoma Creek enrich life for residents.