Sonoma Developmental Center Specific Plan

In January 2023, a lawsuit was filed against the County and California Department of General Services as real party in interest, alleging noncompliance with the California Environmental Quality Act (CEQA). In April 2024, the court ruled that the County had not complied with CEQA and subsequently issued its final judgment and a writ of mandamus on October 22, 2024. 

On December 3, 2024 the Board of Supervisors voided certification of the SDC Specific Plan Environmental Impact Report (EIR) and set aside all related SDC Specific Plan approvals as directed by the Writ of Mandamus. The Board further directed Permit Sonoma to revise the EIR in accordance with the Writ and Judgment and bring the EIR back to the Board to consider recertification along with approval of the SDC Specific Plan and related legislative amendments in conjunction with the Housing Development Application. 

Analysis of the development application and revision of the Environmental Impact Report (EIR), per the writ of mandamus, will happen concurrently. As the lead agency, Permit Sonoma will manage the environmental review process and prepare the required environmental document for recertification. 
This process will identify and analyze any discrepancies that arise between the Specific Plan and the proposed development application, providing mitigations as necessary.

Permit Sonoma will publish a Notice Of Preparation (NOP), which will notify responsible agencies and interested parties of its intent to prepare a Draft Subsequent Environmental Impact Report (DSEIR) for the project.  The NOP describes the project that will be analyzed in the EIR and identifies areas of probable environmental effects.

The County will hold a scoping meeting to provide an additional opportunity for agency staff and interested members of the public to submit comments, either written or verbal, on the scope of the environmental issues to be addressed in the EIR. Dates for the NOP and Scoping Meeting will be posted on this website as they become available.

Specific plans create a vision for the future of a defined geographic region and address land use designations, development intensity, and necessary infrastructure and public facilities.

The SDC Specific Plan process included:

• Extensive community outreach, including through site tours, community workshops, pop-up outreach events, small group “community conversations,” and an online survey;
• Analysis of existing conditions on the SDC site, including a historic preservation-focused building assessment, a market study, an analysis of opportunities for enhancing biotic connectivity and open space preservation, a mobility analysis, and a water supply assessment;
• Development of project alternatives; and
• Development of the Specific Plan and Environmental Impact Report (EIR).

The SDC Specific Plan was completed over a 4 year period. The first phase, Issues and Opportunities Identification, included project kick-off meetings, initial community outreach, and background studies. Phase 2, Alternatives Exploration, included the development of three concepts for the SDC site's future and extensive community outreach to identify a Preferred Alternative. Phase 3, Draft Plan Preparation, included development of the draft plan and environmental review, and will occur after the selection of the Preferred Alternative. Phase 4, Plan Finalization, included refining the draft plans and holding public hearings, leading to adoption of the Specific Plan. On December 16, 2022 the Board of Supervisors passed the Sonoma Developmental Center Specific Plan and certified an environmental impact report that charts the future of the site.

The former Sonoma Developmental Center (SDC) is reinvigorated as a vibrant and sustainable community in the heart of Sonoma Valley. A mixed-use, pedestrian-oriented core provides a diverse array of housing choices, and serves as a magnet of innovation, research, education, and visitation. The surrounding open spaces flourish as natural habitats and as agricultural and recreational land linked to regional parks and open space systems. Development builds on the site’s rich historic legacy while meeting contemporary needs, emphasizing resiliency and sustainable building practices. Civic uses, community gathering places, and events attract visitors from Glen Ellen, Eldridge, and the broader Sonoma region, making the center a hub of community life in Sonoma Valley.

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.

Webinars

We hosted four live, interactive webinars about SDC! Expert panelists gave their perspectives on market conditions, site ecology, community engagement, and historic preservation, and then answered some of your questions! View recordings of the webinars below.

Virtual Walking Tour of SDC

This virtual guided tour is an interactive way to learn more about the history and landmarks of the Sonoma Developmental Center.

Please note that Sonoma County parks are currently under limited parks access, pending public health concerns due to COVID-19.

We are tracking developments with the virus and will notify people through the SDC Specific Plan mailing list website if there are scheduling changes. Please see Sonoma County’s website for the most up-to-date information.

Take me on a tour!

PAT Meetings

Coming soon.

Specific Plan

• Adopted SDC Specific Plan (January 2023) (PDF: 56.59 MB)
• Proposed Revisions to the Public Review Draft SDC Specific Plan (PDF: 86.9 MB)
• SDC Public Review Draft Specific Plan (PDF: 59.9 MB)
• SDC Specific Plan: General Plan Consistency Overview (PDF: 757 kB)

Board of Supervisors Resolutions

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

• Resolution No. 22-0555 (PDF: 2.11 MB)
• Resolution No. 22-0556 PDF: 73.65 MB)
• Ordinance No. 6400 (PDF: 2.42 MB)

Environmental Impact Reports (EIRs)

• Supplement 1 to the Final Environmental Impact Report (FEIR) (PDF: 1.76 MB)
• Supplement 2 to the FEIR (PDF: 6.7 MB)
• Supplement 3 to the FEIR (PDF: 1.63 MB)
• Supplement 4 to the FEIR (PDF: 1.59 MB)
• Final Environmental Impact Report (PDF: 101 MB)

Other Documents

Note: Documents are located at 3rd party sites. It may take several minutes to download some documents as they are large files.

• Focused Traffic Operations Analysis for the Draft SDC Specific Plan (Memo) (July 2022) (PDF)
• CEQA Notice of Preparation (February 2022) (PDF)
• January 25 Sonoma County Board of Supervisors Meeting Materials (Project Description Presentation, Staff Powerpoint, Summary) (January 2022) (PDF)
• Alternatives Survey Report (December 2021) (PDF)
• Alternatives Workshop Report (Community Workshop #2) (December 2021) (PDF)
• Alternatives Report (November 2021) (PDF)
• Community Engagement Strategy (September 2021) (PDF)
• Key Informant Interviews Report (February 2021, Revised April 2021) (PDF)
• Community Workshop Report #1 (November 2020) (PDF)
• Draft Vision and Guiding Principles (January 2021) (PDF)
  This draft document was developed and refined with community input from Community Meeting #1 on November 14th.
• Profile and Background Report (September 2020) (PDF)
• Community Conversations Report #1 (September 2020, updated October 2020) (PDF)
• Community Survey Report #1 (September 2020) (PDF)

Background Documents

• Sonoma Developmental Center Existing Conditions Assessment (WRT, 2018)
• In 2015, the Sonoma Land Trust and other community members partnered to create Transform SDC, a group committed to identifying future uses of the site and preserving its important ecological functions. Transform SDC held a community visioning workshop in May, 2015. Meeting Report
• Adaptive Reuse Potential Evaluation (PDF)