San Diego County Departments: A Complete Reference

San Diego County operates through a structured network of specialized departments that deliver public services to the unincorporated areas of the county and, in certain mandated functions, to all 18 incorporated cities within county boundaries. Understanding how these departments are organized, which authority governs each service area, and where jurisdictional lines fall is essential for residents, businesses, and researchers navigating county government. This page provides a structured reference covering the definition and scope of county departments, how they operate, the scenarios they address, and the decision boundaries that separate county functions from city and state functions.

Definition and scope

San Diego County government is administered under the authority of the San Diego County Board of Supervisors, a five-member elected body that sets policy and oversees an executive branch comprising more than 40 distinct departments, offices, and agencies (San Diego County Government, official department directory). The county's total operating area spans approximately 4,261 square miles, making it the largest county by area in California that borders another state.

County departments fall into two broad functional categories:

1. Mandated service departments — Operate under state or federal law and must function county-wide regardless of municipal boundaries. Examples include the Department of Health and Human Services (HHSA), the District Attorney's Office, and the Sheriff's Department.
2. Direct service departments — Provide services primarily to unincorporated areas, which account for roughly 452,000 of the county's 3.3 million residents (San Diego County HHSA, 2020 Census data summary).

Key departments include:

• Health and Human Services Agency (HHSA) — The county's largest department, administering public health, behavioral health, aging and independence services, and social services.
• Department of Planning and Development Services (PDS) — Manages land use, zoning, and permits in unincorporated areas.
• Department of Public Works — Maintains county roads, flood control infrastructure, and solid waste facilities.
• Assessor/Recorder/County Clerk — Administers property valuation, document recording, and vital records for the entire county.
• Treasurer-Tax Collector — Collects property taxes for all 18 incorporated cities, school districts, and special districts within the county.
• San Diego County Sheriff — Provides law enforcement to unincorporated communities and contracts with eight municipalities for police services.
• San Diego County District Attorney — Prosecutes criminal cases across all jurisdictions within the county.

How it works

County departments operate under authority delegated from the Board of Supervisors, with the Chief Administrative Officer (CAO) serving as the executive administrator responsible for day-to-day management. Each department is led by a director or, in the case of constitutional offices like the Assessor and Sheriff, an elected official.

Budget authority flows through the county's annual budget process. For fiscal year 2023–2024, the adopted county budget totaled approximately $7.8 billion (San Diego County Adopted Operational Plan FY 2023–24), with HHSA accounting for the largest share of expenditures.

Departments coordinate through formal interdepartmental agreements and joint policy committees. The County's General Management System establishes standardized protocols for procurement, human resources, and information technology shared across all departments.

For public records and transparency, county departments are subject to the California Public Records Act (Government Code § 6250 et seq.), which governs disclosure timelines and exemptions. More on accessing government records is covered at San Diego Public Records Requests.

Common scenarios

Understanding which department handles a specific situation prevents delays and misdirected inquiries. The following scenarios illustrate how the departmental structure applies in practice:

• Property tax dispute — Directed first to the Assessor/Recorder/County Clerk for assessed value questions, then to the Assessment Appeals Board if unresolved.
• Child welfare report — Routed to HHSA's Child Welfare Services division, which operates under California Welfare and Institutions Code § 300 et seq.
• Unpermitted construction in an unincorporated area — Handled by the Department of Planning and Development Services, which has enforcement authority in areas not governed by a city's building department.
• Road maintenance complaint — Directed to the Department of Public Works for county roads, or to the relevant city's public works department for roads within municipal boundaries.
• Mental health crisis response — Coordinated through HHSA's Behavioral Health Services division in partnership with the Sheriff's Psychiatric Emergency Response Team (PERT).
• Environmental health inspection — Conducted by the Department of Environmental Health and Quality, which licenses food facilities, hazardous materials businesses, and land-use site assessments.

A structural contrast is visible between HHSA and the Department of Public Works: HHSA functions under both county policy and direct state and federal mandates (Medi-Cal, CalFresh, and Title IV-E), while Public Works operates almost exclusively under county-adopted infrastructure plans with limited state oversight beyond CalTrans coordination on state routes.

Decision boundaries

Determining whether a county department or a city department has jurisdiction requires evaluating three factors: geographic location, subject matter, and statutory mandate.

Geographic boundary rule: If a property or incident is within an incorporated city — such as the City of San Diego, Chula Vista, or Escondido — the default service provider is that city's department. The county typically steps in only for mandated functions (prosecution, health, elections) or when the city contracts with the county for specific services.

Subject matter rule: Even within city boundaries, certain subjects remain exclusively county-controlled. Property assessment, vital records, and grand jury administration are county functions regardless of where a property sits.

Statutory mandate rule: Federal and state law can override local jurisdictional lines. The county's Public Health Officer, for example, holds authority under California Health and Safety Code § 101040 to issue orders affecting all residents in the county, including those in incorporated cities.

For matters involving regional planning, SANDAG — the San Diego Association of Governments — functions as the regional agency coordinating land use and transportation across all 18 cities and the county, but it is not a county department. Similarly, San Diego Water Authority operates as a separate wholesale water agency governed by its own board.

For a broader orientation to how San Diego's governmental layers interact, the main reference index provides an overview of city, county, and regional entities covered across this resource. County budget structure and appropriation detail are addressed separately at San Diego County Budget, while environmental oversight functions connect to San Diego Environmental Policy.

What falls outside county department scope: State agencies operating in San Diego — including Caltrans District 11, the California Department of Social Services, and the Regional Water Quality Control Board (San Diego Region) — are not county departments and are not governed by the Board of Supervisors. Federal installations such as Naval Base San Diego and Marine Corps Base Camp Pendleton are entirely outside county regulatory reach. The 18 incorporated cities each maintain independent city departments that are not subject to county administrative direction except where state law mandates county oversight.

References

• San Diego County Government — Official Department Directory
• San Diego County Adopted Operational Plan FY 2023–24
• San Diego County Health and Human Services Agency
• California Public Records Act — Government Code § 6250
• California Health and Safety Code § 101040 — Public Health Officer Authority
• SANDAG — San Diego Association of Governments
• San Diego County Assessor/Recorder/County Clerk
• San Diego County Department of Planning and Development Services