County
Contra Costa County
Contra Costa County has an estimated 2025 population of 1,170,070 across about 716.901 square miles of land. The county handles work tied to parcels, records, elections, health, and countywide services. Cities inside it still set many permit and local-service rules.
Starting point
County offices handle the countywide work.
Start with county offices for records, taxes, elections, public health, social services, sheriff services, and work on unincorporated land. Court cases go through the state court system, including the superior court serving the county.
What changes the answer: Cities inside the county can still control city permits, local code, utilities, business licenses, and city-specific rules.
Countywide answer
Contra Costa property tax starts with assessor or tax collector
Contra Costa County property tax questions usually split between the Assessor for property value and records, and the Treasurer-Tax Collector for bills and payment.
Read the local noteCounty offices
Start with the task in front of you.
Contra Costa County handles countywide work and services on unincorporated land. Find the task below, then open the responsible office.
- Property Open the property-tax guide
Assessed value, exemptions, tax bills, and appeals
Contra Costa County assessor handles value and exemptions. The clerk of the board handles a formal value appeal. The tax collector handles the bill, payment, and penalties.
- Records Open the records guide
Deeds, birth and death records, marriage records, and name changes
Contra Costa County recorder is the usual office for deeds and many public records. Vital-record access depends on the record and year. A legal name change or divorce decree can involve Superior Court.
- Property work Open local-office help
Building permits, ADUs, zoning, code, water, and septic
For an unincorporated address, start with Contra Costa County planning or building. An address inside a city or town starts with that local permit counter.
- Housing Open rent and housing help
Rent rules, repairs, notices, and eviction papers
Start with a local rent, housing, or code office if one serves the address. Court papers go to the Superior Court self-help path, and the deadline on the papers keeps running.
- Household help Open the benefits guide
CalFresh, Medi-Cal, CalWORKs, General Assistance, and IHSS
Contra Costa County social-services agency is the main local office. Coverage, food, cash aid, and in-home support remain separate programs with separate notices.
- Public health Open health and benefits help
Vaccines, disease reporting, health records, and local health programs
Contra Costa County public health is the local health jurisdiction. Health coverage and benefits still use separate programs and offices.
- Business Open the business guide
Business setup, seller's permits, local licenses, and regulated work
State filings and tax accounts do not replace county zoning, licensing, building, fire, or health approvals for the address.
- Neighborhood services Open local-office help
Potholes, streetlights, graffiti, trash, and service requests
For a county-maintained road or service in an unincorporated area, start with Contra Costa County. Caltrans, utilities, transit systems, waste haulers, and special districts can own separate reporting paths.
- School and care Open the school and care guide
School enrollment, student records, and child-care checks
The school district handles assignment and records. County offices can help with some family services, while the state licenses child-care facilities.
- Parking Open parking help
Residential, guest, overnight, and local parking permits
A local parking permit is separate from a citation, moving ticket, and toll notice. Match the permit to the address, vehicle, district, or parking facility.
- Tickets Open ticket help
Traffic court, parking citations, and toll notices
Contra Costa County Superior Court handles traffic court matters. A city or issuing agency handles parking. The toll operator handles toll notices.
- Safety Open emergency checks
Emergency alerts, evacuations, smoke, roads, and power
Use the county or city alert system for local warnings. Follow the local emergency office for evacuation wording, then check the matching state fire, smoke, road, or utility update.
Official county links
Open the office that handles the task.
The county links below come from California statewide directories and official county corrections. Property and recorder links open the state directory because several county offices can share one task.
Contra Costa County
City, county, and district responsibilities
County and city rules can share one address.
An address in Contra Costa County can sit inside a city. It can also sit on county land outside any city. That line picks the permit desk and some local rules. It does not move every county job to city hall.
County jobs stay with the county
The county assessor sets property value. The tax collector handles bills. The recorder, elections office, benefits office, and usually the health office also stay with Contra Costa County. The court serves the county but is part of the state court system.
Permits follow the city line
A city or town usually handles permits, zoning, parking, business licenses, and local code inside its lines. Contra Costa County handles these jobs on county land outside a city.
Districts can cross city and county lines
Water, sewer, fire, schools, transit, trash, and flood work may belong to a special district or other provider. The parcel or service bill is often the quickest way to name that agency.
Practical notes
Office, map, permit, and paperwork notes for Contra Costa County
Countywide answer · Rules and licenses · Reviewed July 22, 2026
Contra Costa County planning starts with the city line
Contra Costa County's planning agency reviews projects in unincorporated county areas, while cities and towns have their own planning agencies.
Community answer · Home and property · Reviewed July 14, 2026
Concord emergency alerts start with the county warning system
Contra Costa's Community Warning System can give Concord residents incident details and a specific action such as sheltering, evacuating, locking down, or avoiding an area.
Community answer · Home and property · Reviewed July 14, 2026
Richmond has two alert paths worth knowing
Richmond uses two opt-in systems for different jobs: city Everbridge/Nixle notices and Contra Costa CWS protective-action alerts.
Community answer · Cars and driving · Reviewed July 7, 2026
Bay Area bridge tolls use FasTrak, plates, or invoices
Bay Area toll bridges use automatic toll collection, with FasTrak, License Plate Account, One-Time Payment, and invoice options depending on how the vehicle is set up.
Community answer · Rules and licenses · Reviewed July 7, 2026
Contra Costa County DBA filings are one business-start lane
Contra Costa County fictitious business name filings are handled through the Clerk-Recorder side and sit apart from city licenses, zoning, and other permits.
Community answer · Home and property · Reviewed July 4, 2026
Richmond building permits now start in iMS
Richmond has moved building permit applications to the iMS portal, and older eTRAKiT users can use the same email when setting up access.
Stories & Notes
Stories and local context across Contra Costa County
Countywide story · Outdoors
Mount Diablo gives Contra Costa County the big view
Mount Diablo pairs big summit views with trails, rock formations, varied habitats, camping, and a visitor center.
Community story · History and culture
Richmond's waterfront carries a national home-front story
Rosie the Riveter/WWII Home Front National Historical Park and the Marina Bay Trail connect Richmond's shipyards, wartime workers, waterfront, and public trail stops.
Community story · History and culture
Pittsburg's name changed with the work on the waterfront
Pittsburg's history includes Rancho Los Medanos, fishing and canning, Black Diamond coal, waterfront shipping, industry, and Camp Stoneman.
Community story · History and culture
John Muir's Martinez home began as a fruit-ranch story
John Muir National Historic Site in Martinez connects conservation history with orchards, family life, Mount Wanda, and the Strentzel-Muir home.
Community story · Outdoors
Ruth Bancroft Garden makes dry gardening feel alive
Ruth Bancroft Garden in Walnut Creek shows cacti, succulents, and drought-tolerant plants in a walkable garden that feels especially useful in a dry California climate.
Community story · History and culture
Forest Home Farms keeps San Ramon's farm past in town
Forest Home Farms gives San Ramon a 16-acre historic farm, with Boone family buildings, old outbuildings, a walnut-processing past, and valley agriculture still visible.
Community story · History and culture
Antioch began as a river landing before it grew south
Antioch's early story starts near the San Joaquin River, where settlers chose the name in 1851 and river travel shaped the town before roads took over.
Community story · History and culture
The Richmond Plunge is a pool with a long memory
The Richmond Plunge opened in 1926 as the Municipal Natatorium, later closed for major repairs, and reopened as a restored Point Richmond swim center.
- 2025 population
- 1,170,070
- Land area
- 716.901 sq mi
- Water area
- 86.999 sq mi