CDP
Castle Hill
Castle Hill is a Census-designated community in Contra Costa County covering about 0.585 square miles. It is not an incorporated city. The county is usually the first government layer, while utilities and special districts can follow their own boundaries.
Starting point
Start with the county unless an official district says otherwise.
A Census-designated place is a useful local name, but it usually does not have its own city hall. For permits, records, taxes, courts, and many services, begin with the county layer.
What changes the answer: Special districts, utilities, schools, fire agencies, parks, water agencies, coastal rules, and state maps can still control a specific issue.
How local government works here
The place name, county, and service districts do different jobs.
Castle Hill is a real community name. It does not create a city government. The county and local districts divide the public work for the address.
The community name is not city hall
Castle Hill is what the Census calls a census-designated place. It normally has no mayor, city council, or city permit desk. Start with Contra Costa County for county work.
The county handles the local government lane
County planning and building usually handle an address outside a city. The county also handles property value, tax bills, records, courts, elections, health, and many aid programs.
Services may come from separate districts
Water, sewer, fire, schools, parks, roads, trash, and power can follow lines that do not match the place name. Check the bill, parcel, or district map before assuming the county provides the service.
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 full explanation2025 population
Not available
Land area
0.585 sq mi
Water area
0 sq mi
Local front desk
Start with the task in front of you.
Castle Hill is a Census-designated place, not an incorporated city. Start with Contra Costa County; utilities and special districts can still have their own boundaries.
- Property Open the property-tax path
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 path
Deeds, birth and death records, marriage records, and name changes
Contra Costa County recorder is the usual deed and public-record door. Vital-record access depends on the record and year. A legal name change or divorce decree can involve Superior Court.
- Property work Open the local-office path
Building permits, ADUs, zoning, code, water, and septic
Start with Contra Costa County planning or building. Water, sewer, fire, and other special districts may have a separate approval.
- Housing Open the housing path
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 path
CalFresh, Medi-Cal, CalWORKs, General Assistance, and IHSS
Contra Costa County social-services agency is the main local door. Coverage, food, cash aid, and in-home support remain separate programs with separate notices.
- Public health Open the health path
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 program doors.
- Business Open the business path
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 the local-office path
Potholes, streetlights, graffiti, trash, and service requests
Start with Contra Costa County for county-maintained roads and services. Caltrans, utilities, transit systems, waste haulers, and special districts can own separate reporting paths.
- School and care Open the school and care path
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 the parking path
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 the ticket path
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 the emergency path
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 use the state fire, smoke, road, and utility sources for the matching layer.
Official county doors
Open the office that owns the next step.
California's statewide directories and verified official corrections supply the county-specific links below. Property and recorder links open the state directory because several county offices can share one task.
Contra Costa County
Practical notes
Office, map, permit, and paperwork notes for Castle Hill
Countywide answer · Rules and licenses · Reviewed June 29, 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.
County practical note · 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.
County practical note · 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.
County practical note · 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.
County practical note · 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.
County practical note · 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 in 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.
County place 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.
County place 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.
County place 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.
County place 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.
County place 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.
County place 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.
County place 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.