CONTRA COSTA COUNTY, CALIFORNIA – It’s been a good year for property values in CC county, new data shows. But the gains have been anything but even.
Contra Costa County’s property tax base has reached a new all-time high, with the assessed value of taxable property climbing to nearly $300.8 billion for the 2026-27 fiscal year.
That is an increase of more than $10.1 billion, or 3.48%, from the prior year, according to the newly released county assessment roll. The roll now includes 383,191 assessed parcels, up 1,169 parcels from a year earlier.
But the gains were not evenly distributed across the county.
Interestingly, Oakley posted the largest percentage increase among Contra Costa’s incorporated cities and towns, with its assessed tax base rising 4.44% to nearly $7.9 billion. Danville was close behind at 4.41%, followed by Lafayette at 4.33%.
At the other end of the list, San Pablo saw the smallest gain at 1.82%, while Pinole rose 2.07% and San Ramon increased 2.21%.
Here’s the full breakdown:
| Community | Increase in assessed value | Net assessed value |
|---|---|---|
| Oakley | 4.44% | $7.90 billion |
| Danville | 4.41% | $19.77 billion |
| Lafayette | 4.33% | $12.89 billion |
| Antioch | 4.07% | $16.98 billion |
| Orinda | 3.83% | $10.53 billion |
| Pittsburg | 3.49% | $10.96 billion |
| Brentwood | 3.18% | $15.15 billion |
| Walnut Creek | 2.52% | $26.56 billion |
| San Ramon | 2.21% | $30.26 billion |
| Pinole | 2.07% | $3.50 billion |
| San Pablo | 1.82% | $2.77 billion |
Danville had the biggest dollar increase in the county, adding about $836.6 million in net assessed value over the past year. Concord added roughly $688.4 million, while Antioch, Walnut Creek and San Ramon each saw gains of about $655 million or more.
Walnut Creek still has one of the county’s largest municipal tax bases at $26.56 billion, trailing only San Ramon’s $30.26 billion and Concord’s $23.86 billion among incorporated communities. But Walnut Creek’s 2.52% growth rate was below the countywide average.
The numbers are important because assessed value helps determine how much property tax revenue will flow to local governments, school districts and special districts.
Still, the assessment roll should not be read as a straight measure of what homes would sell for today. Under California’s Proposition 13 system, most properties are generally assessed based on their purchase price, with annual increases usually limited to 2% unless there is a change in ownership, new construction or a qualifying reassessment event. (Caveat: We’re journalists, not realtors or tax lawyers, so consult one if you have specific questions about your own property.)
That means a city’s assessment growth can reflect a mix of home sales, commercial transactions, construction activity and long-held properties receiving routine annual adjustments.
The county’s incorporated cities and towns collectively grew by 3.14%, while unincorporated areas grew faster, at 4.90%. The countywide total, combining both, reached $300.798 billion — another record for Contra Costa County.
For more local property updates like this, join our free 925 News newsletter.
