The U.S. Census Bureau has released the first local level data from the 2020 Census, the once-a-decade count of every person living in the country. This is part of the Census data that will help determine new Supervisorial districts for Contra Costa County during its Redistricting. The actual drawing of Supervisorial District Maps requires the official California State Adjusted Redistricting data, which is expected to be available in September 2021, and will include updated data to ensure incarcerated individuals are counted by each jurisdiction.
The Census data release provides the first look at the demographic characteristics at the local level, including population change, race, ethnicity, age 18 and over population, and housing occupancy status.
The data shows Contra Costa County’s population has increased by 10% or 116,902 people, since the 2010 Census, for a total population of 1,165,927. The 2020 Census data indicate that Contra Costa County has become increasingly diverse and multiracial. The following provides additional detail about the 2020 Census data release.
Detailed Data Summary
The California State Department of Finance (DOF) has provided a number of data products at the State, County, Place, and Census Tract level. These includes tables and PDF summaries.
Visit California Department of Finance Census Data webpage
View 2020 Census Data Profile (PDF) prepared by the DOF
Population by Supervisorial District

Population by Supervisorial District and Deviation from Mean
Districts must be redrawn so that each district is substantially equal in population.
Equal Proportion based on 2020 Census: 233,185 people.
The current spread is 8.08%, this is the difference between the highest and lowest percentage from the mean.
The percentage deviation from the mean is shown in parenthesis below.
District 1 Population: 224,726
8,459 under (-3.63%)
District 2 Population: 243,565
10,380 over (4.45%)
District 3 Population: 239,825
6,640 over (2.85%)
District 4 Population: 229,384
3,837 under (-1.65%)
District 5 Population: 228,463
4,722 under (-2.03%)
Race and Ethnicity by Supervisorial District

City Population and Growth Rate
City | 2020 Population | 2010 Population | Growth Rate |
---|
Brentwood city | 64,292 | 51,481 | 19.9% |
Oakley city | 43,357 | 35,432 | 18.3% |
Pittsburg city | 76,416 | 63,264 | 17.2% |
San Ramon city | 84,605 | 72,148 | 14.7% |
Antioch city | 115,291 | 102,372 | 11.2% |
Richmond city | 116,448 | 103,701 | 10.9% |
Orinda city | 19,514 | 17,643 | 9.6% |
San Pablo city | 32,127 | 29,139 | 9.3% |
El Cerrito city | 25,962 | 23,549 | 9.3% |
Walnut Creek city | 70,127 | 64,173 | 8.5% |
Hercules city | 26,016 | 24,060 | 7.5% |
Lafayette city | 25,391 | 23,893 | 5.9% |
Moraga town | 16,870 | 16,016 | 5.1% |
Pleasant Hill city | 34,613 | 33,152 | 4.2% |
Martinez city | 37,287 | 35,824 | 3.9% |
Danville town | 43,582 | 42,039 | 3.5% |
Pinole city | 19,022 | 18,390 | 3.3% |
Concord city | 125,410 | 122,067 | 2.7% |
Clayton city | 11,070 | 10,897 | 1.6% |