Political Districts


New Maps in 2022

Redistricting is done every 10 years, following each U.S. Census. The Census Bureau is required to provide the small area population counts for legislative redistricting within one year of Census Day (April 1, 2020).

The apportionment data, used to determine the number of congressional seats in each state, was released on April 26, 2021. Census results for state and local redistricting, or the small area population counts, followed in a technical format used in 2000 and 2010 as well as a toolkit on DVDs and flash drives with integrated browsing software.

2022 Assembly Districts Map
2022 Congressional Districts Map
2022 Senatorial Districts Map
2022 Supervisorial Districts Map


Congressional districts and the census can trace their roots to the U.S. Constitution (Article I, Section 2). 

Redistricting in California

The California Constitution (Article 21, Section 1) requires an adjustment of election districts every ten years, in the year following the federal census. The intent of the state and federal requirements is to adjust the number of representatives and people within political districts to reflect the current population.

The California Citizens Redistricting Commission was created by the Voters FIRST Act in 2008. It is responsible for determining the boundaries for the state’s Congressional, Senate, Assembly, and Board of Equalization districts. The 14-member Commission is made up of five Republicans, five Democrats and four unaffiliated.

The California Supreme Court directed the Commission to release preliminary statewide maps no later than November 15, 2021, and to send the approved final statewide maps to the Secretary of State no later than December 27, 2021 (S262530).

You may obtain information about California’s redistricting process from here:

California Citizens Redistricting Commission
721 Capitol Mall, Suite 260
Sacramento, CA 95814
Phone: 916.323.0323
Email: votersfirstact@crc.ca.gov
Website: https://www.wedrawthelinesca.org/

San Mateo County Supervisorial District Boundary Adjustment

California Elections Code § 21500 requires a county that elects its board of supervisors using by-district elections to adjust voting districts following each federal census so that each district is nearly equal in population.

The San Mateo County Board of Supervisors established the Supervisorial District Lines Advisory Commission to engage communities in the redistricting process by holding public workshops and hearings. The 15-person commission is made up of current San Mateo County residents, three from of each of the five districts.

The San Mateo County Board of Supervisors adopted a final map on December 14, 2021.

For additional information about San Mateo County’s supervisorial redistricting process, contact:

County Manager’s Office
Attn: Redistricting
Phone: 650.363.4123
Email: districtlines@smcgov.org
Website: http://smcdistrictlines.org/

Old District Maps based on the 2010 Census 

2012 Congressional Districts Map
2012 State Senate Districts Map
2012 State Assembly Districts Map
2013 County Supervisorial Districts Map