Every ten years boundaries of all local governments that elect by district, including special districts like the Fresno Irrigation District, are updated to reflect how populations have changed based on the most recent U.S. Census. In August 2021, the California State Legislature passed Senate Bill 594 to extend the deadline for final approval of a redistricting map for special districts to April 17, 2022.
Under state law, divisions of special districts should:
Be as compact as possible
Consist of geographically contiguous areas
Have boundaries that coincide with existing recognized natural boundaries; and
Preserve existing communities of related and mutual interest