California Code, Elections Code - ELEC § 14051

(a) “Political subdivision” means a geographic area of representation created for the provision of government services, including, but not limited to, a city, a school district, a community college district, or other district organized pursuant to state law.

(b) “Significant decrease in voter turnout” means the voter turnout for a regularly scheduled election in a political subdivision is at least 25 percent less than the average voter turnout within that political subdivision for the previous four statewide general elections.

(c) “Voter turnout” means the percentage of voters who are eligible to cast ballots within a given political subdivision who voted.