The San Mateo City Council voted Monday to change to a by-district elections system after receiving claims that its current system could violate California’s Voting Rights Act.

Under district-based elections, voters from each district in the city would vote on one councilmember who lives in that district to represent it. Currently, the city of San Mateo has an at-large election system, meaning that voters across the city, regardless of where they live, vote on each of the five City Council members.

San Mateo is one of the latest cities to consider district-based elections after receiving a letter from an attorney stating that its current at-large system could violate the Voting Rights Act. Cities and school districts across California have received similar letters and have adopted district-based elections systems as a result.

The council on Monday unanimously approved a resolution showing its intent to move to district elections.

A Voting Rights Act violation may occur if there is evidence of “racially polarized voting,” in which voters of a racial or language minority group show voting preferences that are different from the rest of the electorate, according to state law.

While the city does not believe the attorney’s letter provided sufficient evidence to support a Voting Rights Act violation, it could face a lawsuit unless it voluntarily changes its election system.

Shifting to district elections would require the city to create a district map, assign election years to each district and hold public hearings to get feedback from the public.

After adopting a resolution showing its intent to change to district elections, state law requires that a city complete the transition in 90 days.

However, San Mateo will likely request an extension to get more public input on how the map should be drawn and to incorporate Census 2020 demographic data.

The city also plans to contract a professional demographer and the transition could cost up to $150,000, according to a staff report.

Changing to district elections will not affect the terms of current councilmembers.

The city’s website offers more information on district elections.

Other cities and some school districts in San Mateo County have received similar letters alleging Voting Rights Act violations, are in the process of changing to district elections or have already made the change. These cities include Half Moon Bay, Menlo Park, Redwood City, San Bruno and South San Francisco.