Common Cause Hawaii is urging election officials to open more than a handful of voter service centers next year to make sure voting numbers aren’t depressed as the state for the first time begins holding all-mail-in elections.

In past years, officials have staffed about 230 polling locations across the islands on Election Day. Those will be gone next year as Hawaii residents cast their votes in a number of key races — including open seats in the County Councils and Legislature, and for president.

Instead, election officials will mail out ballots to all registered voters. Voters can still cast their ballots in person, but they will be limited to eight planned voter serv­ice centers throughout the islands.

Service centers are expected to be opened in Hilo and Kona, in Lihue, in Honolulu and Kapolei, and in Wailuku. Maui County officials also plan to open a voting service center on Molokai, as well as Lanai if they can find a suitable location and enough staff.

The centers are expected to be open beginning 10 days prior to the primary and general elections and to close at 7 p.m. Election Day. Those locations will allow residents to register the same day they want to vote, sort out any problems they might have with their mail-in ballot or cast their ballot in person.

But Sandy Ma, executive director of Common Cause Hawaii, which advocates on behalf of government ethics and accountability, said there need to be more voter service centers next year in case there are unexpected problems and to help residents get used to the new system.

“For the first, we should air on the side of caution. I mean, voting is the foundation of American democracy, and I think we all know that American democracy is under attack,” said Ma. “Why are we just opening up eight statewide for the very first time we are doing this? To save money?”

Research shows that voting by mail helps increase voter turnout somewhat, which is why Common Cause Hawaii was supportive of Act 136, which was signed into law by Gov. David Ige last year and created universal all-mail voting. However, Ma said she worried that Hawaii’s already dismal voting numbers could be even lower next year if state and county election officials don’t do a good job of implementing the new voting system.

“We already have low voting numbers. Do we really want to risk making this worse?” she said.

Ma said there could be various scenarios in which people could find themselves needing a voter service center at the last minute.

“So let’s say someone is like, ‘I misplaced my ballot, and I need to go to a service center.’ … Are you really going to drive through crazy Honolulu traffic to go to Honolulu Hale or Kapolei Hale?” she said.

Ma said this could pose a particular hardship for people in rural areas, such as Hana, Maui.

All ballots also must be received by 7 p.m. on Election Day in order to count — so ballots should be cast several days beforehand to make sure they make that deadline. Voters waiting until the last minute could find themselves scrambling to get to a voter service center or drop-off location to make sure their ballot is counted.

“We wholeheartedly support vote-by-mail, but we want to make sure the implementation is done correctly,” said Ma, noting that voters needed to be educated about it.

Except for the county clerk on Kauai, state and county election officials didn’t address the criticism or say whether they would consider opening more voter service centers.

Kauai County Clerk Jade Fountain-Tanigawa said she was comfortable with having just one voter service center on Kauai, given that ballots will be mailed to each household with prepaid postage.

“So all they really need to do is stick it in the mailbox,” she said.

She said Kauai also plans to have five drop-off places for ballots throughout the island.

Niihau has always done mail-in voting, said Fountain-Tanigawa, so the county is not planning any special arrangements for that island.

Nedielyn Bueno, a spokeswoman for the state Office of Elections, said her office is confident in the preparations underway by county election officials who are in charge of setting up the voter service centers and ballot drop-off locations.

“Accessibility and convenience is the goal for all election officials and we are confident that the county elections divisions have taken great consideration in decisions regarding voter service centers, and how best to serve Hawaii’s voters,” she said by email.

In May, election officials will issue a proclamation officially identifying the locations and hours of the voter service centers and drop-off locations, she said.

Hawaii is one of four states that have approved statewide vote-by-mail systems, according to the National Conference of State Legislatures. All-mail voting is significantly cheaper than traditional voting and easier for election officials tasked with tabulating all the votes.