About 16,000 residents, predominantly military members and students, will be excluded from the state’s population base when the state Reapportionment Commission submits its final plan for redrawing state political boundaries.

The commission voted 5-3 Monday to leave out those residents based on the ability to reasonably determine where they are located and whether they are permanent Hawaii residents.

But their exclusion from the state’s total base population is not enough to shift a state Senate seat to Hawaii island from Oahu, as Big Island lawmakers and political groups have sought.

Whether the majority of military members, their dependents and additional nonresident students — those for whom an exact address or residency status is unknown — may still be counted in the base population for reapportionment purposes is an issue that likely is headed to court.

“I think this matter is ripe for judicial review,” said Stanley Roehrig, a Hilo attorney who represents Hawaii island lawmakers and political groups who have said they would sue if the greater number of military and students were counted.

Including those military members and students — about 63,000 people — would maintain the population base on Oahu and offset population growth on Hawaii island that would otherwise result in Hawaii County gaining a state Senate seat. Oahu would lose a seat.

Roehrig said he would consult with his clients — Sen. Malama Solomon (D, Hawi-Hilo) and members of the Hawaii County Committee of the state Democratic Party — and he would recommend taking legal action once the decision is final.

Commission Chairwoman Victoria Marks, a retired state Circuit Court Judge, said the commission accepted from the start that any decision to include or exclude the nonresident groups was likely to face scrutiny.

“It has no bearing on what we’re doing,” she said. “We’ve heard that from both sides since the beginning. It’s old news.

“We just do the best we can with the information we have, and if the appellate courts decide that we’re wrong, well then, they’ll decide that we’re wrong, but we’re doing the best we can with what we have.”

Monday’s 5-3 vote with one member absent reverses the commission’s 8-1 vote in June to include all so-called nonresident groups.

At that time the commission had scant data on where these people lived and whether they considered Hawaii their permanent home.

Since the June vote, additional data became available, making it possible for the commission’s technical staff to extract some of those groups with varying levels of accuracy. Those excluded by Monday’s vote included military members self-declared as residents elsewhere and living in group quarters on base, and nonresident students, as determined by their school, whose addresses were known.

Commissioners discussed the issue for about an hour, with many arguing that the state Constitution is ambiguous as to the definition of a “permanent resident.” Members suggested the commission make recommendations to the Legislature to clarify the language.

The commission is scheduled to meet again Friday when the technical committee is expected to have new maps drawn reflecting the change in the base population. The commission would then vote on whether to accept the new maps.

The commission has until Monday to submit its final plan to the state Office of Elections. Once the plan is submitted, any challenge would have to be filed within 45 days.