Most every town in Southeast faces a similar summer problem: Boatloads of visitors and not enough public toilets.

Some communities have built additional restrooms, and Sitka this summer is paying downtown businesses willing to open their facilities to the public.

Under a new grant program, Sitka has succeeded in opening six business restrooms to the public this summer, relieving a strain on the limited public facilities downtown. The incentive program is part of the town’s effort to handle a record-setting cruise ship season.

“We were maxed out in terms of infrastructure before we were...