The state Health Department may have issued an islandwide brown-water advisory due to Tropical Storm Olivia, but plenty of tourists were still splashing in the waters fronting major hotels in Waikiki on Thursday afternoon.

Elsewhere on the island, including at Ala Moana Beach Park, there were fewer people than usual on an overcast, blustery afternoon. Yet a few swimmers were in the water, along with a few surfers out on the horizon.

Belinda Goodwin, a visitor from New Zealand, did not know about the brown-water advisory when she went for a swim at Ala Moana, but said it seemed fine and that she even saw a few fish. Having just arrived in Honolulu on Wednesday, it was her first visit to a beach in Hawaii.

Noel Perry from Los Angeles and Justin Todd from Dallas knew about the brown-water advisory because they were visiting a friend who told them about it. They were disappointed but enjoying the view from the beach and hoping to get in the ocean in the next few days.

“I will be swimming, whether or not there’s an advisory, maybe not today,” said Perry. “I may not put my head under. I’ll be smart about it.”

The brown-water advisory was issued Wednesday for the entire island of Oahu, as well as the entire islands of Maui, Molokai and Lanai, and for several beaches on Kauai due to heavy rain from Tropical Storm Olivia. The heavy rain resulted in stormwater runoff entering coastal waters.

The tropical storm made historical landfall on Maui and Lanai, and blew through the Hawaiian Islands on Wednesday, blowing down trees, creating landslides and power outages. But most isles were spared from extensive damage as heavy rain continued into Thursday.

Myron Honda, environmental health specialist with the department’s Clean Water Branch, said he anticipated the brown-water advisory to last for a couple of days and that routine testing was on hold but would likely continue Monday.

The state Health Department issues a standard advisory warning the public to stay out of floodwaters and stormwater runoff due to possible overflowing cesspools, sewers and manholes as well as pesticides, animal fecal matter, dead animals, pathogens, chemicals and associated flood debris.

While not all coastal areas may be affected by runoff, the state recommends the public stay out if the water is brown, continue to practice good personal hygiene and follow up with a primary care physician for any health concerns.

In November the Health Department’s Clean Water Branch revamped its website with more user-friendly features to alert the public of the water quality notifications, which include brown- water advisories as well as warnings on high levels of enterococci bacteria.

Under federal law the state is required to establish a beach monitoring program for its beaches and to provide public notification of sewage spills as well as when bacteria levels exceed a specified threshold level of 130 per 100 milliliters.

Lorna Moglia, a visitor from Oakland, Calif., visiting Ala Moana Beach Park, said it would be nice if visitors received information about water advisories upon arrival at the airport in Honolulu.

The public can sign up for the alerts online as well as through the city’s HNL Info app, available at hnl.info.