As Okinawa continues to mark record high numbers of tourists in recent years, the prefecture is struggling to dispose of snowballing garbage and supplying sufficient amounts of water.

According to data released by the prefectural office in April, tourist numbers in Okinawa hit a record 8.77 million, including 2.13 million foreigners, in fiscal 2016 through March 31.

The total number of domestic and overseas tourists has hit record levels for four consecutive years, according to the local government. Of the fiscal 2016 total, the highest number of tourists came from Taiwan, followed by South Korea, mainland China and Hong Kong.

The increase in tourists, however, brought about more garbage on the islands, the government said. The total amount of waste in Okinawa was 448,000 tons in fiscal 2015, of which 100,000 tons was left in the prefectural capital of Naha.

Adding to the problem, a large portion of the total was leftovers in Naha, prompting the city to soon distribute flyers asking hotels and restaurants to reduce food waste.

At Kokusai Dori, the main street in Naha, which features shopping and dining spots, shop owners and local residents have been annoyed by mounting garbage and cigarette butts tossed by visitors. The municipal government has an ordinance banning smoking and throwing cigarette butts on the street, but the regulation has not proven effective.

Starting in fiscal 2014, the prefecture placed along the street 120 planters with flowers such as hibiscus as a welcome message for tourists. But local officials recently decided to remove most of the planters after people were using them to dispose of rubbish.

“We feel sorry to have to make that decision but we have no other option after seeing the planters used as trash bins,” a prefectural official said.

“We clean them up but they get littered again,” Nobuko Oshiro, a 65-year-old worker at a jewelry shop, said while sweeping up the area in front of the store on Kokusai Dori.

“I want public offices to be stricter on people (who throw away garbage),” Oshiro said.

A group of elderly people who were playing gateball in a park near the Naha Cruise Terminal complained about an increase in tourists who leave their leftovers and garbage in the park.

“It’s us who are picking up such garbage. We want tourists to have good manners,” one of the gateballers said.

The surge in tourists has also potentially threatened the water supply in Okinawa.

The Enterprise Bureau at the prefectural government said the average storage level at 11 dams in Okinawa was 45.4 percent as of May 1, down 23.5 percentage points on the 10-year average.

An official at the bureau blamed the water shortage on low rainfall since October. “But given the record number of tourists, we must study its potential impact” on the whole water supply system, the official said.

Daisuke Kamiya, a civil engineering expert at the University of the Ryukyus in the prefecture, urged local authorities to look at measures to reduce the impact from a growing tourism sector on the lives of local residents not only on Okinawa Island but remote islands in the prefecture.

According to a report released in 2013 by researchers including Kamiya, a hotel guest in the prefecture is estimated to consume between 300 to 1,500 liters of water per day, while the use of water by families on remote islands is estimated to be between 150 and 250 liters per day. This means tourists are using twice to 10 times more water than local residents, the report says.

“If the number of tourists grows too rapidly on remote islands that don’t have ample water supplies, it could affect the lives of islanders, such as possible water restrictions,” said Kamiya, an associate professor at the University of the Ryukyus.

“Okinawa needs to come up with ways to boost tourism that take into consideration the impact on the daily lives of the islanders,” Kamiya said.

This section features topics and issues from Okinawa covered by The Okinawa Times, a major daily in the prefecture. The original article was published on May 2.