TOKYO -- As climate change brings elevated risks of extreme weather events, companies in disaster-prone Japan are seeking business opportunities in providing unique solutions to water problems during disasters. Startups and small companies are finding a place to shine in this relatively niche area.

When it comes to climate change, businesses have tended to focus on minimizing environmental impacts, such as by reducing carbon emissions and saving energy, and large companies with funding power have an advantage here. But there are emerging opportunities in adapting to climate change, such as the new field of disaster tech, where small businesses can make the most of their strengths, said Hidemichi Miyake, an associate professor at Senshu University and expert on the creation of new markets.

In disasters, people often have limited access to water, which leads to higher fatalities and worse hygiene. To solve this problem, Tokyo-based water circulation system company Wota has been selling portable water treatment plants since 2019. They look like a household printer, measuring 82 by 93 cm and weighing around 80 kg. They can reuse 98% of wastewater for showering and hand washing.

On average, a person uses 50 liters of water when taking shower. By using the plant to make wastewater clean again, 100 liters of water suffices for 100 people to take showers.

After water passes through six filters to remove impurities, it is sterilized with chlorine and deep ultraviolet. Sensors inside the plant detect the level of contamination in the water, and then it uses artificial intelligence to automatically determine how the water should be purified. The sensors and AI-based process enable the plant to recycle water with as little waste as possible.

According to the World Meteorological Organization, the number of disasters related to weather has increased over the past 50 years, mainly driven by climate change. Wota primarily sells its portable plant to municipalities, and it thinks the need to prepare for disasters will further grow among local governments.

Wota has provided the plants in 13 municipalities and 20 emergency shelters, enabling 20,000 people to access water. The company aims to expand its business overseas in the future to cater to the need for safe and clean water, said Shin Ichikawa, public relations manager for the company.

One of the problems faced by people after earthquakes and in other natural disasters is finding access to clean toilets. A survey conducted by the market research company Neo Marketing found that 59% of those who had fled to a shelter had difficulties over toilet facilities.

In emergencies, it often takes three to four days to set up portable toilets. Due to their limited availability and long waiting times, some people avoid having to urinate by drinking little water, but that increases the risk of deteriorating health.

Kokenawa, an Aichi Prefecture-based startup, aims to solve this problem through portable toilet bags. Each comes folded in a roughly 7-cm square, along with a coagulant and disinfectant, and the user puts it over a toilet bowl or even on the ground. The coagulant and deodorant go inside the bag, which after being used is tied up and disposed of. A bag, though only one-fifth as thick as standard plastic bags, can hold up to a liter of liquid and waste.

Kokenawa's portable toilet bags are the world's most compact, coming folded almost as small as a credit card. (Photo courtesy of Kokenawa)

The company began selling the portable toilets in September across Japan and looks to earn 200 million yen ($1.8 million) from them in the next 12 months. Yoshinori Kokenawa, president of the company, said the market for disaster-related products is "blue ocean" and sees space for a startup like his to grow its footprint.

Asia is the region most affected by natural disasters -- floods, droughts and other extreme weather. "As there is growing risks of natural disaster, I expect more countries in the region to start preparing and stockpiling emergency supplies," Kokenawa said. "We want to expand our footprint globally."

Shizuoka-based Asutekku, which has six employees, provides water tanks that can store up to 72 liters of water that is constantly kept fresh. A tank is connected to a home's water pipes, and every time someone turns on the water, fresh water flows through the tank. A tap at the bottom dispenses the water during disasters.

"It is difficult for the elderly and other vulnerable people to carry water at a time of disaster. By installing a tank in every four or five households, we can distribute enough water for the community to survive until aid comes," Michio Miyakawa, president of the company, told Nikkei Asia. The company sells 50 to 60 tanks every year to ordinary homes and small factories.

"Startups and small companies can play an increasing role in the disaster response field that is currently addressed by local municipalities," said Cosmo Takagi, project research associate at Tokyo's Keio University and an expert on the U.N.'s sustainable development goals and local municipalities.

Compared with large companies, startups can be more agile in developing new services. In fact, it took only around one year for Wota and Kokenawa to develop their products.

"Unlike large companies that provide uniform, large-scale services, startups can provide services that are best suited to their customers' needs," Takagi said. "That is their biggest strength in this fast-changing era."