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Reimagining Sanitation in Light of Climate Change Action

Experts warn that even toilets and sanitation systems are not immune from the impact of climate change, a reality that both developed and developing countries face.

By Asian Development Bank

November 18^th, 2020

For many in the Philippines, it was the recurrence of a nightmare. The night of 11 November 2020 brought back flashes of Typhoon Ketsana (local name: Ondoy) along with the haunting memories of losing loved ones and leaving hard-earned homes as torrential rain, howling winds, and rising floodwaters struck many parts of Manila and other provinces in the country due to Typhoon Vamco (local name: Ulysses).

Typhoon Ketsana (Ondoy) dropped 455 mm (17.9 inches) of rain on Metro Manila in a span of 24 hours on 26 September 2009.

A boy drags some possessions through the flooded streets of Metro Manila.

Many homes were flooded or washed away during both Typhoon Ketsana and Typhoon Vamco. Several families were also stranded on rooftops to escape high waters.

The increasing frequency and intensity of disasters, especially in Asia and the Pacific, due to climate change is now well known, unlike in 2009 at the height of Ketsana.

Of the 10 countries with the highest disaster risk worldwide, seven are ADB developing member countries.

From 1989 to 2018, the region has suffered $843.6 billion in direct physical loss.

IMPACTS OF CLIMATE CHANGE ON SANITATION

Every 19 November is World Toilet Day. This year, the theme is “Sustainable Sanitation and Climate Change,” recognizing that even toilets and sanitation systems are not immune from climate impacts—a reality that both developed and developing countries face.

In Asia and the Pacific, about 1.2 billion people still lack access to basic sanitation services.

Floodwaters can inundate toilets, septic tanks, and sewerage systems. In some cases, where aging infrastructure carry sewage and rainwater in the same pipes, untreated sewage is released into waterways during heavy rains. This overflow contains bacteria and pathogens that can flow back into the sea or groundwater, which can affect water supply, agriculture, environment and biodiversity, and public health.

Only a small fraction of the region's population is connected to sewerage systems; and in some countries, informal settlements dump waste directly into the river.

Aging infrastructure in Asia are susceptible to flood risks.

In times of calamities, low-income communities often struggle with sanitation.

When floods damage towns and displace residents, people lose access to sanitation facilities. Utility personnel are also cut off from their work and sanitation workers become burdened with the hazardous tasks of addressing clogged drainage and sewers.

As for those without a clean and decent toilet to begin with, extreme weather events could mean further deniability of access or, in times of droughts, the lack of water supply for proper hygiene and a clean environment.

A camp for internally displaced people after a 2010 flood in Pakistan.

Without adequate sanitation facilities and services, women are exposed to risks of harassment and violence.

An outhouse remains standing after a house is overturned during a disaster.

Sanitation workers often toil in precarious conditions to serve communities.

More than 800 children under five die every day from diarrheal diseases due to poor sanitation, poor hygiene, or unsafe drinking water, based on WHO data.

INVESTING IN RESILIENCE AND INCREASING ACCESS

Resilient infrastructure is a must, as well as ensuring equal access for everyone, whether through centralized or decentralized sanitation systems, so as to make communities just as resilient.

Reimagining Sanitation in Light of Climate Change Action

Toilets and wastewater treatment can be adapted toward addressing climate change, and even managing human waste safely along the entire sanitation service chain can reduce emissions.

Aerial shot of Palau at the location of the Koror-Airai Sanitation Project.

Tackling climate change, building climate and disaster resilience, and enhancing environmental sustainability is one of the operational priorities of the Asian Development Bank (ADB) under its Strategy 2030. ADB is also contributing toward the achievement of Sustainable Development Goal 6.2 – sanitation for all – through its technical assistance (TA) on Accelerating Sanitation for All in Asia and the Pacific, which is cofinanced by the Urban Climate Change Resilience Trust Fund. One of the main focus of this project is supporting the adoption of citywide inclusive sanitation principles in urban development investments.

Rokeya Akter (second from right) is the site engineer responsible for the construction of a multipurpose cyclone shelter, which will include water supply and sanitation facilities, in Patuakhali District, Bangladesh.

A community sanitation project in Samoa aims to provide sustainable access to better sanitation in various villages.

Installation of a septic tank in a village. Citywide inclusive sanitation means unserved and vulnerable communities enjoy the benefits of safe sanitation.

The lives of Vasanthi and Gopal have been transformed because of the low-cost toilet funded by ADB.

The TA project will also promote sustainability and resilience by identifying project risks and vulnerabilities and developing resilience strategies and responses to disasters. When appropriate, circular economy principles will be integrated in project designs. Human waste and wastewater are increasingly regarded as precious resource, such as for energy, reusing water for different applications, and as fertilizer to boost crop yield.

Reimagining Sanitation in Light of Climate Change Action

The TA project also sees toilets as an entry point for innovation. The Bill & Melinda Gates Foundation, through the Sanitation Financing Partnership Trust Fund under the Water Financing Partnership Facility, is another cofinancing partner of the project and part of the Foundation’s work is reinvented toilets or pursuing technologies that can help transform sanitation. The TA project similarly is looking at introducing or pilot-testing technologies that can improve services, safety, and sustainability in communities.

Aerial view of a floating village in Tonle Sap Lake in Cambodia, where the Sanitation Financing Partnership Trust Fund supported the pilot-testing of floating toilets.

A floating digester is an example of an appropriate and affordable sanitation technology that can improve the lives of families in the flood-prone, floating villages in Cambodia.

Additionally, ADB is currently calling for innovators to join the Technology Innovation Challenge for Urban Development, which seeks solutions for efficient wastewater treatment and sanitation. Another intervention that has been studied and being assessed for promotion is optimizing energy efficiencies in water and wastewater utilities, which can help minimize fossil fuel-based energy use.

Numerous solutions are already available to combat the worsening climate, both big and small, from the top-down to the bottom-up. Inclusive sanitation is one of them. This World Toilet Day, let’s reexamine the way toilets and sanitation systems are viewed, and reimagine their role in strengthening climate resilience and advancing climate action that helps protect people and the planet.

Project site of the South Tarawa Sanitation Improvement Sector Project in Kiribati.

A wastewater treatment plant in Suva, Fiji.

Villagers by the toilet block supported under a climate-resilient infrastructure project in Bangladesh.

© 2026 Asian Development Bank

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