Tracking Malagasy Flooding in Real-Time
You can also read the French and Malagasy version of the article here by pressing the links.
“Flooded water means that any waste out in the city’s environment before the flood — from trash to faecal waste due to poor access to toilets — will end up in the flooded water people are wading through and infiltrating buildings and other structures. It will ultimately bring the waste to the waterways, including the Ikopa River that runs through the city.”
1. What’s Happening Now
In January 2022, Madagascar got hit by heavy rainfall, including Tropical Storm Ana, which brought heavy rainfall and flooding to Antananarivo. Since the storm, the city has had landslides and significant flooding that has killed dozens and destroyed over 7,000 houses. The flooding has also damaged roads and other infrastructures, including the city’s water treatment plant. Unfortunately, Madagascar also started in February 2022 with a hurricane touching down, causing more flooding and damage to an already battered country.
Unfortunately, this flooding puts people’s lives at risk over the long term from potential famine due to destroyed crops, and disease outbreaks from contaminated water. In particular, flooded water means that any waste out in the city’s environment before the flood — from trash to faecal waste due to poor access to toilets — will end up in the flooded water people are wading through and infiltrating buildings and other structures. It will ultimately bring the waste to the waterways, including the Ikopa River that runs through the city. In places without good access to sanitation, pathogens in waste lead people to get ill with deadly diseases such as cholera, typhoid, yellow fever, hepatitis A & B, and other brutal infections.
2. Antananarivo’s Flooding Risks
Antananarivo is no stranger to major floods — the city has had documented floods since at least the early 1950s. Some of these floods are because of dike breaks on the Ikopa; the worst was in 1995. As a result, the local government in the capital has been well aware that the city has major flooding risks. In this report from 2019, the Schema Director indicated that “Dumping of waste into canals and water outlets can reduce the flow and worsen the impact of flooding. Some of the Fokontany [areas] from the 1st and 4th arrondissement are at risk of flooding during heavy rains or cyclones.”
Part of the flooding risks in these Fokontany — particularly the 1st and 3rd arrondissements — are from informal settlements congested with people, building structures, and waste disposal. Additionally, these areas lack basic infrastructure essential to maintaining essential social services, such as roads, water supply, and sanitation.
To make things more complicated, the city’s elevation varies widely. Many western Fokontanies (including the 1st and 3rd arrondissements) are at lower altitudes, meaning that rainfall often pools in these areas, causing flooding. In 2021, Gather ran a flood risk analysis of the city to start mapping the flood risk of the 5th arrondissement, in anticipation of growing flooding due to climate change. Our flood risk map for this area is seen below.
3. Background on Madagascar
Madagascar ranks 172nd globally for sanitation provision out of 180 countries. As a result, the economy loses $600 million a year in lost productivity and increased health costs due to water and sanitation-related diseases (UNICEF, 2017). For example, 88% of people do not have access to a working toilet (JMP, 2020). In the capital city, Antananarivo, 32% of people live in high flood-prone areas (Ramiaramanana & Teller, 2021). As a result, water-related diseases cause a quarter of all deaths of children under five in urban areas.
In the capital of Madagascar, Antananarivo’s municipality has an ambitious goal of ensuring every household has a toilet by 2037. However, when surveying our partners, two-thirds said they were uncomfortable using existing data to help them achieve this target. Only 10% had access to laptops and software. The lack of data is slowing their progress and increasing their operating costs. Ultimately, this limits the number of toilets they can serve and provide to community members.
4. What Gather is Doing
Gather has seen the current flooding in Antananarivo as a trigger to understand how flooding affects the communities in need of sanitation. We want to ensure that stakeholders in Antananarivo start understanding how to prevent disease outbreaks from flooding events.
To do this, we have constantly been monitoring local media to understand how the flood affects the city’s population, particularly those vulnerable communities in informal settlement areas. In addition, we have started taking the data presented in local media and mapping out the details to expand our flood risk work beyond the 5th arrondissement. As a result, we have two aims: (1) obtain a larger, richer dataset that will clearly indicate critical areas of the city that are particularly vulnerable to flooding impacts, and (2) identify who are also at higher risks because of lower sanitation coverage.
We have already started to notice that elevation correlates with greater flood damage. This knowledge could help government officials and other sanitation stakeholders start working on measures to prevent waste from concentrating in certain areas during flooding. With this, we can make future sanitation systems resilient to the flooding behaviours due to the city’s terrain.
About Gather
Gather is a UK-headquartered non-profit organisation that sits at the cross-sector of data, systems change and social justice. Our vision is to see thriving cities where every individual and community have access to essential services. Gather’s key strength is its facilitating power as a small organisation, rather than implementing projects. This entails bringing different stakeholders together in the same room, building their trust, and getting the group on the same page.
We started with urban sanitation in Antananarivo, Madagascar. There, we are working to improve sanitation for 1.7 million people by equipping municipal sanitation organisations to work together and collect, share, and analyse data. The city can create comprehensive sanitation maps with this data, helping them get toilets to people in their communities who need them the most. We have facilitated the partnership in Antananarivo to demonstrate that a city-wide, cross-sector approach is feasible. Together, we have broken down the barriers to sharing data and created an online map that visualises how to improve sanitation for 350,000 people in the city’s fifth arrondissement.
Follow our work on our website, Twitter and Linkedin.
Pictures collected by Gather team
