Pontianak, the capital of West Kalimantan, has always been a city shaped by water. Located at the meeting point of the mighty Kapuas and Landak Rivers, it was designed by its early settlers to live with the tides, not against them.

In the past, water was not seen as a threat, it was part of life. People built stilt houses to adapt to rising tides, carved canals to drain and guide water, and understood that the rivers were their lifeline. This harmony earned Pontianak its famous nickname: “The City of a Thousand Canals.”

Those canals were once acted as the city’s natural drainage network, keeping floods under control and connecting communities. But concrete buildings are growing, the canals are buried under roads, leaving few green spaces. Floods that once came once a year now strike as many as six times annually.

“86% of buildings and 79% of residents in Pontianak are now directly exposed to flooding.”

To better understand the worsening floods, researchers from Syiah Kuala University and the University of Waterloo, through the FINCAPES Project (Flood Impacts, Carbon Pricing, and Ecosystem Sustainability), conducted a data-based flood simulation study. This simulation combined rainfall, tides, river discharge, soil types, and land-use changes to model the city’s flood risks.

The study paints a clear picture of why Pontianak’s floods have grown more frequent and severe. First, the city faces a dual threat: its land sits just 0.4 to 1.5 meters above sea level, leaving it extremely vulnerable to rising water. To make matters worse, Pontianak is literally sinking as certain parts of the city, particularly in the north and southeast, are subsiding by as much as one centimeter per year. This is especially pronounced in areas built over soft peat soils and dense urban zones.

Adding to this physical challenge is the pace of rapid development. Since 2005, Pontianak’s built-up areas have expanded by nearly half, replacing natural wetlands and peat swamps that once functioned as the city’s natural water absorbers. As these spaces disappear, water has fewer places to go, turning rain that once drained smoothly into stagnant floods.

The research also highlights the growing danger of compound flooding, when heavy rainfall coincides with high tides, creating a dangerous mix that overwhelms drainage systems. Under these conditions, even moderate rain can quickly escalate into significant flooding.

The simulation suggests that Pontianak could be heading toward a submerged future. In the next 50 years, shallow floods are projected to decrease as deeper floods, those over half a meter, become more frequent, rising by about 17%. In extreme cases, water levels could reach up to two meters and remain for more than five days, disrupting homes, transport, and livelihoods across the city.

Without intervention, Pontianak’s delicate balance with water may tip irreversibly toward crisis.

The Human Side of Floods: Social Vulnerability

Flooding in Pontianak is not only about water levels and rainfall, it’s also about how people live and who is most affected when the water rises. The study’s Social Vulnerability Analysis reveals that the communities most at risk are concentrated along the Kapuas River corridor, particularly in South, Southeast, and East Pontianak. These areas are densely populated and sit on low-lying ground, where limited drainage and semi-permanent housing make daily life precarious during the rainy season.

Traditional stilt houses, once a smart adaptation to the city’s wet landscape, still provide some protection. But when floods linger for days instead of hours, even these elevated homes can’t withstand the damage. Families lose their belongings, small traders are forced to shut their businesses, and children are kept from school.

For many residents, especially vulnerable groups, each flood is a personal setback. They are often the first to respond, protecting family members and salvaging household items, yet they also bear the heaviest losses.  

From Concrete to Green: A Hybrid Strategy for Resilience

The FINCAPES study calls for a hybrid approach to managing floods in Pontianak, combining the reliability of engineering known as grey infrastructure with the nature-based solutions or green infrastructure. 

On the grey infrastructure side, the study recommends improving the city’s drainage network, especially in areas that flood repeatedly. Regular maintenance can make a big difference in how quickly water is cleared after heavy rain. Another key step is elevating the floors of houses in flood-prone areas and reinforcing semi-permanent housing structures, making them more resilient to prolonged inundation. 

To address one of Pontianak’s hidden threats, such as land subsidence, the report suggests limiting groundwater extraction and strengthening building foundations. The city can also benefit from building water gates, pumping stations, and retention ponds to store and redirect excess rainwater during peak tides. Finally, a better early warning system and well-planned evacuation routes would ensure that communities are prepared before disasters strike.

The green infrastructure component encourages Pontianak to restore its natural defenses by giving space back to nature. This includes expanding parks, sports fields, and urban forests that can act as natural sponges, absorbing rainfall and reducing runoff. The study also emphasizes restoring wetlands, mangroves, and peatlands, which not only help control floods but also store carbon and support biodiversity. Open public spaces can be designed to serve dual purposes, functioning as gathering areas in dry times and temporary water retention zones during floods.

Flooding in Pontianak is a reflection of how the city has evolved, and how it must adapt once again.With scientific data, realistic simulations, and empowered communities, Pontianak has a chance to survive floods and to coexist with them in a smarter, greener, and more inclusive way.

Watch the story unfold:

1. Behind the growing flood risk in Pontianak City

2. Understanding Pontianak’s Flood Dynamics through Modeling and Simulation

3. Turning Data Into Action for a Flood-Resilient City