HANOI – In response to a year marked by relentless storms and widespread flooding, Vietnam is re-evaluating its flood management strategies. The country faced numerous landslides and urban areas submerged under water, prompting a significant shift in focus.

Vietnam is channeling billions of dollars into innovative solutions, such as mapping high-risk zones and developing “sponge cities” that naturally absorb and release water. This initiative is part of a comprehensive national master plan extending through 2030, with the government committing over $6 billion to enhance early-warning systems and relocate vulnerable communities to safer areas.

These transformative ideas are being implemented in smaller cities like Vinh in central Vietnam. Here, drainage systems are being expanded, flood basins constructed, and riverbanks converted into green spaces designed to absorb and gradually release water after heavy rainfall.

The urgency of these efforts has been highlighted by a series of devastating storms this year. Named Ragasa, Bualoi, and Matmo, each storm left a trail of destruction, with record rainfall transforming streets into rivers and causing frequent landslides, leaving little time for recovery.

This week, as Typhoon Kalmaegi intensified on its approach to Vietnam, scientists issued warnings about the potential for more such events. This situation paints a stark picture of Vietnam’s climate future, where warmer ocean temperatures could lead to more frequent, prolonged, and intense storms, disproportionately affecting the nation’s most impoverished communities.

“Vietnam and its neighbors are on the front lines of climate disruption,” said Benjamin Horton, a professor of earth science at City University of Hong Kong.

Climate change is reshaping Vietnam’s storm season

Scientists say the succession of storms battering Vietnam is not a fluke but part of a broader shift in how storms behave on a warming planet. Vietnam usually faces about a dozen storms a year, but the 2025 cluster was a “clear signal” of global warming, said Horton.

Ocean waters are now nearly 1 degree Celsius (33.8 degrees Fahrenheit) warmer than before the industrial era. So storms carry more moisture.

The economic toll has been severe for Vietnam, a developing country that wants to become rich by 2045. Floods routinely disrupt farming, fisheries, and factories — the backbone of its economy. State media estimate extreme weather has cost the country $1.4 billion in 2025.

Vietnam estimates it will need to spend $55 billion–$92 billion in this decade to manage and adapt to the impacts of climate change.

Vietnam’s cities aren’t built for climate shocks

About 18 million people, nearly a fifth of Vietnam’s population, live in its two biggest cities, Hanoi and Ho Chi Minh City. Both are on river deltas that once served as natural buffers against flooding. But as concrete spread over wetlands and farmlands, the cities lost their capacity to absorb downpours.

Flooding in Hanoi in October lingered for nearly a week in some neighborhoods. The city of over 8 million has outgrown its infrastructure and its colonial-era drainage system failed as streets turned into brown canals. Motorbikes sputtered in waist-deep water and the Red River’s levees were tested.

Vegetable seller Dang Thuan’s home flooded knee-deep, spoiling her stock. Her neighborhood used to have several ponds, but they were filled in to build houses and roads. Now the water has nowhere to go.

“We can’t afford to move,” she said, “So every time it rains hard, we just wait and hope.”

In 1986-1996, the decade coinciding with ‘Doi Moi’ economic reforms that unleashed a construction boom, Hanoi lost nearly two-thirds of water bodies in its four core urban districts, according to a study by Kyoto University’s Center for Southeast Asian Studies.

Between 2015 and 2020, it lost water bodies spanning the area of 285 soccer fields, state media have reported.

More than three-quarters of Hanoi’s area — including much of its densely populated core — is at risk of flooding, according to a 2024 study. Flooding in the city can’t be solved by building more, said Hong Ngoc Nguyen, lead author of the study and an environmental engineer at the Japanese consultancy Nippon Koei.

“We can’t control the water,” she said, pointing to Singapore’s shift from concrete canals to greener riverbanks that slow and hold stormwater instead of rushing it away.

A global problem with lessons in nature

The idea of designing cities to “live with water” is gaining traction globally, including in Vietnam.

City officials and residents in India’s Bengaluru are working to save the city’s remaining lakes, while Johannesburg in South Africa is trying to restore its Jukskei River.

Vietnam’s recent floods have sparked a wider conversation about how cities should deal with storms.

The former director of the National Institute of Urban and Rural Planning, Ngo Trung Hai, told the state-run newspaper Hanoi Times that the city must learn to live with heavy rainfall and adopt long-term strategies. European business associations have urged Vietnam’s financial capital Ho Chi Minh City to adopt a “sponge city” approach.

Real estate developers have faced criticism in state media for improper building practices, such as building on low-lying land or roads unconnected to storm sewer systems and treating water bodies as “landscape features” rather than ways to drain storm water.

Some of Vietnam’s biggest property developers have begun to adapt. In the coastal tourism hub of Nha Trang, the Sun Group is building a new township modeled as a “sponge city” with wetlands covering 60 hectares (148 acres), designed to store and reuse rainwater to reduce flooding and absorb heat.

City planners must account for future climate risks, said Anna Beswick, who studies climate adaptation at the London School of Economics.

“If we plan based on past experience, we won’t be resilient in the future,” she said.

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