How cities cope with climate-caused floods and drought

Yahoo

12-03-2025

Urban areas, which are home to more than half of the 8 billion people on the planet, are known to be heating faster than rural regions. They are also, according to new research by the international charity WaterAid, particularly at risk from water-related natural disasters.
The study examines more than 100 major cities where climate patterns have dramatically changed over the past four decades. And in unexpected ways.
"I assumed dry places were getting drier and wet places wetter, but the most surprising thing to me was that many cities are experiencing a complete change in what they were used to managing," Katherine Nightingale, WaterAid's global international affairs director, told DW.
Cities such as Cairo, Madrid, Hong Kong, and the Saudi cities of Riyadh and Jeddah — once prone to floods — now struggle with drought.
Meanwhile traditionally dry cities in India, Colombia, Nigeria and Pakistan are now likely to experience flooding.
"Infrastructure that was designed and built at a time when these were dry cities are now having to deal with this idea that these are now flood-prone cities," Nightingale said.
All but three of the cities facing increasing floods are in Asia — half of them in India.
Europe, North Africa and the Middle East are experiencing the greatest drying trend.
Cities in China, Indonesia, the United States and East Africa are most at risk from a climate whiplash — meaning that they must deal with both increased wetness and dryness, often within the same year. And that's especially hard to handle.
"Droughts dry up water sources, while floods destroy toilets and sanitation systems and contaminate drinking water," Nightingale said.
Such breakdowns in water, sanitation and hygiene services are often felt most by vulnerable communities through impacts on health, education and livelihoods that can push them deeper into poverty.
Nightingale said it was vital to "map who's most at risk and work with these communities on the front lines."
That's exactly what Pakistan's first female architect, Yasmeen Lari, now in her 80s, has been doing for years. She has found creative and inexpensive ways to protect the most vulnerable people against flooding.
WaterAid ranks Pakistan's largest city, Karachi, among the 10 most at risk from a combination of intensifying climate hazards and the high vulnerability of its communities. As many as half of its 20 million people live in slums.
In an effort to make the city more resistant to floods, Lari made use of terracotta — drawing on Pakistan's rich craft traditions.
"I'm surprised it's not used more because it's a wonderful material, it's permeable, it absorbs water," she said. She added that it also "helps cool down the air."
Taking a street-by-street approach, Lari has replaced impermeable asphalt surfaces with terracotta tiles, installed stormwater wells and planted native trees along streets to absorb rainwater and reduce heat. Her work has already cooled streets by 10 degrees Celsius (18 degrees Fahrenheit) and prevented flooding, she says.
"In a very complex environment such as our urban centers, it's very difficult to take up a whole area and revamp it," Lari said, "but it's possible to take sort of neighborhood enclaves which are then flood-free and free of any kind of heat islands."
During Pakistan's devastating 2022 floods, which affected 33 million people and left Karachi underwater, the only dry street was the one Lari had already revamped, she said.
Lari didn't just want to flood-proof streets — a process in which she involves residents — but has also set out to create inexpensive flood-resilient housing.
"We don't have to go for big ambitious space schemes," she said. "If you do everything locally, with local materials, then it makes it affordable for people."
Having experimented with sustainable low-cost materials, she has come up with a simple bamboo hut with that costs just $87 (€80) — one-tenth the price of a cement house in Pakistan — and is resilient in the face of floods and earthquakes.
"I never thought bamboo was worth looking at. But ever since I started building with it, I never looked back. I just use bamboo now," Lari said.
The plant's natural flexibility allows it to bend rather than break under pressure, and, unlike concrete, it doesn't trap water, thereby preventing structural damage. It also grows rapidly — some species over a meter per day — and is easy to replant.
She sees potential for bamboo housing in cities worldwide, even in the Global North.
While Pakistan faces floods, the southern African country of Zambia struggles with droughts that disrupt access to water, sanitation and electricity — affecting low-income communities most severely.
The country relies on hydroelectric power, which is also used to supply the population with clean water. But when scarce rainfall causes levels to drop, it results in power shortages and limited access to clean water. Stagnant water during drought can also become a breeding ground for disease.
"2024 saw the worst cholera outbreak that the country has ever experienced," said Yankho Mataya, WaterAid's country director in Zambia.
She said the spread of the disease was closely linked to the water supply and that the capital, Lusaka, was identified as the "epicenter" of the outbreak.
WaterAid helped residents of Sylvia Masebo, a hard-hit neighborhood in the city, by installing solar panels to generate the electricity needed to pump water collected in tanks. The project was a success.
"When production of water supply from the utility company was low due to the electricity crisis triggered by the next drought, this community continued to enjoy full access to safe drinking water," Mataya said.
The initiative is easily replicable, particularly in rural areas. WaterAid has since expanded it to schools, communities, and healthcare facilities.
Applying such solutions on a broader level, requires funding that Mataya says is slow in coming. "The problem is, we're not seeing as much public investment and instead a significant dependency on external funding," she said.
Nightingale stresses the need for government plans and investment to be specifically targeting the most vulnerable communities.
"It isn't rocket science. The solutions are out there, and they are very simple, but they require effort and commitment," she said. "Our data shows that this is a global issue. Cites on every continent and in every corner of the world are affected. So, we all need to act now and work together to make cities more resilient."
Lari also advocates for working together. She believes change can happen if people are encouraged to participate in bringing it about.
"We need to really see how we can get to people and say you can do it yourself, as well. You just have to share the knowledge, empower them, get them to do it, and, if you can put women in the lead, you are a winner," she said.
Edited by: Tamsin Walker