Nepalese capital Kathmandu was inundated by floodwaters last week after record-breaking rains caused the Bagmati river to breach its banks.

More than 200 people have been killed and thousands of houses damaged in the worst flooding and landslides in the Kathmandu valley in years.

So what caused the flooding and landslides? Was it climate change or unchecked urban encroachment of the river that passes through Kathmandu valley? We speak to experts to understand the deadly flooding in the Himalayan region.

How much did it rain in Kathmandu?

From Thursday to Sunday, the Kathmandu valley recorded about 240mm (9.4 inches) of rain – the biggest deluge since 2002, according to a monitoring station at the Kathmandu airport.

Some parts of Kathmandu reported rain up to 322.2mm (12.7 inches).

The intense downpour was mostly seen in Kathmandu and surrounding regions.

Popular tourist destination, the mountainous Pokhara which is more than 200km (124 miles) from Kathmandu, was also hit by flooding.

How many people died in the Nepal flood?

On Wednesday morning, the Nepal Police Headquarters reported that the death toll from the floods and resulting landslides had risen to 228.

At least 25 other people are missing and 158 injured, according to the police report cited in local news outlet, The Kathmandu Post.

What is the status of flood recovery efforts in Nepal?

Recovery work by the police, paramilitary forces and the army was ramped up on Monday.

Nepal’s army reported that more than 4,000 people were rescued using helicopters, ziplines and rafts.

However, damaged infrastructure and blocked roads are hindering rescue operations, local media reported.

Prime Minister Khadga Prasad Sharma Oli called an emergency meeting after returning on Monday from the United Nations General Assembly session in New York. He was criticised for not cutting short his trip in the wake of the disaster.

What caused the worst flooding in years?

The last time an intense flood was reported in Nepal was in 2002. Relief Web cited the country’s Home Ministry as saying that 198 people were killed and 105 were injured.

The Nepal-based think tank, the International Centre for Integrated Mountain Development, said the flood was worsened by unplanned urban encroachment around the Bagmati river.

Pawan Bhattarai, an assistant professor in the Department of Civil Engineering at Tribhuvan University, says man-made factors contributed to the severity of the flooding caused by record rainfall.

“Natural flood events turn into a severe disaster due to the lack of preparedness or early warning, unscientific land-use practices and haphazard development activities among others,” said Bhattarai.

Urban planner Neeraj Dangol said multiple factors were behind the latest disaster.

The Bagmati river, he says, was narrowed due to haphazard planning and urban development that took place after a drastic population boom in Kathmandu in the early 1990s.

“In the past 40-50 years, houses and roads have been built on areas that used to be part of the river system,” Dangol explained.

He added that before the chaotic development, the ground was made of porous, absorbent, agricultural land. Now, the concrete material of roads and pavements causes water to run off, “adding load to drainage”.

Urban development has also led to deforestation. Forested land helps hold water and also prevents runoff. Hence, deforestation makes land more vulnerable to flooding.

He added that the drainage system has not been updated to cater to Nepal’s growing population.

Between 1991 and 2001, the population grew from 18 million to 23 million. As of 2021 when the last census was published, the population was 29 million, according to Nepal’s Central Bureau of Statistics.

Did climate change make the flood worse?

Experts say climate change has indeed made floods in Nepal more frequent and intense in recent years.

“Extreme weather events are occurring more frequently and the rainfall pattern is becoming increasingly unpredictable which can be attributed to climate change,” said Bhattarai.

However, “we cannot blame climate change to hide our ill management of rivers,” he added.

Who suffers most from Nepal’s flooding?

Communities living in informal squatter settlements on riverbanks have been hit hardest by floods, Dangol, the urban planner,  said. These communities comprise working-class families and daily wage workers.

“Not only are they directly affected by floods, they also suffer loss of belongings, loss of jobs and lack of clean water for many days,” he said.

He added they have to spend money and energy on rebuilding their houses in the aftermath of floods without a safety net to fall back on.

Local media cited the Ministry of Urban Development, saying that 10 percent of Nepal’s urban population lives in informal settlements.

The daily wage is fixed at 668 Nepali rupees ($5) per day, according to an August 2023 update on local media.

“Also, the women and children are highly vulnerable to such extreme weather events in Nepal,” Bhattarai added.

How can floods be prevented?

Dangol, the urban planner, says: “It’s better to be prepared than just react after [flooding] takes place.”

He added that in the long term, urban planning needs to be improved and efforts should be made not to disrupt the original course of the river.

The use of porous material in construction and infrastructure upgrades to handle a growing population are other measures needed to mitigate future disasters, Dangol said.

Bhattarai, from Tribhuvan University, added that water resources projects like hydro-power and irrigation systems should be designed to withstand extreme floods and landslides.

Additionally, “dissemination of warning information should be made effective and awareness should be raised about the safety measures during floods and other water induced disasters,” he said.

He added that government agencies should collaborate with research institutions on developing research-based solutions to flood and water-related problems.

“We should not forget that this is not happening for the first time. It happens every year but this time the scale is huge,” Dangol said.