SEOUL, Aug 11 – The heaviest rain in Seoul in 115 years has spurred the South Korean capital to revive a $1.15 billion plan to improve drainage after flood exposed how even the affluent Gangnam district is vulnerable to climate change-driven extreme weather.
Experts say the city’s capacity to drain water is far behind what’s needed to handle a deluge like the one suffered this week. That has disastrous implications for low-lying areas like Gangnam, as these bouts of extreme weather are becoming increasingly common.
This week’s torrential rain killed at least 11 people across the northern part of the country as of Thursday morning. The downpour, which began on Monday and shifted southwards on Wednesday, knocked out power and caused landslides and flooded roads and subways. read more
Monetary estimates of the damage were still being compiled.
In the wake of the downpour, Seoul Mayor Oh Se-hoon announced on Wednesday the city would spend 1.5 trillion won ($1.15 billion) in the next decade to build six massive underground tunnels to store and release rainwater to prevent flooding.
“The damage from this record rainfall shows that there are limits with short-term water control measures when unusual weather conditions due to global warming have become common,” Mayor Oh said, vowing to establish a city-wide system capable of handling 100 mm (3.94 inches) rainfall an hour from the current 95 mm.
The city’s development meant increased pavement and impermeable surfaces, leading to higher runoff and flooding. Experts said that more than 50% of Seoul’s land areas are impervious, much higher in the affluent Gangnam district with wide boulevards and office buildings.
“It’s always a see-saw game between cost and safety,” said Moon Young-il, a professor of civil engineering at the University of Seoul. “We must find a balance point, and 100 mm seems reasonable enough.”
Seoul lacked any detailed plan for water control as it grew from a city of 2 to 3 million people in the 1960s to one with over 10 million by the 1990s, Moon said.
The underground tunnels were initially proposed in 2011 after heavy rains and landslides killed 16 people, many of them in Gangnam. But put the plan on hold amid decreased precipitation and budget issues in the following years.
Seoul city also plans to ban basement or lower ground apartments after three family members, including a woman with developmental disabilities, drowned in their home on Monday. read more
The calamitous wet weather prompted President Yoon Suk-yeol to hold several meetings with officials this week to find fundamental ways to improve South Korea’s preparedness against similar climate change-induced disasters.
Warmer weather increases moisture levels in the air, leading to more intense rainfall. So while there has been little change in the annual precipitation over the past four decades, the frequency of heavy rains in Seoul has increased by 27% since the 2000s, according to a 2021 report by the Seoul Institute.
“It was indeed extreme weather. But we can no longer call this kind of weather event unusual,” President Yoon told a meeting on Wednesday. ” it can break the most extensive, highest record at any time.”
($1 = 1,302.2400 won)