Seoul's Lessons for Asian Urban Flooding

A year ago, heavy summer rains wrought havoc on Seoul, triggering political implications that continue to play out in South Korea's capital city. Due in part to the city's mountainous terrain, 69 people died in landslides and floods, homes were ruined, the subway was paralyzed. There were concerns that landmines left over from the Korean War could surface and cause accidents.

In the aftermath, Seoul's citizenry chastised the city's government for not having done more to prepare. Seoul's mayor at the time was Oh Se-hoon, who came under particular fire for having chosen to direct the city’s resources towards what were considered unnecessary prestige projects like remodeling Seoul as a ‘World Design Capital’ and improving the parks along the Han River (which, it should be mentioned, are far nicer and more popular now than they were a few years ago).

Seoul is hardly alone. Just how much urban flooding has become a regular occurrence across the region was detailed in a 638-page report by the World Bank released in February, describing the problem as a “global phenomenon which causes widespread devastation, economic damage and loss of human lives.” Heavy summer rains in cities including Beijing and Manila this year have caused severe flooding that led to loss of lives and extensive damage. There is no lack of money in either of those places, but for whatever reason it hasn’t been used to develop effective drainage systems to deal with the heavy rains that come annually.

Unlike most other Asian cities, Seoul has chosen to do something about it. The city’s response to the floods should be a lesson not only to Beijing and Manila, but to Bangkok and Indonesia as well, which have suffered perennial flooding for decades.

Immediately in the aftermath of the 2011 flooding crisis, Oh said he would make improvements to Seoul’s drainage system and response capacity, but he didn’t last long enough to enact them. He staked his political future on a referendum in October, which his side lost. He then made good on a pledge and stepped down. An election was soon held and he was replaced by Park Won-soon, a liberal civic group leader.

Park treated improving the city’s flood infrastructure as an important part of his mandate as mayor. “Sixty-nine people died in Seoul. We were shocked so we decided we needed measures to prevent it from happening again,” Park told Asia Sentinel in an interview at his Seoul office.

“We needed a natural disaster governance system. City officials can’t do everything on their own, they need input from residents, experts. We have provided a link between city officials and the residents of flood-prone areas so that they can interact and find ways to solve this problem together.”

In 2011, Seoul’s budget for dealing with summer rains was a modest KRW360 million (US$318,670). After the events of last summer, it was bumped up to 580 million. Mayor Park plans to have the budget rise all the way to 5 trillion by 2021.

There was opposition to this from both sides of the political spectrum, as conservatives called Park’s plans too expensive and environmentalist groups argued against digging new tunnels and building new reservoirs.

Park has devised and implemented comprehensive improvements to Seoul’s drainage infrastructure. He established a task force that would respond to citizen requests (made on a specialized flood hotline) by going out and assessing areas that residents identified as vulnerable to flooding or landslides. Throughout the spring and winter, Seoul city government planned and implemented a series of measures, some basic, some specific to what could be the world’s most wired city.

As South Korea boomed in the 1970s and 1980s, Seoul was built quickly and is now home to far more people than it was probably designed to accommodate. The speed at which the city was built led to some slapdash construction of pipes, so basic improvements to drainage were the first order. Pipes all around Gwanghwamun Square, Seoul’s symbolic epicenter, were reconstructed to fix leaks and improve drainage. An underground tunnel was built to connect the square with the Han River.

Also, Seoul is a concrete mass with only minimal tree cover, meaning very little rainwater is absorbed into the ground. “The problem is permeability. Most of the rainwater doesn’t permeate the ground when it falls,” said Park.

In addition,, since Seoul is surrounded by mountains, there is widespread risk of landslides. Thirty-four particularly dangerous areas were designated by the taskforce.

Mayor Park thought it essential that Seoul residents have a forum to communicate with city officials and share information among themselves. “We developed an online system so that residents can report online by uploading photos and share information that way.”

Park recognizes that this only possible in a city like Seoul where residents have access to technology and are savvy about using it. “Our community mapping system was only possible because Korea is such connected country where so many citizens have smartphones.” Still he hopes that other cities will benchmark Seoul’s measures and use them to improve. “I believe that this will become a worldwide model,” Park said.

The big question is, whether this is a result of global climate change, or is it just a change of conditions in one city.

“It can be somewhat attributed to global warming because we are seeing repeated instances of heavy rain, we’re seeing temperatures rising, we’re seeing difficulties in agriculture," Park said. “So part of this is global warming, but there are still roles that we can play as a local government by continually discussing ways that we can improve this situation.”

This year in Seoul the summer rains have been lighter, but no serious damage or deaths have been reported. While it’s impossible to say with certainty, the city’s measures appear to have worked.