Peeling Back Pavement to Expose Watery Havens

[김재균22]

July 17, 2009

Peeling Back Pavement to Expose Watery Havens

Since its opening in 2005, hundreds of thousands of people have visited the Cheonggyecheon stream in Seoul, South Korea, with friends and family.

After its opening in 2005, hundreds of thousands of people have visited the new stream with friends and family.

By ANDREW C. REVKIN

SEOUL, South Korea — For half a century, a dark tunnel of crumbling concrete encased more than three miles of a placid stream bisecting this bustling city.

The waterway had been a centerpiece of Seoul since a king of the Choson Dynasty selected the new capital 600 years ago, enticed by the graceful meandering of the stream and its 23 tributaries. But in the industrial era after the Korean War, the stream, by then a rank open sewer, was entombed by pavement and forgotten beneath a lacework of elevated expressways as the city’s population swelled toward 10 million.

Today, after a $384 million recovery project, the stream, called Cheonggyecheon, is liberated from its dank sheath and burbles between reedy banks. Picnickers cool their bare feet in its filtered water, and carp swim in its tranquil pools.

The restoration of the Cheonggyecheon is part of an expanding environmental effort in cities around the world to “daylight” rivers and streams by peeling back pavement that was built to bolster commerce and serve automobile traffic decades ago.

In New York State, a long-stalled revival effort for Yonkers’s ailing downtown core that could break ground this fall includes a plan to re-expose 1,900 feet of the Saw Mill River, which currently runs through a giant flume that was laid beneath city streets in the 1920s.

Cities from Singapore to San Antonio have been resuscitating rivers and turning storm drains into streams. In Los Angeles, residents’ groups and some elected officials are looking anew at buried or concrete-lined creeks as assets instead of inconveniences, inspired partly by Seoul’s example.

By building green corridors around the exposed waters, cities hope to attract affluent and educated workers and residents who appreciate the feel of a natural environment in an urban setting.

Environmentalists point out other benefits. Open watercourses handle flooding rains better than buried sewers do, a big consideration as global warming leads to heavier downpours. The streams also tend to cool areas overheated by sun-baked asphalt and to nourish greenery that lures wildlife as well as pedestrians.

Some political opponents have derided Seoul’s remade stream as a costly folly, given that nearly all of the water flowing between its banks on a typical day is pumped there artificially from the Han River through seven miles of pipe.

But four years after the stream was uncovered, city officials say, the environmental benefits can now be quantified. Data show that the ecosystem along the Cheonggyecheon (pronounced chung-gye-chun) has been greatly enriched, with the number of fish species increasing to 25 from 4. Bird species have multiplied to 36 from 6, and insect species to 192 from 15.

The recovery project, which removed three miles of elevated highway as well, also substantially cut air pollution from cars along the corridor and reduced air temperatures. Small-particle air pollution along the corridor dropped to 48 micrograms per cubic meter from 74, and summer temperatures are now often five degrees cooler than those of nearby areas, according to data cited by city officials.

And even with the loss of some vehicle lanes, traffic speeds have picked up because of related transportation changes like expanded bus service, restrictions on cars and higher parking fees.

“We’ve basically gone from a car-oriented city to a human-oriented city,” said Lee In-keun, Seoul’s assistant mayor for infrastructure, who has been invited to places as distant as Los Angeles to describe the project to other urban planners.

Some 90,000 pedestrians visit the stream banks on an average day.

What is more, a new analysis by researchers at the University of California, Berkeley, found that replacing a highway in Seoul with a walkable greenway caused nearby homes to sell at a premium after years of going for bargain prices by comparison with outlying properties.

Efforts to recover urban waterways are nonetheless fraught with challenges, like convincing local business owners wedded to existing streetscapes that economic benefits can come from a green makeover.

Yet today the visitors to the Cheonggyecheon’s banks include merchants from some of the thousands of nearby shops who were among the project’s biggest opponents early on.

On a recent evening, picnickers along the waterway included Yeon Yeong-san, 63, who runs a sporting apparel shop with his wife, Lee Geum-hwa, 56, in the adjacent Pyeonghwa Market.

Mr. Yeon said his family moved to downtown Seoul in the late 1940s, and he has been running the business for four decades. He said parking was now harder for his customers. But “because of less traffic, we have better air and nature,” he said.

He and his wife walk along the stream every day, he added. “We did not think about exercising here when the stream was buried underground,” Mr. Yeon said.

The project has yielded political dividends for Lee Myung-bak, a former leader of construction companies at the giant Hyundai Corporation. He was elected Seoul’s mayor in 2002 largely around his push to remove old roads — some of which he had helped build — and to revive the stream. Today he is South Korea’s president.

Even strong critics of the president tend to laud his approach to the Cheonggyecheon revival, which involved hundreds of meetings with businesses and residents over two years.

A recent newspaper column that criticized the president over a police raid on squatters ended with the words “Please come back, Cheonggyecheon Lee Myung-bak!” — a reference to the nickname he earned during the campaign to revive the stream.

The role of Seoul’s environmental renewal in Mr. Lee’s political ascent is not lost on Mayor Philip A. Amicone of Yonkers, a city of 200,000 where entrenched poverty had slowed a revival project. Once the river restoration was added to the plan, he said, he found new support for redevelopment.

Yonkers has gained $34 million from New York State and enthusiastic support from environmental groups for the river restoration, which is part of a proposed $1.5 billion development that includes a minor-league ballpark. The river portion is expected to cost $42 million over all.

A longtime supporter was George E. Pataki, who helped line up state money in his last year as governor, Mayor Amicone said. “Every time he’d visit, he’d say, ‘You’ve got to open up that river,’ ” he added.

Part of the plan would expose an arc of the river and line it with paths and restaurant patios that would wrap around a shopping complex and the ballpark. Another open stretch would become a “wetland park” on what is now a parking lot.

Mr. Amicone, who has a background as a civil engineer, said the example of Seoul’s success had helped build support in Yonkers. In an interview, he recalled the enthusiasm with which Mr. Lee, then Seoul’s mayor, toured Yonkers in 2006 and discussed the cities’ parallel river projects with him.

“Whether it’s a city of millions or 200,000, the concept is identical,” Mr. Amicone said. “These are no longer sewers, but aesthetically pleasing assets that enhance development.”

Jean Chung contributed reporting.