INTERVIEW Ecologist wants to call in the dam busters

A drone shot of Yeouido Saetgang Ecology Park in Seoul's Yeongdeungpo district. The park's preservation is managed by the non-governmental social cooperative HANgang, established in August 2018. Courtesy of HANgang

By Ko Dong-hwan

• Published Jan 22, 2020 6:15 PM KST
• Updated Jan 24, 2020 8:22 PM KST

'Pristine sandy shores will come back to Han River without dam's blockade': ecologist

By Ko Dong-hwan

SUNCHEON ― A well-preserved wetland at southern Yeouido, flanking a stream from the Han River, is a rare natural habitat in Seoul. Thick foliage offers shelter for Korea's various native birds like eagle owls, kestrels, Eurasian hobbies and other protected species.

Broken mossy tree trunks on the ground remain untouched, providing hiding places for animals, while several ducks occasionally hunt on the river. A sign-posted path invites visitors to appreciate the natural setting, while warning not to mess it up.

Yeouido Saetgang Ecology Park started receiving new care in August 2018 from ecologist Yum Hyung-cheol, general director of social cooperative HANgang located next to the park. By inviting people to plant trees (only certain species that can withstand gales) and expanding its monitoring along the river, he has been transforming the once-neglected wasteland closer to its pristine state ― and drawing public attention to its beauty.

The park is part of the Han River that stretches out like a web across 32,000 square kilometers in Gyeonggi and Gangwon provinces (that's 34 percent of six major river jurisdictions nationwide). It provides locals with water for drinking, farming and other uses and exits to the West Sea through Incheon.

Yum now wants to transform the entire river like Yeouido. How? By removing the Singok submerged dam in Gimpo, 35 kilometers inland from the river's estuary at the West Sea, to let the ocean water in.

“The West Sea surface rises and drops by five meters and the river, even with the dam shut, still vertically moves by about one meter,” Yum told The Korea Times. “If the dam wasn't there, the seawater would flow in and the river surface fluctuation would increase to about three meters. That would bring incredible ecological diversity, forming a large river bath in the morning and, in evening, ebbing away to reveal sandy shores and attract crabs and birds.”

His opinion is built on understanding Korea's unique river environments that are largely different from other countries. While discharge coefficients (the differential between a river's peak amount and its lowest) in other rivers like France's Seine and England's Thames range from 8 to 110, Korean rivers have a much higher range of 71 to 272. That's because Korea's monsoon climate sees concentrated annual rainfall during summer floods compared to the rest of the year. This has created large river paths that fill up during floods and, in the rest of the season, dry out revealing sandy shores.

“In the 1960s, some 100,000 people used to flock to Seoul river shores to bask under the sun,” Yum recollected. But the Han River's sandy shores have been dredged and filled with concrete to support riverside parks, parking lots, entertainment venues and other infrastructure in the city's development plans that started in 1982.

“Ten percent of Seoul is rivers and 45 percent mountains, allowing the rest of the area for over 10 million people to cram into under high land prices,” Yum said. “But if a pristine river ran across such a cityscape, wouldn't that be an eye-opener?”

Opening dam

But demolishing the Singok dam isn't as simple as it sounds. This also applies to 16 other dams built under the controversial Four Major Rivers Project (2009-12) during President Lee Myung-bak's term. The project is still criticized for having spent a record amount of tax money for national civil engineering projects ― over 22 trillion won ($19 billion) ― only to ruin the ecology of the Han, Kum, Nakdong and Yeongsan rivers.

The project, to secure enough water in times of drought, dug 570 million cubic meters of earth from the riverbeds to a depth of six meters and built dams to create reservoirs. For a project with such sheer scale of finance and excavation efforts, its completion came quickly. Critics said the project was hurried to be completed before Lee's presidential term was over.

As a result, the rivers became stagnant, millions of fish died and the habitats of species thriving on the shores were destroyed. Large amounts of green algae formed like a froth, which people called “green algae latte.”

Last August, a presidential water management committee of 39 members was launched under the Water Management Act introduced the previous year. With 20 civilian experts, its top priority is to decide what to do with the dams based on reports from four major river jurisdiction chiefs by early February. The time, however, is not enough for thorough studies, according to Yeongsan River jurisdiction chief Jung Jae-sung.

“We need at least three years to compare and examine water qualities before and after we open the dams in terms of temperature, water flow speed and algae formation,” Jung told The Korea Times.

“If we open the dams only briefly, that will only clear the contaminants on the river surface and not affect lower areas much.”

Jung, also a Sunchon National University professor of civil engineering, said the committee has decided to forgo the status quo ― which has been to keep the dams shut and maintain the rivers' current 3.5-meter depth. The committee was left with three options: flexibly control the dams to adjust water levels to meet different demands from annual farming seasons; keep the dams open at all times to keep the rivers flowing; or demolish all the dams. But different regions will require different solutions.

“Getting rid of those dams as demanded by environmental groups is another challenge because it will once again disrupt the ecosystems, cost additional money and who will want to manage the debris and toxic contaminants left on rivers?” Jung said. He said the best method would be to keep the dams for now and dismantle them at the end of their lifespan in 50 years.

For the committee to make the decision, it will comb through data from the environment ministry's Four Major Rivers Project audit committee, the Board of Audit and Inspection of Korea, and feedback from scholars and local residents.

But in addition to such a scientific approach, the committee has more sensitive voices to hear ― local interests.

The Nakdong River draws the most clashes because the country's longest river, running 213 kilometers through North and South Gyeongsang Provinces, is, unlike other rivers, one huge drinking water supply source, from upper to lower streams. So any movement in one region ― like a dam opening ― has a ripple effect on other regions.

“Because regional complaints surrounding the Nakdong River and its eight dams have been so great, the dams have almost never been open long enough,” Jung said. “Waste water from Daegu and other cities ends up mixed with drinking water for Busan. The issue has been problematic in Busan for 20 years now.”

Yum, a member of the committee, said closing dams at Nakdong is a “politically contentious” matter.

Wrong decisions, damage

The most evident damage from blocking the flows of four major rivers almost 1,000 kilometers in total with dams ― three each on the Han and Kum, two on the Yeongsan and eight on the Nakdong ― is the ecological disaster it caused.

At the Kum River running through North Jeolla Province and Chungcheong Provinces, 600,000 fish, including a catfish weighing 40 kilograms ― a record for Korean rivers ― died in just 10 days following the project's completion in 2012. Sludge worms and midges that were believed to live only in sewers were spotted in the riverbed.

At the Yeongsan River in South Jeolla Province, chlorophyll A surpassed the warning level of 35 milligrams per cubic meter, hitting 135. Magnificent bryozoan and other foreign species, adapted for a still-water environment, mushroomed in number while indigenous species at home in moving water decreased.

Yum said gobiobotia naktongensis, a Nakdong-endemic fish, became endangered and long-billed plovers decreased in number. Both had sustained their safety in the river by laying eggs beneath sandy shores or staying in shallow fresh water above sand to live under camouflage.

Such ecological disasters were highlighted in the 2018 Korean documentary film “Rivercide: The Secret Six.” It was directed by journalist Kim Byung-ki from Oh My News, who has been tracking politicians who pushed for the four rivers project and those from construction companies and news outlets allegedly bribed and silenced by former President Lee.

One of the journalists behind the documentary told an audience at one of the film's guest-visit sessions that he once swallowed a sludge swarm at the Kum River to prove how toxic they are and suffered headaches and stomach aches.

The project's problems date back to the 1980s when the central government first tried to streamline water management policies that were divided between four ministries (environment; agriculture and food; land and infrastructure; and interior and safety). Until 2017, eight attempts were made to put the policies under a single top-down jurisdiction but all failed due to partisan objections.

The Korea Environment Institute in its 2017 report called the country's national water management policies “inefficient and repetitive” and called for structural reform. The report said the country's water supply was monitored by 22 separate systems under the environment ministry, 11 under the land and infrastructure ministry, and other systems by three further ministries.

“As of June 2019, there are 84 water management-related policies,” the state researcher said. “The diversification in water management has ill-begot its own default of diversification in execution of the laws.”

The history of delinquent law enforcement led to the country's inefficient spending.

According to the environment ministry's 2018 report, the country paid 2.53 trillion won for 1,704 national projects under river restoration between 2002 and 2018 and claimed it restored 5.7 percent of the country's entire lower river streams ― 26,789 kilometers in total. But the ministry's 2016 report said 35 percent of the streams' ecological environment still remained damaged.

“Water-managing infrastructures in Korea built after the 1990s were all unnecessarily planned,” Yum said, adding the central governments then had orchestrated all internal affairs without watchdogs calling for correct data or stringent fact-checks.

“Economic efficiency for Soyang Dam, built in 1974, to provide one ton of water was just 3.3 won,” Yum said. “But Jangheung Dam, built in 2014, saw the figure jump to 19,000 won. Dams built later, including Yangsu Dam, had worse indexes, reaching tens of thousands of won. This is why numbers matter before each state decision.

“Our rivers are now excessively abundant with water, as opposed to those who had argued Korea has scarce water resources and pushed for the four rivers project. They were preoccupied with an idea similar to Europeans that rivers must always be maintained full. So they built the dams to fend off drought that comes to Korea once every century or two.

“The better way for Korea would have been going through floods or drought with better welfare systems and water-saving campaigns. That is less costly and a wiser way to adopt to the climate change.”