Speaking on hugely expensive project, Hans Helmut Bernhart says, “You can’t design nature, and you shouldn’t try”
By Kim Jeong-su, environment correspondent
Hans Helmut Bernhart, a professor at the Karlsruhe Institute of Technology in Germany, is an expert in river development and the design of canals and weirs. Now 72, he decided to specialize in river restoration after observing and listening to complaints of residents near the Iffezheim Weir on the Rhine River, who said flooding patterns had changed since its construction.
Hankyoreh (Hani): While the Four Major Rivers Project was going on, you came to South Korea to see the rivers. Now you’ve looked at the sites after the project’s completion. What are your impressions?
Hans Helmut Bernhart (Bernhart): From looking at the construction sites on the rivers when I came to South Korea two and a half years ago, I had some idea of what was coming. Still, it’s sad. What I want to know is how it was possible for the rivers here to be destroyed, or why nobody learned anything from the failures in Germany. It’s frustrating. Two and a half years ago, I had some hope. I even wrote a report expressing my strong opposition and submitted it to court [through groups opposing the project]. Now it looks like it’s too late. I don’t think I can be any real help anymore. Now it’s you who need to work for change.
Hani: In past interviews, you’ve said that it would be impossible for something like the Four Major Rivers Project to happen in Germany today. Why is that?
Bernhart: First and foremost, it’s about legal and institutional factors. Water management guidelines established for the European Union in 2000 require member countries to preserve and improve their river ecosystems. Citizens aren’t going to accept it if their government’s water policy violates these terms. In the end, it’s a matter of civic consciousness, which takes some experience with failure to form. It’s important to have that sense of civic consciousness that comes from learning through failure.
Hani: You also wrote an opinion saying the best solution for the rivers would be a restoration. What would be the best approach, a restoration or a re-naturalization?
Bernhart: The first step is to open the weirs. After that, you allow the riverbed to fill in. If there isn’t enough sediment flowing down from upstream after the weirs are opened, then you need to “feed” the river by artificially filling it with sediment. Visiting the Nakdong River, I saw that there was a lot of dredging sand along the banks. That needs to be put back in the river.
Hani: Wouldn’t opening the sluice gates accelerate headward erosion?
Bernhart: It might. That’s why it’s better to have a controlled opening, where you take into account the standardization of the water level.
Hani: If restoration is the best option, then it could also be argued that we should have an ecosystem restoration project along the same lines as the Four Major Rivers construction. What are your thoughts on that?
Bernhart: We need to knock down the weir and leave the rest to nature. You can’t design nature, and you shouldn’t try.