Natural restoration is the key
Anyone who has spent time in the Korean countryside over the past decade, as I have, knows that a traumatic and unprecedented transformation has been inflicted on the nation’s waterways.
Almost every river and stream, up to the smallest mountain trickle, has been modified into straight lines of concrete trenches. The reason given for such a radical and wide-scale bio-engineering project was ``flood prevention."
From what I have seen, however, much of this construction was unnecessary, environmentally-damaging, and obviously very costly. It may have been merely a job-creation exercise for the powerful construction industry. It may have actually increased the risk of flood damage to the nation.
This would seem to be confirmed by the article entitled ``New anti-disaster system needed" (The Korea Times, Friday July 29). Reporter Kim Rahn quotes engineering experts who say ``areas which used to sustain little flood damage in the past, are seeing more now…"
Even a decade ago in Korea, it was easy to find beautiful and untouched waterways bursting with life, fringed by reeds and picturesque willow trees. Such watercourses meandered naturally, their flow slowed by aquatic vegetation ― nature’s water-purification and filtration service.
In the uplands, smaller creeks intercepted rainwater, pooling and collecting it in stages before gradually releasing it to the lowlands. Such brooks often held clean, potable water year-round. In the lowlands, rivers transported fertile sediments to agricultural land. This was a stable equilibrium, a self-sustaining system, in place since time eternal.
This has been replaced virtually overnight, however, by the insertion of thousands of kilometers of concrete ditches and channels countrywide. In many cases such drains are built running vertically down mountainsides. These sterile structures are not only ugly, but do not support fish, frogs, insects or vegetation, thus eliminating swathes of flora and fauna in the countryside.
They also form inescapable death traps for wildlife, such as deer, that happen to fall into them. Such lifeless stretches are also useless to fishermen. Neither do they perform flood prevention, because they prevent rainwater from permeating into the ground ― and also increase the velocity and force with which it rushes downstream.
In the event of heavy rainfall, this massive instant runoff creates a far greater, sudden storm surge downstream, as we saw along the Han River in Seoul last week. Peak flood events are thus set to become more dangerous. The U.S. Environmental Protection Agency said, ``When wetlands are converted to systems without water retention capacity, downstream flooding problems increase."
On the larger low-lying rivers, bulldozers have spent the last decade systematically stripping away the natural flood defenses. In many cases riverbanks have been cleared of the deep-rooted trees that held them secure, and a superficial layer of concrete or brickwork has been applied.
Korea is well-positioned to learn from the previous developmental mistakes of countries such as the U.S. and U.K., which formerly dammed, dyked and otherwise mutilated their catchment areas until resulting system failures forced a re-think. Scientists now agree, for example, that the draining, dyking, and degradation of the Louisiana swamplands was a major cause of the catastrophic 2005 flooding of New Orleans.
Both countries are now actively restoring rivers and streams back to their natural state. The benefits include increased water quality, management cost-effectiveness, and flood control. In April this year, the U.K. government committed 600 million pounds to wetland restoration, including ``removing dams, weirs, landings and other man-made structures" and creating natural ``buffer strips along rivers."
In the U.S. there is likewise a strong movement to restoration, where current federal initiatives include the natural "restoration of 25,000 miles of stream, and establishing two million miles of conservation buffers."
For an effective, ethical and sustainable solution to the issue of flood protection, isn't it better to work with nature rather than against it?
The writer is a conservationist and environmentalist affiliated with Birds Korea Organization. He can be reached at http://birdskorea.org/BK-Startpage.shtml.