Interview – KIM Sang-Bae, director of Water Quality & Environment, Office of National River Restoration
Starting to collect water in the weir from rainy season of June after test operation, we would meet four rivers with abundant river water. As collecting water inside weir, water quality became a key subject of attention. Reporter asked to Mr. KIM Sang-Bae, director of Water Quality & Environment
Sixteen weirs start to collect water from June. What if green algae occur?
Out of concerns that stagnated water inside weir might result in water deterioration, environmental groups opposed to our project. However, water inside the weir, unlike that of dam, does not stand still. River water is bound to overflow in static sector of the weir. And then, depending upon the circumstances, movable
floodgate can retain the river-water for a while or discharge it out. Additionally, as to proliferation of algae, inflow of nutritive substances like phosphorus mostly affects. Green algae tend to be influenced by the inflow of nutritive substances, water temperature and amount of sunshine rather than stagnation of water flow. If algae were a biggest factor, dams in the Bukhan River should be affected by algae.
Thanks to the Four Major Rivers Restoration Project, riverside farmlands (which have been a source of nutritive substances into river) are removed. There had been many attempts for that. However, because of many obstacles, it was not easy. In the long run, just by removing illegal riverside farmland, it served for water quality improvement.
Does the investment on environmental infrastructures go smoothly?
The works of environmental infrastructure facilities are in the current progress in 1281 destinations, with 34 basins highly polluted as the center. Though not the Project, we have built facilities that can dispose of various contaminants. That’s the undertaking on treatment facilities about livestock sewage, sewage disposal plant, excreta treatment facilities. In addition to that, the Project added phosphorous treatment facility to them. Farmland-free riverside environment and phosphorous treatment facility will doubly reduce the potential of algae. We have many backup countermeasures for efficiency of water quality improvement.
It seems very large that the parks created in basins of the Four Major Rivers. Could you tell us detail about the management of basic sanitation facilities?
Things about sanitation facilities are very important. When a park gathering people is created on the riverside, public toilet and waste disposal lots (or at least recycling bins) are prerequisites. We contemplate how these facilities not to affect river water’s health. For instance, public toilet can be a problem in flood, but we devised a floating-type one. In waterfront parks of the Han River, we can utilize with those technologies. At any case we consider environment effects for minimize any harmful effect on water quality.
How do you pave the bike path?
There are various materials for paving bike trails. Water permeable or impermeable materials are used depending on the conditions. Since the urban course needs to fast water drain-away, permeable materials are used. On the contrary, when it comes to riverside circumstance, it is easily wet or sometimes inundated, so you don’t stick to expensive water-permeable materials. It depends on locations and circumstances. Some area can match with cement paving or other place has a better chemistry with red clay. We will adopt the best materials and method depending on regional characteristics. At any reason, materials with potential danger of toxic substances cannot be used at all.
Exterior lighting could affect aquatic ecosystem. Foreign experts advised to
lower the height of streetlamp. Is there any adverse effect from it?
Since my specialty lies on water quality, I am afraid that it is hard to elucidate on the matter about lighting or structures. However structure experts advise ecosystem-oriented design. The executive team will also find a way that does not affect plants and aquatic creatures like fishes. I think it is important that making balance with local residents, riparian buffer zone and surrounding environment. After contemplating various possible factors, specialized team will reflect them in their planning.
Environment groups insist that the Project reduced the number of migratory birds, on the other hands, field workers witness birds increased. Which one is true?
Concerning to migratory birds, there are many complex set of factors like temperature, feeds and so forth. Construction noise can affect temporarily. Last year, some habitats were empty without them. It probably results from a long freeze-up of last winter. Experts say whether effects could be a considerable factor for migratory birds. Noises of construction yard can be temporary but not perpetual. After completion of the project, all the Four Rivers will have enhanced environments for wild species including migratory birds.
There are residents’ testimonies that fishes increased in number. Some media opposing the project seemingly does not deal with the fact. Did it really increase?
Exact ecological study will be done by related organization. Most of all, the voices from the rivers says unanimously that there has been obvious increase of fisheries in its number and in diversity. The more the river water, the better the aquatic ecosystem. It is a natural progress. Biodiversity also surely undergoes improvements. In the long run, virtuous circle structure gets into the stabilized orbit. 1980’s Han River Development Project already proved that fluvial environment improvement works are bound to enrich the natural assets in a long-term perspective.
The key point on the river is water. When there is abundant water, wetlands flourishes. The Four Major Rivers Restoration Project also creates artificial wetlands which will provide better and much opportunity of survival and proliferation. We created fishways where the weirs located. Creating fishways cost more expenditure; however the reason why we added it to earlier planning phases is to commit our duty and initial promise for ecosystem restoration.
There were some oil spill accidents from dredger or excavators. Could you tell us about preventive measure for that?
We have provided constant safety education programs to workers. In spite of that, moment’s carelessness can trigger accident. Therefore, regional officials from Ministry of Environment take charge in intensified safety education and inspection. Education for the field workers is more directly effective.
