Continuous heavy rain brought by tropical storms Trami and Kong-Rey has inundated south and central Taiwan, resulting in widespread damage and public complaints. Local government leaders have now jointly appealed to the central government for flood-prevention assistance. The central government’s response has been to accuse local governments of not making sufficient flood control preparations. The eight-year, NT$80 billion (US$2.68 billion) flood-prevention program, which ends this year, has been virtually drowned in the flooding.
Local government leaders say that the flood prevention budget is being paid out in annual stages, which means that many projects are only half-finished. They are therefore asking that the president extend the budget so that the flood-prevention projects can have their intended effect.
Minister of the Interior Lee Hong-yuan (李鴻源) said that local governments cannot simply ask for more money. They must complete the full flood control program before they start talking about how much money they need, lest the pumping stations be completed and continue to pump out too much ground water, further aggravating land subsidence. If that happens, Lee says, giving out another NT$60 billion or even NT$600 billion will not help.
Both the central and local governments have their own political agendas, and both are right and wrong.
If the overall environment is compromised, it will restrict the effects of any flood control program. Logging in mountainous areas, excessive hillside development, developing river areas and filling low-lying land exposes soil to the elements. When it rains, there will be landslides and excessive groundwater pumped out from low-lying land, causing further subsidence. When such an environment is further destroyed by human intervention, any amount of flood control projects will only be able to deal with the effects rather than the cause of flooding. If flood control programs are not well-planned, the quality of work is inferior and contractors try to skimp on materials, the programs will be even less effective.
As urban areas are turned into concrete deserts and permeable land is replaced with impermeable surfaces — for example by covering running tracks with polyurethane surfaces at schools, building underground parking lots below parks and school buildings, covering sidewalks in impermeable paving slabs, covering river park areas in concrete and asphalt — flooding will continue regardless of how many billions of dollars are spent on sewers and pumping stations.
Judging from failed flood control projects in the past, future projects must take a comprehensive approach. The government should create a task force with personnel from the interior ministry, the Environmental Protection Administration and the Council of Agriculture to consider upper, mid and downstream solutions such as forest, soil and water conservation, riverside development and sewer systems. The goal should be to diminish sudden peak drainage flows during heavy and torrential rain and avoid flooding by considering the ability to naturally hold and drain water. Bioengineering using soil, green areas or detention ponds, rather than relying on concrete and other impermeable construction materials, should be a priority.
Climate change is now a recognized fact, and urban and rural development must be based on considerations of what the natural environment can bear. Taiwan is a natural disaster risk area, and land is continually being developed for industrial use or housing. This deprives nature of its limited natural tolerance, and any money invested in flood controls will only have a limited effect. The fundamental principle for flood control should be to avoid competing with nature, and to return that which can be returned to a natural state. In cases where it is not possible to return something to its natural state, it should be strengthened by engineering.