Rescuing land before it subsides

By Lee Wu-chung 李武忠  / 

Sun, Sep 08, 2013 - Page 8

In the wake of Tropical Storm Kong-Rey, politicians have engaged in a veritable war of words. Each time there is a flood, the aquaculture industry becomes the target of public criticism because they pump groundwater and cause the land to subside. Is this because fish farmers are stubborn or because government officials are incompetent?

In the 1960s and 1970s, the government encouraged aquacultural use of low-lying coastal land and land not suitable for agriculture to provide more employment opportunities. Although the conditions were less than ideal, business operators worked hard to turn the low-value land into fish ponds. As they started farming, selling and exporting fish and shrimp, they brought a lot of foreign currency into the country.

However, because the issue of fresh water supplies was not considered at the time, and because the industry developed faster than the government had expected, the resulting water shortages made operators dig wells to sustain their fish farming. This practice was not addressed promptly by the competent authorities and land subsidence was a direct result in some areas.

This is not disputed by the fish industry, but other industries also had been pumping groundwater for a long time — although this has been overlooked. Therefore, for many years fish farmers have had to bear full responsibility for a problem that was not entirely of their making.

Today, many coastal areas have dropped below sea level, making it difficult to remove water that has collected in them. The government must now consider costly flood prevention measures in these areas.

However, it is most important to ascertain the cause of land subsidence — which is not only the result of pumping by the fish farming industry — and devise an effective response. The government should consider changing how the aquaculture industry operates and uses land, and help the coastal population lower their reliance on fish farming.

It could use aerial photography to mark the distribution of major fish ponds and land subsidence, divide the areas into mild, moderate and severe according to the levels of subsidence, and then design separate solutions for the different areas.

In mildly affected areas, the government could subsidize equipment for water circulation, implement strict controls on the use and discharge of water, implement an environmental and ecological certification regime and guide ecological fish farming.

In moderately affected areas, it could set up special aquaculture parks to be able to handle discharged water in a uniform manner.

In severely affected areas, it could encourage farmers to exit the industry and set up a mechanism to help make that possible while also planning big water catchment areas and floodways as well as areas for hobby fishing.

By addressing the needs of areas with different levels of land subsidence in different ways, it might one day be possible to prevent flooding and the loss of land.

Lee Wu-chung is a professor of agricultural economics.

Translated by Perry Svensson