Why is rain-soaked Taiwan always running out of water?

Taiwan receives on average 2,510 mm of rainfall every year, 2.6 times the world average. Compared with the rainfall of 180 countries in the climate data published by the United Nations’ Food and Agriculture Organization (FAO) in 2014, Taiwan ranked 13th. In other words, we have abundant rainfall.

Yet no matter how abundant rainfall is, Taiwan faces a number of challenges to keeping its water tanks full. Our densely populated country has an uneven rainfall distribution, as around 80% of the annual rainfall occurs mostly during typhoon season, between May and October, resulting in a disparity of water levels in the wet and dry seasons. Moreover, the geographical features of Taiwan – high mountains, short rivers, and high velocity water courses – cause rainwater to flow into the sea quickly, making it even more difficult to collect and utilize water resources. Together with the huge difference in humidity between wet and dry seasons, as well as the unequal distribution in regional precipitation, Taiwan faces difficulties in water storage and allocation.

Other than that, low effective water storage capacity caused by reservoir sedimentation, wear and tear on water mains, pipe leakage due to road work, and the high numbers of heavy vehicles, all contribute to the problem of water shortage in Taiwan.