A reservoir only has a life of 40 to 50 years, and Taiwan only has some 40 remaining sites suitable for building new reservoirs. If we are to build a new one every year from now on, then 90 years from now all Taiwan's reservoirs will be silted up, and there will be nowhere left to build more.
一個水庫的壽命不過四、五十年，今天台灣能建水庫之處所剩不過四十個，若未來每年增建一個，九十年後台灣所有水庫都淤滿了，再沒地方可建壩了。