Taiwan's rivers are an engineer's nightmare. Often a single torrential tropical rainstorm will fill silt traps and weirs full of silt. Removing silt is too costly and is impractical, and so once these structures are overwhelmed, they simply become part of the river bed.
台灣河川是工程的終結者，往往來一場豪雨，攔砂壩、攔河堰就被泥砂淤滿了，清砂的成本太高，不切實際，因此，淤滿了，工程也就成為河流河床一部份了。