As t forest was replaced by orchards, large quantities of soil were washed down the Tachia Stream, silting up the Techi Reservoir downstream and shortening its lifespan by an estimated 50 years.
森林被果園代替後，大量的沙土沿大甲溪沖蝕而下，據德基水庫管理處工程人員計算，汙泥淤塞將使下游的德基水庫減壽五十年。