Although research reports say that the Shihmen Reservoir's water quality is poor, the Tahan River, which in the dry season fails half of nearly 20 different water quality tests, relies on water released from the reservoir to "dilute" its pollution.
雖然學昔報告指出，石門水庫水質不佳，但旱季十幾項水質檢測有一半不符合標準的大漢溪沿岸，卻等著水庫放水才能「稀釋」汙染。