The Shihmen Reservoir helped rally the nation, and as well as providing a public water supply, it was also given the "four great objectives and five great functions" of supplying irrigation water to farmland in Taoyuan County, preventing floods, generating electricity, promoting tourism and so on. This made it the one among Taiwan's reservoirs expected to fill the largest number of roles.
石門水庫「多難興邦」，除公共用水，更被賦予灌溉桃園農地、防洪、發電、再加上觀光等「四大目標，五大功能」，身兼數職，是台灣任務最多的水庫。