The branched check gate of the southern and northern main canals of Chianan Canal is an important hub connecting the water diversion channel of Wushantou Reservoir as well as regulating the water volume of the south and north main canals, providing agriculture-use water for 64,000 hectares in the Chianan irrigation area and for the daily household use and industry use water use of 2.5 million people in Tainan City and Chiayi County and City.