Ⅰ. Hydraulic
  Within the county, there are two main rivers and they are Wu River and Zhuoshui River. Wu River originates on the west side of Hehuanshan of the Central Range. The flow discharge of the river is abundant and the branches flow through Puli, Guoxin, Renai, Nantou, Zhongliao and Mingjian. Zhuoshui River gained its name as the water is muddy. It originates at Zuojiujian Saddle which is in between the main peak and the eastern peak of Hehuanshan. It is the longest river in Taiwan. The branches flow through Zhushan, Jiji, Shuili, Xinyi, Lugu, Yuchi and Renai. It is the river with the highest potential water power in Taiwan.
  By the end of 2007, the drinking water supply prevalence rate in Nantou County is 79.18%. Places with more than 90% of prevalence rate include Nantou City (94.21％), Caotun Township (98.55％) and Mingjian Village (95.73％). Moreover, places with lesser than 50% of the prevalence rate include Guoxing Village (42.22％), Xinyi Village (17.64％) and Renai Village (9.86％).

II. Power
  As the water resource in Nantou County is abundant, there are three hydraulic power plants and they are Mingtan Power Plant and Daguan Power Plant located in Shuili Village of Nantou County and Wanda Power Plant located in Renai Village of Nantou County. The scale of Mingtan Power Plant is the largest in Asia and it is also one of the four largest pumped-storage units in the world. There is also Mingjian Hydraulic Power Plant which is currently under construction.