This paper presents the economic-analysis results and calculated potentials to study future installation of micro hydro power (MHP) plants in some selected canals of Chia-Nan Irrigation Association in Taiwan. There are total 17 Irrigation Associations in Taiwan and each Irrigation Association has a number of irrigation canals with available water captured from several large streams in Taiwan for farmland irrigation. These irrigation canals have potentials to generate electric power using MHP plants. This paper studies the potentials and economics of seven irrigation canals with water heads higher than 2 m. Direct cost, indirect cost, standby budget, and maintenance cost, etc. are employed to compare with the average annual return that the generated electric energy delivers to the utility grid using a simple payback-period method. With the proposed economic-analysis results and potential outcomes, Chia-Nan Irrigation Association may determine the best locations with minimum payback years to install suitable MHP plants for electric power generation. This economic method can also be applied to other Irrigation Associations in Taiwan to take best advantage of water resources.