Before the construction of the Irrigation Canal Greenway (Chianan Canal), the Chianan Plain was a vast expanse of land that suffered from water scarcity and high soil salinity, rendering it unsuitable for cultivation at the time. During the Japanese colonial period, in response to the growing demand for food, the Governor-General’s Office proposed the “Guantian River Weir and Irrigation Project,” which aimed to construct a dam on the upper reaches of the Zengwen River (Guantian River) to irrigate approximately 100,000 jia (around 66,000 hectares) of farmland in the Chianan Plain. Subsequently, the “Direct Water Diversion from the Zhuoshui River Project” was drafted to irrigate an additional 50,000 jia (approximately 33,000 hectares) of farmland in the Yunlin Plain using water from the Zhuoshui River. These two projects together formed the foundation of what is now known as the Chianan Canal System, designed to irrigate a total of about 150,000 jia (approximately 100,000 hectares) of land.

In 1919, the “Public Weirs and Guantian River Irrigation Association” was established, with Japanese engineer Yoichi Hatta appointed to oversee the design and construction. Construction of the Chianan Canal officially began in 1920 and was completed in 1930, marking a milestone in Taiwan’s irrigation history. With a legacy spanning over a century, the Chianan Canal is also referred to as the “Century-Old Canal.”

Following its completion and the initiation of water delivery, the Chianan Plain was transformed into a fertile agricultural region, making an immense contribution to Taiwan’s agricultural development. The system now irrigates approximately 150,000 hectares of farmland, increasing the area of premium rice paddies in the region by a factor of 30 and boosting rice production fourfold.

Currently, the Chianan Canal and the Wushantou Reservoir have been officially registered as cultural landscapes by the Tainan City Government (formerly Tainan County Government) in accordance with Article 53 of the Cultural Heritage Preservation Act, under the official document number府文資第0980238254A號.