Four ancient Chinese irrigation sites were honored as World Heritage Irrigation Structures (WHIS) on Tuesday, according to the Ministry of Water Resources.

Granted by the International Commission on Irrigation and Drainage (ICID), the inclusion of the four irrigation projects has brought the total number of Chinese irrigation projects on the list to 23.

The Tianbao Weir, one of the newly awarded projects, is located in Fujian province. With a history of over 1,200 years, the weir is the oldest extant water project specifically aimed at barring saltwater and storing freshwater.

The Longshou Canal and Ancient Luohe River Irrigation district in Shaanxi province is said to involve the first underground canal in China's history, making use of the shaft-tunnel method.

The canal helps divert water from the Luohe River, a major tributary of the Yellow River, providing irrigation to local farms in the face of drought and water shortages.