Ancient irrigation systems earn recognition

Construction of the Jianjiangyan irrigation system began around 141 BC in Pengzhou, Sichuan province. It continues to irrigate 10,800 hectares of farmland. Builders used bamboo cages filled with pebbles to create weirs that coordinated irrigation, floodwater discharge and sediment removal.

The system also features weirs that divert spring water from artesian wells, ensuring irrigation even during droughts when river water is scarce.

The Yongding River ancient canal irrigation project in Mentougou district, Beijing, is believed to have been built during the Liao Dynasty (916-1125). It still irrigates about 133 hectares and provides supplementary water for orchards and ecological areas.