Share Tech & Science ancient china Engineering dams hydraulics Liangzhi A recently excavated hydraulic system is rewriting the history of early Chinese engineering. Four years of research have revealed that the water management system of the Liangzhu, an agricultural Neolithic society known for their jade objects, took an estimated 3,000 people nearly a decade to build, and pushes back the date of China's earliest known large-scale water engineering project to about 5,100 years ago. From 2009 to 2013, a team of researchers used a combination of archaeological samples, remote sensing data, geographic modeling, and satellite imagery to analyze how the Liangzhu people managed the water in the Yangtze Delta between 5300 B.C. and 4300 B.C. The delta, which drains into the east China Sea, was underwater up until about 7,000 years ago. (According to Forbes, it's currently poised to become a "megaregion" that already contains many of China's wealthiest cities and generates almost a quarter of the nation's GDP.) The researchers traced a system of high dams, low dams, and levees that they propose represents one of the world’s oldest and largest known hydraulic engineering projects. Previously, the oldest known comparable systems were Mesopotamian, from around 4,900 years ago. A paper describing the findings was published December 4 in the journal Proceedings of the National Academy of Sciences.  Keep up with this story and more by subscribing now Corresponding author Yijie Zhuang, who researches Chinese archaeology at the University College London, told Newsweek over email that the dams were built surprisingly quickly given their sheer scale. Top photo: A structure of the Meirendi bank with wooden planks still standing upright. Bottom photo: The Bianjiashan pier, wooden stakes still were preserved, forming a T shape. PNAS The Liangzhu society was agrarian, and the Yangtze Delta was its hub. The researchers estimate that the thousands of laborers moved more than 10 million cubic feet of earth to build the dams, in addition to what they describe in the paper as a network of artificial canals, ditches, and moats more than 18 miles long that supplemented the river's