A large water project that dates back about 5,000 years was discovered by Chinese archaeologists in Zhejiang Province in east China, the Xinhua News Agency reported.
Believed to be the oldest large water system in China, the finding included 11 dikes and it was found on the outskirts of the provincial capital Hangzhou. Archaeologists believe the dikes were used for irrigation, flood control and transportation.
According to the report, the dikes are located near Liangzhu, an ancient city that existed about 4,000 to 5,300 years ago, which was discovered in Hangzhou's Yuhang District in 2007.
Wang Ningyuan, the lead researcher with the provincial institute of cultural relics and archaeology, said that three of the 11 dikes excavated by archaeologists between July 2015 and Jan. 2016 have identified pottery shards belonging to the Liangzhu culture. Between 1996 and 2010, the "mound" excavated has been identified as a dike, Wang added.
The site was estimated to be between 4,700 and 5,100 years old as results of the carbon-dating tests on construction materials such as bamboo and straw taken from the dikes show.
Three reservoirs may have been formed, with high dikes erected along the mountains and low ones linking the mountains. One of the dikes reportedly covered 9.4 square kilometers or about 1.5 times the area and four times the volume of Hangzhou's West Lake.
The high dikes could withstand continuous rainfall of more than 800 millimeters, while the low ones 1,900 millimeters, according to Liu Jianguo, with the Institute of Archaeology of the Chinese Academy of Social Sciences, who carried out geographic information system (GIS) studies.
"Maybe our ancestors designed them to counter typhoons that brought torrential rain," Liu said.
Professor Xu Shijin of Nanjing University, who visited the dikes over the weekend together with a group of senior archaeologists, speculated that the dikes were built to water paddy fields, since that time poor yields required large-scale planting.
"There were many craftsmen who made jade articles in Liangzhu 5,000 years ago, so they needed a large amount of grain," Xu said, adding that the Liangzhu culture is well-known for its exquisite jade.
Researchers urged for better protection of the site as they said that they will continue to look for spillways and ditches.
Professor Zhao Hui of Peking University said that the site's discovery indicates that people who settled in Liangzhu were highly advanced.