Mulanbei Water Conservancy Project
Mulanbei Water Conservation Project, which has served for nearly 1000 years, adopted unique planning, design and construction techniques well ahead of its contemporaries to retain fresh water and resist saline water intrusion. The project is situated on Mulan river, 4 km southwest to Putian city of Fujian province in southeast of China. The structure, completed in 1083, during the northern Song Dynasty, continues to be in operation to this day, irrigating over 9133 ha of farmland in the Putian Xinghua plains takes an important place in the world civil engineering.
It was scientifically designed as a structure that served the purpose of water retention, tide prevention, flood discharge, sand removal and water diversion. The site of this weir was selected based on early experiences perfectly balancing the shock from the upstream flood and the downstream sea tide. Located on the weak riverbeds near the ocean, the head works structures of Mulanbei water conservancy project included overflow weir, gravity dam, diversion dike, and sluice gate and diversion mouths at both banks. The adopted raft foundation effectively alleviated pier pressure on unit area. The sluice foundation and the weir were made of local granite.
Gate walls or piers were built on the weir while stone pillars inserted through the walls or piers into the river-bed base rock, pig iron was melted to fill the gaps, the pier stones of the weir and the gates were linked with shoe-shaped iron ingots. As such, the weir/gate formed an integrated whole. Iron ingot was used among the masonry to effectively maintain more than 930 years operation of Mulanbei project. Till this day, the project keeps its basic form of engineering construction in historical period.
Before the construction of Mulanbei project, no crops except cattail could grow in south and north plains. The project has ensured water supply for agriculture, industry and domestic life in the command area. It irrigates a farmland area of 10867 ha and benefits more than 500,000 people. Mulanbei project had completely changed the plain to a main production area of grain and sugarcane in Putian city.Mulanbei water conservancy project is a middle scale multi- purpose irrigation project for water diversion, water storage, water drainage and water retaining. It has contributed to the development of Xinghua plain. Not only does it supply water to industrial production, agricultural production and domestic life, it also plays a part in shipping transportation, aquaculture, especially in defending flood disaster. The project witnessed the increase in population and the fast development of agriculture in south China during Tang and Song dynasties.
Architects and builders of Mulanbei project are considered as guardians of the area and are fondly remembered to this day.Construction of Mulanbei project has been supervised under the government since Song dynasty. Special personnel took charge of annual repair outlay, labor expenditure, and construction supervision and so on. This kind of management mechanism continues til today. Currently, Mulan river administrative office and the local administrative office of the south and north canals are responsible for flood wall management in the area.
