The Huang Ju Irrigation Project (the Project) lies in Huotong Town, Jiaocheng District, Ningde City, Fujian Province. Over 1400 years ago, the Huangju family, led by Huang Ju, an official in charge of admonition in Sui Dynasty (581 AD-618 AD), built it along the Huotong Stream. It is the most complete water project with the highest technical level in Sui Dynasty. In fact, besides its irrigation function, the Project also plays a role in domestic water supply and makes full use of potential water energy, so it is also named as a small comprehensive water project with multiple purposes. In 2017, the Project was added to the World Irrigation Project Heritage List.
Figure 1. the Huang Ju Irrigation Project
The Project consists of the Pipa Tunnel water diversion project on the left bank and the Longyao Canal irrigation project on the right bank, extending over 10 km and watering an area over 20,000 mu (1,333 ha). The Pipa Tunnel is over 700 m long in total, 2.4 m high and about 1 m wide in average. Sediment discharge holes were drilled along the Huotong Stream to facilitate dredging and sediment discharging.
Figure 2. the Pipa Tunnel
The trunk canal of the Longyao Canal is an open channel with a total length of over 5,000 m, a width of 1.51-2.72 m and a depth of 0.95-3 m. Five-stage water hammers were built by the means of using water level difference, and water wheels drove grinding, crushing, pounding and sieving tools to process agricultural byproducts, grains and oil. What’s more, this waterway was then divided into two branches. One was used to irrigate the farmlands of over 1,000 mu (67 ha) in Shiqiaoyang, while the other was employed to provide domestic water to local villagers, forming a complete system of irrigation, waterpower and water supply for people's livelihood.
Figure 3. the Longyao Canal
The technical accomplishment of the Project is mainly reflected in the following. Despite the harsh geographical condition in an unpowered driven era, the ancient people, by taking advantage of elevation difference and through scientific planning, dammed water and diverted water through open channel and drilled tunnel, forming the rational layout of diversion, transfer, storage, irrigation and drainage and realizing the multiple functions of this irrigation project. The rock-cutting method of baking by fire and freezing with water was adopted, thus shaping the proper cross section of tunnels and stepping up the structure stability.
The Project is a model project built by local community with self-raised funds and guided by the government. Prospering for over 1,000 years, it still retains its original appearance and plays an integrated function in agricultural irrigation, domestic water supply and water power processing, thus becoming the historical witness of irrigation civilization for present and future generations.
