China News Service, Lanzhou, October 15 (Reporter Feng Zhijun) is a rare example of the intensive use of large tunnels in ancient river diversion projects; the perfect integration of Dujiangyan's construction technology and northern pirion technology in the arid areas of northwest China; the traditional water distribution system of the river basin can be called the living fossil of the water distribution system in arid areas... The Gansu Tolai River Oasis Irrigation System, newly added to the World Irrigation Engineering Heritage List, has various core items that are still in operation today, and has outstanding engineering and technical historical value and rich historical and cultural connotations.
The reporter learned from the Gansu Provincial Department of Water Resources on the 15th that the "Gansu Tuolai River Oasis Irrigation System" has been selected into the 13th batch of World Irrigation Engineering Heritage List in 2026. This system is located in the middle of the Hexi Corridor, where the Jiayuguan Pass, the western end of the Great Wall of the Ming Dynasty, is located, and has always been an important border defense location. It has a profound cultural and historical heritage, with a documented history of water conservancy development of two thousand years, and its heritage structure and appearance are obviously typical and representative.
Kang Dekui, director of the Tuolai River Basin Water Resources Utilization Center of the Gansu Provincial Department of Water Resources, said on the 15th that the irrigation system uses the surface runoff of the Tuolai River originating from the Qilian Mountains and its main tributaries, such as the Flood River, Linshui River, and Qingshui River, as irrigation water sources. It originated in the Western Han Dynasty, developed in the Tang Dynasty, and matured in the Ming and Qing Dynasties. The current irrigation area is 947,800 acres.
Kang Dekui said that the core items of the system include the Hongshui River Dongzi Canal, the Tolai River Mainstream Canal System, the Linshui River Qingshui Canal System, and the matching traditional water distribution system of the Toolai River Basin. They were first built over 300 years ago and have a complete chain of documentary evidence, playing a key supporting role in regional ecological, economic and social development.
For example: the Flood River Dongzi Canal was built by the ancestors of water conservancy in the Ming Dynasty on the cliffs of tens to hundreds of meters on both sides of the river. Through the technology of "horizontal guide tunnels and multi-head excavation", an underground tunnel with a total length of more than 30 miles was drilled to divert water out of the mountain and onto the shore. The cross-section of the tunnel is "as high as the human body and as wide as an arm's length" and can accommodate a human being stretching out. It is a rare example of the intensive use of long tunnels in ancient river diversion projects, allowing Qilian snow water to irrigate thousands of hectares of farmland downstream.
The Heihe River water equalization system, which originally originated during the Yongzheng period of the Qing Dynasty, cleverly resolved water disputes by strictly stipulating exclusive irrigation periods for the upstream and downstream rivers, and safeguarded the order of the river basin and the harmony between people and water. This system was born out of considerations of fairness and water distribution, and has always been extremely strictly implemented in the basin. It can be called a living fossil of the water resources distribution system in arid areas.
Kang Dekui said that as a typical representative of the oasis irrigation system in arid areas of the Eurasian continent, the Tolai River Oasis Irrigation System Project in Gansu has a long history, diverse remains, a complete chain of documentary evidence, and a clear inheritance context. It has long been an important irrigation project that maintains the smooth flow of the Silk Road, ensures long-term peace and stability on the border, promotes ethnic exchanges and integration, and shapes the oasis ecological landscape.
