Chengdu Dujiangyan 都江堰

Near Chengdu, Sichuan there’s an irrigation system that is over 2,200 years that is still in working order. I am talking about Dujiangyan 都江堰, the ancient water diversion project that has changed the history of an entire nation.

Dujiangyan 都江堰 is a large-scale water diversion and irrigation project organised and built by Li Bing 李冰, who was 蜀郡太守 Governor of Shu County (the olden name of Sichuan) and his son, who happened to be an engineer too. It is located on the Min River 岷江 in the western part of Chengdu Plain and was built around 256-251 BC towards the end of the reign of King Zhaoxiang of Qin 秦昭襄王 (325-251 BC).

Today, it serves two functions – a scenic area for tourist and a functioning water irrigation system. Let’s take a walk in one of the ancient engineering wonder of the world, starting with an ancient park built on top of a manmade water diversion weir called Lidui 离堆.

Lidui Park 离堆古园

The first section of the Dujiangyan Scenic Area is Lidui Park 离堆古园. The ancient park was built in 1929 and was originally named Dujiang Park 都江公园. After the expansion in 1931, the name was changed to Lidui Ancient Park 离堆古园 because it was built on the top of a manmade stone weir.

The ancient garden is surrounded by mountains and rivers. There are many famous ancient trees and stumps. It is known as the birthplace of Sichuan bonsai art and also known as the Ancient Pillar Garden 古桩园 for showcasing the old iron pillars buried on the riverbed.

One key procedure of the maintenance of Dujiangyan is removing excessive mud from the riverbed. Engineers over the centuries know how to regulate this thanks to iron bars marking out the optimum level of mud for the irrigation system to work. Over time the bars themselves have become artefacts.

Known as wotie 卧铁 or “lying iron rods“, the four bars here are from the last four periods of Chinese history. The first one was positioned during the Ming dynasty, the second in the Qing dynasty, the third during the Republic of China and the last one from the People’s Republic of China.

He directed a team of workmen to build an artificial island at a crucial point of the river – where the riverbed was shallow and water flow was rapid at a turn – susceptible to frequent flooding. He used long, sausage-shaped baskets of woven bamboo filled with stones called zhulong 竹笼 to form the foundation of the artificial island.

Tianfuyuan Teahouse 天府源茶馆 is hidden in the Dujiangyan Scenic Area. It is a modern building built in the Sichuan architecture style at the approximate location of Li Bing’s “site office”. According to historic records, the “site office” of Li Bing is on the left side of the entrance to the scenic spot. You can have a spot of Sichuan tea and watch some shadow puppet show about how Dujiangyan came about.

Path of Meritorious Persons 堰功道

On both sides of the path are statues of people past that have contributed to the building and maintenance of Dujiangyan. Among those, three persons were quite interesting.

Zhuge Liang 诸葛亮 (181-243) was not famous for water works, but was put here because he approved the maintenance of Dujiangyan. Shi Qianxiang 施千祥, Ming dynasty Sichuan Governor of Water Works, rebuilt the Yuzui using cast iron in 1550 明嘉靖二十九年 when it was destroyed by a 1,000 year flood, but that did not help when it was destroyed again at the end of Ming dynasty (1644) by another flood. Ding Baozhen 丁宝桢 (1820-1886), Qing dynasty Governor of Sichuan, was responsible for the upkeep of Dujiangyan and inventor of Gongbao Chicken. The sweet and spicy chicken was named after him (his alias was Gongbao).

Along the path are gingko trees 银杏树, and they would be a sea of golden during autumn. But now it is winter, and everything is bald. There’s one famous tree along the path called Zhang Song’s Gingko 张松银杏. It was planted during the late Eastern Han dynasty (202-220 AD) by Zhang Song and is over 1,800 years old. A trivial, this was the tree used in the scene in the classic TV series “Journey to the West” 西游记 when Monkey God 孙悟空 stole the ginseng fruits from garden of the Empress of Heaven.

The two sides of the path are 248 dragon fountains that lined the water feature leading up to Taming Dragon Temple 伏龙观. This is inline with the Taoist idea of the origins of the Universe (2-4-8), where the world is divided into the Ying and Yang, and from the two extremes come the four directions, and four directions come the bagua (eight elements).

Taming Dragon Temple 伏龙观

Fulongguan 伏龙观 or Taming Dragon Temple is an ancient Taoist temple built on the Lidui Weir. It is surrounded by water on three sides, and can be accessed at the top of 42 steps from the Lidui Park.

Fulongguan is said to be the place where Li Bing subjugated the evil dragon during the construction process. In the back courtyard of the temple, you can see the working principles of Dujiangyan Irrigation System replicated in an electric model of the irrigation system.

Huazhou Ancient Way 花洲栈道

Huazhou Ancient Way 花洲栈道 was built in the 4th year of Jiading Period of Song Dynasty (1211 AD) which was ruined by war later. There were multiple attempts to rebuild the walkway in Ming and Qing dynasties. In 1992, it was rebuilt to the current form.

The main part of Dujiangyan Irrigation System is the headwork project, which is the key facility of Dujiangyan Irrigation System. The three main parts of the headwork composed of Baopingkou 宝瓶口 (bottle neck) channel and Feishayan 飞沙堰 (flying sand) spillway, and the Yuzui 鱼嘴 (fish mouth) levee. 

1/3 Baopingkou 宝瓶口 Bottle-Neck Channel

Baopingkou 宝瓶口 or Bottle-Neck Channel works as a control valve, and it can automatically control the inflow of Inner River. It was carved out of the Yulei Mountain, which formed the Lidui Weir 离堆 (currently Lidui Park) and the channel.

It is named Baopingkou because it is shaped like a bottle mouth. The natural beauty of Baopingkou is stunning, and it has been famous attraction since ancient times. 

The channel provided the Chengdu plains the water needed for irrigation for the past 2,000 years. The water has not stopped flowing since the channel was chiselled out of the Yulei mountain.

Yulei Mountain 玉垒山

Yulei Mountain 玉垒山 was split at the cliffside to form a channel and an weir. This was done before dynamite was invented. Li Bing asked the locals to heat up the stone face of the cliff and through sudden cooling of the heated rocks, cracked the stones to form Lidui Weir 离堆. Water passed through the Bottle-Neck Channel 宝瓶口 formed between the weir and the mountain.

2/3 Feishayan Spillway 飞沙堰

After walking past Fulongguan, you come to a suspension ropeway 小索桥 over a smallerl spillway 溢洪道 to get to the V-shaped Embankment 人字提. On the end of the embankment facing the onward flow of the Min River 岷江, you will see the Feishayan Spillway 飞沙堰.

Feishayan Spillway 飞沙堰 has significant functions of flood discharge, sediment discharge and water regulation. It looks very ordinary, but actually the function is very important. It can be said that it is the key project that ensure Chengdu Plain is not affected by flood. The main function of the Feishayan is when the water flow of the Inner River exceeds the upper limit of the Baopingkou, the excess water will overflow from the Feishayan. 

For more than 2,000 years, Dujiangyan has played the role of flood control and irrigation, making the Chengdu Plain a “country of heavenly man and fertile land” 天府之国. So far, the irrigation area has reached more than 30 counties and cities with an area of nearly 10 million mu. In the Steele Pavilion 碑亭, a plaque has been put in place by the Sichuan Provincial Government when the irrigation area reached 10 million mu.

3/3 Yuzui Water Dividing Dyke 分水鱼嘴

The upstream front end of this newly formed bund in the river was shaped like a fish head, called yuzui, or fish mouth. It diverts water flow to both sides of the new riverbed structure, separating the water flow into outer and inner streams.

Due to the judicious location of these features, under normal weather conditions, 60 percent of the flow volume is directed to the Feishayan side for effective irrigation.

However, during times of high flow with torrential rain upstream, only 40 percent of the water flow is led to the inner stream 内江, freeing up the much wider western leg of the river to divert the flooding water.

For the outer stream, a V-shaped cross-section was formed to facilitate smooth flows with increasingly large flow volume, allowing torrents of floodwater to be led downstream without flooding the farmland on the inner side. 百丈堤

Anlan Suspension Bridge 安澜索桥

Located on Jingang Dyke 金刚堤 and spanning the Inner and Outer rivers is a magnificent suspension bridge called the Anlan Suspension Bridge 安澜索桥. The construction of the bridge originally commenced before the Song Dynasty (960-1279). At that time, the body of the bridge was constructed with wooden blocks and the handrails were made of bamboo. Recently the wood and bamboo were replaced with steel and reinforced concrete to ensure the security of the visitors. Seen from afar, the bridge looks like a rainbow hanging over the river. From the bridge, you can clearly see the entire layout of the Dujiangyan Irrigation System.

Dujiangyan Irrigation System

Dujiangyan Irrigation System is one of the most famous projects in China. The project was built in the third century AD, it is the oldest and only remaining grand project that characterized by water diversion without a dam. For more than two thousand years, it has been playing an important role in flood control and irrigation.  

Visited in Dec 2021