Did the ancient city have a sewer system? What did the ancient drainage system look like?

Sewers are the most basic public facilities in modern cities. Sewers can not only remove all kinds of sewage, but also alleviate flooding caused by heavy rain. The sewer system first originated in the ancient Roman period, while the modern sewer originated in France. At present, Paris, France has the largest sewer system in the world. So were there sewers in ancient China? In fact, there were, which was more important for areas with a large population. Without a good drainage system, the city's livable capacity will decline. Historically, the abandonment of Chang'an City had something to do with the gradual deterioration of its living conditions.

"The sewers are the conscience of the city." Hugo said in "Les Miserables". The original intention was that the wide sewers in Paris are the shelter for those socially disadvantaged groups, but in fact the city's intricate drainage system never sleeps. , to maintain a city sewage treatment, to say that the city's conscience could not be more correct. "Water loses its nature, hundreds of rivers overflow, destroy towns, drown people, and become disasters." A little carelessness can lead to disasters.

The earliest drainage system discovered so far is the pottery drainage pipe of the Longshan Culture period discovered in Pingliangtai, Huaiyang, Henan Province, 4300 years ago. These pipes are buried underground and can be socketed by tenons, which is already very advanced. In the Han and Tang Dynasties, Chang'an's drainage system has been the basic configuration of a city's construction. In the following, we will go to Chang'an of Han and Tang Dynasties to experience the conscience of the ancients for the construction of urban drainage.

After Liu Bang established the Han Dynasty, he built Chang'an City in 202 BC on the basis of the old Qin Palace south of the Wei River. There is a perfect urban water system around it, which can solve problems such as urban water supply and drainage. City as the object, with the nature of historical and geographical textual research, which describes the Han Chang'an
"There is a pool under the city, three feet wide and two feet deep." At that time, the Han Chang arranged the water system to be mainly composed of a moat and an open canal.

The discharge of rainwater and domestic sewage is mainly collected through the floor drains in the building complex and the road ditches in the street, and then discharged through the drainage pipes to the canals outside the building complex, connected with the open channels in the city, and finally into the nearby rivers. The drainage facilities of palaces, government offices and other buildings in the city mainly include seepage wells and drainage pipes, which constitute a perfect urban drainage and flood drainage system in Han Chang'an. The picture below shows the sewers of the Zhicheng Gate of Chang'an City in the Han Dynasty, which looks like an uncut tile pipe. All adopt the mortise-and-mortise structure, and the bottom of the pipe is wide, so far it looks very spectacular.

In 581 AD, when Yang Jian changed his dynasty, he still used Chang'an City as his capital. However, after 800 years of use, the sewage in Chang'an City of the Han Dynasty did not leak, and the people's domestic water was seriously polluted, which could no longer meet the needs of urban life. According to the records of Sui Dynasty, Geng Jicai, a minister of the Sui Dynasty, played on Emperor Wen of Sui: "Han camped in this city, it will be 800 years old, and the water is salty and bitter, which is not very pleasant." Emperor Wen of Sui was an aspiring king, and he finally chose A new capital was built on the plain on the south slope of Longshou original southeast of Chang'an City in the Han Dynasty and named Daxing City, while the predecessor of Chang'an City in Tang Dynasty was Daxing City in Sui Dynasty. Although Guozuo in the Sui Dynasty lasted for more than 30 years, it also laid the foundation for the prosperity of Chang'an City in the Tang Dynasty.

"Book of Sui" records: "When the capital was moved, Kai had an ingenious idea, and he commanded the deputy supervisor of the new capital. Although Gao Jiong had a general outline, all the plans came from Kai." Yu Wenkai, the deputy supervisor of the Ying Zongmiao The Miyagi and the Imperial City were built in only about 9 months, and the capital was officially moved in March of the third year of Kaihuang (583). Chang'an City in the Sui and Tang Dynasties was carefully surveyed and carefully designed before the city was built. The site selection was relatively flat. Except for Longshouyuan, the terrain of Chang'an City was high in the southeast and low in the northwest. Located between the Weishui River and the Qinling Mountains, it is surrounded by many rivers originating from the northern slope of the Qinling Mountains.

The Chang'an water system in the Sui and Tang Dynasties can be summarized as eight waters and five canals. The "eight waters" refer to the eight rivers around Chang'an City. From the city, there are Qingming Canal, Longshou Canal, Yongan Canal, Huang Canal, and Cao Canal. Among them, the Qingming Canal, the Longshou Canal and the Yongan Canal were excavated in the Sui Dynasty. After flowing through the Lifang and Chiyuan in the city, the three canals were injected into the Weihe and Huhe rivers. In addition to supplying urban water, they also played a role in flood distribution. In the Kaiyuan period of the Tang Dynasty, the Yellow Canal was dug to supply water for the Qujiang Pond, and it also provided a beautiful sightseeing spot for Chang'an City; in the second year of Emperor Xuanzong of the Tang Dynasty, the Cao Canal was dug to store wood to meet the needs of urban water transportation. "Eight Waters and Five Canals" shows us the powerful water conservancy system of Chang'an City in Tang Dynasty.

In addition, there are many branch canals and ditches in the city, which together with the large canals form a complete network of water supply and drainage systems. You may be wondering if it is really like the plot in "The Twelve Hours in Chang'an" that the wolf guard Cao Poyan escaped from the underground canal in the West City. You may wish to learn about the ruins of the Hanguang Gate crossing the water culvert in the picture below. It was covered under the imperial city built by the Sui Dynasty. The original culvert channel was once equipped with a diamond-shaped water grid. It is difficult for children to enter through this gap, let alone adults? The city gate must pass through before it can pass, and the culvert below has a water gate. The two echo each other and the management is strict to ensure the safety of the imperial city.
Did the ancient city have a sewer system? What did the ancient drainage system look like?

In the Sui Dynasty, Daxing City had 106 squares. In the Tang Dynasty, it increased to 110 squares. Later, due to the construction of Xingqing Palace and sixteen houses, it became 108 squares. With continuous construction and expansion, Tang Chang'an City became a mega city with an area of 83 square kilometers and a population of over one million. The drainage system affects the normal operation of the entire city. In fact, the drainage system of Chang'an City is spread all over the streets and squares. Basically, there will be open drainage ditches on both sides of roads such as inside and outside of each lifang, Hengjie, and Cross Streets. The picture below shows the brick drainage ditch unearthed from the site in the West City of Chang'an. Tang Chang'an City is surrounded by eight waters, and water is diverted into the West City, which not only provides water transportation, but also solves the problems of water supply and drainage. It is one of the basic conditions for the prosperity of the West City.