Drainage system in the Summer Palace

In the landscape site, the concentration of trees, flowers and plants, the needs of tourists’ activities and the requirements of maintenance and management lead to a great demand for water. It is very important to solve the problem of water use in landscape architecture. With the rapid development and great effect of modern landscape architecture, many excellent construction methods and technologies have emerged in water supply and drainage engineering, but the fast-paced engineering also brings problems such as extensive techniques, lack of rationality, weak ornamental and obvious artificial traces. For the optimization of modern water supply and drainage engineering, we need to go deep into the classical garden, trace the source from the achievements accumulated by our ancestors for thousands of years, and realize the wisdom of our ancestors.

Qingyi Garden, or we can say the Summer Palace, is a great example of water supply.

Qingyi Garden is located in the northwest of Beijing, to the west of Yuanmingyuan and to the east of Yuquan mountain. It covers an area of 242 hectares, showing the pattern of North Mountain in the north and water in the southern part. Among them, Wanshou mountain in the north is 60 meters high relative to Kunming Lake, the mountain body is about 1000 meters long, and the mountain area is about one third of the whole park. Kunming lake is a natural landscape garden with a combination of landscape and water. It was built by Emperor Qianlong in 1750 to regulate the water system in the west of Beijing and celebrate his mother’s birthday.

After the Qianlong reign of the Qing Dynasty, Kunming Lake expanded to the north and reached the southern foot of Wanshou mountain. It actually served as a reservoir in the northwest suburbs. Longwang temple is preserved as the “Nanhu island” of the lake. The East Bank of the lake was reinforced by the West dike built in Kangxi period and the old West dike in Yuan Dynasty and Ming Dynasty. After reinforcement, it became the main dike on the East Bank of Kunming Lake and was renamed “East dike”. Erlong sluice will be built at the north end of Dongdi to control the flow of Kunming Lake eastward. This practice made a large area of low-lying land to the east of the dike and the west of Changchun Garden to be irrigated and turned into paddy fields. The water area to the east of West dike is quite deep and wide, which is the main body of Kunming Lake reservoir. Water near West dike are small and shallow. In the west of Kunming Lake and the south of Yuhe River, a shallow lake named “Yangshui Lake” was excavated by using scattered small river bubbles, which was used to store the natural water of this generation. In order to collect the water from the lake into Kunming Lake, a short canal was built at the west end of Yuhe River to connect with it. However, the topography of Yangshui lake is slightly higher than that of Yuhe river. Therefore, a sluice bridge is built at the junction of the short canal and the Yuhe River to control the flow and stabilize the water level of the lake. In this way, the two sides of the Yuhe River have gained the benefit of irrigation to open up paddy fields, and the increase of paddy fields has brought about high water demand. In 1759, a “gaoshui Lake” was built outside the Jingming garden of Yuquan mountain. Gaoshui lake and Yangshui lake are equivalent to two auxiliary reservoirs of Kunming Lake. In the northwest corner of Kunming Lake, another river is opened to extend northward, passing through the West foot of Wanshou mountain, and connecting with Qinghe River in the north along the water diversion channel of Baifu weir in Yuan Dynasty through Qinglong bridge, which serves as the main overflow channel of Kunming Lake. A gate is set under the Qinglong bridge to release water to the north when the water rises suddenly in rainy season. The position of this gate is very important, and it is an important spillway hub of Kunming Lake reservoir. The main canal bypasses the Western foot of Wanshou mountain and divides into a branch canal to turn eastward. Along the northern foot of the main canal, the original scattered small river bubbles are connected into a river channel, namely “Houxi River”, also known as “Houhu Lake”. Houxi river is divided into three parts at the northern foot of Shandong Province, flowing eastward into the Yuanmingyuan.

The shaping of terrain and water system is not the process of building plane pattern, but should be considered together with function and crowd use. If we can really master the wisdom of the relationship of space opening and closing, the terrain and water shape obtained can be really amazing. All in all, Logic is the highest guidance of design.