Chengmen River

Chengmen River

Shing Mun River, also known as Shing Mun River channel, is a river in Shatin District of Hong Kong. There are many multi-storey residential buildings on both sides of the river, as well as some commercial and industrial buildings. There are many bridges across the river to facilitate residents to travel between the two sides. Most of today's Chengmen river is a man-made river course. Its original purpose is to discharge the sewage and possible flood from Shatin District to the sea. The drainage area is 37 square kilometers. It also provides a place for local residents to engage in recreational activities, including cycling, jogging, rowing and dragon boat racing.

Historical development

The upstream of Chengmen river is Chengmen reservoir. There are several water diversion channels leading the mountains and waters from Damaoshan, Zhenshan and lead mine valley to the reservoir. When the reservoir overflows, the mountains and waters will flow to xiachengmen reservoir through Chengmen gorge. The smuggling Valley and Caoshan water source near Chengmen gorge will also flow into xiachengmen reservoir. Whenever xiachengmen reservoir overflows, the water in the reservoir will be discharged into Chengmen River, and the outlet used to flow to sand Tian Hai, near today's Tai Wai. In the past, Shatian sea, also known as Chaoshui Bay, was a long and narrow bay shaped like a trumpet connecting Tolo harbor. When the tide rose, the sea water would flow into Shatian sea.

The end of the early Chengmen river is near the present shiziqiao. The mouth of the river is the Shatian sea surrounded by mountains on both sides. At that time, the coast was already to the west of the Kowloon Canton Railway, while Huotan and xiaoliyuan were small villages along the coast, and yuanzhoujiao was an island in the middle of Shatin sea. Later, after numerous reclamation projects, the Sha Tin sea became a straight Shing Mun River, stretching all the way to Ma On Shan and Pak Shek Kok, Tai Po.

Upper reaches of Chengmen River

In the 1970s, the government developed a new town in Shatin, carried out reclamation projects on both sides of the Shatin sea, and extended the Chengmen River into a 7 km long, 200 m wide man-made river channel, starting from Dawei, flowing through the city center of Shatin and Shatin Racecourse, to Shatin sea and Tolo port. Other small rivers that used to flow to shatianhai have also been changed into tributaries or open channels that flow into Chengmen river. There are three tributaries, including Dawei channel, Huotan channel and xiaoliyuan channel. Dawei channel was closed into a closed channel in the 1970s and 1980s. However, at the exit of Chengmen River, there is an open channel, leipo Dongkeng, which flows through dashuikeng and Fuan garden. As it flows into Chengmen River and out of Shatian sea at the exit of Chengmen River, leipo Dongkeng is generally not considered as a tributary of Chengmen river.

Most of the area of Shatin sea became the land on both sides of Chengmen river. At that time, Yuanzhou Island, which was located in the middle of Shatin sea, became a part of the land on the east bank and was renamed yuanzhoujiao. The outlet of Chengmen River, the bay between maliushui and Ma'anshan, is still called Shatian sea.

pollution problem

In the 1980s, the Chengmen river was once polluted by the sewage discharged from nearby industrial areas and residential buildings, and the river was totally unfit for any living things. In 1988, the British Hong Kong government began to implement a number of measures to improve the water quality of the Shing Mun River, including banning the discharge of any waste water to the Shing Mun River, prohibiting the residents of Sha Tin District from raising livestock, and discharging the sewage from all villages in the district to the Sha tin sewage treatment plant for treatment. The government has also collected alum sludge from the Sha Tin water treatment works for treatment and discharged the treated sewage from the sewage treatment works to Victoria Harbour. In recent years, the government has also built a 250 metre long artificial river embankment near wenlige and excavated a section of the river bed from the Hong Kong Institute of physical education to wenlige to alleviate the pollution and odor. The odor of Chengmen river is due to the fact that the river was polluted by organic matter (livestock waste, domestic sewage) in the past. The pollutants deposited on the riverbed and decomposed, resulting in the reduction of oxygen in the water. Although the pollution problem of Chengmen river has been greatly improved in recent years, the microorganisms in the sediment of the original river bed will decompose organic matter under the condition of anoxia, and release malodorous sulfide, which is the source of malodor.

These measures have achieved remarkable results, and the water quality of Chengmen river has been gradually improved. Since 1993, the water quality index has changed from normal to good, and fish and invertebrates have been found in the river. In 1987, the biochemical oxygen demand of organic pollutants in Chengmen river was about 9000 kg per day. By the end of 1997, the sewage discharge of Chengmen river had been reduced by nearly 90%, and the biochemical oxygen demand had dropped to about 1050 kg per day.

Artificial river

Artificial river channel includes excavating river bed and embankment, changing width, shape, structure and position of river channel, covering concrete on the surface of river embankment and riverbed, so as to prevent flood, speed up river discharge and facilitate River maintenance. The artificial river course will destroy the habitat provided by the river and reduce the biodiversity of the river bed and embankment. After the natural river bed such as gravel or bog is covered with concrete, and the river course is straightened, the original shallow channel with rapid flow and deep channel with slow flow in the river will disappear, and the water flow will become unified. Finally, the river will flow so that it is no longer suitable for living creatures.

To widen the river, it may be necessary to clear the trees on both sides of the river, so that the shade of the river bank will disappear, the habitat of birds and mammals will be destroyed, and the natural cover of fish and river creatures will be lost. The concrete channel dissipates and absorbs heat faster than the natural river bed, so the temperature of the river becomes unstable and there is a large temperature difference, which makes it difficult for river organisms to adapt.

River maintenance works generally include the work of cleaning the river bank and riverbed. Sediment and plants in the riverbed will be removed, and the habitat of organisms is often damaged, making it difficult for the ecosystem to recover. During the construction of the river regulation project, a large number of pollutants are produced, which affect the water quality and increase the suspended solids and sediments of the river. These sediments are mixed in gravel, and fish eggs and many invertebrates will die due to lack of oxygen, which will have a profound impact on the ecosystem.

recreation

After the water quality reached an acceptable level, in June 1996, Chengmen river held the first International Dragon Boat Invitational race, and also carried out various water activities such as rowing and canoeing. Every year, the Dragon Boat Race in Sha Tin District is also held in the Chengmen River between Cuirong bridge and Shayan bridge.

There are jogging path and bicycle path on both sides of Chengmen river. The terrain is slightly lower than that of the adjacent road, and trees and other plants are planted to separate from the road. Starting from the Hong Kong Museum of culture in Sha Tin, the jogging trail connects Tai Po along the West Coast via Sha Tin Racecourse and Tolo Highway, and Ma On Shan on the east coast.

Major events

In the Hong Kong torch relay of the 2008 Summer Olympic Games, Shi Xingyu, the 64th torchbearer, took a dragon boat to carry the Olympic torch on the Chengmen river for 11 minutes. This method of carrying the Olympic torch is the first time in the history of the Olympic Games and the longest one in the Hong Kong torch relay.

Future development

In 2003, the Democratic Alliance for the betterment of Hong Kong (DAB) proposed that the Hong Kong Jockey Club (HKJC) and real estate developers jointly build a number of facilities to enhance the attraction of the Shing Mun River, including the construction of a shopping bridge connecting the Jockey Club and the Shimen station of the Ma On Shan Railway (now known as the Ma On Shan line), and the construction of an artificial island at Shing Mun River near Sha Tin Park as a shopping and catering area. However, the proposal has not yet been implemented.

Address: Shing Mun Ho, Sha Tin, Hong Kong

Longitude: 114.20315439154

Latitude: 22.391626579336

Traffic information: Shatin railway station

Chinese PinYin : Cheng Men He