Hong Kong Water Supply – The East River Scheme
Hong Kong Water Supply – The East River Scheme
Tymon Mellor: Following the failure of the 1963 summer rains, it was clear that Hong Kong needed additional sources of drinking water. With no natural major rivers, the obvious choice was to extract water from the East River, some 60km north of Hong Kong (now known as the Dongjiang River) and pump the water to Hong Kong through a new pipeline. An initial proposal was presented to the Mainland authorities in the summer of 1963 but the scheme was rejected in favour of an alternative arrangement that would become the Dongjiang Water Supply Scheme.
East River Scheme Options
The source of the East or Dongjiang River in Xunwu county in Jiangxi province and flows south-west through Guangdong province into the Pearl River estuary. With a catchment area of 35,340km2, the main river channel is approximately 562km long[i]. The river starts life in the hills of the Sanbai Mountains which rise up to over 1100m above sea level[ii]. The river basin has a subtropical monsoon climate, with an annual rainfall of approximately 1,800 mm of which 70%–80% occurs during the rainy season from April to September. Given the large catchment and the large Xinfengjiang Reservoir regulating tributary supplies, the river never runs dry, even during the driest of winters.
Following the construction of the Shenzhen Reservoir in 1960, the Mainland authorities thought this would supply all the water needs, but the drought of 1963 demonstrated the limitations of the single reservoir. Under pressure from the Chinese General Chamber of Commerce in Hong Kong and the Hong Kong Federation of Trade Unions in the summer of 1963, the Hong Kong and Guangdong authorities explored options for an additional water source. The closest reliable source was the Dongjiang River, some 60km north of Hong Kong and separated by a range of low hills.
Under the guidance of the Kwangtung Provincial Hydro-electric Water Conservancy Bureau now known as the Design Institute of Guangdong Hydropower Department, three schemes were explored, with the focus on completing the works within 12 months.
The first option was similar to the scheme proposed by the British Government in June, 1963 where by a pipeline would be laid from the East River to Hong Kong following the route of the Kowloon Canton Railway. However, the revised proposal would transfer the water to the Shenzhen Reservoir and distribute to Hong Kong through the existing infrastructure. The Mainland authorities considered this scheme to have only a limited supply capacity and was unable to be constructed within the time frame. It is also likely there was concern over the ability to supply the necessary pipework as steel was in short supply. For the short lengths of pipes required for the construction of the Shenzhen Reservoir project, support was required from the central government. Supply of the necessary components would be problematic and procurement of pipes from outside China would have been unthinkable.
The second proposal was to construct a new water channel from the East River in Dongguan county and transfer the water east to the Shenzhen Reservoir. This approach would provide sufficient capacity but due to its length, would take too long to construct.
The third proposal was to utilise the existing Shima River corridor for the transfer of the water. The river descends from the hills to the north of the Shenzhen Reservoir and flows north into the East River. The scheme would reverse the direction of flow through the provision of a series of dams to create new lakes and pumping stations to transfer the water up the corridor.
A number of new channels would be constructed along with a new reservoir at the highest point, Yentian, allowing water to flow down into the Shenzhen Reservoir. The system would also have the benefit of supporting irrigation to the adjacent farm land and could be completed within the 12 month timeframe.
By the end of 1963 Zhou Enlai, then Premier of China, approved a fiscal fund of 38 million yuan ($5.86 million)[iii] for the Dongjiang-Shenzhen Water Supply Project and in February 1964[iv], the Guangdong Authorities announced their proposal to utilise the existing Shima River corridor. The scheme would require the construction of eight pumping stations, six dams and 16km of new channel to transfer the water from the East River. The Mainland authorities would fund the works if Hong Kong was willing to increase the cost of supplied water from 23 cents to 80 cents for 1,000 gallons.
Following a number of discussions in Guangzhou, on the 22nd April, 1964 the Deputy Director of Public Works, T O Morgan and C C Liu of of the Guangdong Authorities signed a new water supply agreement. From the 1st October, 1965 the Mainland authorities would supply a minimum of 15,000 million gallons of water a year at a rate of $1.06 per 1,000 gallons[v].
The supply agreement would actually commence on the 1st March, 1965 but the supply period would be from the 1st October to the 30th June the following year. On this basis, the new supply would add 55 million gallons a day to the Territories supply, supplementing the average daily demand of 39.2 million gallons a day.
Work on the scheme commenced in late 1963 with a detailed survey of the river, investigations in the ground conditions and the design of the major structures. Once the decision was made to progress the scheme, the designers were given four months to prepare drawings to allow work to commence. Design offices were established at three key construction sites to prepare the working drawings. The Director of the scheme was Huang Fa supported by a young design team of 80 students from the 65th Department of Farmland and Water Conservancy of the former Guangdong Institute of Technology[vi].
The scheme would transfer 6m3 of water per second[vii] from the Dongjiang River using a series of channels and the existing river corridor, pumping stations would raise the water the 46 metres necessary to pass over the low hills and flow in to the Shenzhen Reservoir. To confirm the practicality of the scheme, model tests were undertaken on the key designs at the Kwangtung Hydro-Electric Science Institute, Guangdong Hydropower Planning & Design Institute. To meet the requirements for the Hong Kong of 15,000 million gallons a year, the scheme only needed to handle 3.3 m3 of water per second, thus there was lots of capacity for future additional supply to the territory.
Few documents have been located describing the construction of the scheme, but Lo Kwanhung, a Hong Kong based filmmaker, shot on location in Guangdong a documentary film on the project entitled “Water Comes over the Hills from the East” (东江之水月山来)[viii]. The film was a great hit with the Hong Kong public and over three quarters of a million people watched it when screened in Hong Kong in 1965[ix]. Most of the images and information presented here have been sourced from this documentary.
Work on the project started on the 13th February, 1964, and 5,000 people were mobilized from Guangzhou and more than 5,000 from Dongguan, Huizhou, and Bao’an to undertake the construction. During the peak construction period, more than 20,000 workers were reported to be on site[x], although other reports suggested as many as one million people were mobilised[xi].
Factories in Guangzhou supported the construction works, with steel mills producing the 105 sets of the steel flood gates, each unit measuring 4.1m by 6.4m and weighing 5T. Production of the motors, pump, pipe-works and power components was undertaken by sixty different companies and all were brought together for assembly on site.
In addition to the water works, the scheme required the installation of 82km of 35kV electrical distribution system and two 35kV transformer substations to supply the electricity for the pumps[xii].
Despite the construction being disrupted by five typhoons and the largest storm in 50 years, by November 1964 installation of the electrical and mechanical equipment commenced using 500 skilled workers[xiii] and the works were completed on programme.
East River Channel
From the East River a channel was constructed south to connect to the Shima River and to remove a 10km dog leg in the river alignment. To ensure a continued flow in the now isolated lower reaches, the course of an adjacent river was diverted and passed below the canal in a syphon to provide flowing water.
The new channel was 73m wide and 6m deep, with the material excavated being used to form raised embankments alongside the waterway. From the East River connection, the channel headed inland, crossing through rice paddy and fish ponds. After nearly 3km the channel intersected the Shima River at the village of Ch’iao-tou or Qiaodong, the location of the first bridge across the river. To protect the excavation from inundation, temporary dams were constructed at each end and eventually blown-up once the works were completed.
Qiaodong Pumping Station and Channel
At Qiaodong, a pumping station was constructed with 6 pumps to raise the water 5m into a second excavated channel[xiv]. This channel passes though areas of marsh land and a shallow Muk-ch Lake, the channel being raised above the adjacent water level with raised embankment.
Shima Pumping Station and Channel
At the village of Ssu-ma or Shima, 8km from Qiaodong, a second pumping station was constructed to raise the water 7.5m using 7 pumps. The water was discharged into a new channel that extended a 5km channel from the plains and into the rolling hills.
Excavation of the channels was undertaken with thousands of workers using only basic digging tools and carrying shoulder baskets. However, mechanical cranes using drag buckets and grabs were also used, doing the work of 700 men. In areas of very soft ground, high pressure water jets were used to loosen the ground and the slurry material being pumped out into settlement ponds. This approach was as efficient as 600 workers.
The new channel re-joins the Shima River at Ch’i-ling or Qiling, where the river emerges from a range of low hills. A new 200m long regulating dam was constructed to create a reservoir and control the water discharge down-stream. This new structure allowed the water level to be raised over the course of the river to the upstream dam. The new dam also included an overflow channel and 13 sluice gates to allowed any excess water to be discharged into the original water course.
To provide a safe working area for the construction of the new dam, a temporary soil dyke was constructed across the river to control the water flow. An existing dam at the site had to be removed and was demolished through controlled explosions allowing the new structure to be built in its place. Rock and aggregate for the construction was sourced from a quarry in the adjacent hills. The stone was broken down in to smaller size using hammers and chisels.
Matan Dam and Pumping Station
The village of Matan is located at a bend in the river with mountains on both sides. At 28km from the East River, a 100m long dam was constructed with 14 sluice gates and a pumping station. This would raise the river water a further 6m.
Construction of the dam required the existing narrow water channel to be widened to accommodate the structure. Much of the ground consisted of rock and had to be excavated using a mixture of pneumatic hand drills and manual splitting.
Tangxia Dam and Pumping Station
At 38km along the scheme, by the village of Tangxia and adjacent to the Kowloon Canton Railway, the Tangxia dam and pumping station was constructed. The dam was located between a hill and the KCRC railway. It was necessary to lower the site, by excavating a large hole to accommodate the 12m high dam with its 8 sluice gates, and a pumping station to lift the water around 6m.
Zhutang Dam and Pumping Station
The Zhutang dam and pumping station is located at 50km into the scheme where the water is raised a further 7m. Along the length of the scheme, new irrigation channels were constructed to provide water to the adjacent fields, reducing the volume of water to be managed. By Zhutang with substantially reduced catchment area only five sluice gates were required, along with a smaller pumping capacity.
Shaling Dam and Pumping Station
At 57km along the scheme is the Shaling dam and pumping station. This has four sluice gates and pumps to raise the water a further 8m, discharging into the remaining section of the river, before a new channel transfers the water to the next pumping station.
Shangpu Dam and Pumping Station
The Shangpu dam and pumping station at 62km along the scheme raises the water a further 6m, sufficient for the water to flow into a plateau area surrounded by hills. A manmade channel takes the water to the final pumping station at Yantian Reservoir.
Yantian Dam and Pumping Station
The Yantian Reservoir, at 64km along the scheme was constructed on a raised plain at around 60m surrounded by hills which rise to over 200m. The area was formally a marshland and provided a collection basin for all the tributaries to the Shima River. On the low side of the basin, to the north a new dam was constructed along with a pumping station necessary to raise the water the final 15m into the reservoir.
From the Yantian Reservoir, a 3km channel was constructed to transfer the water from the reservoir into the catchment of the Shenzhen Reservoir. From the channel, the water joins a tributary to the reservoir. The inside face of the main dam of the reservoir was upgraded with a concrete facing and stone-cladding was added to the other structures. The 8km pipeline to the boundary was upgraded with a second pipe line.
In addition to supplying water for Hong Kong and domestic use for Shenzhen, the scheme also supplied water to irrigate 168,500 acres of farmland and drain 6,000 acres of waterlogging farmland. Channels and local pumping stations were constructed to distribute the water to the surrounding farm land. The scheme included a multi-span concrete aqueduct across a valley to extend the distribution of the water.
Hong Kong Upgrades
Within the Territory, upgrades were made to the pumping station at Man Kam To and a second 1.2m diameter pipe was added to the pipe installed in 1960 as part of the Shenzhen Reservoir scheme. The twin pipelines conveyed the water to Lo Wu to connect into the twin pipes supplying water from the Indus pumping station and to the pumping station at Tai Po Tau, part of the Plover Cove Scheme.
Following completion in February, 1965, the Dongshen Water Supply Project was formally inaugurated at a ceremony held at the Tangxia dam on the 1st March, 1965. Senior Guangdong officials and Hong Kong compatriots attended the completion ceremony.
Speeches were given by Liu Chao-lun the Director of the Kwangtung Provincial Hydro-electric Water Conservancy Bureau and M J Wright, the Director of Hong Kong Public Works. Mr Wright congratulated the team on the design of the works and the speed of construction. He noted, “In Hongkong, we too have been busily engaged. Whereas you have dammed reservoirs, built canal and constructed pumping station, we have had to drive many miles of tunnels through hills, lay several miles of large diameter steel pipelines and construct filtration plants as well as pumping stations.”[xv]
He was referring to the works associated with the Plover Cover Scheme, the largest construction project to date undertaken by the Hong Kong Government.
Water Comes over the Hills from the East, Lo Kwan-hung, 1965
The East River Scheme, Far Eastern Economic Review, 3 December 1964
[i] Impacts of Land Use on Surface Water Quality in a Subtropical River Basin: A Case Study of the Dongjiang River Basin, Southeastern China, Jiao Ding, Yuan Jiang ,Lan Fu, Qi Liu, Qiuzhi Peng and Muyi Kang, 2015
[ii] Three Hundreds Mountains, https://zh.wikipedia.org/wiki/%E4%B8%89%E7%99%BE%E5%B1%B1
[iv] Channel from East River to Bring Water for HK?, SCMP 7 Feb 1964
[v] Agreement on Water Signed, SCMP 23 April 1964
[vii] The East River Scheme, Far Eastern Economic Review, 3 December 1964
[ix] The Roots of Regionalism: Water Management in Postwar Hong Kong, David Clayton, 2017
[x] Holding up Hong Kong’s “source of life” with loyalty and great love-remembering the “model of the times” the group of builders of the Dongshen Water Supply Project, http://www.wenming.cn/sdkm/sj/202105/t20210507_6039181.shtml
[xi] Agreement on Water Signed, SCMP 23 April 1964
[xii] East River Water Project Ahead of Schedule, SCMP, 16 May 1964
[xiii] Work on East River Project on Schedule, SCMP, 21 Nov 1964
[xiv] Hong Kong’s Water-Supply Problem and China’s Contribution to its Solution, John Rose, 1966
[xv] New Chinese Water Scheme Opened At Shumchun, SCMP, 2 Mar 1965
This article was first posted on 13th July 2021.
Related Indhhk articles:
Please look under Reservoir, Reservoirs and Hong Kong Water Supply in our Index to see our many articles on these subjects