Hong Kong Water Supply – The 1963 Water Drought
Tymon Mellor: The year of 1963 was an exceptionally difficult for water supply in Hong Kong. For the fourteen months between November, 1962 and December, 1963, the total rainfall was only 901mm, as compared with an average expectation of 2,220mm. Severe restrictions were imposed on water consumption with the house supplied service being cut to four hours every fourth day. Emergency actions were taken to supplement the water supplies, using streams, shallow wells and the new Shenzhen Reservoir, but this was not sufficient and a new water supply source was needed, which was to be the Pearl River.
The maximum demand for water occurs during the summer months and coinciding with the 5 months of the wet season, thus water supply was not usually a problem. However, for the 7 months of the dry season, the water supply had to be met from reservoir storage[i]. To support the growing population, ever larger reservoirs were constructed to meet the demand. The table below shows the forecast daily unconstrained water demand assumed in a 1960 assessment.
|Year||Approximate Population||Demand in million gallon day (mgd)|
In the post war environment of 1946, the combined capacity of the reservoirs was 5,970 million gallons supporting an average winter supply of 29-million-gallon-day (mgd) but which was below the need of 33 mgd. Thus, water rationing was endemic.
With the completion of Tai Lam Chung in 1957, an additional 22 mgd was available during the winter months, providing a total of 51 mgd verses a demand over 52 mgd. Shek Pik Reservoir was commissioned at the end of 1963, and it would have added a further 27 mgd to the winter supply if it had been full, but there was still insufficient supply to support the forecast winter demand. All of these assumptions were based on average rainfall, but in 1963 the rainfall was the lowest on record at only 40% of the average.
Throughout 1962 water was in great demand while short in supply, and during the summer months only 8 hours was made available during the day and 5.5 hours during the winter. This limited service was only made possible by the additional water supplied from the Shenzhen Reservoir[ii]. However, in 1963 with the failure of the summer rains, both the Hong Kong and Shenzhen reservoirs were depleted. Under the 1960 water supply agreement with the Guangdong authorities, the Shenzhen reservoir would normally provide 5,000 million gallons a year provided there had been more than 1.6m of rainfall. This constraint had been included to protect the Shenzhen supply for the local market. However, despite the low water levels and the rainfall criteria, the Mainland authorities were still able to release 1,400 million gallons to Hong Kong.
With falling reservoir levels, additional water rationing was introduced[iii]:
- 2nd May: 3 hours of water supply per day
- 16th May: 4 hours of water supply every two days
- 1st June: 4 hours of water supply every four days
With no domestic water for most of the week, street standpipes were the source of water for most people. People, but mostly the women and children, would queue up in the street to collect water for cooking, drinking and washing. People used every means to carry water home and a good trade was made in the supply of containers. The hardest hit people lived in the squatter huts on the hillsides, having to carry the water up the steep slopes. Thousands of hectares of paddy fields were abandoned because of the drought and water intensive industries had to apply for special supply permits. The Buddhist monks gathered people to pray for rains for three days and nights. With millions of people suffering, the Chinese General Chamber of Commerce contacted the Guangdong Provincial Government for help.
Water rationing continued until the 27th May 1964 when the typhoon ‘Viola’ helped fill the depleted reservoirs.
Plover Cover Scheme
The need for greater water storage had always been a recognised problem, but finding practical solutions had always been the challenge. In 1958, the idea of converting a sea inlet into a freshwater lake gained momentum. The idea was to dam inlets, pump out the sea water and fill the new reservoir with fresh water. Building on the geotechnical experiences from Shek Pik, there was confidence that suitable dam foundations could be secured in these complex marine environments. In July 1958, Finance Committee approved the appointment of Messrs Binnie, Deacon and Gourley to make a preliminary investigation of Plover Cove and Hebe Haven in collaboration with Scott and Wilson Kirkpatrick & Partners. The latter had recent experience and local knowledge obtained from the construction of the Kai Tak Runway, which would be invaluable in dealing with the problems of under-sea dams[iv].
These studies resulted in 1961 with the construction of the Plover Cove Scheme, which will be addressed in future articles.
The Pearl River
With diminishing water supply, the Government had to find alternative sources of water. A Water Supply Emergency Committee was convened in May 1963 under the chairmanship of the Colonial Secretary, and they went on to meet on 40 occasions throughout the year. Their first task was to reopen old wells, utilise streams and promote water conservation measures. They also explored the opportunities to use returning empty oil tankers to carry water from Japan. The suggestion was concluded to be impractical due to the time taken to clean the oil tanks and the need for 20-30 tankers to provide just a quarter of the needed supply[v].
Under pressure from the public, in May 1963 the Government approached the Xinhua News Agency, the de facto Mainland embassy to explore the opportunity of securing an emergency water supply from the Mainland[vi]. By June, negotiations with the Guangdong authorities had secured access to take water from the Pearl River. The first tanker sailed up the Pearl River on the 26th June, 1963 to an anchorage provided by the Mainland authorities[vii]. The tanker was to have been the Nippo Maru No 3 a converted Japanese oil tanker with a capacity to carry more than 400,000 gallons of water[viii], but its arrival in Hong Kong was delayed by a typhoon. Thus, the 16,678 ton tanker “Ianthe” birthed at Kowloon Docks had its tanks cleaned to became the first of 13 chartered tankers to deliver the water.
Arrangements were made with Hong Kong Oil and Caltex to use their existing piers at Tsuen Wan to birth the water tankers. A new 2km pipe line was laid in 14 days to deliver the water to the existing Tai Lam Chung water pumping station. A second birthing point was constructed by the Port Works Office at Sham Tseng, by what was the Hong Kong Brewery. Using a stock of precast piles, dolphins were installed along with water mains to deliver the water into the Tai Lam Chung water supply tunnel[ix].
The Pearl River water had a salinity below 600ppm and could be supplied directly to the water treatment plant, but there was concern that by December with reduced flow in the river, the salinity would increase and it would be necessary to blend the water with that from Tai Lam Chung. This was achieved by the installation of a new pumping station that could pump high saline water 900m up the hill to discharge into the Tai Lam Chung catchwater. The high saline water would then flow into Tai Lam Chung Reservoir and mix with the local water. There was concern that the water with a high salinity would not mix but sink below the lighter fresh water, following model tests undertaken at Hong Kong University it was proposed that the high saline water should be discharged into the reservoir at a number of points through a 450mm diameter pipeline. In the end, the quantity of water found with unsuitably high saline content was much less than anticipated with only 114 million gallons, and sampling indicated that the water was mixing, so avoiding the need for the pipeline.
The Pearl River water transfer operation was completed on 14th June, 1964 and was recognised as one of the most important emergency measures taken to maintain the Colony’s water supply during the extreme shortage. During the nearly 12 months of operation, 23 ships made 1,371 round trips providing 4,288 million gallons, almost one-third of the total consumption during the period. The cost of this operation was estimated to have cost around $67 million[x].
Shum Chun River
The opportunity to dam the Shum Chun River in its lower reaches was explored. This would create a reservoir allowing the fresh water to be pumped out. Following consultation with the Guangdong authorities the plan was revised to the sinking of large diameter wells close to the river and extract the water from within the wells[xi]. Three wells were sunk in the Muk Wu area and a total of 59 million gallons were extracted during 1963, with the water joining the Shenzhen Reservoir supplies.
Pumping water from the River Indus began in 1960 using a temporary facility and borrowed pumps, connecting into the new pipeline to Tai Lam Chung Reservoir. Monitoring identified that the Indus had low winter flows but had significant summer flows that could be captured, and thus a large pumping station was constructed to transfer the water into the Plover Cover scheme.
Work commenced in 1963 on the new pumping system using a collapsible “Fabridam” across the Indus River, creating a small reservoir. The rubber dam consisted of neoprene-coated nylon envelopes inflated by combined air and water pressure, enabling water to be impounded as required. In times of high flow the dam could be deflated and thus reduce the risk of flooding of the surrounding countryside. This was the first time the technology had been used outside the United States where they had been developed.
The new pumping station had ten pumps with capacity to deliver 20 million gallons of water a day through twin pipelines comprising of 1.4m diameter steel pipes. The 8km of pipeline followed the existing pipeline adjacent to the KCRC and discharged into a newly constructed Tau Pass Culvert to feed the new Tai Po Tau pumping station, constructed as part of the Plover Cove Scheme.
The temporary pumping station continued operation during the construction stage, delivering 30 million gallons during the wet season of 1964.
The catchment area of Shek Pik Reservoir was expanded with a new tunnel with shafts intercepting the streams above the village of Tung Chung.
In May 1963 an attempt was made to seed clouds and create artificial rain. Two planes from the Auxiliary Air Force dropped dry ice from 7,000 feet over Cheung Chau in an attempt to encourage the formation of rain. The attempt was unsuccessful[xii].
In October 1964 work commenced on the investigation of the north-west water scheme, exploring how fresh water from the Yuen Long plain could be tapped. The options considered included:
- Construction of an earth dam to the north-west of Castle Peak;
- Construction of an earth dam on the Fan Kam Road between Fanling and Shek Kong; and
- Construction of a low-level bund near Deep Bay to create a small reservoir from which the fresh water from the Yuen Long plains could be pumped into the storage reservoirs described above.
The use of desalination technology to produce drinking water had been explored by the Government since the mid-1950s. In the budget of 1954 it was noted that “the advent of atomic power in another ten years or thereabout, distillation of seawater will be economically practical”[xiii].
To avoid the Colony being dependent on water supplied from the Mainland, the Colonial Government re-considered the feasibility of using nuclear power for water desalination. In 1964 studies were undertaken with the British Atomic Energy Authority and the Ministry of Defence to understand the scale of the nuclear installation and the security of the facility and possible transfer of information to the Mainland authorities[xiv]. The studies concluded that a medium-size facility would be required and there was little risk as the Mainland already had much of the technology.
At the request of the Government, the two power generating companies commissioned a study to explore the prospect of using desalination technology to produce drinkable water. The final report was submitted in February 1964 and would ultimately result in the development of a trial plant at Lok On Pai[xv].
With the prospect of implementation, the US Consulate-General actively lobbied for the construction of desalination facility in 1965. The US was concerned that Hong Kong would be dependent on water from China and was willing to provide funding for the facility. They were also promoting American companies and the new reverse osmosis technology, seeing Hong Kong as a critical step in capturing the global market.
East River Scheme
In early June 1963 the Colonial Government held talks with the Guangdong authorities on supplying water from the East River now known as the Dongjiang River. The deputy governor of Guangdong, Tseng Shen was willing to allow the transfer of water from the Pearl River but construction of a pipeline would require the approval of the Beijing authorities. Thus, on the 13th June 1963 Governor Black requested the British Government approach the central Government to promote the construction of the 72km pipeline to supply Hong Kong with water. The $80 million pipe line would follow the KCRC from the East River at Sheklung, to Shenzhen Reservoir, then utilising the existing supply pipeline. The pipeline would be constructed from 1m diameter steel pipes and require several pumping stations providing a capacity of 30 million gallons a day. The proposal required the procurement of steel pipes from Japan and was forecast to take 12 months to complete. The British requested access to geological and hydrological data so they could prepare a detailed proposal for the Guangdong authorities to consider. The Colonial Government was ready to offer to fund the construction works but was concerned that it might jeapardise the scheme as it would imply that the Mainland authorities would be dependent on Western technology and aid[xvi].
Work continued on the proposed pipeline during 1963 and the scheme was refined, requiring an 80km pipeline, 1.4m in diameter, and four pumping stations for a total cost of $30 million[xvii]. In January of 1964 the Mainland authorities[xviii] advised that they had examined a number of proposals and had come to the conclusion that the provision of multiple dams and pumps station along the Shima River, a tributary of the East River, would ultimately allow them to transfer water to the Shenzhen Reservoir and into Hong Kong. So was born the Dongjiang Water Supply Scheme.
[i] Augmentation of the Water Supply of Hong Kong, George A R Sheppard, 1960
[ii] Annual Departmental Reports 1962-63, Director of Public Works
[iii] Roving Exhibition for the 50th Anniversary of Dongjiang Water Supply to Hong Kong, WSD, 2015
[iv] Hong Kong Annual Report 1960
[v] Tankers May Bring Water, SCMP 25 May 1963
[vi] The Roots of Regionalism: Water Management in Postwar Hong Kong, David Clayton 2017
[vii] Hong Kong’s Water Supply Problem and China’s Contribution to its solution, John Rose, 1966
[viii] HK Official’s water mission, SCMP 9 June 1963
[ix] Annual Departmental Reports 1962-63, Director of Public Works
[x] Hong Kong Annual Report 1964
[xi] Water Pipeline From China, SCMP 10 July 1963
[xii] Water for a Barren Rock, Ho Pui Yin, 2001
[xiii] Colony’s Budget Approved, SCMP 25 May 1954
[xiv] The Changing Nature of Boarder, Scale and the Production of Hong Kong’s Water Supply System since 1959, Nelson K Lee 2013
[xv] Annual Departmental Reports 1963-64, Director of Public Works
[xvi] The Roots of Regionalism: Water Management in Postwar Hong Kong, David Clayton 2017
[xvii] 50 Miles of Pipe are Required to Bring Water from China, SCMP, 11 Jan 1964
[xviii] Hong Kong Annual Report 1964
This article was first posted on 22nd June 2021.
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