TNAG-0093-FCO40-129-Water-supplies-1968 — Page 77

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Plover Cove

100 M. G.

Other Reservoirs

1,900

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Total:

2,000 M. G.

To be able to maintain the present supply, we must, therefore, find 12,620 M. G. (20,700 - 6080 - 2000) from rainfall in August and September, or from some other source. Although the yield from rainfall varies considerably with its intensity, it can be said that about 25 inches of rainfall would be required during August and September to provide 12, 620 M. G. of yield. This is approximately average rainfall for these months. Another way of expressing these results is that our storage must be built up to 15,000 M. G. by the end of September to maintain the present supply of 62 M. G. throughout a dry winter, without external sources of water.

6

If, on the other hand, it were acceptable to drop to a supply of 45 million gallons per day from 1st October 1967 until 1st July 1968 (and this might be achieved with a supply of about 5 hours once a week), the corresponding target storage on 30th September would be 10, 300 M.G. and the rainfall required during August and September to achieve this would be about 21 inches about 84% of average rainfall for the two months.

M

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If the water from China is resumed on 1st October at the rate of 62 - 65 M. G. D. and continues until the full 15, 000 M. G. is drawn, the supply position will be transformed, and a daily or alternate day supply could be provided, depending upon the rainfall in August and September.

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In consideration of all these factors, it is necessary now to consider means to increase resources and to reduce consumption.

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The means of increasing resouces are limited:

(a)

Importation of water by tanker

(b)

It is proposed that a survey team be formed to investigate the feasibility and cost of a tanker operation. The team would be set up in mid-August to report in mid-September for implementation of the scheme as soon as possible after 1st October if it proves to be necessary. In the meantime relevant information on water supply, shipping of off-loading facilities is being collected.

Increased use of saline water

There are two potential sources of saline water; firstly, the Plover Cove reservoir from which it will be essential to accept saline water if any use is to be made of its contents next winter, and secondly, the River Indus, from which additional yield can be obtained at present if saline water is accepted into supply. The Medical and Health and Urban Services Departments have advised that a sodium chloride content of 1500 p. p.m. would not be

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