3.39 A review of the probable future increase in demand was made in 1970, and it was estimated that the growth rate would be of the order of 8% per annum during the seventies. There are already indications that this growth rate will be exceeded, which demonstrates the need for a continuous planning review so that the necessary resources (such as storage reservoirs and desalting plants) can be developed and the associated treatment works, pumping stations, pipelines, service reservoirs and distribution systems can be built to satisfy the demand for water.
3.40 The variability in the rainfall into, and the volume of storage and size of catchment areas of the sixteen reservoirs, which at present provide Hong Kong's fresh water supply, imposes a need to plan the various draw-offs so that the productivity of the collective sources is maximized.
3.41 Planning for the development of the salt water flushing systems is similarly required. During the year, these systems supplied over 35 million gallons daily for sanitary purposes.
The Machinery
3.42 In the early post-war years, staff was scarce, and the need for work obvious. There was no specific planning section in the Waterworks Office. Much of the thought on where new works were needed was done personally by the head of the office. As the organization grew, and planning became more complex, a single planning officer was appointed in 1965 and planning is now undertaken by a staff of four or five engineers responsible to a Chief Engineer. Outline proposals are prepared for new water supply schemes for proposed development throughout the Colony and also for revision of requirements in existing developments.
3.43 The planning for and development of operational programmes for existing resources is carried out by the Supply Division, and includes the management, by computerization, of storage and supply.
The Method
3.44 The planning of resource development must begin with an estimate of the need—in this case, the future demand for water. Crudely, this can be done by extrapolation of the past trend. This method, however, ignores possible changes in the community which