the added guidance of a record of demand growth. All of this planning is duplicated for salt water flushing supplies.
3.46
Reservoir operational planning has historically depended on frequent adjustments of the supply zones of the various reservoirs so that the rate of draw-off from the individual reservoirs is changed. The object is to avoid overflow from some reservoirs emptying before others.
The 'normal' complications of this work are the physical limitations on rate of draw-off from any particular source, the estimation of demand in the supply zone selected, and the rapid changes which can take place in the relative storage positions of the reservoirs due to uneven and unpredictable distribution of rainfall.
The Time Scale
3.47 The horizon for the different planning purposes varies. Thus, from conception to completion, a large reservoir may need 8-10 years, a desalter 7-8 years, a treatment plant 5-6 years, service reservoirs and pumping stations 3-4 years and trunk mains 1-2 years. The arrangements for draw-off from reservoirs to maintain a proper distribution of resources must be planned months ahead, but sudden storms may require alterations to be made overnight.
3.48
All of this planning requires experienced professional staff trained in many inter-related disciplines, and maintaining such an organisation might be said to be the most important planning function of the management of the Waterworks.
NEW TERRITORIES DEVELOPMENT
3.49
The basis of the development programmes for the expansion of New Towns and rural service centres is the equating of available resources with a desired rate of public and private housing production and infrastructure within a balanced development concept. The programmes are subdivided into groups of projects arranged in order of priority thus providing a series of development 'packages' which are to a large extent self-contained. Development programmes for Sha Tin, Tuen Mun, Tsuen Wan/Kwai Chung and Tsing Yi were prepared in August 1974, and approved by the Public Works Sub-Committee of Finance Committee. Provision is made for the cost, timing and implementation of land resumption and clearance, site formation, provision of engineering services, requirements of the Public Housing Programme, community facilities and land sales within each package.
3.50 The programmes are reviewed annually to take account of actual progress of works, changes in policies and standards and any financial or other restraints.
3.51 The need for a Rural Housing Programme in the rural New Territories outside the New Towns, for the provision of housing units, roughly estimated to be 0.3 million, has been recognised in addition to that for the 10-year Housing Target of 1.8 million units. In order to quantify the demand, location and priorities of rural housing, detailed preparatory work for a housing survey has been carried out, including preparation of a questionnaire, selection of samples and a pilot survey, to obtain information for the formulation of a programme to clear up rural slums and provide a balanced development of public and private housing, work opportunities and community facilities.
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