The Water Supply System Up to A.D. 2001

Abstract

BY the end of the century the capacity of the present public water supply system will be between 2000 and 2500 million gallons per day (m.g.d.) short of conservatively estimated water requirements. A minimum investment of approximately /iooom. will be needed to provide sufficient capacity to meet the shortfall. In planning the increase, however, more than financial considerations are involved. If the deficit were to be met by conventional catchment schemes, between 50 and 70 new reservoirs would need to be constructed, a high proportion of which would inevitably have to be sited in national parks or similar high amenity areas.' The public resistance to the Ullswater and Windermere schemes of Manchester Corporation and to the Cow Green and Forndale schemes indicates that a programme ten to twelve times larger could only be achieved at the expense of a great deal of social and environmental upheaval. Even so it is obvious that water resources to support an improved standard of living for an expanding population must be forthcoming, even where this involves the imposition of some social costs on the community. At the same time it is equally necessary that social as well as financial costs should be reflected in the choice of investment made. This is particularly true at the present time when a number of schemes with widely differing specifications are available to meet given economic requirements. Whereas the social losses brought about by damming one valley rather than another are broadly similar, allowing a choice between them to be made on strictly financial grounds, the social costs and benefits of conventional conservation schemes, barrages schemes and nuclear desalination are so disparate that they must necessarily receive explicit attention in investment planning.