Environmentally-sensitive water resources planning: I. Methodology

In this paper, the traditional problem of matching supplies to competing demands, referred to as water resources planning (WRP), is re-visited. With the pressure of continuing growth in the world's population, efficient development and management of available water resources are of greater importance than ever before. It is equally important in today's world that the environmental implications of any activity should be minimised. The aim of this research is to develop a methodology for including environmental considerations in the WRP process. This is achieved by weighting the costs of the various water resource options (both constructional and operating) to reflect their environmental impacts, prior to their inclusion in an economic planning model. The effect of such a weighting procedure is to encourage the selection of environmentally-friendly schemes at the expense of environmentally-damaging ones. The objective function of the combined methodology is to minimise the totally environmentally-adjusted costs, discounted to a base year. A comprehensive planning tool named ENRES has been developed to carry out this task. The model allows the environmental impact assessment of all development options, either source components or transfer structures, to be undertaken prior to running the allocation procedure which is carried out by means of an optimisation technique. With the help of all the facilities provided, the model can be used in a planning exercise both with and without environmental considerations. In this way, it is possible to quantify the cost of environmental impacts in the planning process.