Operational water quality management: Problem context and evaluation of a model for river quality

Abstract

In river basins where water is used intensively and by many activities and facilities, the essential questions of water quality management are changing from being issues of planning alone to being problems of operational decision making. In the past 10 years in the United Kingdom, for example, the technology, economics, legislation, and institutional structure of management have all changed substantially. Together these changes have overturned the traditional assumptions made about the nature of managing river water quality. This paper discusses the foundations for a case study in operational water quality management. The basis of the case study is a dynamic model for stream discharge and quality covering a 54‐km stretch of the Bedford Ouse River in England. The model describes interactions among biochemical oxygen demand, dissolved oxygen, ammonium N, nitrate N, and chlorophyll a concentrations at various points along the river; preliminary identification results are presented using daily time series data for the whole of 1974. The behavior of the river, which relates the effects of a major upstream discharger to a downstream abstractor, is dominated by the dynamics of algal population growth and mortality. In addition to the presentation of these results the paper sets out the technical, economic, and policy questions central to the practical feasibility and potential of operational water quality management. This includes questions in quantifying the stochastic, dynamic aspects of river basin management, the development of improved operating strategies, and the development of operational decision support systems.