Renewal of urban water distribution systems- An economic approach to optimization

Abstract

Many approaches have been developed for analysing the deterioration of water distribution systems: these can be classified as reactive approaches and predictive approaches. The approaches have been modelled using descriptive statistical models or predictive probabilistic models. The Proportional Hazard Model, proposed by Cox in 1972, is a probabilistic predictive model which gives an accurate description of how water systems fail independently of the stresses to which the pipes are submitted. Economic studies have been carried out to fill out the model. The problem consists in determining the optimum time for replacement. This paper puts forward a new ageing model. A detailed study of the various costs was carried out and some of the costs were analysed. A feasibility study of this model on the basis of nine streets in the Urban Community of Strasbourg was made using technical data provided by the Paris Suburban Water Company.