Decision-making aid for rehabilitation of sewer networks: addressing socio-economic aspects in the CARE-S project | Aide à la décision pour la réhabilitation des réseaux d'assainissement : aspects socio-économiques dans le projet CARE-S

[Departement_IRSTEA]RE [TR1_IRSTEA]GES / USAGES

English. Rehabilitation of sewer networks has to serve various objectives, both in terms of present general performance, and in terms of long term sustainability. Part of these stakes are external to the sewerage utility operation, such as social impacts of sewer failures, or social impacts of works. These external impacts are to some extend considered in real life decisions, and should therefore also be taken into account in decision support systems. CARE-S project (2003-05), Computer Aided Rehabilitation of Sewer systems, has developed a decision support environment and software prototype, including data management procedures, a set of performance indicators, models describing the condition and evolution of sewers, models describing the risks and consequences of failures, a database describing rehabilitation technologies with their characteristics, an assessment of socio-economic criteria, a long term planning tool, multi-criteria decision tools. The objective is to help utility managers to rehabilitate the right pipe, at the right time, with the right technology. The project has been supported by the European Commission under the 5th Framework Program, joining 17 sanitation utilities and 15 research and development teams. Knowledge and assessment of social and economic external costs have been addressed in CARE-S, in order to propose decision making criteria. In addition, public perception and acceptance have been analysed towards critical events : sewer failures and rehabilitation works. Recommendations have been issued for communicating with the public concerning these events. In this paper we will focus on the criteria developed within this project and present the valuation of the impact loss of trade on one hand during rehabilitation works, criteria used for the selection of the best technique for rehabilitating the concerned pipe in a multi-criteria decision making procedure, on the other hand during a failure, criteria used for the selection of pipes candidates for rehabilitation.