A decision-making approach to assess and prioritise intervention solutions in water distribution systems.

Abstract

The present paper aims at proposing and demonstrating the application of a decision-making approach that allows the identification, assessment, comparison and prioritisation of different intervention solutions. Infrastructural, financial, performance and economic perspectives are taking into consideration in the study. The proposed approach is composed of three main modules: 1) Analysis planning and database construction; 2) Infrastructure, asset or component diagnosis and prioritisation; and 3) Study of intervention solutions for the assets or components priority for intervention. Three assessment levels – macro, meso and micro – are proposed and the decision-making approach is adapted to each assessment level. A water distribution system located in Portugal is used to demonstrate the proposed approach. This case study is composed of five water subsystems, including different assets, such as water storage tanks, pumping and booster stations and water distribution pipes. Five intervention solutions were defined through the identification of the main problems associated with the priority subsystem and the respective causes. The intervention solutions are compared considering the financial metrics and performance indicators, such as standardized energy consumption, energy in excess per unit of the authorised consumption, infrastructure value index and non-revenue water. Results have shown the influence of considering different assessment criteria and performance indicators in the solutions’ prioritisation, highlighting that not always the solution with the lowest associated capital cost corresponds to the solution with the highest overall performance.