Planning rehabilitation actions on water distribution networks in condition of data scarcity

The paper shows a viable approach to the selection of water networks rehabilitation actions, in condition of data scarcity and uncertainty, based on the use of four concise performance literature indices, allowing the analysis and identification of efficient, reliable and robust rehabilitation alternatives, even if assessed on the basis of a relatively small amount of data. A promising statistical sampling method of water consumptions is also described, that may be fruitfully employed within the proposed approach for drafting water balances at network district scale in order to quantify the extent of leakages. The illustrated case study shows that the selected indices are capable to describe suitably the performance the network would achieve, with respect to water demand satisfaction and to service efficiency, if the proposed rehabilitation options (e.g. leakage detection and reduction, cleaning and replacement of mains) were undertaken, as well as the reliability and robustness of the options themselves, and hence provide a good selection criterion of alternative rehabilitation options. The application of the statistical sampling method to water consumptions of a small municipality in Sicily, (Italy), shows that it may be applicable in practice and that it provides results having the accuracy level predictable by the theory.