Evaluation and Adjustment of Infrastructure Leakage Index for Towns in Developing Countries

Abstract

Evaluating water loss and the performance of urban water supply utilities is critical. The objective of this research was to evaluate the  applicability of the Infrastructure Leakage Index (ILI) formula for towns of developing countries and suggest adjustment factors. Basic  water supply data from nine towns of Ethiopia was used to calculate ILI and develop modification factors. Water supply development  level factor was determined based on the actual water production and optimal consumption if there was sufficient supply. Asset  management factor was developed considering the categorization of Ethiopian towns which was related to expected water supply level  based on development level. The study showed the Unavoidable Annual Real Loss (UARL) formula gave similar values for any type of water supply system whether developed or not. Except for Addis Ababa, the calculated ILIs utilizing the standard formula were less than  four indicating unrealistic very good performance. Applying the adjustment factors, realistic ILI values were obtained reflecting the  realistic performance of water utilities in developing countries, requiring timely appropriate water loss reduction measures.