© 2008 COST Office. Performance Assessment of Urban Infrastructure Services. Edited by Enrique Cabrera Jr. & Miguel Angel Pardo. ISBN: 1 84339 191 0. Published by IWA Publishing, London, UK. 35 Definition of performance indicators for urban water distribution systems in drought conditions C. M. Fontanazza 1 , G. Freni 1 ,G. La Loggia 1 and V. Notaro 1 1 Dipartimento di Ingegneria Idraulica ed Applicazioni Ambientali, Università degli Studi di Palermo. notaro@idra.unipa.it, Viale delle Scienze 90128 Palermo (Italy), Tlf +39 0916657720, Fax: +39 0916657749 Keywords: Drought condition, Equitable water supply, Intermittent water service, Urban water distribution systems ABSTRACT The present study proposes a procedure for analysing urban water distribution system characterised by intermittent supply service under drought conditions. Namely, ten new performance indicators have been defined able to identify