KPIs Fit for Purpose

Strengths and Weaknesses of

Performance Indicators

ALL Water Loss KPIs have Limitations –

understand before you choose!

This webpage is a ‘One Stop Shop’ for Theory and Concepts, free Software, Blogs, Case Studies, and Articles, Papers and Presentations on this website, relating to the topic of Performance Indicators for Real Losses and other components of Non Revenue Water. Taken together, this information shows how an improved approach to selection of  Fit for Purpose KPIs has gradually developed since 1999.

For Real Losses and NRW, fundamental problems associated with the traditional KPI ‘percentage of system input volume’ (however defined) have been clearly exposed, leading to decreasing use of this KPI internationally.  In contrast, the Infrastructure Leakage Index ILI, developed by the 1st IWA Water Loss Task Force specifically for technical performance comparisons in leakage management on an  International, National, Regional, Utility and within-Utility basis, continues to be adopted by more countries every year.

From the ‘Concepts’ Webpages:

  • Key Performance Indicators Overview: KPI
  • Unavoidable Annual Real Losses and Infrastructure Leakage Index : UARL and ILI

From the ‘Free Software’ Webpages

Oct 2017NRW as % of SIV fails yet again to identify major NRW savings in Romania; possible motivations for users of this failed KPI are reviewed. Weblink: Blog NRW as % of SIV fails againAug 2017ILI Overviews by Country
Aug 2017Reliable operational Performance Indicators are critical to address water losses (IWA blog)Aug 2017Netherlands ILIs
Aug 2016EurWB&PICalcs now available in GreekDec 2016AquaFlanders Utility ILIs
May 2016Interpreting Leakage in England & WalesMay 2016New Zealand ILI's
Sept 2015Some Misconceptions about ILI in the UKFeb 2016Croatian LILs
Danish ILIs
July 2015NRW Management and Misperceptions in the USAOct 2015Austrian ILIs
June 2015Bulgarian NRW KPIs: Update of Bulgarian OrdinanceSep 2015Canadian ILIs
June 2015UK Water Distribution Leakage: CIWEM Policy Position Statement UpdateJune 2015North American ILIs (AWWA and Georgia)
Jan 2015EU Good Practices on Leakage ManagementApr 2014European ILIs
Oct 2014The Zero-Sum Leakage Performance Indicator and Play the % GameMar 2014Australian ILIs
May 2014The Water Conservation World Cup: Leakage needs a level playing fieldFeb 2014Global ILIs
Nov 2013Percentages don’t work for tracking NRW and Leakage ReductionJan 2014Portuguese ILIs
Merks C, Shepherd M, Fantozzi M, Lambert ANRW as a % of System Input Volume just doesn’t work! PI 2017 Conference of the IWA
benchmarking and performance assessment group in Vienna, Austria, May 15-17 2017
Presentation 2017C
Laneuville M, Demard H, Estrada Côté V, Lambert AWater Loss Reduction: How Low Can We Go? Americana Réseau Environnement, Quebec AWWA Section. Montreal, 23rd March 2017Presentation 2017B
Jernigan W, Lambert ABenchmarking Water Loss Performance: The Death of Unaccounted Water. North American Water Loss 2015, Atlanta, Georgia, Dec 2015Presentation 2015Q
Merks C, Lambert A, Trow SImproved leakage management by European water utilities to safeguard Europe’s Water Resources. North American Water Loss 2015, Atlanta, Georgia, Dec 2015Presentation 2015P
Lloyd Owen DHow can we optimise the way we measure leakage? Article originally appearing in Global Water Intelligence, Volume 16, Issue 6, June 2015Article 2015K
Lambert AArticle ‘Leakage Indicators fit for purpose’ for Special Report on Water Losses (Dossiê especial Perdas de Água). March 5th 2015 edition of Água&Ambiente" (Water&Environment) Magazine, Portugal.English Article 2015H
Lambert AGood Practices on Leakage Management - The 2015 EU Reference documents and the Zero Sum KPI. SMI Smart Water Systems Conference, 29th/30th April, LondonPresentation 2015F
Merks C, Lambert A, Trow SImproved leakage management by European water utilities to safeguard Europe’s Water Resources. IWA International Conference, Water Efficiency and Performance Assessment of Water Services, Cincinnati, U.S.A., April 20-24 2015.Presentation 2015D
Abstract 2015C
Lambert A:
presented by Fantozzi M
Smart Water Loss Performance Indicators for Smart Water Networks. Keynote Speech, IWA Conference 'Water Ideas 2014: Intelligent Distribution for Efficient and affordable Supplies'. Bologna, Italy, 22-24 October 2014
See also EU Good Practices on Leakage Management blog
Presentation 2014Q

Lambert A, Koelbl J, Fuchs-Hanusch DInterpreting ILIs in Small Systems. IWA Conference 'Water Ideas 2014: Intelligent Distribution for Efficient and affordable Supplies'. Bologna, Italy, 22-24 October 2014Presentation 2014M
Paper 2014N
Koelbl JLearning's from implementing the IWA methodology to National Water Loss Guidelines IWA Conference 'Water Ideas' 22-24 October 2014: BolognaPresentation 2014L
Lambert ABest practice international approaches to monitoring improvements in NRW and leakage management. SMI 3rd Annual Conference on Smart Water Systems London, UK, 29th April 2014Presentation 2014K
Lambert A, Charalambous B, Fantozzi M, Kovacs J, Rizzo A, Galea St John.SPaper and Presentation: 14 Years’ Experience of using IWA Best Practice Water Balance and Water Loss Performance Indicators in Europe. Vienna, Austria, 1st April 2014IWA Water Loss 2014Presentation 2014F
Paper 2014G
Appendix A
Reid CampbellPresentation: Halifax Water’s Water Loss Journey 1999-2014. Vienna, Austria, 1st April 2014 IWA Water Loss 2014Presentation 2014D
Pearson D; Lambert A,Article by David Pearson & Allan Lambert ‘Accounting for Water Leakage and Measuring Performance’, pp 135-139 of ‘Sustainable Cities, building for the future’. Climate Action, United Nations Environment Programme (UNEP), June 2013 . ISBN: 978-0-9570432-8-2

Article 2013H
Lambert AInternational Water Losses – Lost in Translation’. Extended version of article ‘Water loss lost in translation’, Water and Wastewater Treatment, Jan 2013Article 2013A
Lambert ATechnical (metric) comparisons of Real losses using the ILI. International Conference on Non-Revenue Water Issues, Malta, November 2012Presentation 2012U
Lambert A‘Some things Hydrologists need to know about Water Utility Leakage in the UK’. Article in British Hydrological Society ‘Circulation’ No 113, May 2012Article 2012Q
Fantozzi M; Lambert A; Liemberger RSome Examples of European Water Loss Targets, and the Law of Unintended Consequences. IWA Specialised Conference ‘Water Loss 2010’,Sao Paolo, Brazil, June 2010Paper 2010K Presentation 2010J
Lambert A; Waldron TManaging Australia’s real loss levels. Water 21, June 2010Paper 2010G
Johnson E,
Vermersch M,
Guidance Notes on Apparent Losses and Other Non-Revenue Consumption. IWA Water Loss 2010 Conference, Sao Paulo, Brazil, June 2010Paper: AppLoss 2010L
Koelbl J; Gschleiner RAustria’s new guidelines for water losses. Water 21, December 2009Paper 2009T
Lambert ATen Years Experience in using the UARL Formula to calculate Infrastructure Leakage Index. IWA Specialist Conference ‘Waterloss 2009’,Cape Town, South Africa, March 2009Paper 2009J
Presentation 2009H
Liemberger R; Brothers K; Lambert A; McKenzie R; Rizzo A; WaldronWater Loss Performance Indicators. IWA International Specialised Conference ‘Water Loss 2007’, Bucharest, September 2007. Conference Proceedings (3 vols) ISBN 978-973-7681-24-9; Session B2 of Volume 1Paper 2007T
Rizzo A, Vermersch M,
Galea St John S,
Micallef G,
Riolo S, Pace R,
Apparent Water Loss Control: The Way Forward. Water 21, Aug 2007.Paper Apploss 2007P
Kovac JCase Studies in applying the IWA WLTF Approach in the West Balkan Region: Results ObtainedPaper 2006T
Lambert AInternational Report on Water Losses Management and Techniques: Report to IWA Berlin Congress, October 2001. Water Science and Technology: Water Supply Vol 2 No 4, August 2002Paper 2002N
Presentation 2002M
Lambert A; Brown T G; Takizawa M; Weimer DA Review of Performance Indicators for Real Losses from Water Supply Systems. AQUA, Dec 1999. ISSN 0003-7214Paper 1999M