IWA Water Loss

Cape Town

May 2018


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We are privileged to have had our abstract entitled 'Going Beyond ELL for Strategic Infrastructure Asset Management' selected for presentation at this years IWA conference in Cape Town.


The Water Loss Conference and Exhibition 2018 runs from 7th to 9th May and will be one of the world’s largest water loss conferences with over 500 participants expected from more than 50 countries. Many of the world’s leading experts in the field of Non-Revenue Water Management will be present and will discuss the latest developments, strategies, techniques and applications of international best practices as well as successful case studies. In addition, they will present a 1-day pre-conference workshop on 6 May 2018 to provide an introduction to the issue of Non-Revenue Water Management and an overview of the latest IWA Methodology for reducing water losses from Municipal water supply systems.

Going Beyond ELL in Strategic Infrastructure Asset Management


The Challenge


A utility companies’ ability to provide its customers with the level of service they desire is ultimately dependent on how it manages the performance and reliability of its assets. With the level of service expected by customers ever increasing, their tolerance of failure ever reducing, and levels of funding perpetually constrained, organisations are under more pressure than ever before to optimise investment. In order to address this challenge, utilities must effectively understand the interaction of key investment drivers such as supply resilience, leakage management and capital maintenance. While these have been traditionally managed in silos, a more integrated risk-based totex approach is required to achieve the combination of service and value demanded by modern consumers. This approach is becoming commonplace in the global water industry, enabling companies to optimise overall cost, risk and performance.


Although the Economic Level of Leakage (ELL) has been used in isolation to successfully drive leakage management and network rehabilitation of distribution mains, it is less effective in addressing middle ground leakage and has a limited benefit beyond its primary driver. Where ELL is applied as an investment driver on strategic infrastructure assets, such as trunk and raw water mains, it can often determine that the cost of maintenance is far greater than the cost of water lost, and is therefore uneconomic. Where ‘leak-before-break’ principle (LBB) is applied, however, the economic case for managing middle ground infrastructure becomes far more compelling.


While LBB is long been employed as an engineering principle in the Nuclear and Oil & Gas industries, the water industry has only recently begun to accept it as a scientific principle. As a result of the work carried out by Monash University as part of the Advanced Condition Assessment and Pipe Failure Prediction Project, LBB has been scientifically proven as a feature of cast iron water mains. A feature which cannot be ignored.


When a leak propagates into the catastrophic failure of a large diameter, high-pressure main, the scale of economic and societal impact cannot be measured as the cost of water lost through initial leakage. In this context, leakage becomes not only a factor of non-revenue water (NRW), but also of network resilience, third party damage impact, public health and safety and large-scale interruption to supply. Calculating and managing the true economic level of leakage for strategic infrastructure requires a comprehensive, robust and integrated approach.


The Case


Our paper presents the case for LBB motivating companies to go beyond traditional ELL in order to make the right investment decisions for the right reasons. Proactive, effective and efficient intervention strategies can be developed via the concept of ‘Asset Profiling’. Asset Profiling involves the production of high-quality asset intelligence, which is used to scientifically assess probability and consequence of asset failure, asset criticality and overall cost of failure. Asset Profiling can be used as a holistic and integrated approach to managing totex investment on strategic assets. 


This paper will focus on the advanced techniques used to build detailed asset profiles. These are compiled from a structured, consistent and quantitative assessment of criteria including:


  • Network resilience

  • Pipeline criticality

  • Damage impact potential

  • Asset integrity


This method allows the business to undertake cohort analysis at sub-asset, asset, system and inventory levels by identifying and quantifying corporate risk thresholds. From these profiles, ‘Full Spectrum Pipeline Management Plans’ are generated which set out a detailed and integrated plan for on-going active management of all aspects of asset risk and performance. This includes an optimised program of targeted inspection & testing, capital and operational maintenance and risk mitigation measures.  


The Benefits


The benefits of this comprehensive Asset Profiling approach have now been realised on a number of strategic systems, with the integrated analysis of both criticality and integrity assessments enabling improved leakage and risk management, and also the deferral of significant capital maintenance.