Not just leaking pipes. What is non-revenue Water?

In this episode of the IMC Worldwide International Development Podcast, we talk to chartered engineer Malcolm Farley about the impact of non-revenue water.

Monday 11 April 2016, Malcolm Farley, Ben Walker

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A transcript of the podcast is below.


Hello and welcome to the IMC worldwide international development podcast my name is Ben Walker.

Now today we are going to be talking about non-revenue water.  This has become a big topic of conversation in WASH circles recently with the recent International Water Association Water Loss Specialist Group conference in Bangalore giving it special mention.

Now, non-revenue water generally refers to water that has been produced, entering a system and is lost before it reaches the customer. Losses can be through called real losses, such as leaks or apparent losses such as theft or metering inaccuracies. 

Today I’ll be talking to Malcolm Farley, a chartered engineer who has more than 45 years experience specialising in water loss management and leakage control. He is the co-author of the IWA book “Losses in Water Distribution Networks – A Practitioner’s Guide to Assessment, Monitoring and Control”. 

Welcome to the programme Malcolm.


Thank you Ben, good to be here.

Malcolm Farley
Non-revenue water expert Malcolm Farley


So could you explain, briefly what is considered non-revenue water and additionally how can we quantify it?


Ok, well, all water companies produce water, that’s their role in life. They produce water to sell – to customers – that’s their income or their revenue stream. So non-revenue water is really the difference the water they produce and the water that they sell to customers. So the difference between those two is non-revenue water. It’s as simple as that.

The, algorithm, the calculations and the components in between and the calculation of whatever else is causing non-revenue water is more difficult.


So what effect does this have on water systems? Especially in developing countries? 


In developing countries, particularly it increases the scarcity of water of course and demand in developing countries is often higher because people need more water, they need more of the diminishing resources for hygiene, for washing and so every time there is a leak of course it adds to the problems that water companies have. And so, customers as well in poor areas, in poor, urban areas, they can’t afford to buy water so they tend to take it illegally, or tamper with meters and falsify meter records. And again this is another problem for companies, the ever decreasing volumes of water for ever increasing demand. So its a vicious circle really. The more water that’s lost, the more difficult it is to replace that. So water companies in effect are sitting on a reservoir of leakage, a reservoir of water, a hidden source of water underneath the ground, which my job is to try and overcome that and try and help water companies to increase the efficiency of their operations and the network, so they reduce the non-revenue water.

And again this is another problem for companies, the ever decreasing volumes of water for ever increasing demand. So its a vicious circle really.


You mention, some of the causes there so can you elaborate, what are the main causes of non-revenue water?


Well basically you’ve got 3, main components of non-revenue water. We’ve just talked about some of them, we’ve talked about real losses, which are the leakage from the pipe network. Apparent losses, which are losses to the company income stream caused by illegal connections, or theft of water – customers tampering with meters. Or by under registration of the meters. Customer has a meter, if that meter is not recording properly, the company is not getting the correct amount of revenue from that customer. So we call that meter under registration. A third component, which is quite a small one is water taken but not billed for by the company. This is sometimes a political, or an institutional policy, where the company lets people have water that they don’t charge them for or they don’t bill it. 


So what you mention there are the main challenges that water utilities have in addressing non-revenue water, what is stopping these utilities from implementing these strategies?


Well, the biggest problem, i think, in my experience, is creating an awareness that non-revenue water is quite a significant factor. You know, not many companies produce goods and expect then 50% of those goods to be disappear between production and the customer so, this is exactly what happens in many water companies where the water is lost. 

And this is sometimes a lack of awareness, a lack of perception, by the senior management, who don’t feel that it’s necessary to do anything about it. They prefer to maybe put their budget, their allocation of finance in to augmenting water treatment systems, you know. This is really chicken and egg because they have a large wasted resource of water underneath the ground and its relatively simple to start addressing that. 

So there are physical reasons why we get non-revenue water, leakage from the pipe network, they could be old or broken, poor materials, poor workmanship, probably lot’s of leakage. Companies may only repair the leaks they see on the surface, but know that for every leak on the surface, there are nine leaks underground so its a matter of addressing the, being aware of the problem of non-revenue water, being aware of the causes of it and the steps the company can take to correct this. 

Well, the biggest problem, i think, in my experience, is creating an awareness that non-revenue water is quite a significant factor.

And it is a step-by-step process, nobody expects water companies to suddenly go from 50% of non-revenue water to 10% of non-revenue water. The steps have got to be achievable, practicable and appropriate. So this is, my philosophy that I try to bring in to my programmes when I am developing non-revenue water reduction strategies.


Do sometimes cultural and social factors play a role in non-revenue water?


Oh often, very often, especially in the poorer countries. The culture very often, is for the water company to provide very low tariffs, very low cost to water and sometimes these are heavily subsidised by government. Which lends itself to abuse. Customers don’t value water so they waste it, a chicken and egg situation. There are very real reasons sometimes for political policies where customers in some areas or in the periphery of some areas like Karachi or in Brazil, where they have to supply water free of charge and its bright for life. So there are cultural and social aspects and most of these are linked to theft of water, and waste of water. So again its an education and awareness policy that required as well as a more technical solution. 


So what measures can a water utility put in place to sustain non-revenue water reduction?


Sustainability, this is one of the bones of contention, because once an expensive non-revenue water programme has been put in place, it often fails. And I’ve been to many countries where exactly that has happened, where the consultant has come in and put in a very good demonstration in a pilot area, consultant goes away and then the programme fails because there hasn’t been enough transfer of knowledge, there hasn’t been enough monitoring and follow-up by the consultant or there hasn’t been enough budget allocated and the company decides to use the budget on other things. So this is one the great problems of keeping a programme going. Sustainability and the fact that a water company has to lead from the top and understand and actually support the sustainability of the non-revenue water programme. 


Where can people learn more about addressing non-revenue water?


There are quite a few publications around and one of the best ways is to join the International Water Association and then join one of the specialist group that specialise in water loss management. It’s called the Water Loss Specialist Group – obviously. It’s a group of about 500-600 people who are all water and utility practitioners or consultants or suppliers. So that’s a good first step and the IWA website, its easily accessible if you google it, it will tell you how to join the IWA and there is a very good new document produced by the European Union, called “Good Practices on Leakage Management” which has a wealth of background materials, case studies, good practices from across the world. 


Thanks very much Malcolm.


Your welcome, good to be talking to you here.


That was Malcolm Farley, a consultant and a fellow at the International Water Association. If you would like to learn more about non-revenue water, you can visit the international water association website at and if you would like to listen to more international development podcasts you can log on to our website at



As part of the Ideas to Impact programme (managed by IMC Worldwide and funded by DFID) we are running the Dreampipe Challenge which is offering cash prizes for innovative solutions to the problem of non-revenue water.

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