A long journey to 12% Non-Revenue Water at Yarra Valley Water
Leaks and bursts appear to be a fact of life for water network operators. Pipes, joints, and other parts spring new leaks under the normal wear and tear water network infrastructure is subjected to. The question is: how do you deal with leaks and bursts? Can you delay their onset? How soon can you find and repair them?
Water loss control, as its name implies, strives not so much to eradicate this phenomenon, as to restrain it. For example, for a constant rate of occurrence of new leaks, the amount of water lost depends simply on the time it takes for operations staff to find and repair those leaks, so earlier detection and repair means less Non-Revenue Water. Incidentally, it also means less leaks have time to develop and escalate into large, visible bursts and service interruptions, so keeping water loss under control may improve several distinct measures or KPIs.
So, what is the “magic tool” for water loss control? Some products are marketed as “THE tool to stop water loss”, but I’m not sure that’s possible. I always like to say that it’s a problem which takes a toolbox, not just one tool, and just recently I ran into this fantastic chart presented by a great customer of ours, Yarra Valley Water (from Melbourne, Australia), which I think demonstrates this very neatly. It’s from a slide in this very interesting presentation by Ken Thompson. This graph shows YVW’s total Non-Revenue Water (dark vertical bars) and estimated leakage per connection per day (orange line) over 16 years, with an overlay of the water loss control measures put into use during those years (captioned grey arrows, running from the year each system or method was deployed). In percentage terms, that last bar is somewhere under 12% NRW.
I can’t help saying that Yarra Valley still reduced about one fifth of their remaining annual loss rate when they deployed TaKaDu, although they managed to reduce water loss considerably over the years.
It’s an amazing journey, and one has to applaud Yarra Valley Water not just for persevering and succeeding so spectacularly, but for managing to zoom all the way out and see the “big big picture” of this process, and then finally for sharing it so clearly.
There is a lot to be learned from this graph, but here are my five quick takeaways:
- Non-Revenue Water (and leakage, specifically) is clearly influenced by technology and methodology. It is no exaggeration to state that the nine tools shown here have revolutionised water loss control at Yarra Valley Water, leading to a four-fold improvement. Water loss is clearly not some insurmountable “force of nature”. Interestingly, the reduction in water loss has been economically beneficial for YVW, as changing methods and systems have in effect driven down the company’s Economic Level of Leakage.
- Getting the “low-hanging fruit” can have a dramatic effect. Improved metering in the first few years of this water loss control program was responsible for most of the reductions achieved to date.
- Conversely, even smart, well-performing network operators can (and should) still improve. It’s not always easy to decide how to attribute the impressive reduction in water loss to the various solutions in use, and some benefits may only play out fully after some years of practice and process integration. But the continued downward trend is unmistakable, as is the immediate contribution (abrupt year-on-year decrease) when certain solutions were introduced, most lately TaKaDu. A number of individual measures each seem to have cut 10-30% off the existing water loss numbers. Cutting total NRW and leakage by about 20% at an already well-performing water company – the latest step in this chart – is an impressive improvement, and I believe Yarra Valley Water will continue to drive water loss further down, both through realising more completely the benefits of deployed solutions and through continued adoption of cost-effective technologies.
- “Bad years” do happen, but a well-directed multi-year campaign to reduce water loss can show consistent improvement almost every year.
- There is no magic bullet to individually stop water loss. However, there is quite an array of available tools to add to the water loss control toolbox, some of them effective even after the easy problems are fixed. That’s not so bad: six “small” step-changes, each improving just 20% on previous achievements, add up to a 75% reduction, and based on YVW’s example, could be deployed effectively at a rate of one every year or two.