Parrod Perrine
In regions with aging and decaying infrastructure, water utilities around the world have been dealing with reducing non-revenue water for decades, particularly the water leakage part.
Because leaks continue to occur and grow, finding and reducing leakage is continuous work. Underground leaks can generate high costs for a water utility: treated water is lost, including unnecessary costly chemical dosage; pumping water that will never make it to customers leads to avoidable operating costs; and potable water will not generate any revenues from customers.
With regions facing droughts, utility customers might be applying pressure on water utilities to reduce water leakage further and conserve water, even if the utility has already worked hard to control water leakage in their water system.
Implementing water distribution modelling and asset management solutions can help water utilities find and reduce water leakage, pipe breaks, and water theft, and prioritise damaged pipes to be replaced while minimising the impact on communities and infrastructure. Mixing operating and capital strategies using software technology promotes leakage detection, system pressure management, and targeted pipe replacements, to ultimately mitigate water loss and reduce leakage.
Ways to actively detect and reduce leaks
InfoWorks WS Pro contains several tools to help water engineers find and address leaks.
One of the most helpful ways to spot leaks is to connect hydraulic models to live telemetry data. It will show you the current behaviour of the water system, allowing you to pick up any system configuration changes not considered in the hydraulic model.
For instance, a change in a District Meter Area (DMA) boundary could indicate a significant increase in water leakage. But it could also mean there has been a change in a valve’s status, for example. When you’re using live data, these issues can be found and investigated.
If you have an approximate idea of the size of your leak, either from a change of pressure reading or from the operation team reporting it, the Leakage Location tool can find the area where the leak will most likely be using telemetry comparison. This enables you to direct field crews to the leak area to fix it. This tool is also helpful for locating illegal water connections.
With a telemetry data connection, InfoWorks WS Pro gets the observed flow in and out of the DMA. The Demand Area Analysis tool can find the unaccounted-for water volume for each DMA, including the expected leakage, which is estimated using the number of customers and the length of water mains, both of which are within the DMA. In this way, you can see the leakage results in all network areas and prioritise addressing the areas with the most leakage.
Monitor leaks in real-time
Addressing water leakage requires a sustainable strategy. Leaks will keep happening and growing, as leaking pipes get fixed. Based on what is reported by UKWIR as the natural rate of rise of leakage, operation monitoring of leakage can proactively help manage leakage in real time.
The IW Live Pro software product models the status of the water network as it is now, what can be expected (including problems and incidents) in the next day or two, and how many customers will be affected. For instance, to best respond to a pipe rupture incident, you can assess and identify the valves to close to isolate a pipe burst and limit customer disruption. You could also report on water leakage, including the volume of leakage, the number of impacted customers, how quickly the damaged pipe can be fixed, and what the impact on the rest of the network will be.
Active leakage methods are undoubtfully helpful to contribute to water loss mitigation, but water leakage can be further reduced with pressure management by reducing hard-to-find leaks.
Reduce leakage through pressure management
A pressure management strategy can help reduce non-revenue water, including leaks and pipe bursts. Managing pressure will not only assist in reducing background leaks but will also assist in reducing customers’ plumbing problems – and help conserve water.
Leveraging your water system DMAs, design pressure reducing valves (PRVs) and pressure sustaining valves (PSVs) to achieve pressure reduction in areas with high pressure is also helpful. InfoWorks WS Pro can help model valves, and find the optimum location and valve size, by setting the pressure levels the valve is trying to maintain. When you do this, you still have control to ensure that customers are receiving enough pressure.
We have seen that hydraulic models empower water engineers to get a full understanding of the network, and how leakage strategies impact the rest of the network and customers. Combining hydraulic modelling with asset management can also contribute to making the right asset investment decisions to proactively fix leakages before they grow.
Proactively target asset investment and intervention
To improve water system resilience, fixing pipes that are likely to break or leak needs to be prioritised based on the number of customers who might be affected by low pressure or lack of service.
You can model the impact of pipe breaks and leaks using pipe break criticality. Choose the break location in the pipe, the type of break, and the duration of the break (whether during the length of the simulation or during a specified time range), and InfoWorks WS Pro will calculate the break volume. This can help you find out which customers will be affected by a break. When planning to assess which areas will impact more customers, you can simulate multiple locations of the pipe rupture and see the number of affected customers and what pressure level they will get in each area. This will help plan maintenance and renewal activities.
Criticality results can then be fed into a risk-based prioritisation tool. To analyse the risk of pipe failure accurately, hydraulic-determined criticality can be an input into the consequence of failure (CoF) model, which, added to the likelihood of failure (LoF) and other CoF proximity components in InfoAsset, would help prioritise water pipe intervention. By targeting maintenance and capital investment budgets, the right pipes can be fixed before leaks damage water utilities’ costs, customer satisfaction, and reputation.
By mixing the approaches above that follow the International Water Association’s four-pillar best practices, water utilities can manage leakage to either remain at a similar level (given leaks keep appearing) or to a reduced level.
Learn more
To discuss how the software products listed in this blog can help you control leakage, please get in touch.