In partnership with HWM and SME, Hydrosave AES have been working with Severn Trent Water (STW) to implement Dynamic Pressure Modelling (DPM) across their network.
The smart network of 6000 loggers have been installed by Hydrosave AES, with each one including GPS Levelling, with data used for detecting anomalous activity. When analysed, this data can localise bursts as well as changes in demand, which could cause strain on the network and lead to leakage.
The loggers have been deployed in over 500 District Metered Areas (DMAs) across five counties, enabling easy collaboration with local leakage teams sharing areas of interest in order to cut leakage detection time, as well as helping to tackle the AMP7 leakage target of reducing reported leakage by 15% over the next five years. Hydrosave are continuously maintaining this fleet of loggers by reacting to non-communicating sites and responding to zero pressure events. The case study below shows how the DPM loggers have been used to detect leakage events.
Following a flow alarm in a DMA that had seen an increase in Minimum Night Flow (MNF) of 22m³/hr, our automated system identified a localised area of interest in the DMA for investigation, as shown in Figure 1.
Figure 1: Leak localisation in the DMA dramatically reduced the search area
Initial sounding of the area found no likely burst locations and the local leakage team asked us to review the analysis of the areas and confirm the area of interest before they moved on to plan step testing for the whole team.
A manual review of the analysis found it to be correct and we had a high confidence in the area of interest. As this area had already been sounded with no results, the technician conducted a step test within the portion of the network highlighted. This resulted in a burst being detected on the property of a large customer, which was located in the centre of the area of interest we had identified.
By utilising the DPM loggers and analysing the pressure data within the DMA, this particular burst was detected within 9 days of the flow alarm, with some of this time being taken up by scheduling night work for the step test. Without the aid of the area of interest provided, it is estimated that the technician would have had to spend 4 additional nights conducting step tests around the entire DMA, which would have left the burst undetected for over a week. Given the size of the burst, reducing the detection time by a week has saved approximately 4,000m³ of water. In addition to the volume of water saved, it was also found that the customer’s logger was faulty and had been recording a continuous flow, which is why it was ignored during the original survey.
We continue to work closely with Severn Trent Water on the DPM project and have found that the leakage teams’ confidence in the solution is increasing week on week. The solution will continue to assist in localising bursts and reducing time to find significantly. This is already demonstrating a significant reduction in hours spent on leakage detection, which we expect will create additional capacity in the leakage teams as we move into the winter months, where the high volume of bursts make cutting time to find extremely important.