A post by Rich Evans
In 2022 we launched a challenge to help deliver a significant increase in the number of in-sewer monitors on key assets and at key locations. The monitors utilise radar to provide sewer level readings that help us understand how our sewerage network is operating.
Increased monitoring enhances our ability to proactively identify developing network issues (such as blockages) and direct our operational teams accordingly.
The benefits from this Marketplace challenge are now clear to see, with numerous examples each month of the additional sewer level data helping to prevent flooding and pollution incidents.
Challenge recap
The challenge was principally an information-gathering exercise around cost-effective monitoring options to inform requirements for a future tender, alongside improving our understanding of the accuracy and ease of installation of these monitors.
As part of the challenge, we trialled devices from three suppliers. Each supplier installed ten monitors, and we assessed performance against multiple criteria in a range of operational conditions (eg, dry/wet weather and urban/rural environments) to verify the potential benefit of devices and validity of the data.
Following this we undertook a first phase of monitor deployment from October 2023 to December 2024.
More recently we have completed a tender exercise for subsequent phases of monitor deployment, with learnings from the trial shaping our understanding of requirements.
The second phase of monitor installation began in August 2025. This phase will see the installation of 4,000 monitors by March 2026. One of the monitor suppliers, UDLive, was a participant in the original trial. By the end of AMP8, we will have installed over 10,000 monitors, with input from operational teams to prioritise locations where additional monitoring would be most beneficial.
Benefits
We are seeing significant benefits from the additional monitoring. The data is fed into an AI tool called StormHarvester, which was identified in one of our early Marketplace challenges. The StormHarvester tool facilitates more intelligent interpretation of sewer level data by generating alerts when the actual sewer level deviates from the expected operating level (based primarily on rainfall). These alerts indicate potential network issues.
In the example dashboard below, the orange and purple points indicate sites that are in alert while the blue points show normal operation.
In response to these alerts, we direct our operational teams to investigate and resolve potential network issues. In the first six months of 2025, there have been over 300 “good catches” arising from the additional sewer level monitoring data. These are issues that have been identified and resolved that may have otherwise caused a pollution or negative operational impact.
A recent example is the detection and clearing of a blockage in Bristol, preventing a pollution into a popular swimming spot on the River Avon during one of the hottest weeks of the year.
As we increase the area of our network covered by monitors, thereby providing the StormHarvester tool with more data, we anticipate it becoming even more effective at identifying issues. It’s great to see the output of two different challenges come together to enhance the operation of our wastewater network.