Ofwat's new requirements for trunk mains leakage: satellite leak detection as the optimal solution
By Nick Haskins and Emma Lean
The water industry is witnessing a significant shift in the way leakage should be measured and recorded, particularly on trunk mains. The water services regulation authority, Ofwat, has issued new guidance that is set to revolutionise the approach to leakage management. This article explores these changes and demonstrates how satellite leak detection is emerging as an extremely efficient solution to meet these new requirements.
Ofwat's New Requirements
The Ofwat document, PR24 Common performance commitments for Leakage, republished on 31 March 2025, outlines several key changes regarding trunk mains leakage. The most striking change is the phasing out of the Bursts and Background Estimate (BABE) approach, which has been the default method for most UK utilities. Instead, a flow balance approach is now the default for monitoring trunk mains leakage.
Other significant changes include the requirement for companies to use only their own data to estimate trunk main leakage, the need for annual review of leakage figures if trunk main leakage exceeds 5% of total leakage, and the requirement for companies to report their total length of trunk mains to Ofwat by 31 May 2025.
Furthermore, if trunk mains losses form a significant element (>5%) of total leakage, or the MLE water balance gap is greater than +/-2%, a proactive leakage monitoring approach should be applied. This approach can be a combination of flow balance methods, field inspections, analytical techniques, and innovative techniques.
The Challenge of Traditional Methods
The new requirements pose a significant challenge for water utilities. To measure using flow analytics, meters are needed on the mains, which is rare. Field inspections, i.e., physically walking the length of the main annually, would require substantial resources. Given that each water utility has hundreds, if not thousands, of miles of trunk mains, these traditional methods are not feasible.
The Solution: Satellite Leak Detection
Satellite leak detection offers an efficient and effective solution to these challenges. This cutting-edge technology uses satellite imagery and advanced algorithms to detect leaks in water networks. It covers the inspection, analytical, and innovative techniques required by Ofwat's new guidance in one go.
Satellite leak detection allows for the monitoring of large areas of the water network, making it ideal for trunk mains that span vast distances. It offers a high level of precision, enabling water companies to pinpoint the location of leaks relatively quickly, focusing the efforts of field teams. This technology can detect changes in soil moisture levels before a leak becomes significant, allowing companies to address the issue proactively.
Moreover, by using satellite leak detection annually, water utilities can fulfil the measurement criteria laid down by Ofwat. This technology not only meets the new requirements but also aligns with Ofwat's emphasis on sustainability and customer value. By enabling more efficient leak detection and repair, it helps to conserve water resources, reduce environmental impact, and minimise disruption for customers.
In conclusion, as Ofwat continues to redefine the standards for trunk mains leakage, water companies need to embrace innovative solutions like satellite leak detection. This technology offers a highly efficient, precise, and proactive approach to leak detection, aligning closely with Ofwat's strategic objectives and paving the way for a more sustainable and customer-focused water industry.
About the authors: This article is a collaborative effort between Nick Haskins and Emma Lean, both respected figures in the water industry. Nick has extensive experience garnered from his significant tenure at SUEZ and Bristol Water, is a recognised expert in the water leakage field. Emma contributes valuable insights from her specialised work in satellite water and wastewater management at SUEZ and Anglian Water.