The progression from passive monitoring to active network management is the defining technological shift of the current regulatory period. Connected IoT sensors placed across sewer networks, in manholes, at overflow chambers, on rising mains, and at pumping stations, provide continuous level and flow data that feeds into operational dashboards and automated control systems. By alerting systems to impending overflow before heavy rain hits, automated controls can head off spills that used to be inevitable. This capability is moving from pilot deployment into network-wide programmes, prompted by the AMP8 requirement set out in Ofwat’s Price Review 24 final determination to nearly halve average spills per storm overflow by the end of the decade against a 2021 baseline.
Digital Twins and the Network Intelligence Layer
Digital twin models, continuously updated virtual replicas of physical sewer systems calibrated against real-time sensor data, weather forecasts, and hydraulic simulation outputs, have become a central operational tool in combined sewer overflow reduction programmes. By running predictive simulations ahead of rainfall events, operators can identify which overflows are at risk, when intervention is needed, and how control actions could affect downstream flows. A review published in the journal Water in October 2025 confirmed that IoT-integrated digital twins consistently reduce overflow volumes when validated against operational network data. Forecast-driven decision support lets operators modulate inflows and protect sensitive receiving water bodies ahead of storm events.
For technology providers, water utilities, and engineering consultancies, the commercial and regulatory implications of smart network capability are far-reaching. Utilities that invest early in sensor coverage and digital twin calibration are better placed to demonstrate compliance with the AMP8 combined sewer overflow reduction targets, access regulatory outperformance incentives, and direct capital towards overflows where intervention delivers the greatest environmental benefit. Water companies are also increasingly specifying integrated monitoring and analytics as a performance requirement in procurement, rather than an optional enhancement, shaping the supply chain supporting AMP8 contracts accordingly.
Urban Drainage UK 2027 examines the operational evidence emerging from early smart network deployments across the UK, how digital twin models are being calibrated and validated for network-wide use, and what the regulatory data environment created by full event duration monitor coverage means for the procurement and specification of monitoring and control technology across the water utility sector.
