Tetra Tech Europe Partners Thames Water on Smart Sewers Initiative

The Partnership

Tetra Tech Europe — the European operating arm of Tetra Tech Inc — has entered into a partnership with Thames Water to provide operational maintenance support for the Smart Sewers Initiative. The contract covers approximately 2,000 radar sewer depth monitors (SDMs) deployed across the South Mogden area of Thames Water's network.

The system provides continuous real-time monitoring of sewer flow depths, enabling early detection of conditions that could lead to flooding or pollution incidents. Gareth Ingram, Operations Director at Tetra Tech Europe, described the initiative as a reactive system that demands action and is designed to deliver sustainable outcomes and long-term community value.

What Smart Sewers Does — and Why It Matters

Radar sewer depth monitoring (SDM) sits at the intersection of two long-running pressures on water companies: the obligation to eliminate sewer flooding and the obligation to prevent sewage entering the environment via storm overflows and combined sewer overflows (CSOs).

Traditional sewer management is largely reactive — blockages, overflows and flood events are identified after they occur, either by customer report or by a field team responding to an alarm. Smart monitoring transforms this: when a network has continuous real-time depth readings across thousands of chambers, operators can identify rising risk before an overflow occurs and dispatch a response in time to prevent it.

South Mogden is served by the Mogden Sewage Treatment Works — one of Europe's largest treatment sites by capacity, processing wastewater from approximately 1.8 million people across a dense west London catchment that includes Heathrow, Hounslow, Richmond and parts of Ealing. The area's combined sewer network — which carries both foul sewage and surface water in the same pipe — is inherently vulnerable to capacity exceedance during heavy rainfall events, particularly as urban drainage stresses increase with development.

Supply Chain Context

Thames Water's AMP8 investment plan, submitted to Ofwat in October 2023, includes significant expenditure on sewer network monitoring and smart network technology as part of its programme to reduce storm overflow spills and eliminate internal flooding. Thames Water's broader network position — serving a highly urbanised, partially combined sewer catchment — means real-time monitoring is a strategic priority rather than a discretionary improvement.

For suppliers in the smart water and wastewater monitoring space, this type of partnership signals several things. First, it confirms that Thames Water is actively deploying and maintaining radar SDM infrastructure at scale — the 2,000-device figure is a meaningful network. Second, it shows that Tetra Tech Europe is positioned as a maintenance delivery partner for this category of infrastructure, which typically requires specialist knowledge of both the monitoring hardware and the operational drainage network it sits on. Third, it is consistent with the broader AMP8 pattern of water companies disaggregating capital delivery, operational maintenance and data services as separate procurement categories.

Related Technology Categories

The Smart Sewers Initiative sits within a wider cluster of AMP8 technology investments that companies across the sector are deploying or planning:

• Radar sewer depth monitors (SDMs): Continuous, non-contact depth measurement in manholes and chambers. Radar is preferred over float or pressure sensors in foul sewers because it is unaffected by debris and grease.
• Acoustic logging for leakage and blockage detection: Used across both clean water and wastewater networks to identify anomalies in pipe condition and flow.
• Flow and level data telemetry: RTU-based systems that transmit SDM data to a control centre in real time, enabling dynamic network management and predictive dispatch.
• Combined sewer overflow (CSO) monitors: Ofwat's requirement that companies monitor 100% of CSO spill events is driving a separate but related wave of sensor deployments.
• Predictive drainage modelling: Using real-time sensor data as inputs to hydraulic network models, enabling operators to forecast flood risk from incoming rainfall events.

Businesses supplying any of these technologies — and the maintenance and integration services that surround them — are positioned in a category that is growing in every AMP8 business plan. Thames Water, with 32,000 km of sewers across London and the Thames Valley, represents one of the largest individual procurement opportunities in this space.

Tetra Tech Europe in the UK Water Sector

Tetra Tech Europe operates across environmental consultancy, water asset management, and infrastructure services. The company is active across multiple UK water companies and has a presence in both capital delivery and operational services. The Smart Sewers role with Thames Water represents an operational maintenance position — distinct from a design or construction engagement — reflecting the company's positioning in the full lifecycle of water network intelligence infrastructure.

Source: Tetra Tech Europe, LinkedIn, July 2026 (announcement by Gareth Ingram, Operations Director, Tetra Tech Europe). Independent analysis by Water Industry Hub. Water Industry Hub is not affiliated with Tetra Tech Europe or Thames Water.