South West Water expands project to tackle groundwater infiltration risks
Enhanced mapping techniques aim to make sewer networks more resilient
Last updated 6th Jan 2026
South West Water has entered the second phase of an innovative project aiming to identify and address areas at risk of groundwater infiltration within its sewer network.
The Groundwater Infiltration Risk Mapping Project, delivered in partnership with the University of Exeter’s Centre for Resilience in Environment, Water and Waste (CREWW), uses geospatial technology, mapping, and groundwater modelling to reduce the operational challenges caused by ageing infrastructure and climate change.
Phase 1 of the project, completed in October 2024, focused on the Lower Otter catchment and developed a detailed risk map highlighting zones in need of urgent action, areas requiring monitoring, and regions with low risk levels. The success of this initial pilot demonstrated the potential of these methods to make sewer network operations more efficient, prioritising maintenance and tackling possible issues early.
Phase 2, now underway and running until October 2026, will extend the mapping and modelling approach into two larger catchment areas in Dawlish and Camborne. Expanding the project will allow South West Water to collect data that can inform future sewer maintenance, drinking water management, groundwater pollution prevention, and long-term infrastructure plans.
Mark Jacob, Senior Asset Manager at South West Water, said: “Groundwater infiltration can be hard to see, but it can have a real impact on how our sewer networks perform. By combining local knowledge with new data and modelling techniques, we can make better decisions about where and when to intervene. This helps reduce the risk of pollution, lowers carbon emissions, and keeps costs down for customers.”
Nejat Zeydalinejad, Postdoctoral Research Fellow at the University of Exeter, added: "The Groundwater Infiltration Risk Mapping Project is delivering cutting-edge geospatial and physics-based models to produce high-resolution hotspot maps for sewer networks across the South West.
“These outputs offer substantial benefits for South West Water and the wider community, supporting more targeted, efficient and climate-resilient decision-making. The global significance of this work is already clear, with four Q1 journal publications to date, including two in Water Research.
"We are excited to see Phase 2 progress and hope the project advances to Phase 3, where this multidisciplinary expertise can be applied to triage the entire sewer system of the South West, helping move towards a more resilient and sustainable wastewater infrastructure in a changing climate."
This project forms part of South West Water’s wider commitment to invest in science-led and data-driven innovations that improve environmental outcomes. Once completed, the company plans to investigate how the new data can be further utilised in the future.