Case Study: Portsmouth Water reduces nitrate pollution risk with Rezatec

Protecting Natural Water Sources Using Space Data To Analyse Agricultural Land Use

Portsmouth Water, a groundwater-dependent utility supplying 85% of its water from boreholes and springs, faced rising nitrate pollution and concern that farm-related contaminants such as manure and FIOs were entering its raw water sources. The company wanted to better understand overland flow and identify where pollutants were likely reaching groundwater so it could improve water quality, reduce treatment costs, support compliance, and lower the risk of future nitrate pollution.

Rezatec used Earth Observation data, geospatial analytics, hydrology modelling, and Lidar-enabled feature detection to map agricultural land use, predict nitrate and FIO flow paths, and identify previously unknown karst features such as swallow holes and chalk pits. The results helped Portsmouth Water pinpoint pollution hotspots, target mitigation efforts more cost-effectively, and explain risks more clearly to landowners and farmers; Rezatec’s work also informed the utility’s business planning and catchment management strategy for the years ahead.

Portsmouth Water

Alastair Stewart

Project Manager