Total storm overflows

Total spills

Duration of spills (hours)

Leaflet | Contains Ordnance Survey data © Crown copyright and database rights [2025] OS [AC0000813358]

Circles represent sewage discharge locations, including sites where there were no spills in 2024. The size of a circle is based on the number of counted spills at that location. Click on the circles to see monitoring data for individual sites. The shaded area represents the constituency boundaries. Storm overflows that spill into the sea may be outside the boundary of any constituency - they have been assigned to the nearest constituency.

Total storm overflows

Total spills

Duration of spills (hours)

Leaflet | Contains Ordnance Survey data © Crown copyright and database rights [2025] OS [AC0000813358]

Click on the map to add additional rivers to your selection. Circles represent sewage discharge locations, including sites where there were no spills in 2024. The size of a circle is based on the number of counted spills at that location. Click on the circles to see monitoring data for individual sites. River catchments correspond to the Environment Agency's 'operational catchments'. They typically include tributaries to the primary river. Note, however, that waterbodies within operational catchments may have been grouped because they face similar water quality issues, rather than because they are hydrologically linked. Not all storm overflows are located within a river catchment - these are excluded from the map.

Total storm overflows

Total spills

Average duration of spills (hours) per overflow

Leaflet | Contains Ordnance Survey data © Crown copyright and database rights [2025] OS [AC0000813358]

Circles represent sewage discharge locations, including sites where there were no spills in 2024. The size of a circle is based on the number of counted spills at that location. Click on the circles to see monitoring data for individual sites. Dŵr Cymru data covers the company's storm overflows in England only.

Cookie policy | Privacy notice