Hundreds of Dead Fish in River Wensum Linked to Heatwave
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- Environment Agency concluded that heavy Thursday rainfall flushed contamination from surface water drainage systems into the River Wensum, coinciding with low flows and high temperatures that 'significantly' reduced dissolved oxygen.
- Sarah Eglington of the Wensum Riverkin campaign group said she had swum the river with her son on Wednesday, calling the water 'beautiful', and told the BBC the scene three days later was 'absolutely heartbreaking'.
- Lucy Galvin, Green Party leader of Norwich City Council, identified dead pike, carp, roach, eel, rudd and dace and framed the kill as 'the effects of climate change' that are 'catastrophic'.
- Rose, 24, a member of swimming group Cow Tower Dippers which meets at the river most weekends, said 'it's never been like this, it is devastating'.
- River Wensum is designated a Site of Special Scientific Interest and Special Area of Conservation, stretches about 44 miles (71km) through Norfolk, and is recognised as one of England's most important chalk river habitats, home to more than 100 plant species.
- The Environment Agency said its officer 'promptly attended the scene' and would continue monitoring the river and working with partner organisations.
Why it matters: The Environment Agency's technical finding points to a dual cause — surface water drainage infrastructure releasing contamination during heavy rain AND heatwave-driven oxygen depletion — on a river legally protected as a Site of Special Scientific Interest and one of England's most important chalk river habitats. The kill therefore exposes both ecological fragility and an infrastructure vulnerability, with residents and the Green Party framing the same episode as direct evidence of climate change's local toll.
