As wildfires take hold across Northern Ireland and the border counties of Ireland, in the worst spring fire season for over two decades, The Rivers Trust is warning of the hidden, but serious, impacts these fires are having on the health of rivers, water quality, and freshwater biodiversity.

Driven by a changing climate, record spring temperatures, and more than two weeks without rainfall, vast areas of gorse and vegetation across upland areas in Northern Ireland and Ireland have gone up in flames, destroying habitats and leaving behind scorched, unstable landscapes. But the damage does not stop at the burn sites. Rivers and streams – already under pressure from pollution, habitat loss, and potential summer drought – are now facing an added crisis.

All-Ireland Director of The Rivers Trust Mark Horton said: “We see the immediate impact of wildfires on the landscape, but they are also damaging our river systems in both the short and long term. These fragile freshwater ecosystems cannot withstand such repeated extreme environmental shocks, especially when water levels are low.

“It is also worth noting that as firefighters bravely battle these blazes, they are often having to draw water directly from local rivers and streams, especially in remote areas. But as water levels continue to fall during this prolonged dry spell, this becomes increasingly difficult, placing even more strain on an already vulnerable freshwater system.”

placeholder image — All-Ireland Director of The Rivers Trust Mark Horton

In the short-term, wildfire impacts on rivers and loughs include increased runoff, flash flooding resulting from the bare landscape left behind being unable to slow the overland flow of rainwater, and water contamination as ash, debris, and heavy metals enter rivers, streams, peatland bogs and loughs. With soil left bare and vegetation burned away, rain can wash pollutants directly into watercourses, endangering aquatic life and water quality.

Long-term consequences are equally bad. Increased nutrients like phosphorus and nitrogen in dry, compacted soil, will move and reanimate when it does rain, unlocking these accumulated pollutants into rivers. Additionally, eroded soils raise sediment levels in rivers, while altered river flows and temperature shifts disrupt the delicate balance that freshwater species depend on to survive. Pollutants from burned landscapes can linger in the environment for years, degrading water quality far beyond the initial fire season.

“Northern Ireland’s rivers are already vulnerable – facing a combination of climate stress, declining water quality, and reduced biodiversity. Wildfires are now compounding these pressures. As dry, hot weather continues into summer, we could see rivers dry up, impacting on fish populations and water-dependant biodiversity such as otters, as well as causing lasting damage to our freshwater environment,” Mark continued.

The Rivers Trust is urging the public to stay alert. Preventing wildfires starts with individual responsibility. When out in the countryside, do not light open fires or barbecues during this particularly dry season. Dispose of cigarettes properly and never drop them on dry grass. Take glass bottles home—sunlight through glass can spark fires. If you see smoke, flames, or suspicious activity, contact the Northern Ireland Fire & Rescue Service or the Police immediately.

Mark concluded: “Just as we see the devastation wildfires cause to landscapes, habitats, and wildlife above ground, we must also recognise that our rivers are suffering from them too. Rivers are not separate from the ecosystem – they are at its heart. If we allow them to be damaged, the ripple effects on biodiversity, water supply, and climate resilience will be felt by us all. Protecting rivers must be part of integrated landscape management and part of our collective response to climate-driven emergencies like wildfires.”