How Road Run-Off Affects London's Rivers

The quality of London’s rivers and waterways is being significantly compromised by run-off from road pollution, according to a new study. Commissioned by the government, the research is the first of its kind to highlight the most damaging sources of pollution and chart how they affect the dozens of rivers which run through the UK capital.

The paper makes for uneasy reading and is a testament to how human activity can have a wide variety of detrimental impacts. London Mayor Sadiq Khan has called on the government to intercede and implement measures geared towards curbing run-off pollution, which can be harmful and even life-threatening for flora and fauna living in the rivers themselves.

An underpublicized concern

Most of the headlines taken up by environmental issues in the British capital city are focused on measuring and managing nitrogen oxides emissions from the exhausts of cars and how this can hamper the quality of life for those exposed to the unclean air. While that is a significant problem – air pollution is thought to account for at least 9,000 premature deaths per annum – there are other consequences of road traffic, too.

Road run-off pollution is caused primarily by spills of petrol, diesel and oil when servicing cars, as well as from the residue left by tyres and braking systems as they become worn out over time. This cocktail of heavy metals and other toxic chemicals is then washed into waterways by rainfall, contaminating the delicate balance of the water itself and potentially killing countless fish, crustaceans and other water-based organisms.

What’s more, the pollution can even compromise human life. If such run-off pollution is allowed to infiltrate drinking water supplies, it can potentially endanger the human population. As such, meticulous testing must be carried out on a regular basis and comprehensive clean-up methods employed if contamination is found. This is not only dangerous to health, but hugely expensive.

Government intervention needed

At present, only one waterway in London – the Carshalton Arm, from which stems the River Wandle – has achieved “good” accreditation from the EU, highlighting the ubiquity of the problem. Armed with this latest research, the government now has the knowledge of where major run-off pollution is occurring – and so must act upon it, according to Sadiq Khan, mayor of the city.

“The government must step up to provide the Environment Agency and highways authorities with the appropriate funding for measures to properly protect the capital’s rivers,” he said. One of the biggest obstacles to tackling run-off pollution at the moment is that the riverways often fall under different governmental and municipal jurisdictions, all of which have been hamstrung by cuts to their funding under the incumbent government in recent years.

Of course, the best way to clean up flooded lakes, rivers and reservoirs is to prevent them from becoming contaminated in the first place. Transitioning to electric vehicles (EVs), creating or expanding wetland areas, planting vegetation to act as barriers and filters and improving drainage networks are just some of the ways in which the government can make inroads on the issue.