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Ellen Halliday: The life and death of an English river

Friday 5 February 2021

As the River Lea progresses to the Thames, it is sullied and poisoned. Its plight, shared by waterways all over the country, should not be ignored


In a suburban park in the eastern Chilterns, the River Lea rises. An ancient chalk stream – one of just 200 in the world – it is, almost from the outset, defiled.

In ecological terms, the place where the Lea takes its first breath under the gaze of tower blocks is a fragile wetland. If left well alone, its waters, naturally rich in nutrients, could give life to otters, kingfisher and mink, as well as to fish, insects and plants. 

Yet the Lea is a victim of its circumstance. On its journey to London, where it is subsumed by the Thames, it passes through areas of intense agriculture and toxic industry. For centuries, its banks have offered respite and its waters a livelihood for the communities nearby. Those same communities – growing over time – have unknowingly driven the river to its ecological death. 

Travelling towards Luton, shallow and fast-flowing, the river is joined by its first unwelcome companion: water known as run-off that carries chemicals and microplastics from roads, car parks and building sites, tumbles down drains, unmeasured and ignored. Silent and invisible, but toxic. Even small volumes can build up in the food chain into doses fatal for birds, fish and mammals. 

In those early moments of its life, the river is sent underground again, straight-jacketed for two miles through subterranean concrete channels that protect it from the worst of the Luton’s run-off. South of the town, between green fields overlooked by the ruins of a 15th-century castle, the Lea pools and rests before rushing, once again, on. 

English rivers are the least healthy in Europe. Under the European Water Framework Directive, 21 per cent of English rivers initially had at least a “good” ecological status, and a target was set for 100 per cent to be “good” by 2015. Instead, it fell to 16 per cent.

The UK government set a new target that 100 per cent of rivers would be certified “good” by 2027, with 75 per cent intended to be “good” even earlier. Following a 2018 inquiry into nitrate pollution from agricultural run-off, the government said its River Basin Management Plans (RBMP) would enable them to meet this commitment. 

However, the chemical health of rivers was much worse than originally thought. In 2020, it was announced that the 97 per cent of rivers judged to be in good chemical health were in fact “bad”. Mercury and man-made chemical compounds used in electrical equipment and plastics, previously thought to dilute away in large water masses, were shown instead to persist. Every single river in England is dying. 

According to the Environment Agency, the regulator tasked with protecting and improving the environment, it will be 200 years before 75 per cent of England’s bodies of water are in good health again.

In the fields of Hertfordshire, the Lea revives. Wildlife volunteers suggest that a sewage works, which treats water from Luton, perversely means the water quality is good, for a stretch. Birds, plants and insects like damselflies flourish. Parts of the riverbank are retained for wildlife. Fishermen catch barbel, chub, rud and roach. 

Barry Killinger has been a member of Verulam Angling Club, which has two stretches on the Lea, since the 1960s. The club has invested in building backwaters that give anglers more space but also provide a refuge for fish away from the main flow if there were to be pollution coming downstream. They have current projects to cut back invasive species like Himalayan Balsam, letting in light. Past projects have increased the river’s speed and oxygen levels. 

“That stretch of river now is probably one of the best places you can fish in the area,” he said. “It is prolific.”

At other spots, families picnic and paddle in the summer. Most farmers in the region have crops, not cattle. One who does keep herds leaves just a small stretch of fence open, for his cows to reach fresh water without damaging the riverbank. 

Yet, considered in the round, agriculture is the single biggest cause of river pollution in England. Nearly 70 per cent of England is used for farming, and the industry accounts for up to 60 per cent of nitrates, 75 per cent of pesticides and 30 per cent of phosphorous lost to waterways.

Fertilisers, pesticides and slurry – manure mixed with water – slide directly from the fields into rivers, where they increase the concentration of nitrate and phosphate. Algae proliferates, multiplies and turns the water green before itself dying, broken down by fast-multiplying bacteria which consume the river’s oxygen. The Environment Agency found that, on the River Axe, 95 per cent of farmers did not invest in slurry containment, so 49 per cent were polluting the river.

Andrew Bott is an arable farmer whose fields run alongside the Beane, a chalk stream depleted by overuse which feeds into the Lea. “My grandfather used to fish for trout in the river – that would be my dream. That’s what drives me to try and keep it clean,” he said.

He favours no-till farming, where the soil is not mechanically ploughed to plant new seeds, and cover crops grown through the winter whose roots help maintain soil integrity and minimise run-off from the fields. Natural phosphate builds up in untilled soil, meaning it need not be added artificially. Organic matter like roots and worms become denser, holding huge volumes of water and reducing direct run-off into the river. 

Mr Bott also hopes it will make his crops more resilient. “We’ve been getting increasing summer droughts and heat waves – so we need to be doing everything we can to protect the soil and build the solid up with water in the winter,” he said. 

North of London, the Lea twists south and becomes the Lee Navigation – still itself but now a canal – with a network of brooks feeding in from east and west. It passes the Lee Valley White Water Centre built for glory at the London 2012 Olympics and slips under England’s busiest road, the M25. Around 169,000 vehicles thunder along each section of the London ring road every day. Without storm drains to catch the chemicals and microplastics coming from tyres and exhausts, it all pours straight into the Lea. 

At Tottenham, our river hugs Walthamstow Wetlands, a haven of tall grasses and wide pools where wintering and breeding birds take shelter in the heart of a densely populated industrial zone. At the same moment, yards from where police shot Mark Duggan, sparking the 2011 London riots, the Lea is silently fed by one of its most polluted tributaries.

Pymmes Brook again carries chemical-rich urban run-off from the industrial surroundings into the Lea, along with sewage flowing from misconnected drains that should have been directed instead to treatment plants. Thames Water estimates that one in ten properties in its region are misconnected, resulting in 1.7 Olympic swimming pools of wastewater reaching rivers and streams.

In 2018, it was the site of an oil spill that turned the river black as it spread downstream. Community campaigners expressed frustration that none of the stakeholders involved – Thames Water, the Environment Agency and the Canal and River Trust – took swift action. Volunteers took to their canoes to clean up the waste and houseboat residents forged homemade booms to contain the mess.

From Tottenham to the Thames, the Lea is frequently polluted with sewage. The scale of the problem is huge – it is the reason why 55 per cent rivers are not in good ecological health. The Guardian reported that sewage was pumped into the Olympic Park for over 1,000 hours in 2019.  

After heavy rain, the city’s sewers fill with such sudden bursts of storm water that they cannot cope. The excess spills, by design, through Combined Sewer Overflows (CSOs) into the Lea, multiplying bacteria which guzzle oxygen and choke all else. The sudden crash in oxygen levels – made worse in warm weather – can leave hundreds of fish floating dead and putrid on the surface, as happened in Somerset in 2019 and on the Lea itself in 2020. 

These are the incidents that provoke outcry, because they are seen. Campaigners like the London Waterkeeper group, led by Theo Thomas, are pushing for water companies like Thames Water to publish live, real-time alerts whenever CSOs overflow. For its part, Thames Water has previously said that it does not have the resources to meet this obligation on the Lea. 

This is a theme. The existing regulator, the Environment Agency, has also said it lacks resources – in its case, to pursue polluters – after a 50 per cent cut in its enforcement budget. Rules brought in to target agricultural pollution have brought no prosecutions at all. Last year, its boss said that unless funding was boosted back to its previous level, the government’s 25-year plan to improve the state of wildlife was doomed to fail.

From July, the new Office for Environmental Protection (OEP), created through the Environment Bill 2020, will be responsible for bringing legal action against those who break laws about air, water and waste. Until 1 January 2021, this was the EU’s task. 

Mark Lloyd, CEO of the Rivers Trust, says it is imperative that the OEP is truly independent of government if it is to meet the UK’s Brexit-deal obligations to maintain a level playing field in terms of environmental protections.

He argues that agricultural pollution must be reigned in, through better funding of independent regulators: “Agricultural pollution and breaches of the rules for farming are endemic and yet the government has progressively cut the resources of the environmental agency to enforce them, and has failed to do so.”

MPs will soon have the chance to take action, to tackle sewage pollution at least. When Covid allows, Parliament will discuss a bill that seeks to put a legal duty on water companies to make sure untreated sewage is not discharged into rivers and other inland waters.

Katy Hogarth, who rents canoes and kayaks to groups looking for inner-city adventure, is certain that a cleaner Lea would be even better loved. “It has survived where so many of London’s rivers have been lost, winding through to the heart of our city. This beautiful blue space could benefit London for generations to come,” she says.

At Canning Town, the Lea turns one last time before merging into the mass of the Thames, which in turn joins the sea. Compared to our oceans and air, the rivers that run by us are all too often overlooked. It’s time that changed.