Like many major cities, London and Paris are located on great navigable rivers. The Thames runs for 215 miles, 346 km, through southern England and London to the North Sea. The Seine runs for 483 miles, 777 km, through northern France and Paris to the La Manche, the English Channel. Rivers have long been used for navigation and two conflicting purposes: as drains and as sources of drinking water.
These major rivers are why London and Paris are there. The rivers provided food and transport links upriver and downstream to the coast and the sea. Images of the Seine and Thames and the bridges that cross them provide the iconic riverscape views enjoyed and celebrated by visitors, artists and photographers, and the riverside walks on the embankments and views from the bridges across the water. Rivers like the Seine and the Thames are major tourist attractions providing emblematic sights of the river and from riverboats, floating bars, and restaurants – imagine Paris or London without their iconic rivers.
Feargal Sharkey is a punk band artist from Northern Ireland and a campaigner described by Tim Adams in The Guardian as “the vocal frontman for the campaign to highlight the scandal of sewage in Britain’s inland and coastal waters”. Sharkey points to “The chronic shortfall of investment in water infrastructure, the £56bn debts of the water companies, the £66bn paid out in dividends since privatisation, the slashing of Environment Agency budgets by Liz Truss, the procession of hapless, ineffectual Defra ministers, the built-in 25-year statutory notice period to remove a water company licence.” Feargal is convinced that “Sewage is going to cost the government the next election.”
Rivers are particularly vulnerable to the Tragedy of the Commons. The advantage to the polluter of discharging into the river, if downstream of their property, is obvious. The polluter benefits from not having to pay to discharge or clean waste, and the negative impacts fall on others. Economists call these impacts externalities – they are someone else’s problem.
The “polluter pays” principle was asserted in the 1992 Rio Declaration and was briefly widely and successfully applied. Those who produced pollution were required to bear the cost of managing it to avoid damaging human health or the environment. The PPP, the polluter pays principle, originated in the 1920s.
For centuries the River Thames was an open sewer; in 1858 a hot summer resulted in the Great Stink. “As the heat increased, centuries of waste in the Thames began to ferment.” The Thames flowed past the Houses of Parliament, and the government accepted a proposal for a new sewage system for (…) preventing, as far as may be practicable, the sewage of the Metropolis from passing into the River Thames within the Metropolis.”
After years of efforts to clean up the Thames, in July 2009, the London Evening Standard reported, “Teeming with fish, Thames is cleanest for two centuries. (…) More than 125 species, including wild salmon, trout, Dover sole, plaice, haddock and bass, now live in the 215-mile waterway, which was declared biologically dead in 1957.” Heady days. Just four years later in 2013, over 55 million tonnes of dilute raw sewage was dumped in the Thames, killing fish, leaving raw sewage on the river banks and decreasing water quality. A 2022 investigation by the Environment Agency found “widespread and serious non-compliance with the relevant regulations”. Thames Water has an interactive map showing real-time data on overflow discharges meaning that “there could be sewage in this section of the watercourse.”

Rather than the polluter paying to clean up the river by not putting untreated waste into the river, the UK government is reducing stormwater discharge into the river, constructing the Thames Tideway Scheme at a cost of £4.2 billion. Tideway’s estimates suggest that around two million tonnes of sewage are still likely to be dumped into the Thames yearly. Mercury pollution in the Thames is higher than in many other UK and European river estuaries, and the Thames has relatively high levels of plastic pollution.
Potable water and wastewater treatment in the UK is provided by private companies. In France, according to the Ministry of Environment, 75% of water and 50% of sanitation services are provided by the private sector, primarily by two firms, Veolia and Suez, but supervision and regulation is stronger than in the UK
Swimming in the Seine was banned in 1923 because of high levels of pollution with high levels of e.coli and overflowing sewers when it rains. People caught swimming in the Seine were fined. As part of its 2016 bid to host the Olympics, Paris announced a €1.4 billion (£1.2 billion) plan to ensure a clean river in time for the games. The “Swimming Plan” was launched with the aim of making the river safe to use for the 2024 Summer Olympics. The project includes constructing a basin to store rainwater, which will then be slowly released into the sewer system and treated, preventing overflow. Plans also provide for several public swimming areas to be made available by 2025, ending a 102-year ban instituted in 1923 due to the polluted water. Twenty-six swimming pools are scheduled to open after the Olympics.
In France, the state has invested in cleaning the waters of the Seine to create a place for Olympic athletes, residents and visitors alike to swim. In August 2022 the UK Government published its Storm Overflows Discharge Reduction Plan to cease all storm overflow discharges by 2050, in a report titled “The affluent and the effluent: cleaning up failures in water and sewage regulation”.
Regulation is essential to deal with Tragedies of the Commons, what the economist label as externalities: someone else’s problem. The PPP, the Polluter Pays Principle is fundamental to making “better places for people to live in, better places for people to visit.”