What’s remarkable is not that a water company knowingly and deliberately poured billions of litres of raw sewage into the sea to cut its costs. What’s remarkable is that the Environment Agency investigated and prosecuted it. Every day, water companies pour tonnes of unprocessed filth into England’s rivers and seas, and the government does nothing.

Even in the wake of the sentence last week, under which Southern Water was fined £90m, the company’s own maps show a continued flow of raw filth into coastal waters. Same shit, different day. The only occasions on which water companies are allowed by law to release raw sewage are when “exceptional rainfall” overwhelms their treatment works. But the crap keeps coming, rain or no rain.

The prosecution, in this land of lions led by donkeys, was driven above all by one official at the Environment Agency, Stephen Bailey, who managed to stick with the case, breaking through layers of water industry deception and raising, within his organisation, a stink about the stink. Even so, though this was a deliberate and long-lasting crime, though “very serious widespread criminality” was established, though Southern Water obstructed the investigation, no executive is being prosecuted. The fine will be swallowed by its gigantic profits like a stone thrown into a settling tank.

As the court documents show, the company knew it ran the risk of big fines, but calculated that they would cost less than upgrading its plants and treating the sewage. Even now, this calculation may have been vindicated. Hiding its discharges saved it more than £90m in penalties, even before the huge savings it made by failing to upgrade its infrastructure are taken into account. So while the £90m fine and the £126m penalty imposed by the Water Services Regulation Authority, Ofwat, were heralded as “massive” and explained as “deterrents”, I don’t see them as either. The occasional prosecution, which holds an amorphous thing called the corporation – rather than any human being – liable, seems to be treated by water companies as a business cost.

The truth is that the governments of all four nations have lost control of the pollution crisis, and in some cases this seems to be, like Southern Water’s releases, knowing and deliberate. Since 2010, the Westminster government has cut the Environment Agency’s grant by almost two-thirds. It knew the budget was already stretched. It knew the water companies and other polluters were already getting away with murder, but it went ahead anyway. When you look into your local river and see, instead of sparkling water and leaping fish, stools and wet wipes, sanitary towels and sewage fungus, please remember that this is what “cutting red tape” looks like.

Even worse, David Cameron’s administration shifted from external regulation to relying on water companies to “self-report” pollution incidents. In other words, the government depends on these ruthless, offshored corporations to blow the whistle on themselves. The Tories claim to be “tough”, “realistic” and “businesslike”, but their wilful naivety in expecting companies to regulate themselves would astonish a six-year-old.

Morale at the Environment Agency seems to have plunged even faster than its budget. Over the past few years, I’ve been contacted by whistleblowers telling similar stories: of having their hands tied behind their backs by the indifference or hostility of successive Tory governments. I’ve seen how a lack of grit on the part of the agency’s top brass, who raise public objections only in the mildest terms, has allowed the government to keep dumping on them.

Last month, the chief executive of the Environment Agency, Sir James Bevan, told a parliamentary inquiry that his organisation perceived “the overall performance of water companies is improving” and “serious pollution incidents” were falling. A few minutes later, however, he admitted that “over time there are, exactly as you said, greater volumes and greater frequency of spillage”.

How can he reconcile these positions? Well, since 2016, according to answers it has sent me, the Environment Agency’s monitoring budget has fallen by 55%. So it relies to an even greater extent on water company confessions. The Southern Water case revealed “very significant under-reporting” of its own malfeasance. Who would have guessed?

Despite repeated public complaints, it took the Environment Agency years to spot the tides of sewage on the south coast. Around the country, people keep stumbling across severe pollution that neither the Environment Agency nor the water companies claim to have noticed.

As a paper in Nature shows, the evidence gaps are gigantic and the bias is all in one direction. “We’re seeing less pollution” doesn’t mean there’s less pollution. It means there’s less seeing. Bevan also agreed that court actions against polluters fell by 98% between 2002 and 2020. Law enforcement has been dying as quickly as our rivers.

But this is not the worst of it, because water companies, reckless as they may be, astonishingly are not the country’s biggest polluters. After a six-month investigation, with a team of independent film-makers led by the director Franny Armstrong, tomorrow we will be broadcasting the world’s first live investigative documentary, Rivercide. We will expose an astonishing record of filth and failure, leading to the transformation of rivers across the UK, in just a few years, from thriving ecosystems to open sewers. Livestreamed on YouTube, it will identify culprits and press for action.

Across the country, as monitoring, enforcement and prosecution have collapsed, local people are stepping up to fight the rising tide of filth. A national citizens’ science project is building, as people around the country take samples and get them analysed, then demand change. But this is no vindication of Cameron’s dream of a deregulated “big society”. It’s a sign of desperation. We love our rivers. We want to swim and paddle and feed the ducks and fish and boat without needing to worry about what’s in the water. We do not consent to their use as cheap disposal chutes by ruthless corporations, exploiting the governments’ regulatory failures. We do not consent to the tsunami of shit.

Our film is grounded in the same principles. It’s crowdfunded, made with the help of volunteers, using citizen science to fill reporting gaps. If change is going to happen, it won’t come from the centre. It will come from the margins.

We are no substitute for government, as we have no powers. But we can expose the neglect of those who claim to lead us, and demand that the law is upheld. They might be happy to wallow in filth. We’re not.