It is dispiriting that in 2021, after heavy rain, scientific instruments are not needed to measure water quality in Chichester harbour: the smell makes it obvious. Southern Water is discharging raw sewage.

After it was issued with a record GBP90m fine for routinely breaking the law elsewhere on its patch, the company says there is now a concerted effort on its part to try to prevent this heavily protected bird sanctuary becoming an ecological disaster zone.

But no one is optimistic. A simple calculation suggests it is cheaper for water companies everywhere to keep paying record fines than to spend the huge sums required to update sewage works. Even if Southern Water’s promises are genuine, the popularity of this area means developers are constantly adding new estates to the already failing drainage system. The company has not objected and gets extra revenue.

As the climate crisis makes heavy rainfall events common, it seems likely the raw sewage discharges will get more frequent. With the Environment Agency short of funds and regulatory powers, and a complacent government, protesters are considering hitting where it hurts – withholding 45% of their bills. This is the proportion paid to Southern Water for legally required water treatment that frequently does not happen. What is needed is a slogan. One suggestion is BNT – birds not turds.