In the late summer, on an unusually warm, sunny day in the UK I took the opportunity to try my hand paddle boarding along the River Thames. Whilst experiencing a rare moment of calm in the middle of West London I asked our guide what she thought of the cleanliness of the water.
She pointed out the large concrete pipes at various points in the riverbank and explained that they exist to carry the run-off from the nearby roads. She remarked on the short-sightedness of the concept of ‘solution by dilution, which is the prevailing idea that has led to cities being built by rivers since the dawn of time. It worked very well, up to a certain point.