Allowing rainwater to seep into the ground instead of redirecting it into the nearest river to flow out into the sea is definitely important, and something prev

Allowing rainwater to seep into the ground instead of redirecting it into the nearest river to flow out into the sea is definitely important, and something previous (and current) generations have put too little effort into. At the same time this can be very hard to retrofit. Having a lawn instead of a concrete pad is only a small part, you need areas that you are willing to allow to flood in a rain event. London wasn't built with this in mind, so any significant improvement that would make improvements to the sewer system unnecessary take way too long.