Found a blog entry about their efforts, from before the anarcho-tyrants got involved. I used to pass that stretch of river a lot. It flows through a nasty grey and brown(-skinned) part of East London, but is right at the extremity of one of the green tendrils of nature reaching down into London from Essex, right by Wanstead Flats, Wanstead park, City of London Cemetery (very expansive, green and well manicured) and Ilford Golf Course.

In other words it's a small pocket which has resisted some of the ugliness of its surroundings. I'm honestly surprised there are still white people around in the area to want to try and clean it up. Small wonder the anti-white apparatchiks are taking offence: this resembles something too much like morale.

EDIT: Here's another guy enthusiastic about local history walking the area. He even bumps into 2 ladies picking up litter by the Aldersbrook - must be the community group in question. The section at the end of the vid shows you the area of London it all backs onto.