A programme in the PBS documentary series Sinking Cities looks at London's history of serious flooding, the (temporary) solution provided by the Thames Barrier and the rapidly growing threats posed by extreme weather events and rising sea levels, both of these being consequences of human-induced climate change.
Work to reduce the threat of flooding is proceeding along various different lines, on scales ranging from huge - the Thames Tideway and a prospective new Thames Barrier - to the small, but useful - rain gardens. Of local interest is the "daylighting" of rivers and streams that were hidden underground in pipes and conduits as London's built-up area grew. There is footage of a conduit containing the Houndsden Gutter under Grangeway in Grange Park, but in particular of the impressive wetlands scheme at Firs Farm, on the Palmers Green/Winchmore Hill/Edmonton borders.
