This German WW 2 (1940) picture of the Thames shows the Arsenal (Plumstead Marshes).
With the sewage embankment and works at Crossness clearly visible.
©IWM (C 5424)
The only main difference for this area, from early 1900hundreds. Was the military change over from horse (mainly Royal Artillery) power to mechanical power.
With the resulting environmental drop in grassing and its upkeep in general.