This is what's left of Battersea Creek, the outlet into the Thames of Battersea's now underground river, the Falcon Brook. 
The creek's position is confirmed by the National Library of Scotland's interactive map at https://maps.nls.uk/geo/explore/#zoom=18&lat=51.46848&lon=-0.18024&layers=163&b=1.
Battersea Creek was used as a wharf for Price's Candle factory, which stood next to it.
https://www.londonslostrivers.com/falcon-brook.html reports the creek was  filled in during the late 20th Century, but this last section has been turned into an attractive wildlife pond (see https://www.flickr.com/photos/155548392@N07/50423100817).