The River Wandle runs largely underground through the main part of town. One of the few places where it was visible was Wandle Park, but the stream (for it is little more just there) was culverted in 1967. In the last year or so it has been excavated & now runs through the park. Work still continues as as part of a all round makeover of the park with many improvements & additions including a bandstand.
Further south, the river flows above ground through Beddington Park & Carshalton Ponds & on to Morden. It has been hugely cleaned up in recent years & is no longer the health hazard it was when, as a schoolboy, I had to run through, along & across it as part of an assault course. (My school adjoined Beddington Park & treated it as part of the school grounds).
Somewhere just this side of the “Stone Bridge” in the picture below buried in the mud is one of my running shoes from back then, though given the toxic nature of the waters then it probably dissolved within minutes!!