you might want to try the James around Shelvin access. It gets shallow around there.
Also, on the Finley, park by the 14 bridge, where the Jeep dealer used to be. There's a trail along there that will lead to shallower sections past the pool that's under the 14. From there you can go down stream quite a ways with few deep pools, probably until you get near Riverdale.
I was thinking of hitting that section this weekend actually