It is possible to access the falls from Mt Barrow road but it would be quite difficult to do avoiding all the private property that surrounds the falls reserve now. More importantly the very shear cliffs and rock screes that surround it are quite dangerous particularly if it is wet. Have a look at the maps and you can walk behind all the private property off the road and take a big loop to the cliff face of the falls on the Western side.
Walking up the creek would be pretty hard going as it's very thick down their these days. The whole area on the western side of the reserve is soon to be logged right to the boundary of the reserve I understand, so it may open up on that side soon after they strip it bare as the reserve boundary is only 80M from the falls on the closest side.
It is almost impossible to get a full view of the falls these days due to the growth of the trees around the base and the only decent photo opportunity is hanging quite high up off a ledge of the Southern cliff face if that is your goal? You need ropes to do it safely.

- Mt Barrow Falls in 2008 compared to Spurlings 1909 photo
- Mt Barrow Falls 1909-2008.jpg (356.3 KiB) Viewed 8926 times
The attached photo I took last year from the base of the falls very close to where Spurling took his famous photo to give you an idea if it is really worth while? You can not get to the exact spot any more due to the growth of all the trees and scrub. Amazingly however the tree laying at the base is still present after 90+ years although some what more decayed.
There is some efforts to get the area opened up but nobody is too keen on it due to the significant hazards in the immediate area and the fact that it is now land locked by private land. Have a search on the Wildcare site and you will turn up a little information.