Hi there Nature Sprite,
Haven't been to Parsons falls myself yet, but can confirm the (gated) road as far as the Blue Peaks track turnoff is still the same as in the link below. No permit or keys needed to my knowledge. There's space for plenty of cars to park just before the gate.
http://www.touringtasmania.info/parsons_falls.htmI was there the other day, with the dam level very high, and an unusual amount of overflow. Falls should be good.
EDIT: Oops - just read the "Access is not recommended if the river level is high" bit.
Maybe someone who's been there could shed light on that.
There's heaps of great walking around there, if you're used to navigating. I'm much happier now i've got a GPS, as compasses can be unreliable in the area, and the mist regularly rolls in to make it tricky - few landmarks in reduced visibility, and tracks can be lost reasonably easily in places. What sort of walking are you looking for?
Cheers