In reply to jamie_adcock:
Was up there on Friday - the gates weren't locked. I parked by the gate at the bottom without blocking it and and had brief word with the farmer who was driving up it with some animal feed. So those with agreed access are about and may spot a car !
For walking up the road could you not just take trail shoes / trainers and put boots on at the reservoir?
This is what conditions looked like Friday afternoon - I doubt they've changed much
http://twitpic.com/bhvjyl