Hi Shawn
I did make some calls a couple of years ago to United Utilities, when I found out that a local sailing club were using it whilst they were having work carried out at their venue.
There must be access as I see people walking round the wall most nice days.
Apparantly, the water level stays pretty much 100% year round. You can see images on a Google image search. The biggest problem is the twitchers though, as it is treated like a bird reserve and they complained like billyo when they sailed on it!.

Would be a great venue due to the elevation for Stocky folk though. The people at UU I spoke to didn't want to be mithered looking into it and gave me no route forward, so there may be some mileage in giving it a fresh try perhaps. Who knows!