I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
I was able to park in one of the "pull in's" along the dam which is also a public road way. My wife and I spent a very enjoyable couple of hours flying my Mavic air 2 & mini 3 pro around the reservoir.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 14/07/2022. It remains the responsibility of any pilot to check for any changes before flying at the same location.