I have paid $5 at the gate just to empty the black water here locally in Austin. They didn't charge me the daily use fee since I have an Annual Parks Pass but I don't know if they would charge that fee if all you want to do is clear your tank. I am guessing all State Parks are the same but just ask at the office.
Yes you can that's what it's there for you don't have to have camped
Yeah, I don't know about that. You would have to ask the ranger station at the entrance to the State Park.
That would be a question to ask the Ranger Station, as this IS a State Park. I do not KNOW the answer.
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