Today I was at Barton Springs Austin TX and I Saw..?

Is it prohibbited for a women to take her top off at Barton Springs? I mean there were children there and many age groups. For me im a 16 so when I was swimming and I looked up there was a lady with here top off showing her boobs in front of like 350 people life guards didnt say anything and my friends and I were like WOW. They werent even round they looked like water bottles. My main questin is. Is it prohibited to do that. Barton Springs is like a community pool no water with chemicals though. Just clean fresh springs water i think