Specifically, "The 3rd Annual Great American Water Balloon Fight" on Saturday September 6. This is a local event that draws about 1000 people.

This year it is being held in Schenley Plaza. (Which is right next to the Carnegie Library main branch and Pitt's Cathedral of Learning.)

I figure, I'm going to be attending in any case. So if this is the kind of event you'd want to go to anyway, there's no reason we couldn't just meet up there.

Event goes from 11 AM - 3 PM. Music and activities start at 11, water balloon fight starts around 1. It's $30 dollars to participate in the water balloon fight, the charity is an organization that supports poor families in Haiti through job preparation and placement.

Any locals that want to meet there, please respond to let me know you're interested.

Links for the event:
http://greatamericanwaterballoonfight.org/pittsburgh/
https://www.facebook.com/events/522457501220192/?ref=22
http://teamtassy.org/