I like this one the best.
ftp://ftp.ci.austin.tx.us/GIS-Data/P...146%205250.pdf
Photo from the KUT article
It has an open plan event hall that can be flexible, plus it would have a district chiller plant that would create cold water for Austin Energy's district cooling system. (All these new buildings planned for the area have to be cooled.)
Hikers & bikers could either use the boardwalk along the water's edge or stay on the existing trail between the front of the building and Cesar Chavez. It's got the balcony that would be open to the public. Restrooms and a refreshment kiosk would be in front of the building and there's a circular drive that would be used as a transit stop.
If they wanted to get really fancy, they could have the waterfall floodlit at night - maybe with changing colors like the fountain at Butler Park. I think it would look awesome at night reflected on the lake.
It's not nearly as ornate as some of the other plans, but it's pretty and it's practical (i.e. the chiller plant.)
I have to admit though, that I do like the plans that show the floating stage out in the lake. Maybe they could incorporate that into the above plans and the audience could sit on those limestone steps.