http://www.sanantonio.gov/planning/p...4b_era_map.pdf
the above link is a map of HemisFair as it currently stands, with buildings color-coded by the time-period from which they came...
as you will see, there isn't much "green" space to save. and like SKW said, they'll have to move a bunch of historic structures if they hope to have any large green space at all.
the convention center will eventually expand over market street (with market being straightened where the old SAWS building rests).
hopefully, UTSA ITC will be razed, making way for a larger area that could be green space and pueposeful development.
the 2004 hemisfari master plan is on the city parks website (
http://www.sanantonio.gov/planning/pdf/hemisfair) and is woefully inadequete for what hardberger is trying to push through now.