In honor of the 30th Anniversary of the Barton Springs/Edwards Aquifer Conservation District they produced a central Texas water resources map in cooperation with an artist Molly O'Halloran. The District has limited copies to give to interested members of the public, agencies, schools, libraries etc.
There are two scales, tabloid (11x17 inch) or poster (24x36 inch) that can be downloaded here. Contact Brian Hunt (brianh(at)bseacd.org) if you would like a hard copy.