Section Aquarena Center , Spring Lake, San Marcos
Length and duration Roughly 1 mile, 3 hours
Resources Aquarena Center, aquarena.txstate.edu, 512-245-7570
Reward yourself Tuck into a yummy sandwich from Alvin Ord’s, in San Marcos.
Aquarena Springs has come a long way since the days of the underwater shows that featured Glurpo the clown and Ralph the swimming pig. In 1996 the old theme park was taken over by Texas State University. Refashioned as the Aquarena Center, it now offers enlightening guided tours of the second-largest artesian springs in the Southwest. Through the glass floor of your kayak or motorboat you can see the sandy bottom of the lake whirl and bubble as about 150 million gallons of water a day are squeezed out of the Edwards Aquifer. (Research suggests that some of this water has been stored so long it carries radioactive isotopes from aboveground nuclear testing.) These springs, which have never gone dry, not even during the worst drought, have been the cradle of life in Central Texas for eons. The River Systems Institute, which runs the center, has done a wonderful job of restoring the lake to as natural a state as possible, and teams of volunteer divers spend countless hours tending to this underwater garden. The institute, which is leading the development of environmentally sustainable public water policy in Texas, is almost entirely dependent on contributions. If you’re feeling generous, a modest donation of $5 million would put it on a firm financial footing—and also help replace the center’s aging glass-bottom boats.