Sun City Hilton Head, for example, "was basically an alligator swamp with five farms, and now they have carefully carved lagoons to drain the water to various places," Norris said.
If years of drought are followed by rainy seasons, water might flood the lagoons there and cause problems, Norris said.
"The way our county is described with 50-percent water ... in most cases around the country this would not be buildable," Norris said. "If you look at a national soils manual, they would advise not to (build). But these are the beauty spots. This is where people come. Everybody will scratch out their own pad and make it buildable to the sacrifice of something else."