The drought tolerant zone will contain the plants that only need to be watered when there has been no rain for about 7 to 10 days. The natural zone will be the farthest from the house and will contain, once they are established, those plants that thrive with just rainfall. Mulching cools soil in the summer and warms it in the winter. It soaks up moisture and prevents evaporation and soil erosion. Florida does have a dry period, usually September through June, and our soil can be dry and sandy .
Rain tends to run right off without soaking in, with the exception of mulched areas.
Non-porous hardscapes tend to let water run off into the sewers and storm drains. Consider wood decking or gravel instead of concrete patios. Some cities, such as St. Petersburg, offer recycled water. They reuse all waste water and don't empty into the surrounding waterfront. This reclaimed water is available at a reduced rate for lawns and is separate from drinking water.