WATER RESOURCES OF ORANGE COUNTY 143
The most extensive use of surface water is for recreation. Fishing, boating, swimming, and water skiing are all popular sports in Orange County. The aesthetic value of lakes is difficult to evaluate; but lakes certainly have contributed much to the City of Orlando's reputation as "The City Beautiful." The 1,100 lakes and ponds in Orange County also moderate the air temperature in surrounding areas by releasing heat during cold weather and absorbing heat during hot weather.
SUMMARY
Large quantities of potabje ,wajer are available from the artesian (Floridan) aquifer inKall parts of Orange County except in the extreme eastern part near the St. Johns River, where the water is too mineralized for most purposes.
The maximum sustained rate at which water can be withdrawn from the Floridan aquifer is not accurately known at present (1964). However, the information currently available indicates that, in most parts of the county, water can be withdrawn at a rate at least several times the present rate without seriously depleting the water resources of the county. Lesser quantities of water are available in the surficial sand that forms the nonartesian or water-table aquifer. In some areas moderate quantities of water can be obtained from porous sand, gravel, or shell beds that form secondary artesian aquifers within the confining bed that separates the nonartesian and the Floridan aquifers.
The top of the cavernous limestone that comprises the Floridan aquifer ranges from about 50 feet below the land surface in the western and northwestern part of the county to about 350 feet below the land surface in the southeastern part. The Floridan aquifer in Orange County is known to be at least 1,400 feet thick. Water level, chemical, and geological evidence indicate that the aquifer is a hydrologic unit, but there are several different permeable zones within the aquifer separated by less permeable zones. The most productive zones in the Orlando area are dolomitic layers-one at depths between 400 and 600 feet and the other at depths between 1,100 and 1,500 feet. The limestone is overlain by sand, clayey sand, and occasional lenses of relatively pure clay. The water in- the lirhestone in Orange County generally flows northeast and eastward. The major recharge areas of the Floridan aquifer in Orange County are the highlands in the western part of the county and adjacent areas in Lake and Polk Counties.