6 REPORT OF INVESTIGATIONS NO. 50
Wells referred to by number in the text can be located on figure 2 by this system.
DESCRIPTION OF THE AREA
LOCATION AND EXTENT
Orange County is in the east-central part of the Florida peninsula (fig. 1). It has an area of 1,003 square miles of which about 916 square miles are land and about 87 square miles are water. It is bounded on the east by Brevard County, on the north by Seminole and Lake Counties, on the west by Lake County, and on the south by Osceola County.
The estimated population of Orange County in 1963 was 290,000. In that year, the estimated population of Orlando, the largest city in the county, was 90,000 while Winter Park, the second largest city, had an estimated population of 20,000. The growth rate of Orange County's population has increased enormously since 1950 (See figure 63) and this trend is expected to continue. The population of Orange County is expected to reach 530,000 by 1975.
The principal agricultural products in Orange County are citrus, ornamental plants, vegetables, cattle, and poultry.A In 1960 there were about 67,000 acres of citrus groves, more than 600 nurseries and stock dealers, about 6,000 acres of vegetables-mostly in the Zellwood muck lands northeast of Lake Apopka-about 23,000 head of cattle and about 180,000 laying hens in the county. )J
TOPOGRAPHY
Orange County is in the Atlantic Coastal Plain physiographic province described by Meinzer (1923, pl. 28). The county is subdivided into three topographic regions: (1) the lowlying regions where altitudes are generally less than 35 feet; (2) -intermediate regions where altitudes are generally between 35 and 105 feet; and
(3) highland regions where altitudes are generally above 105 feet. (fig. 3).
The lowland regions include the St. Johns River marsh, the northern part of the Econlockhatchee River basin and the northeastern part of the county east of Rock Springs. Altitudes range from about 5 feet above msl (mean sea level) near the St. Johns River to about 35 feet above msl where there is a relatively steep scarp in many places in Orange County. The St. Johns River marsh