WATER RESOURCES OF ORANGE COUNTY 111
including nearby discharge points such as Rock and Wekiva Springs. The flow of the springs increases during high-water stages and decreases during droughts. (See table 11.)
The relatively small fluctuations of the water levels in well 822-138-1 in the southwest corner of Orange County; well 833-137-3. in the western part of the county, and well 823-104-1 in the eastern part of the county (figure 52) indicate that recharge and discharge occur at a more uniform rate in these areas. Rain infiltrates through the sand overlying the aquifer in the western areas and Srecharges the Floridan aquifer and flows through the aquifer to the eastern area. Discharge is largely by outflow through the aquifer.
The range of fluctuation of the piezometric surface from the high level (September 1960) to the low level (May 1962) is shown in figure 53. The piezometric surface does not rise and fall uniformly. The range of fluctuation is much greater in and northwest of Orlando (20 to 25 feet) than it is in the outlying parts of the coi (5tI0feet). The-- ain reasons for the greater fluctuation in Orlando and vicinity are twofold: first, the area has greater recharge especially through the more than 300 drainage wells in the area; and second, there is much more pumping in Orlando and vicinity than in other parts of the county.
Large natural recharge, augmented by the unusually large quantity of water that entered the aquifer through drainage wells during the period of exceptionally heavy rainfall in 1958-60, caused record-high artesian levels in the Orlando area. Drainage wells in Orlando and vicinity contributed recharge to the aquifer in sufficient quantities during the time of heavy rainfall to create a localized temporary mound or high on the piezometric surface. From September 1960 through May 1962, severe drought conditions caused water levels to decline markedly from their abnormal high. The area of greatest decline, shown by the 20-foot line on figure 53, encompasses most of the drainage wells in the county. Most of the ground water used in Orange County is pumped within this area, and during the drought pumping rates were far above normal.
The well fields of Orlando and Winter Park are within the 20-foot line (See fig. 2.), but the decline from 1960 and 1962 near the well fields was about the same as it was in the area between Lake Apopka and Orlando where there was relatively little pumping. Most of the decline during this period was probably due to abnormally high-water levels at the start caused by abnormal recharge followed by abnormally low recharge during the drought. This indicates that withdrawal in 1963 (See Water Use section.)