WATER RESOURCES OF ORANGE COUNTY 97
deep well is cased to 601 feet and bottomed at 1,281 feet. Automatic water level recording gages were installed on each well to compare the fluctuation of the water levels in the two zones in response to hydrologic changes. If the two zones were effectively separated, the water levels should respond differently to local hydrologic changes such as pumping and rainfall. Figure 41 shows that the water levels in the two zones are almost identical when the water levels are stable or slowly declining. Both zones react rapidly to local rainfall, but the rise in the upper zone is usually about twice the rise in the lower zone. After the rain, the upper zone declines more rapidly than the lower zone so the two levels again approach each other. This indicates that the two zones are somewhat separated; but given time and a difference in pressure head, water will move from one zone to the other.
Further evidence of interconnection of the two zones is shown by the hydrograph of an observation well at the Orlando Air Force Base (well (833-120-3). This well is about 11/ miles north of the
W
u 12 -Well 833-123-10
Depth 400 feet
o Cased 105 feet Upper Zone I 1
Cased to 601 feet
327 Lwr on.
Well l33-123
J FMAM JJASOND JFMAM JJ ASOND JFMAMJ JASOND
Depth 1962 1963 194feet
Figure 41. Relationship between water levels in the upper and lower zones
Casedof the Floridan aifer at Orlando.
W 32 Lower Zone
(n
W
L- I
F M AM JJ AS 0 N D J F MA M J 'J A S ON D J FM A MJ J A SON D
1962 1963 1964
Figure 41. Relationship between water levels in the upper and lower zones of the Floridan aquifer at Orlando.