FLORIDA GEOLOGICAL SURVEY


change observed during the period of record was 13 feet. The water
level was highest, 56 feet above sea level, in 1949, and lowest, 43 feet
above sea level in 1955.
 The hydrograph for well 037-645-1, which penetrates the upper lime-
stone of the Floridan aquifer, shows very different fluctuations. The
hydrograph shows a progressive decline in the artesian pressure head of
21 feet during the period of record. Artesian pressure was highest, 88
feet above sea level, in 1948 and lowest, 67 feet above sea level, in 1962.
The artesian pressure head stood above the water level in the sand-and-
gravel aquifer during the entire period of record.
 The hydrograph for well 037-645-1 shows the decline of the artesian
pressure head that has occurred in the upper limestone of the Floridan
aquifer, in the Fort Walton Beach area. Barraclough and Marsh (1962)
found this decline to be greatest at Fort Walton Beach, about 17 miles
to the southeast, where one well had a decline of about 56 feet between
1948 and 1960, and a net decline of 125 feet between 1936 and 1962.
The amount of decline increases toward Fort Walton Beach and results
from use of water by Fort Walton Beach, Eglin Air Force Base, and
others. In addition, the decline relates to thinning of the upper limestone
northward from about 400 to about 40 to 60 feet thick. This thinning has
a restricting effect on the amount of water moving through the aquifer.
Barraclough and Marsh (1962) noted the large amount of clay in the
aquifer, both in beds and clay-filled voids, and suggested that the clay
within the aquifer reduces both the permeability and effective porosity
of the aquifer, resulting in the large drawdowns.
 The artesian pressure head in well 037-645-1 has declined at an av-
 erage rate of 1.4 feet per year. Wells that tap the upper limestone of the
 Floridan aquifer in southeastern Santa Rosa County around Navarre
 probably have had a similar rate of decline which may continue. Farther
 away from the Fort Walton Beach, the artesian pressure heads have de-
 clined at a slower rate.
 Figure 36 contrasts changes of the water level in an area affected
 slightly by pumping, as shown by well 031-716-1 at Ensley, with changes
 of the water level in areas of heavy pumping, as shown by well 036-719-1
 at Cantonment and well 036-716-1, 3 miles east of Cantonment. All three
 wells are in the sand-and-gravel aquifer. From 1940 to 1962, the water
 level at Ensley varied a maximum of 26 feet; the water-level high of 75
 feet above sea level was recorded in 1948, and the water-level low of
 49 feet was recorded in 1956. Well 031-716-1 is 239 feet deep. The rise
 and fall of the water table in this area, as shown by the graph, closely
 follows variations in rainfall. In general, whenever the annual rainfall