ANALYSIS OF WATER-LEVEL-LAKE JACKSON


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 Figure 4.-Yearly rainfall at Tallahassee, Florida, from 1886 to 1965.



 According to Kohler and others (1959, Plate 3), a yearly pan
coefficient of 0.77 is applicable to Class A pan evaporation in the
vicinity of Tallahassee. Thus, on the basis of this coefficient and
records of pan evaporation in table 1, yearly lake evaporation
averages about 50 inches or 4.2 feet per year.


 SURFACE WATER

 Most of the time there is little or no surface-water inflow to
Lake Jackson; however, following periods of above average rain-
fall substantial inflow may occur from intense rainstorms. Small
rivulets fed by ground water or by drainage from small ponds and
lakes also contribute inflow to Lake Jackson during unusually wet
periods, however, no measurements of surface-water inflow have
been made.
 There is no surface-water outflow from Lake Jackson. The lake
can spill into the Ochlockonee River only when the lake level is
above about 115 feet. This altitude is almost 19 feet above the
present record-high level of the lake.
present record-high level of the lake.