FLORIDA GEOLOGICAL SURVEY


4, 1953, reached a crest elevation of 81.3 feet above sea level at State
Highway 4 and a peak flow of 17,200 cfs.
 The lower 6 miles of the Blackwater River channel varies in depth
from 10 feet to as much as 60 feet in holes. A depth-profile graph is
given in figure 32. At least 6 holes in the lower river are 35 to 60 feet
deep_ These deep holes trap salt water moving in from the Gulf and
could be a source of contamination of the surrounding ground water if
large capacity wells are located nearby and pumped heavily enough to
cause major drawdowns. The salt front during extreme high tides ex-
tends upstream about 6 miles from Blackwater Bay.









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Figure 32. Channel bottom profile of lower Blackwater River.