FLORIDA GEOLOGICAL SURVEY


 CLASSIFICATION OF SPRINGS

 There are two general types of springs in Florida, seeps (water table springs) and karst
springs (artesian springs). Rainwater, percolating downward through permeable
sediments, may encounter a much less permeable or impermeable formation, forcing the
water to move laterally. Eventually the water may reach the surface in a lower lying area
and form a seep (for example the steephead seeps along the eastern side of the Apalachicola
River). Karst springs form when groundwater discharges to the surface through a karst
opening. The vast majority of Florida's more than 700 springs and all of the first order mag-
nitude springs are the karst spring type.

 Springs are most often classified based upon the average discharge of water. The clas-
sification listed below was utilized by Rosenau et al. (1977):

Magnitude Average Flow (Discharge)

 1 100 cfs or more (64.6 mgd or more) cfs = cubic feet per second
 2 10 to 100 cfs (6.46 to 64.6 mgd) mgd = million gallons per day)
 3 1 to 10 cfs (0.646 to 6.46 mgd) gpm = gallons per minute
 4 100 gpm to 1 cfs (448 gpm) pint/min = pints per minute
 5 10 to 100 gpm
 6 1 to 10 gpm
 7 1 pint to 1 gpm
 8 Less than 1 pint/min

 Current Florida springs tabulations list 33 first order magnitude springs (modified after
Rosenau et al., 1977) (Figure 3). The list includes individual springs, spring groups and
river rises. This listing has created some confusion due to the grouping of hydrogeological-
ly unrelated springs into groups and the inclusion of river rises and karst windows (Wilson
and Skiles, 1989). Often, individual springs comprising a group do not have the same water
source region or spring recharge basin and are not hydrogeologically related. The individ-
ual spring vents within a group may not discharge enough water to be classed as first mag-
nitude. Wilson and Skiles (1989) recommended grouping only hydrogeologically related
springs into spring groups. Spring groups are used in the report as presented by Rosenau
et al. (1977).

 River rises are the resurgence of river water that descended underground through a
sinkhole some distance away. The resurging water may contain a significant portion of
aquifer water but are primarily river water therefore should not be classified as a spring
(Wilson and Skiles, 1989). River rises have continued to be considered in the first magni-
tude listing for this report.

 Karst windows are where the roof of a cave collapsed exposing an underground stream
for a short distance. One karst window is included in this report.

 Future springs recharge basin delineations will identify the hydrogeological relation-
ships between springs and facilitate changes in the first magnitude springs list and will
address these issues. This will be done considering the recommendations put forth by
Wilson and Skiles (1989) and by hydrogeologists representing the government, private sec-