160 DOCUMENTARY HISTORY OF THE FLORIDA OANAL

 8. The flow of water within the underground reservoir Is largely activated by
two plesometric "highs" corresponding closely with the two topographic highs,
75 and 40 miles, respectively, south and north of the canal route. Where the
canal route crosses the peninsula between these highs it roughly parallels the
paths of maximum subterranean discharge of the reservoir system. This
system is one of intermittent charge and continuous discharge, the reservoir
surface automatically adjusting itself to its outlets in order that the balance
may be maintained between total intake (rainfall in excess of evaporation),
and total run-off (surface and subterranean drainage). The development and
enlargement of subterranean channels within the porous Ocala and Tampa
limestone has been proceeding for geological periods and the capacity of such
drainage systems today is enormous. Aside from numerous passages devel-
oped at considerable depths below the water table, such as those discharging
under artesian head, there exist many subterranean drainage systems just
below the water table but draining the land as truly as do surface streams.
Blue Springs and Silver Springs systems are typical The flow from all of
these drains and some of the flow of the surface streams represent surplus
water above that which today can be stored within the underground reservoir
and will aid in preventing serious lowering of the water table beyond limited
areas.
 9. Of the 195 miles of canal from deep water to deep water, excavation along
 only 14 percent, or 27 miles, will have any appreciable effect on the level of the
 ground-water table in the open reservoir, or on artesian conditions. The Ocala
 limestone will not be cut beyond the vicinity of Silver Springs. The artesian
 reservoir will not be cut anywhere.
 10. The canal eut, insofar as its effects on the water reservoir are concerned,
 will be but a "nick" in the western coast line of the peninsula, for, to the
 east, beyond Silver Springs, neither the "open" nor the "closed" reservoir will
 be materially affected by excavation.
 11. Studies of the slopes of the existing water-table surface indicate that
north and south from the canal cut between the Gulf and Silver Springs, along
which portion of the route the water table will be drawn down close to
sea level, the water-table surface will rise approximately to its present
position within a distance of 10 to 15 miles.
 12. The ultimate effects of a sea-level canal on springs and lakes in the
 area contiguous to the canal cannot be predicted with certainty at the present
 time. An analysis of the possible effects on these features is reserved until
 further extensive investigations now in progress have been completed. Studies
 made so far lead to the belief that should the lowering of the water table
 encroach upon such features of intrinsic value as Silver Springs and Blue
 Springs, regulatory works could be constructed which would minimize, if not
 entirely obviate, the damages. The flow into the canal from these points of
 heavy discharge must, in any event, be controlled and, therefore, any expense
 incurred in their preservation would serve a double purpose.
 18. The shallow farm wells adjacent to the canal right-of-way between
 Dunnellon and Silver Springs will need to be deepened.
 14. The pursuit of agriculture and the growth of vegetation, even in the
 area contiguous to the right-of-way where the ground water table will be
 lowered by the canal cut, will not be affected.
 15. The water supply of the city of Ocala will continue to be adequate.
 1& The domestic water supplies of Jacksonville, Tampa, Orlando, Palm
 Beach. and Miami will be entirely unaffected by the canal cut.
 17. The city of Sanford derives its artesian water from the slopes of the
 water table high to the southwest of the city. These waters are In places
 already somewhat salted from bottom-water infiltration. Present information
 indicates that the quality and quantity of the artesian water supply of the
 city of Sanford and vicinity will not be adversely affected.
 18. Salt-water encroachment inward from the Gulf and Atlantic ends of the
 canal, or by upward movement from the bottom of the fresh-water reservoir,
 insofar as it may take place, cannot cause salted water to enter and thereby
 contaminate the main body of the readjusted ground-water reservoir against
 the fresh-water discharge into the canaL