Water and the opposite
flow systems of Florida’s two great swamps
Water and life are inextricably linked. Too much and things
die, too little and things die. Like the
heat range needed to thrive, both flora and fauna have the need for a range of
moisture availability. Water and temperature both come in cycles. Some cycles
are regular and predictable, others are short and sporadic. Seasons define the
normal ranges for temperature and water in Florida. The water season is typically the most
important, but most wildlife here would not survive with water in its solid
state. Wet season defines the efficiency of Florida’s two great hydrologic
systems, and by extension both the plants and animals that live there.
The greatest of these
is the Southern Florida -Everglades Hydrologic
System. Historically, the two main ecosystems formed in the Everglades
system were the saw-grass plains in the north and the ridge and slough
(pronounced slew) landscape in the south. Communities of freshwater wetland
vegetation including tree islands made the ridge and slough landscape resemble
peat lands. These vast wetlands are home to wildlife and vegetation unique to
the subtropics, as well as great seasonal migrations of birds. First, the
Greater Everglades Ecosystem is vast; it is more than half the distance from
Florida’s northern border to its outlets in Florida Bay and the Gulf of Mexico.
It stretches from near Orlando in the North to Biscayne and Florida Bays and
the Gulf of Mexico in the South, to Indian River Lagoon on the east coast and
San Carlos Bay on the west. Historically, the Kissimmee-Okeechobee-Everglades
Watershed covered about 9,000 square miles in a single hydrologic unit.
The slight change in
elevation from Lake Okeechobee to Florida Bay made a 30 mile-wide sheet of water
flowing over and through the peat. Ridges were alternately spaced and a
historic lack of drainage channels or stream beds implies that water spread out
uniformly over the entire width. The water was rarely stagnant traveling about
100 feet a day. The water is described as flowing silently and slowly as one
great mass. Although reliable historical
documentation of the ridge and slough landscape is not available, there is a
strong similarity between the original direction of flow, the alignment of the
ridge and sloughs, and the tree-islands tear drop shape orientation.
Plant detritus and peat accumulation depths between the
ridges and thesloughs differed by about 1 and 3 feet, resulting in a
perpetually wet ecosystem, with areas flooded or dry depending mostly on the
season. Biologist at Corkscrew Swamp
Sanctuary think during the pre-canal days, that the sloughs were covered by
water approximately nine months of the year, and the tree islands were flooded
for perhaps three months each year.
Rainfall during the summer in Florida falls from storms
formed on sea-breeze fronts. Those fronts form near the coasts and move inland.
That rain water falls and collects in
springs and lakes that start to flow into the Kissimmee River. The Kissimmee
River flows south into Lake Okeechobee and joins the water already stored
there. Lake Okeechobee is shaped like a very large shallow bowl. In the past,
when it collected too much water it overflowed its southern edge and water
flowed out across the sawgrass plains and the sloughs creating the Everglades.
With canals,ditching and mounding for roads, flood control dikes, and great
areas put under intensive agriculture, that was not the case anymore. That is
slowly being reversed.
As the water flows through the Everglades, its sheet flow
eventually drains into Florida Bay and the Gulf of Mexico. As the water flows
through the Everglades to the bay, some of it starts to slowly soak into the
limestone rock underground. Once it soaks into the limestone, it gets stored in
porous underground limestonerock called aquifers. In the Everglades it is the
Biscayne Aquifer, and it is the principal source of drinking water for
southeastern Florida. There are several similar, but much smaller sloughs that
form over southwest Florida and run west and southwest in a similar fashion.
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