River-fed Swamp?

Did the Caloosahatchee …

Once feed the swamp?

The dredging of the Caloosahatchee River, and specifically blowing up of Ft. Thompson Falls in the 1880s, is often invoked as the starting point of drainage of Lake Okeechobee and the Everglades.

The Caloosahatchee Watershed is bigger than WCA1 and WCA2 combined

In the years and decades that followed, the Caloosahatchee would go on to become the primary outlet for controlling Lake stage, a status it retains to this day. In many ways it functions as spillway for the greater Kissimmee-Okeechobee-Everglades (KOE) flow way, and in particular for the Lake.

How he Caloosahatchee and Big Cypress were connected … once upon a time

Not a single act, direct dredging of the river – including digging a straight channel through its tailwater oxbows, blowing up the Ft. Thompson Falls, connecting it to the Lake, and deepening the channel for nautical purposes throughout – and construction of a vast network of tributary canals that drained into it (from the north and south) occurred over a span of decades.  The Caloosahatchee River was a rare case where nautical and drainage interests initially fought against each other but ultimately both won. 

The original Caloosahatchee was more reminiscent of a stream in terms of its meanders and relatively shallow depth.   The river was sinuous to the point of being unnavigable, requiring larger vessels to “warp-around” the curves, requiring running their bow on the shore and using a rope to swing the boat in the right direction (Antoni et al, 2002).  Moreover, the stream stopped short of the Lake, about halfway to be exact, where the smaller (and now dried up) Lake Flirt basin served as its headwater source.

Artistic representation of the relationship between Lake O, the Caloosahatchee, the Immokalee Rise and the Big Cypress Swamp prior to drainage

As a result,

  • Caloosahatchee is now a channelized spillway, not a natural river
  • Historic Lake Flirt and Lake Bonnet no longer exist,
  • Modern-day water levels north of Ft Thompson falls are upwards of 10-15 lower than their pre-drainage condition.

The Caloosahatchee doesn’t just drain Lake O, it’s also the primary getaway canal for draining lands to the north and south of the river.  This drainage capacity is enhanced by a series of tributary canals along the modern-day river’s entire length.

Water elevation along the Caloosahatchee, prior to drainage (blue) and today (red)

The result?

  • Not all the water that discharges through the S-79 is from Lake Okeechobee.  Approximately half comes from the Caloosahatchee watershed and those tributary canals. 
  • The water table under the Immokalee Rise dropped below the regional surface water table.
  • Drainage of the Caloosahatchee caused the headwaters of Okaloacoochee Slough to reverse course.  At some point Big Cypress Swamp’s pre-drainage watershed now flow north into the Caloosahatchee River, both groundwater (unseen) and surface water as seen at Okaloacoochee Slough.


Today we think of Lake Okeechobee feeding flows into the Caloosahatchee. But prior to drainage, (1) there was no connection from the Lake and (2) the headwaters of the Caloosahatchee actually helped feed water south into the Big Cypress Swamp.

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