Once upon a time, the Kissimmee Valley was a chain of loosely-connected isolated lakes separated by a marshy expanse. Unconnected was the operable term. It simply wasn’t a place that drained very fast. Farther to the south formed two lakes, one called Kissimmee and the other Istokpoga. The waters made its journey from Lake Kissimmee to Lake Okeechobee by way of 103 miles of meandering river that often overflowed its banks and filled the floodplain. Lacking a similar river, Lake Istokpoga sent its water to Lake Okeechobee through a grassy waterway dotted with tree islands that resembled a miniature version of the Everglades.
And then came channelization.
The modern-day Kissimmee Valley still drains into Lake Okeechobee, just like it always did, but the journey from Point A to Point B is largely through canals, and you guessed it – as mediated by a series of regulation schedules. Channelization has made the Kissimmee both more navigable and drier than its previous self, and also affected water delivery and quality to downstream Lake Okeechobee. The good news is that starting the 1990s restoration work has been done to redivert and resuscitate flow back into the nature river channel that the canal and levee works shut off.
Even so, drainage has dramatically changed the lakes. Prior to channelization, large rain events swept away sediments that kept the lake bottoms clean and fed nutrients into the wetlands below. Today, the lakes are maintained a at a lower level, and with less natural variability, causing an accumulation of sediments in the lakes.