The S-79 has two sources of water:
Lake Okeechobee and the Upper Caloosahatchee Watershed.
If you consider that the Lake holds about 4 million acre feet of water, the equivalent of about one third of the Lake discharged through the S-79 so far this calendar year. But only half of that – or 1/6th Lake – was from the Lake itself (red).
The other 1/6th was from the watershed (blue).