St. Johns River Facts

Published August 25, 2008 - Central Florida News 13
The land area that drains into a water body is called a drainage basin - also called a watershed. St. Johns is divided into three drainage basins.

Saltwater enters the river at its mouth in Jacksonville. In periods of low water, tides may cause a reverse flow as far south as Lake Monroe - 161 miles upstream from the rivers mouth.
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