Many ancient ports ( Roman and others thousands of years ago ) have silted up and went away .
The Colorado River [ and other rivers , likely ] has had many dams ( thru landslides or volcanic intrusions ) and resulting lakes...which , over time, had the expected results ( went back to a river ).
Ephesus is a fine example. A metropolis in its day...and over the centuries the River Cayster gradually silted up the port. This brought disease...and the whole town moved from the marshes.
Men, especially liberal men (Gore) doesn't seem to get the fact that the natural world is always changing.