The movie Waterworld is pure fiction. There isn't enough water in the earth's water cycle to cover the planet entirely. However, if all of the water in the world were in liquid form, some estimate that oceans would be approximately 400 feet higher than they are today. St. Louis, at elevations ranging from 405 ft/msl (Mississippi River) to 610 ft/msl (Sublette Park), surrounded by areas with elevations less than and greater than these extremes, might best be characterized as a "coastal city", along an estuary similar to Chesapeake Bay.....