Due North: The St. John's River is One of Many

There is a common belief in northeast Florida, especially in the city of Jacksonville, that there are only two rivers in the world that flow north: One is the St. Johns and the other one is the Nile. For the past 15 years, I have been reminded of this so-called geographical fact too many times -- every time, in fact, that the geography classes I teach begin a new term. A few of my students will no doubt mention it to me every term. But I correct them, and I’d like to use this article to correct others. Contrary to popular belief, more rivers run north than any other direction!

Direction of rivers has less to do with magnetic forces than gravity, topography and geomorphology. As the source of a river is higher than the mouth, it will follow a path of least resistance along its course. In my assessment of the world’s rivers, excluding small ones and those with no clear pattern, I identified more than 245 rivers that flow north.    

In recent years, the claim that the St. Johns is one of just two rivers to flow north has been replaced by the claim that it is “one of the few” to do so. Online sources mention several rivers that lay claim to this distinction, including the Fox (in eastern and central Wisconsin), the Genesee River (in New York), the New River (in Ashe County, North Carolina), the Red River (in Minnesota) and the St. Johns. If we add the Nile to the above list, we have a total of five rivers. Obviously the claim that there are “only two” north-flowing rivers is incorrect. But the “few” statement is misleading, too.

A river is a natural waterway that carries runoff fresh water over a landscape from higher to lower altitudes. The direction of the flow of each river in the world is determined by the topography between the headwater and the mouth. Rivers, like all other objects, flow downhill. They all take the paths of least resistance. This path thus could take any direction -- east, west, north, south, and many others in between. Rivers that meander may flow in many directions. Where there are low gradients and gentle slopes, some rivers may flow almost in full circles. Compass directions, then, do not influence flow. Unfortunately, some people associate “north” with “uphill” and “south” with “downhill.” To them, north is always higher than south. This may be the original myth leading to false conclusions about rivers. But in many parts of our planet, north is actually lower than south.

Over geological time, many rivers have changed course. Before the break-up of the super continent of Pangaea and before the beginning of the mountain-building process that happened nearly 250 million years ago on the west coasts of North and South America, both the Amazon and Mississippi rivers emptied into the Pacific rather than the Atlantic Ocean. Back then, the continent of Africa did not have its own coastlines; thus many rivers, including the Nile, had interior deltas on large, interior lakes. Post-drift African rivers built new deltas on the coast, with sudden changes in the direction of their flow, including descending from the high plateau. Most of them have rapids and waterfalls, in fact, which is why about half of the world’s potential hydroelectric-power is found in Africa.