Bifurcation

A natural connective overlapping of two adjacent watershed areas is called bifurcation, and a bifurcation lake is one that unites two such watersheds in a natural way.

Such overlapping connection occurs, where the water parting divide is not markedly determinative and therefore waters may run off in both shed directions. Bifurcation lakes are, among others, the Lumenne and the water divide at Padasjoki, which both belong to the watershed area of Kokemäenjoki on the one hand, and to that of another river, Kokemäenjoki, on the other.

Such a lake may even divide the water of a river descending from a certain watershed system into two, in other terms, there is one river which descends to the lake, and there are two rivers starting from it, running in different directions. The most well-known bifurcation lakes of Finland are Inhottujärvi and Isojärvi within the water drainage basin of the river Karvianjoki in Northern Satakunta.

The watershed areas of Karvianjoki include three rivers which run to the sea: of the two draining riverbeds which start from Inhottujärvi the first one runs to the sea. The other river flows into Isojärvi, from where two different rivers run on to the sea.

bill curry AND kelly grant
OTTAWA AND TORONTO— From Wednesday's Globe and Mail
Published Tuesday, Mar. 27, 2012

Somehow Google can give us the name of every dinky lake, backwater, and canal on Portland's Sauvie Island, but not the name of the mighty Columbia River. River names are conspicuously absent around the globe, in rural and urban areas, in plains and mountains, in coastal and inland areas, at every zoom level. We may not have La Seine in Paris, my dear, but we'll always have Ditch #1 in Osceola, Arkansas.