Water divide

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Image:Wasscherscheiden.png Image:Basin New.png A water divide (also known in Commonwealth usage as a watershed) is the separation between neighbouring drainage basins, and lies along topographical peaks and ridges. Water divides are important geographical, and often also political, boundaries. A water divide is also sometimes called a water parting or a height of land (in North America, especially Canada).

[edit] Types of water divide

Water divides can be grouped in three types:

Continental divide — A divide in which the waters on each side flow to different oceans (example: the Nile and Congo divide)
Major water divide — The waters on each side of the divide never meet again, but do flow into the same ocean (example: the divide between the Yellow River basin and the Yangtze)
Minor water divide — The waters part but eventually meet again at a river confluence (example: the Mississippi and Missouri divide)

Water divides are a hindrance to river navigation. In pre-industrial times water divides were crossed at portages. Later canals were built to connect the adjoining drainage basins.