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River source
Starting point of a river / From Wikipedia, the free encyclopedia
"Headwater" redirects here. For other uses, see Headwater (disambiguation).
This article is about the heads of rivers. For the insurance company, see RiverSource.
The headwater of a river or stream is the farthest point on each of its tributaries upstream from its mouth/estuary into a lake/sea or its confluence with another river. Each headwater is considered one of the river's sources, as it is the place where surface runoffs from rainwater, meltwater and/or spring water begin accumulating into a more substantial and consistent flow that becomes a first-order tributary of that river. The tributary with the longest course downstream of the headwaters is regarded as the main stem.
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