What is a Watershed?
A watershed is the land area that drains to a common waterway. Rivers, lakes, estuaries, wetlands, streams, and oceans receive water from the land adjacent to them.
Groundwater aquifers are replenished by water flowing through the land area above them. Simply put, watersheds are drainage basins.
One way to visualize a watershed is to think of it as a leaf. The edge of the leaf is the watershed boundary, and the veins represent its streams and creeks. The central vein of
the leaf that widens to the stem is the main stream, usually a river, that carries water downstream to a larger river or a terminus such a lake, bay, or ocean.
Watersheds are comprised of a number of streams and creeks that drain into progressively larger streams to eventually form a river. Each of the streams or creeks have their
own watersheds, or sub-basins, that flow from higher elevations to lower elevations.
Watersheds include surface and groundwater - both flow together into the main stream of the watershed. A ridge of high ground forms the watershed divide. Precipitation and snowmelt
on one side of the divide will drain into one watershed, while runoff on the other side drains into a different watershed.