What is a Watershed?

Well, in a nutshell…
Watershed... the word means a parting, a shedding of waters. But a watershed is a gathering place, also. It is a place where hills and plains and people's lives are connected by falling rain, melting snow, and flowing water. A watershed is any area of land that drains to a common point. It can also be defined as the area of land that catches rain and snow and drains into a marsh, stream, river, lake or groundwater. See Figure below.

We all live downstream
A watershed is measured by the hilltops and ridges that are its boundaries. It is shaped by the hills, valleys and plains that are the landscape and is tempered by the forests, fields, lakes, and marshes that are habitats for its creatures. Most of us know a watershed through its streams and rivers that connect forest with farm and farm with city, and each of us changes the watershed day by day, bit by bit, as we go about the business of our lives.

You're sitting in a watershed now
Homes, farms, forests, small towns, big cities and more can make up watersheds. Some cross county, state, and even international borders. Watersheds come in all shapes and sizes. Some are millions of square miles, others are just a few acres. Just as creeks drain into rivers, watersheds are nearly always part of a larger watershed.

The largest watershed management unit is the basin. A basin drains to a major receiving water such as a large river, estuary or lake. Within each basin are a group of subbasins, that are a mosaic of many diverse land uses, including forest, agriculture, range and urban areas. Subbasins are composed of a group of watersheds, which, in turn, are composed of a group of subwatersheds. Within subwatersheds are catchments, which are the smallest units in a watershed, defined as the area that drains an individual development site to its first intersection with a stream. See below for an illustration of this (Source: CWP, 1998).

Water cycle
In a watershed, the rain, the rivers, the lakes and wetlands, even our drinking water are all parts of an intricate cycle. Rain falling on the land soaks into the earth; some runs off to streams; some evaporates before it ever reaches the earth. The water that soaks into the ground becomes part of the groundwater and feeds streams and wetlands and supplies much of our drinking water. Surface runoff in Mid-Michigan forms streams, then rivers that eventually empty to Lake Michigan. Rivers are the sign that the cycle is working... returning water to the Great Lakes where it evaporates, forms clouds, and falls again.

Which watershed are you in?
On a large scale, the Greater Lansing area falls within the Grand River Watershed, which eventually drains into Lake Michigan. The urbanized area around the City of Lansing lies within a portion of the Upper Grand River Watershed which has been broken into three smaller watershed areas to aid in analysis. For the purpose of this analysis, the local watershed areas are identified as the Grand River Watershed, the Looking Glass River Watershed, and the Red Cedar River Watershed and are depicted in the below map.

Because watersheds cross political boundaries, twenty of the communities that fall within these defined local watersheds are a part of a cooperative effort and have formed the Greater Lansing Regional Committee for Stormwater Management (GLRC) to address water quality in our lakes, rivers, streams, and wetlands.

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Watershed words:
• Headwaters: Source of a stream.
• Watershed: The land from which rain collects and runs to a single point.
• Groundwater: Water that lies beneath the earth's surface.
• Infiltration: The slow movement of water from the surface to the groundwater.
• Hydrologic: Related to water in all its forms.
• Aquifer: An underground water supply flowing through rock.
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For more information on the GLRC see the “About Us” section of this website.

For more information on why watersheds are important and ways you can protect our water see the “Watershed Protection” section.