Home

What Is A Watershed?

The term "watershed" describes a catchment basin that conveys all surface and groundwater that falls within it and runs through it. It is geographically defined by the highest ridgelines, or watershed divides, that encircle it. It is these watershed divides that differentiate it from the adjacent watershed.

Restoring ans Protecting Our Watersheds book

Illustration by Jim Coleman

From Basins of Relations: A Citizen's Guide to Protecting and Restoring
Our Watersheds

The word watershed is used to describe basins, catchments or drainages of varying sizes. For example, The WATER Institute is located in the headwaters of Dutch Bill Watershed, an 11 square mile area nested within its larger watershed, the 1480 square mile Russian River basin. Watersheds can be as small as the property you live on or as large as the Mississippi basin which drains 40% of the North American continent.



The WATER Institute is located in the headwaters of the Dutch Bill Creek Watershed, which is an 11 square mile tributary of the lower Russian River Basin. Dutch Bill Watershed is the small purple one in the map above that flows from Occidental to Monte Rio.

It is common for people to focus on the creek, or river, alone when, in fact, it is everything that occurs from the ridgeline to the rivermouth that makes up the watershed. The movement of water over and through the living ecosystem connects us to one another and to all species living in our Basin of Relation. The quality and quantity of this precious liquid, can determine which and how many of each species can sustainably live in each watershed. The better we understand the relationship between our actions and the watershed we live in, the more likely we are to ensure water security for all species that share a watershed.



In this aerial image of the Dutch Bill Watershed we are zooming in a bit closer from the previous map and able to get a more detailed sense of the watershed and some of it's land cover attributes. The Occidental Arts and Ecology Center and the WATER Institute reside on the 80 acre property indicated by the rectangle. Notice how the property is located in the uppermost headwaters of the watershed.

 


 

http://static.flickr.com/64/230376087_c787f72701.jpg

Here we see a much more detailed imaged of just the
80 acre property. In red dashed lines we have demarcated
the various watershed boundaries or drainage divides
and in blue are their associated waterways. As you can
see, due to the topographical diversity of our site we have
nine seperate watershed areas on the land and the how
well e are doing with honoring our water responsibilities
can be judged by observing the quality and quantity of
water that flows past each of the nine exit points on
the right site of the image.

 


A true "Watershed Moment." This ridgeline sheds rainwater in
to two distinct watersheds.