Are cities part of a watershed?
by T. Jones
What exactly is a watershed? Are cities part of it, or does the city absorb too much water.
Editors' Reply: In a word, yes. A watershed is simply an area where the rain or melted snow that does not soak into the ground runs toward a common tributary, stream, or river. So all parts of cities are part of a watershed.
In the U.S., the Environmental Protection Agency has a cute little slogan about everybody being in a watershed.
It's true. Cities, suburbs, small towns, farms, and in between--every place has some rain or melted snow that doesn't soak into the ground and becomes part of what people might call a ditch, a tributary, a stream or creek, or a river.
In the U.S. there is an eight-number category system for describing watersheds and their sub-watersheds. For instance, your rain water ultimately might end up in the Mississippi River, but first it goes to a local stream, which might end up in the Wabash River, then the Ohio River, and then finally the Mississippi River.
If you know your watershed, and what larger watersheds your local watershed is part of, it simply will raise your awareness about clean water. Also you will understand that pollution that drains off of parking lots upstream from you is affecting the water that might flow in a nice little stream behind your house. And perhaps you will appreciate too that if you just throw that paint thinner into the creek, you are sending pollution out to the ocean ultimately.
Watershed awareness has been on the rise in recent years, because it's the reasonable geographic area where water quality issues should be addressed. Watersheds cross political boundaries, cultural boundaries, and every type of man-made line and only abide by the topography (pattern of the height of the land above or below sea level).
In many parts of the world citizen volunteers have become the main stewards of the watershed, simply because government bureaucracies have to think about geography differently than usual. They can't seem to make that shift.
We hope you will decide that even though you live in a city, you still are part of a watershed that you would want to help clean up.
In fact, to answer the second part of your question, the city doesn't absorb nearly as much water as farm land, parks, or open space. That's because water runs off of pavement and sidewalks and roofs much faster than it runs off a lawn or a wheat field.
So a city is even more responsible for the end result in a watershed than the rural area!