Why Watersheds?
by Elbert Traylor,
Nebraska Department of Environmental Quality
Watersheds. You rarely heard about them before, but now it's there, somewhere, almost every week. Why this added interest in watersheds?
The answer is that water runs downhill. And when it does it picks-up stuff from the landscape and carries it along downstream. Stuff like soil, fertilizer, pesticides, oil, litter, bacteria, salts. The accumulation of all that stuff can lead to big water pollution problems downstream. Those problems can affect the health and well-being of our environment and of humans.
All that stuff comes from the watershed.
A watershed, simply defined, is the drainage area for a particular body of water: a stream, a wetland, a lake, a bay. It can be mapped by delineating the high ground above and around the bodyof water of interest. It can be as small as a few acres draining to a farm pond, or as vast as the Mississippi basin that drains the central United States.
From the standpoint of water pollution, watersheds are more complex than that, however.
They represent the shared interactions of soils, wildlife, plants, meteorological conditions, human influences and many other components and processes occurring in the watershed.
Human influences in particular tend to disrupt the natural processes in a watershed and often lead to water pollution.
Watersheds of moderate size (a few hundred square miles) are convenient units to measure and manage the influence of human activity on water quality. They are convenient because they tend to have well-defined ecological conditions, predictable responses to disturbance and generally uniform land uses.
Also, the humans within a watershed tend to share common attitudes, knowledge and demographic factors that help determine how willing and able they are to change behaviors to improve and protect the quality of the water in the watershed.
Within a watershed, we also share the pollution water accumulates when human activity exceeds nature's ability to repair the disturbance. Chemicals carelessly spilled on the ground, leaking and unattended fuel storage tanks, fertilizers that are wastefully over-applied can percolate through the soil and contaminate aquifers that supply drinking water.
Landscapes that are laid bare for construction; fields plowed for farming, carelessly applied pesticides; paints, solvents and debris may foul surface waters downstream. Aquatic habitats, recreational opportunities and potential sources of drinking water may be ruined.
What we do, or don't do, can affect the quality of our ground and surface water in our watershed.
Watershed may be in the news for a long time to come, but the news could be good. It could be bright stories of people working together to protect the environment of their own back yard, their watershed.
