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What is a
Wetland?
Inland
Wetlands
Where
are all the Wetlands?
Wetlands
for the Future
People
and Wetlands
Classroom
Activities
Facts
Links
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Wetland Definitions!
Lands
where saturation with water is the dominant factor determining
the nature of soil development and the types of plant and
animal communities living in the soil and on its surface.
Lands
transitional between terrestrial and aquatic systems where
the water table is usually at or near the surface or the land
is covered by shallow water.
Areas
that are inundated or saturated by surface or groundwater
at a frequency and duration sufficient to support, and that
under normal circumstance do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions.
Ecosystems
having shallow water standing above the soil surface or having
a soil saturated with water for periods of time that are sufficient
to produce characteristic soils or vegetation. Areas that,
whether or not they are covered by surface water, have at
least periodically water-logged soil.
In general
terms,...soil or substrate that is at least periodically saturated
with or covered by water. The water creates severe physiological
problems for all plants and animals except those that are
adapted for life in water or in saturated soil.
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What Is a
Wetland?
Scientists,
politicians, environmentalists, ranchers, farmers, and developers
have all been debating the definition of a wetland for more than
five decades. In fact there are over 50 official definitions
for Wetlands! With variety like this, it's no wonder that wetlands
can be confusing and controversial!
Although more
than 50 official definitions of wetlands exist, two used by the
U.S. Government define wetlands according to federal law. These
two definitions agree that a wetland contains specific:
- Hydrology
(amount and period of time that water is present).
- Hydrophytic
vegetation (plants adapted to wet soil).
- Hydric
soils (soils low or absent in oxygen due to their saturation
in water).
The U.S. Fish
and Wildlife Service (FWS) says an area need have
only one of these conditions to be considered a wetland!
The U.S. Army
Corps of Engineers (Corps) says an area must have all three
conditions before it is considered a wetland!
The Corps administers
the wetlands provisions of the federal Clean
Water Act , so its definition is the one most used by
the federal, state, and local governments.
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OFFICIAL
DEFINITION
The definition, as published in the 1987 Corps of Engineers
Wetlands Delineation Manual, says:
Wetlands
are inundated or saturated by surface or groundwater at
a frequency and duration sufficient to support, and that
under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions.
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Think about
the kinds of places that this definition may include.
Consider the
Palouse Country of eastern Washington and western Idaho. Its rolling
terrain resulted, in part, from the catastrophic floods as ice dams
rose and released millions of gallons of water during the retreat
of glaciers.
You'll find
potholes here — little dips and pockets in the land where water
collects. You'll also find riverside wetlands along the Columbia,
the Snake and their tributaries. And as you ascend the mountains
that border the Palouse, you'll find wetlands scattered through
the forests.
Identifying
Wetlands
Your senses can help identify wetlands. Check the soil: Is it damp
to the touch? Does it glisten with liquid? Can you literally squeeze
the water out? Do you see plants, such as sedges or cattails, that
are adapted for living in wet soil? Do you hear frogs or see salamanders?
 But
what if that pothole or pond has already dried up for the season.
How might you identify it as a wetland? Observe the area carefully.
Is the surface cracked, as when mud dries? Or is it damp beneath
the surface? Look for signs of higher water such as water marks
on the shrubs, trees, or rocks; grasses and twigs collected at the
base of other plants; leaves coated with a thin layer of sediment.
If the area shows these signs it is probably a wetland.
Learn
More About What a a Wetland is...
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