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Wetlands Reference Center
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What
are Wetlands?
Though lacking the glamour and mysticism of rainforests and
coral reefs, wetlands are their equals in terms of being among
the most productive ecosystems in the world. While most Americans
view the rainforests and reefs of distant lands as “exotic”,
most wetlands are viewed with disdain as disease producing swamps
where you sink up to your knees in muck. In part, because of
this attitude and a failure to recognize their importance, wetlands
in the United States have been destroyed at an alarming rate,
often with the full consent and assistance of the government.
There are a variety of definitions ascribed to wetlands including
those with a scientific basis and those that are used for regulatory
purposes. Scientists tend to take a broader look than the government
and generally consider wetlands to be lands where water covers
the soil or where water is at or near the surface, covering
the root zone for all or part of the year. In addition, the
presence of water is the dominant factor in determining soil
development as well as the plant and animal varieties that inhabit
the area.
From a governmental perspective, several definitions have been
promulgated for regulatory purposes, the most important of which
is contained in the Clean Water Act of 1972.
The Clean Water Act (CWA) defines wetlands
as:
“Those areas that are inundated or saturated by
surface or ground water 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. Wetlands generally include swamps, marshes,
bogs and similar areas." (40 CFR 232.2(r))
This definition is accepted by the EPA and the Army Corps of
Engineers (the Corps), and it forms the basis for the regulations
established to identify and delineate wetlands and their boundaries.
Under these regulations an area must have three characteristics
to be considered a wetland, those being wetland
hydrology, hydrophytes,
and hydric
soils.
Though lacking true regulatory authority, the United States
Fish and Wildlife Service is actively involved in wetland analysis.
For their purposes, a wetland is defined as:
Lands that are 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, and that have one or
more of the following attributes:
- At least periodically, the land supports predominantly
hydrophytes;
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- The substrate is predominantly undrained hydric
soil; and,
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- The substrate is non-soil and is saturated with
water or covered by shallow water at some time during
the growing season of each year.
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The critical distinction between these two definitions is that
the Corps, which has primary jurisdictional authority over wetlands,
requires all three characteristics (hydrology, hydrophytes,
and hydric soils) to be present before an area is classified
as a wetland, whereas, the FWS definition recognizes that an
area can be lacking in one or more characteristic while still
being a fully functioning wetland resource.
It is interesting to note that while the Corps often mandates
that a developer construct new wetlands to mitigate those destroyed
as part of a project, the newly created “wetlands”
do not met their own definitional standards. Think about the
reason why and check your answer in the section on Mitigation
and Remediation.
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Ecosystems