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Wetlands: A Key Link in Watershed Management
A Guide for Watershed Partnerships
How Your Watershed Can Benefit With Wetlands.Wetlands are a key link in watershed management. The role that
they play in our watersheds is critical to protecting water quality and moderating water
quantity. Wetland habitat serves as home for many plants and animals. Even the
national—and in many areas the local—economy has a significant connection to
wetlands.
Essentially wetlands are the transition between dry land
and water (streams, rivers, lakes, and coastlines), wetlands take many forms including the
familiar marshes, swamps and bogs. Yet, not all wetlands are "wet" year round.
These "drier end" wetlands also perform significant wetland functions. Yet,
these are often the target for many uses including agricultural and urban/suburban uses.
7 Ways Your Watershed Can Benefit
- Improve water quality by breaking down, removing, using or
retaining nutrients, organic waste and sediment carried to the wetland with runoff from
the watershed
- Reduce severity of floods downstream by retaining
water and releasing it during drier periods.
- Protect stream banks and shore lines from erosion.
- Recharge groundwater, potentially reducing water
shortages during dry spells.
- Provide food and other products—such as
commercial fish and shellfish—for human use.
- Provide fish and wildlife—including numerous
rare and endangered species—food habitat, breeding grounds, and resting areas.
- Increase opportunities for recreation—bird
watching, waterfowl hunting, photography—and outdoor education.
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Why consider wetlands in your
watershed?
Without wetlands, we can expect an increase in flooding, decrease of animal,
plant and bird species, increase in erosion, decrease in water quality, and lost revenue.
Vegetated riparian wetlands in agricultural areas have
proven to remove high percentages of phosphorus and nitrogen from runoff water. Without
these wetlands, increased nutrient loading to rivers, streams and lakes could result in
algal blooms and over-abundant aquatic plant growth. When these algae and plants die,
oxygen in the water is used during the decomposition process. This can result in oxygen
deprivation which may lead to fish kills.
When agriculture and development practices impact
wetlands, the water storage and flood control capacity of the land decreases, increasing
the likelihood of costly flood damage downstream.
Wetland benefits.
Wetlands are valuable systems that provide many benefits to your watershed
including:
Reduced water treatment costs
Wetlands can help improve water quality by removing or retaining nutrients,
organics, and sediment carried by runoff. The flow of water slows as it enters a wetland,
which causes sediment in the water to settle out. Many chemicals — fertilizers, human
and household wastes, toxic compounds —are tied to sediment and trapped in wetlands.
Plants and the biological processes present in a wetland breakdown and convert these
pollutants into less harmful substances. By restoring and utilizing wetland functions, we
can reduce the costs of constructing, operating and maintaining drinking water treatment
plants.
Increased groundwater availability
Wetlands "soak up" water during and after a rainy spell. While wetlands
"hold" most of the water, some water makes its way to the groundwater supply.
Thus wetlands often fill the vital job of recharging groundwater so it’s available
for use at a later date.
Reduced flood damage
Another way wetlands are valuable to humans is their influence on the flow and
quality of water. Wetlands often act like giant sponges, soaking up water that runs off
the land. This feature can help slow floodwaters, lower flood heights and reduce shoreline
and stream bank erosion. Preserving natural wetlands can reduce or eliminate the need for
expensive flood control structures.
Food and related industries
The vast majority of our nation’s fishing and shellfishing industries
harvest wetland-dependent species. This catch is valued at $15 billion a year. Commercial
fishermen harvested nearly ten billion pounds of fish in 1996.
EPA estimates suggest that 98% of the Gulf of Mexico
fishing industry harvest comes from fish and shellfish that are dependent on in-shore
wetlands. The US Department of Commerce reports that 438 million pounds of brown, white
and pink shrimp were harvested in 1995 and 1996 (combined). This was worth more than $838
million dockside.
Other wetland-reliant products include cranberries,
blueberries, wild rice, medicines, pelts and timber.
Diverse plants & animals
Wetlands contribute to diversity by providing food and habitat that supports a wide
variety of plants and animals. Detritus—enriched organic material formed by the decay
of plant and animal material in water—is food for insects, shellfish and forage fish.
In turn, fish (such as striped bass and bluefish), mammals, reptiles and amphibians feed
off of the insects and forage fish. The growth of wetland plants and algae is also
nourished by nutrients the provided in the detritus.
Wetland plants provide food and shelter for fish and
animals. Wetland-dependent mammals include: muskrat, beaver, moose, raccoon, bobcat, swamp
rabbit, and white-tailed deer. Bald eagles, ospreys, hawks, egrets, herons and kingfishers
are just a few of the birds that thrive in wetlands. The high biological productivity of
wetlands makes them vital ecosystems not only to the plants and animals that directly
depend on them for food and shelter, but to humans as well.
Recreation
Revenue is also generated from waterfowl hunters in search of wetland-dependent birds. The
1996 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation reported 3.1
million adult Americans hunt migratory birds. This includes hunting for geese, ducks,
doves, and other game birds. They spend about $1.3 billion on travel, equipment and other
associated expenses.
| Another recreational outlet
is trapping. An EPA report puts the nation’s harvest of muskrat pelts worth over $70
million annually. This, of course, does not include the value of beaver, mink or reptiles
such as alligators. The natural beauty and
solitude found in wetland areas provides opportunities for bird watching, wildlife
photography, painters, hikers and simply relaxing while appreciating the wonders of
nature. For many people, wetlands are a vital part of their lives providing a peaceful
place to reflect while escaping from the everyday stress and strains. |
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Understanding Wetlands.
How wetlands form. How wetlands form.
The formation and role of a wetland is driven by its location in the watershed, the
presence of water during significant periods, soil quality and, ultimately, plants and
animals. In fact, soils and plants act as "identifiers" for each wetland.
As sediment is deposited along river corridors,
opportunistic plants and animals seek out the new habitat and flourish. As these areas
mature, the soils change which impact the variety of plant and animal species. Thus new
species may colonize. This process is called succession.
At the mouths of rivers (where a river meets the ocean)
sediments are often deposited forming alluvial plains. Marsh grasses find these areas
desirable. In addition, other plants and many animals are then attracted to these deltas.
Other wetlands are formed by aging lakes that fill-in
with sediments. This area supports shrubs and trees adaptable to life in a wet
environment.
Types of wetlands.
The diversity of wetland habitat makes the identification and classification of
wetlands challenging. Wetlands are identified and classified according to the types of
plants, soils, hydrology or patterns of water, and fish and/or wildlife communities
present.
Swamps, marshes and bogs are easily recognizable types
of wetlands. Other types of wetlands may be less well known because the amount of water
present will vary seasonally, with specific rainfall events or with snowmelt.
The plants that live in wetlands are particularly
adapted to soils that are saturated with water and, at times, contain little oxygen. These
plants, such as marsh grasses, are called hydrophytes (literally water plants) and the
soils where they thrive are referred to as "hydric soils." Some basic types of
wetlands are:
Riverine Bottomlands/Hardwood Forests
Riverine Bottomlands/Hardwood Forests: Found
along the river corridors, these provide water storage during times of peak precipitation,
reducing flood water and then slowly releasing the stored water. Silver maple and
cottonwood are common in northern regions. Bald cypress and tupelo dominate southern
regions.
Northern Bogs
Northern Bogs: Saturated areas with mossy
carpets and shrubs, grasses and stunted spruce trees. These cool wetland areas produce
wild cranberries, harvested in autumn. Bogs effect the climate by storing carbon dioxide
in decaying plant materials (peat), thereby reducing its release into the air.
Cypress Swamps
Cypress Swamps: Also known as domes, these are
characterized by tall cypress trees growing in the center of the swamp. The trees filter
pollutants like nitrates and phosphates that reach the swamp via water runoff.
Coastal Marshes
Coastal Marshes: Influenced by the tides, these
highly productive ecosystems support the majority of fish and shellfish harvested. These
wetlands provide feeding, spawning and nursing areas for a multitude of invertebrates,
birds and fish.
Prairie Potholes
Prairie Potholes: Formed by receding glaciers
that produced shallow depressions which seasonally fill with water, these are a favorite
breeding and feeding area for North American ducks. These wetlands also play an important
role in recharging freshwater aquifers.
Runoff threats
While wetlands can reduce the impact of some pollutants, too much pollution will
negatively impact the wetland. Thus, the quality of a wetland is dependent on the water
flowing into them...and the pollutants that the water carries with it from activities in
the watershed.
Runoff, originating with rain fall or snow melt, that
contains pollutants—oil, grease, fertilizers or pesticides—is called nonpoint
source pollution. In addition to the potential of runoff polluting wetlands, it also can
pollute other surface waters such as lakes, rivers, and oceans. Eventually it can reach
groundwater, which is often used for drinking water.
The best way to protect the quality of wetlands is for
every person in the watershed to prevent potential pollutants from being carried by runoff
or infiltration.
Other wetland threats.
The loss of the values provided by wetlands impacts watershed residents, plants, and
animals. Filling in one acre of wetland may not seem devastating. Yet, the cumulative
affect threatens the value of remaining wetlands and impacts the entire
watershed...residents, plants, animals, water quality and quantity. Already more than half
the wetlands in the lower 48 states have been destroyed. Some of the causes are listed
below:
Naturally occurring events—hurricanes,
droughts, erosion, drops in groundwater levels—destroyed or severely threatened some
wetlands.
Agriculture production Agriculture production is responsible for many
drained wetlands.
Marinas, housing, roads and other urban structures
Marinas, housing, roads and other urban structures
were
built on filled wetlands.
Dams and dredging Dams and dredging nearly always affect the flow
of rivers and lakes, destroying some wetlands and threatening others.
There are numerous other threats, however those listed
above are the most common.
| Percent Wetland Acreage Lost: 1780s-1980s |
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Twenty-two states have lost at
least 50% of their original wetlands since the 1780s. Seven states—Indiana, Illinois,
Missouri, Kentucky, Iowa, California and Ohio—have lost over 80%. Since the 1970s
states with the most losses are Louisiana, Mississippi, Arkansas, Florida, South Carolina
and North Carolina. Wetlands drained for agricultural purposes has been reduced while
development continues to account for a larger percent. Source Mitch and
Gosselink.
Wetlands, 2nd Edition, Van Nostrand Reinhold, 1993
Managing & restoring wetlands.
Preservation and protection is the most economical way
to "manage" wetlands. Of course, this isn’t an option for the millions of
altered wetland acres. In these areas, restoration is often the best solution to meet a
watershed partnership’s goals.
10 Good Reasons to Restore
Wetlands.
- Re-establish native vegetation...a sustainable food
source for wildlife.
- Provide breeding grounds for waterfowl.
- Connect wildlife corridors for ease of movement and
healthy interactions.
- Reduce downstream flooding.
- Reduce streambank and shoreline erosion.
- Protect fish and shellfish harvests.
- Restore natural biological diversity.
- Improve water quality.
- Enhance threatened and endangered species.
- Provide recreational and educational sites.
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What is restoration?
"Restoration" is the process of returning the wetland system to an
approximation of its predisturbed condition.
This does not mean returning all altered wetlands to
their unaltered state. It simply means replacing the lost values with newly created or
"restored" wetlands. In other words, the goal is to restore the value rather
than restore a particular site with a self-sustaining system that requires little human
"management."
Considerable advances have been made in large-scale
wetland restoration. Yet, restoring wetlands to their original condition—replicating
the complex and diverse physical, chemical, and biological interactions—hasn’t
been well-documented.
The restoration goal.
The major challenge of restoration is the replacement of the structural and functional
aspects of a naturally formed wetland. A "restored" wetland should look
naturally formed. It should also support values—the array of biological, chemical and
physical processes and interactions—found in the naturally created wetland.
The intensity of restoration techniques will depend on
the level of disturbance to the values of the original wetland.
Restore water flow. Restore water flow. The first step in the
process is to restore the hydrology (flow of water) to support conditions favorable for
the return of wetland plant communities. The approach used is dependent on what caused the
initial disturbance.
Altered flow:
- Re-establish flow of a river back into a wetland area.
- Remove dams or other structures that cause
flooding of a wetland.
Filled or dredged:
- Re-establish original landscape.
Re-establish plants. The next step is
planting appropriate native plants. If the soil has been contaminated by toxic chemicals,
it will likely need to be removed. If successful, a diverse and balanced plant community
will establish itself. Then wildlife will colonize.
What you can do.
If you own a wetland...
Before clearing, draining or manipulating wetland areas—including areas which
you’re unsure about—contact one of these government agencies. If the wetland
area is used as cropland, contact your local USDA Natural Resources Conservation Service
(NRCS) office. In non-cropland areas, check with your U.S. Army Corps of Engineers
district. (Look under U.S. Government in the Yellow Pages.)
How to get started.
Successful restoration of wetlands is possible by implementing comprehensive conservation
plans along with watershed protection strategies developed by a partnership of public and
private sectors. In addition to NRCS and the Army Corps of Engineers, the U.S.
Environmental Protection Agency and the U.S. Dept. of Interior are also involved in
protecting and restoring wetlands. Other agencies that often participate include state,
tribal, regional, and local government agencies.
Government and watershed residents must work together to
determine how wetlands fit into their watershed, the values (roles) of wetlands, and how
to best protect and restore these values. Then each public and private partner needs to do
their part in making it happen.
Some activities.*
Locate wetlands and study how they interact with the
watershed.
Bring together people concerned with wetlands in your
watershed.
Improve understanding of the systems and current and
future pressures.
Promote values of wetlands and be aware of potential
threats.
Coordinate wetland protection plans at all levels: local,
state, regional, and federal.
Build nest structures to increase nesting of Canadian
geese, mallards, wood ducks, and
other birds.
Plant food plots to increase survival of pheasants and
other wildlife.
Plant native wildflowers to add color and habitat for
songbirds, mammals, butterflies, and
other insects.
"Adopt A Wetland." Call 800-832-7828.
Help
local schools adopt a wetland, maintain it and
learn about it.
*Source: League of Women Voters.
Sources of information.
To start down the road toward an effective local watershed partnership, you may want to
read some of these other guides from the Conservation Technology Information Center by
calling 765-494-9555. See our catalog
to order this online.
Building Local
Partnerships
Getting to Know Your Watershed
Leading & Communicating
Managing Conflict
Putting Together a Watershed Plan
Reflecting on Lakes
Groundwater & Surface Water: Understanding
the Interaction
Guide to Information and Resources
Nonpoint Source Water Quality Contacts
About this guide...
Because the characteristics of each watershed are unique;
you may wish to select and use the portions of this guide that are applicable to your
particular situation.
This guide is one of a series of guides for people who
want to organize a local partnership to protect their watershed. The series is designed to
provide guidance for going through the process of building a voluntary partnership,
developing a watershed management plan and implementing that plan.
The series of guides will not solve all your problems
and will not replace the collective minds of partners who, together, represent of those
with a stake in your watershed and the technical advice available through local government
agencies.
Although this series is written for watershed-based
planning, the ideas and process can be used for developing other types of plans (such as
wildlife areas) to match the concerns of the partnership. Regardless of the area, remember
a long-term, integrated perspective — based on a systematic, scientific assessment
— can be used to address more than one concern at a time.
Special thanks...
Special thanks to Susan Kaynor, Environmental Scientist,
and Nancy Phillips, Environmental Consultant, who dedicated long hours to writing this
guide. Without their help this guide would not be possible. Special thanks also to the
following professionals who carefully reviewed this guide. Their experience and thoughtful
guidance enriched it. Their time and insight is deeply appreciated.
Connie Cahanap
U.S. Environmental Protection Agency
Tom Davenport
U.S. Environmental Protection Agency, Region 5
Doug Ehorn
Environmental Planning Team
Homer Gray
Tennessee Valley Authority
Linda Harris
Tennessee Valley Authority
Marty Kelly
Southwest Florida Water Management District James A. Meek
Environmental Consultant
Kathy Minisch
Puget Sound Water Quality Authority
Billy Teels
USDA Natural Resources Conservation Service
Chris Lewicki
U.S. Environmental Protection Agency
The Know Your Watershed campaign is coordinated by the Conservation
Technology Information Center (CTIC), a nonprofit public/private partnership dedicated to
the advancement of environmentally beneficial and economically viable natural resource
systems. It provides information and data about agricultural and natural resource
management systems, practices and technologies. The center was established in 1982 under
the charter of the National Association of Conservation Districts.
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