Why are wetlands important (i.e. what are some of the functions that they perform?)?

WATER POLLUTION CONTROL
A major function of wetlands is water quality protection. Wetlands function like living filters by removing polluting nutrients and sediments from surface and ground water. Excess inputs of nutrients such as phosphorus and nitrogen can cause severe problems in aquatic ecosystems. You might say, "I thought nutrients were good." Nutrients such as phosphorus are necessary, but can be a classic example of how "too much of a good thing is bad." Excess nutrients can cause an undesirable increase in algae and aquatic plant growth. The result is water that is reminiscent of pea soup, weed-choked lakes, depleted dissolved oxygen levels, and the rapid aging or "eutrophication" of a lake. Wetlands retain or remove nutrients in four ways: 1) uptake by plant life, 2) adsorption into sediments, 3) deposition of detritus (organic materials), and 4) chemical precipitation.

SEDIMENT CONTROL
As sediment-laden water flows through a wetland from the surrounding watershed, the sediments are deposited into the wetland. This reduces siltation into lakes, rivers, and streams. A combination of wetland vegetation and generally flat topography serves to slow water flow and increase deposition of silt and organic matter. Furthermore, there is a strong tendency for heavy metals and other toxic chemicals to attach to the sediment particles found in surface water runoff. Wetlands can trap these human-induced pollutants and remove them from the water column. However, when the natural ability of wetlands to function as filters is overstressed from human inputs, the wetland and its functions can be destroyed. In fact, when overloaded, wetlands can actually become sources of pollutants, exporting materials that have been filtered and stored for centuries.

EROSION CONTROL
In their natural condition, wetlands function as a barrier to erosion. The root systems of wetland plants stabilize soil at the water's edge and enhance soil accumulation at the shoreline. Wetland vegetation along shorelines reduces erosion by dampening wave action and slowing current speed.

FLOOD PROTECTION
Wetlands act as a hydrologic sponge, temporarily storing flood waters and releasing them slowly, thus reducing flood peaks and protecting downstream property owners from flood damage. Wetlands and adjacent floodplains often form natural floodways that convey flood waters from upland to downstream points. These functions become increasingly important in urban areas where development has increased the rate and volume of runoff.

How can we protect wetlands?

PROTECTION AND CONSERVATION
For many wetland property owners, the best way to manage the wetland for protection and maintenance of the functions it serves is a hands-off approach. The hands-off approach means that you are not actively changing the key components of the wetland to modify the functions it naturally provides. It means that you are conscious of the potential threats to your wetland and are actively managing those threats. If you can protect a wetland and its surrounding uplands from potential threats, the wetland will take care of itself and provide a range of beneficial functions. Many of the management activities that landowners can take to guard their wetlands can occur outside the wetland boundaries.

VEGETATED BUFFERS
Perhaps the most effective management practice to protect wetlands from adjacent human activities is to establish and maintain a vegetative buffer around the wetland. A buffer is simply a strip of upland surrounding the wetland that is maintained in a natural vegetated state. On properties which have had the natural vegetation removed, establishing a buffer involves planting native trees, shrubs, and ground cover, ceasing use of fertilizers and pesticides, and only cutting or removing select vegetation. Buffers around wetlands provide many valuable functions. The vegetation in the greenbelt uptakes excess nutrients and pollutants in overland flow and thereby protects the wetland. The vegetation also serves to slow the velocity of overland flow which helps to prevent erosion and creates a better opportunity for the water to percolate into the soils. This helps to reduce the "flashy" nature of runoff from urbanized areas.

SEPTIC SYSTEMS
Septic systems also are a source of pollutants to wetlands. Be sure your septic system is operating properly. If you notice the area over your drain field is wet or particularly green, or if you can smell sewage during rainy periods, then your system is not working properly. Seepage from your system may be polluting nearby areas, including your wetland. To avoid this problem, have your septic system pumped and inspected every two to three years and commit to upgrading the system when necessary. In addition, water conservation practices such as installing low-flow toilets and shower heads can extend the life of a septic system.

FERTILIZERS AND PESTICIDES
There are many safe alternatives to chemical fertilizers and pesticides around the home. Organic pesticide formulations, use of other insects to fight pests, and composting kitchen and yard waste to enrich soil have all been successful in meeting the needs of homeowners. Many homeowners use fertilizers when they do not need to. Before you decide to use fertilizers, you should get your soil tested to see if it is even necessary. If you do use fertilizers or pesticides, follow manufacturer's directions carefully. Never apply more than is recommended.

County Wetland Inventory Maps

The Michigan DEQ announced in January 2007 that all county wetland inventories required by the state's wetland regulations have been completed and are available online.

The wetland inventory maps for each county show potential and approximate location of wetlands based on statewide aerial photography and soil information. County wetland inventory maps are not intended to define the specific locations and boundaries of wetlands for regulatory purposes. The MDEQ's Wetland Identification Program is available to assist property owners with identifying the specific location of any wetlands on their property and whether the wetlands are regulated.

County wetland inventory maps are available at: www.michigan.gov/deqwetlands then click on "information - wetland inventory maps", or requested in paper format at cost by calling 517/241-7397.

Last Updated: February 2007