Of all the types of properties to own, wetlands can be one of the trickier types to manage. Many people may overlook wetlands in favor of drier, more utilizable areas, but wetlands serve an important purpose in an ecosystem by reducing flooding and erosion, regulating water quality, and more! 

Here are a few examples of the importance of wetlands in the ecosystem!

What is a Wetland Delineation?

Firstly, it’s necessary to know how a wetland is legally defined to understand the importance of wetlands, and this is typically done through a wetland delineation. A wetland delineation is a determination of where uplands (dry) end and wetlands begin. Typically this boundary is defined by the 3 parameters described by the U.S. Army Corps of Engineers, or USACE. You can also have wetland habitats that may not be considered true wetlands under the jurisdiction of the Clean Water Act or the USACE, which is the enforcing agency of the Clean Water Act. 

The 3 USACE parameters used for wetlands delineation are soils, hydrology, and vegetation/flora (plant life). When soils are regularly flooded by water and remain submerged for a time, the lack of exposure to air causes chemical processes to take place that alters the characteristics of the soil. This is usually the most tell-tale sign, or “proof”, of a wetland.

Hydrology is the evidence that an area receives and/or retains water to support a wetland habitat. Indicators of hydrology include the presence of standing water, moss trim lines on buttressed tree trunks, crawfish burrows, and many more.

The vegetation parameter focuses on the plant species that are within the wetland area. Hydrophytic, or ‘water-loving’, plants are adapted to thrive in wet conditions. Tree species like cypress, willow, or tupelo require wetland conditions to survive. The vegetation parameter is assessed by identifying the trees, saplings, shrubs, vines, and herbaceous plants within the area you are evaluating. If the species identified are known to occur in wet areas, then this area would meet the requirement for wetland vegetation.

An area may have 1 or 2 of these 3 parameters and provide many of the same benefits as a wetland, but the presence of all 3 is required for jurisdiction by the USACE.

Landowners can have the USACE perform a JD (Jurisdictional Determination) for free but are at their mercy for the timing of such testing/delineation. They could also have a third-party consulting group such as Three Oaks Engineering perform these delineations, but third-party consultations still need to be approved by the USACE.

How Do Wetlands Reduce Flooding and Erosion?

One of the largest roles wetlands play in the ecosystem is the reduction of flooding and erosion. During storm events, without wetlands, water crosses more impervious surfaces and pushes more water into creek lines which erode the soil in the creek and eventually flow into larger streams where the increased water levels cause further erosion. Wetlands allow for stormwater and flood waters to attenuate, or settle. This slowing reduces the velocity of the water, creating less erosion than the fast-flowing water would have. Reducing erosion leads to better quality streams by preventing sediments from escaping into channels which impacts water quality and habitat. 

How Does the Loss of Wetlands Affect Water Quality?

Allowing water to slow down and filter out any potentially harmful pollutants is one of the most important functions of wetlands in our ecosystems. Pollutants include sediments, metals, and toxins. Loss of wetland areas removes the ability to absorb stormwater flows/treat/attenuate the water flow. Wetlands prevent pollutants from escaping into our streams and rivers. In the same way they prevent erosion by slowing the flow of runoff or stormwater, wetlands allow pollutants to settle out of the water into the soils and they can even be filtered out with the help of certain wetland vegetation. Plants such as cattails and spartina are known to absorb metals and other pollutants. This is true in both fresh and saltwater wetlands, and salt marshes are very effective at filtering out pollutants.

Without a stagnant or slow-moving buffer zone like a wetland, stormwater would have no space to pool which would result in significantly increased erosion and pollution of other waterways.

To add to the importance of wetlands, they provide habitat connectivity for many biological species. Habitat fragmentation, or the breaking-up of contiguous habitats like forests and wetlands by the development of roads and property, is a threat to wildlife. Wetland systems act as a bridge between fragmented areas and are used by wildlife as common as the whitetail deer or as rare as the spotted turtle. Many federally-protected species by the Endangered Species Act occur either only in wetland habitats or use them for foraging. Swamp pink, Canby’s dropwort, Frosted flatwoods salamander, Northern long-eared bats, and many more species rely on wetland areas.

Can You Build on Wetlands?

The short answer is no. It’s important to coordinate with consultants or the USACE to determine the presence of wetlands and jurisdictional limits under the Clean Water Act. Many agricultural uses are somewhat allowed but again are a topic of discussion. 

In short, when disturbing the soil in and around wetlands, it is best to have a consultant or USACE advise on the matter and provide other resources as to what may or may not be able to be done in/on/around wetlands.

If you’ve got questions about the importance of wetlands or how to best utilize wetlands on your property, get in touch with your local National Land Realty Land Professional! 

Additional information provided by Wade Biltoft, PWS, with Three Oaks Engineering in Cayce, SC