Wetland delineation what is it

Sometimes, they might only be flooded for a few weeks in a season. The first step in wetland delineation involves taking soil samples and analyzing them based on color and consistency.

Dark colored soil indicates an abundance of moisture and decomposed plant matter. As we move further away from wetlands, the soil becomes lighter and sandier. Next, we study the local foliage and determine whether or not it is characteristic of wetlands.

Cattails and fallen grasses are telltale signs of a wetland. Water marks on tree trunks are another common indicator of wetlands. Finally, we take a step back and examine the grade of the land. Unsurprisingly, wetlands tend to be in low lying areas. By determining where changes in slope and elevation occur, we can get a better idea of just where a wetland begins and ends.

Wetlands are commonly delineated by wetland sample locations within the wetlands, upland sample locations outside the wetlands, and boundary sample locations defining the edge of the wetlands. Requesting A Jurisdictional Determination. A wetland delineation differs from a jurisdictional determination. A Jurisdictional Determination, on the other hand, is a request, generally made by a consultant on behalf of and authorized by the property owner, to the local Corps of Engineers Regulatory Office, to make an official agency determination if wetlands identified by the consultant are under the jurisdiction of the Clean Water Act as administered by the US Corps of Engineers.

Although a wetland consultant can give you an opinion of whether the wetlands on your property meet the definition of wetlands, only the Corps of Engineers can determine whether the wetlands are jurisdictional Waters of the US WOUS. It is generally recommended that owners who contract wetland delineations on their property also authorize their consultant to request a jurisdictional determination following the wetland delineation to confirm results. These include wetlands directly or indirectly connected to ephemeral and perennial streams under Corps of Engineers jurisdiction.

Projects that impact these WOUS jurisdictional resources wetlands must have a permit to impact the wetlands. Disturbing most wetlands is unlawful unless permitted by the agencies with jurisdiction over the wetland resource. Because of all the many essential needs they provide, wetlands are protected by federal, state and local regulations. If you are planning a development project, building a new road or have an agricultural field that needs draining where a wetland may be disrupted or impacted, a delineation is your first step.

Wetland delineations tell you precisely the wetland location within your project plan. To obtain a permit for impacting a wetland, the delineated wetland boundary must be approved by the USACE and, often, other local agencies that may have regulatory authority. Plants dying or entering dormancy mark the end of the growing season. The growing season varies considerably both year to year and geographically.

Understanding the findings you hope to achieve, here are the three steps of a proper and thorough wetland delineation:. Whether small or large wetland delineation project, a delineator should prepare by researching the project area. This involves using mapping products such as aerial photographs and soil maps to identify potential aquatic resources. Some essential resources available:. If you are working on a smaller project, merely having a map is all you need.

But for larger projects when you're on a team, it's often best to determine in advance who will cover what areas. Before you go, do you have the essential field gear? When you arrive at the project site, where should you begin? Is there an exact start and finish line? What types of vegetation do you see? Rebecca will sometimes touch the vegetation to determine what the plant is. For example, Rebecca could feel edges on one plant picked during a delineation and, as a result, could identify the plant.

Rebecca says some of the descriptive, common names can be helpful to remember a particular plant species. Other vegetation includes milkweed and reed canary grass — both of which can be found in uplands and wetlands. When you locate an area where the dominant vegetation is hydrophytic i. In the video below, Rebecca walks through and discusses the importance of plant identification.

While not an accurate indicator, wetland boundaries are often associated with changes in topography, where the wetland is predominantly lower in the landscape. In the video below, Rebecca places pink wetland delineation flags identifying the wetland boundary.

She also records GPS points as part of her delineation. Additional conditions to note during a wetland delineation include the temperature higher or lower than normal and precipitation wetter or drier than normal. In the video below, Rebecca walks through how to conduct a soil sample during a wetland delineation.

After the draft report is prepared, the project owner then engages a wetland regulatory agency to review and confirm the results. In Minnesota, where Rebecca is located, an approved wetland delineation is valid for five years so long as conditions have not changed the boundary of that wetland during the five years since the initial approval.