Delineating Freshwater Wetlands
As was discussed in the overview, in the State of NJ, the 1989 Federal manual is utilized for the purpose of delineating freshwater wetlands. Anyone who wishes to submit an application for an LOI should be knowledgeable in the use of the manual, and have the proper education, training and experience in hydric soils, wetland hydrology, and wetland vegetation.
The United States Army Corps of Engineers (USACE) utilizes the 1987 USACE Wetland Delineation Manual for delineating wetlands in areas under its jurisdiction. Recently, the USACE has published several Regional Supplements to the 1987 Federal manual. Three Regional Supplements include New Jersey in their geographical boundary: Atlantic & Gulf Coastal Plain, Eastern Mountains & Piedmont and Northcentral and Northeast. Since New Jersey does not utilize the 1987 Manual for delineating wetlands, the subsequent Regional Supplements cannot be utilized to delineate wetlands. However, there are various resources contained within the Regional Supplements that can be used to substantiate a wetland determination.
- The USDA, NRCS Field Indicators of Hydric Soils v7.0 is an important tool in determining the presence of hydric soils and can be used in New Jersey along with any subsequent amendments.
- The National Wetland Plant List, hosted by the USACE, is the approved listing for classifying wetland plants in NJ. Please be advised that if you use the regional lists, New Jersey is split between 3 of the 10 regions, so you have to be careful to note which region your site is located within. In New Jersey, the most up-to-date version of the Plant List should be used.
- Wetland Hydrologic indicators are listed in the 1989 Federal manual and you should use the manual as the default guide for determining wetland hydrology on a site. There are various resources that are described in more detail in the “Difficult Wetland Situation” section of the Regional Supplements that can assist in substantiating wetland hydrology. However, the hydrology indicators themselves provide useful information but are effectively not enforceable under the rules in New Jersey.
In addition to the Federal Manual, there are other resources available to aid in determining the presence and extent of Freshwater Wetlands.
- The United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS) Web Soil Survey provides an online method of obtaining detailed information about soils located on a site.
- The Department has developed a GIS mapping tool, Geoweb, which includes a “Landscape/Natural Heritage” layer (map). This layer divides the landscape into various classifications, including wetlands, which may be useful in providing some guidance. Please be advised that these landscape maps are not ground verified and cannot be considered as a definitive determination of the presence of Freshwater Wetlands. Only a wetlands verification/delineation can accurately determine and verify the presence and extent of freshwater wetlands on a site.
Important Guidance for Agents: When you consider Department regulated features such as wetlands on a property, it is important to think of it as an area and not a boundary.
All types of Letters of Interpretation (LOI) except a Presence or Absence determination, refer to wetlands and/or wetland lines, but when a line is noted, it really refers to the edge of an area of wetlands. An area as displayed on a map appears as a polygon, a multisided shape, the edges of which will either be the property boundary, or a wetlands line delineated or verified by the Department.