WETLAND SERVICES

WETLAND DELINEATION METHODS AND PROCEDURES

EDI conducts all federal wetland delineations in accordance with the guidelines and procedures outlined in the 1987 Corps of Engineers Wetlands Delineation Manual and the Northcentral and Northeast Regional Supplement to the Delineation Manual implemented March 1st, 2010.

A multi-disciplinary team of professional Ecologists and Soil Scientists perform each delineation. The federal method for wetland delineation is a three-parameter test consisting of soils, vegetation and hydrology. An area is delineated as a wetland if it is found to have hydric soil, hydrophytic vegetation and wetland hydrology.

 

The subtle nature of some wetlands can make accurate delineations problematic. In order to provide the greatest degree

 of accuracy, EDI utilizes a multi-disciplinary team of professionals consisting of a soil scientist and wetland ecologist (botanist) to conduct all wetland delineations. This unique team approach paired with EDI’s careful attention to detail has resulted in a record of excellence.

EDI uses the quadrant transect sampling procedure for most sites that exceed 5.0 acres in size. This procedure involves establishing a baseline from which a representative number of parallel transects are laid out, generally 200 feet  apart between opposite property boundaries. At 200-foot intervals along each transect, EDI collects hydrologic, soils and vegetative data at “transect data points.” Each transect data point is evaluated according  to the data collected and the three-parameter test to allow for a wetland determination for that point.

When an area tests positive as a wetland, the wetland boundary is defined and delineated with numbered flags placed along the boundary. Data points are then taken within the wetland and outside of the wetland in order to document conditions on each side of the boundary. The numbered boundary flags facilitate the process of reviewing the wetland boundary and surveying the exact location of the boundary. The delineated wetland is then analyzed for any significant connections to adjacent hydrologic features to determine if the wetland is isolated under jurisdictional regulation.

REPORTS

Data acquired during the field investigations is compiled and summarized in a comprehensive wetland delineation report. EDI structures the reports so as to facilitate U.S. Army Corps of Engineers (Corps) and New York State Department of Environmental Conservation (NYSDEC) determinations of jurisdiction over each project pursuant to Section 404 of the Clean Water Act and Article 24 (Freshwater Wetlands) of the New York State Environmental Conservation Law. Reports are also tailored for the overseeing State agency if the project is located in another state.

Each report includes a project introduction, a site description, a preliminary office review, an explanation of methods and procedures, coordinate data for delineated wetlands and drainageways, results and conclusions and recommendations. The preliminary office review consists of  U.S. Geological Survey Maps, National Wetlands Inventory Maps, USDA Natural Resource Conservation Service Soil Survey Maps, and State Wetlands Maps with the project site and dimensions digitally overlayed, as well as a discussion of the information depicted on each map. A site specific, detailed explanation of the field investigation procedures is also given. Included in the results are a general description of the site conditions; the field data sheets for vegetation, soils and hydrology; a map depicting the general vegetative communities found on-site; a map depicting the wetlands delineated and a discussion of each. The final portion of the report relates the findings to the current regulations and provides recommendations for further action based on EDI’s expertise.