Wetland Delineation and Summary Report
Wetlands are generally described as areas saturated or covered
with water all or part of the year and which support certain
species of vegetation. Wetland areas are regulated by the Federal
government through Section 404 provisions of the Clean Water
Act. In New Hampshire, the alteration of wetland areas have
been regulated since 1967. The State of New Hampshire Wetlands
Bureau has been given approval by the U.S. Army Corps of Engineers
(COE) to administer projects impacting three acres of wetlands
or less, under the New Hampshire Programmatic General Permit.
Further information regarding the wetland permit process is
found in our Permit Acquisition Process section of the Site
Development Information Center. This section will discuss the
activities that occur to identify whether wetlands may exist
on your parcel.
To ascertain whether your project will impact wetland areas,
one first needs to know whether your parcel indeed has wetland
areas, and if they exist, you need to know precisely where they
are located. A wetland delineation study to define the location
of wetland area(s) thus needs to be initiated.
The very first task involves the collection of any existing
data that may be available. Such data might include a review
and interpretation of National Wetland Inventory maps, aerial
photos and a review of existing soil and wetland mapping and
floodplain delineation information which is normally available
at a Soil Conservation Service office near your project. This
mapping would generally locate where areas of wetlands might
likely be found in your area. Each city and town also has generalized
wetland mapping for your review. An initial screening level
sitewalk may also be made by a wetland scientist who is trained
in wetland habitats, to identify whether wetlands appear to
be present on the project site.
If wetland areas are suspected to be present, a thorough wetland
delineation study needs to be undertaken. It is only through
detailed in-field work that wetland areas can be adequately
defined in accordance with state and federal criteria. Such
delineations are completed by a wetland scientist.
Wetland delineation must be conducted in accordance with the
current Federal Manual for Identifying and Delineating Jurisdictional
Wetlands. The delineation may include transects that provide
a cross section of soil types and vegetative community from
upland to wetlands. The New Hampshire Wetlands Board classifies
areas of impact as minimum (<3,000 sq.ft.), minor (3,000 to
20,000 sq.ft.), or major (>20,000 sq.ft.). All major and minor
impact projects are reviewed by the US Army Corps of Engineers
and NH Wetlands Bureau. Some projects may require public hearings
on proposed projects and impacts.
To delineate the wetlands, the wetland scientist places flagging
at the boundary of theses areas. Once the wetlands have been
identified, the land surveyor needs to provide precise location
information regarding the flagged areas. This data is then shown
on an existing conditions topographic site plan which is made
a part of the project plans. Once the wetland areas have been
graphically shown, site design layout activities can be initiated.
The site engineer will locate and layout your site improvements
such that impacts to the wetland areas are either avoided or
A written report of findings is then prepared that shows the
results of the delineation and includes a description of the
various types and value of the identified wetlands.
Should the project impact wetland areas, permits will be needed
from federal, state and local agencies and parties. Further information
regarding the wetland permit process is found in our Permit
Acquisition Process section of our Site
Development Information Center.