[Code of Federal Regulations]
[Title 40, Volume 24]
[Revised as of July 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR230.41]

[Page 268]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 230_SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL 
SITES FOR DREDGED OR FILL MATERIAL--Table of Contents
 
          Subpart E_Potential Impacts on Special Aquatic Sites
 
Sec. 230.41  Wetlands.

    (a)(1) Wetlands consist of areas that are inundated or saturated by 
surface or ground water at a frequency and duration sufficient to 
support, and that under normal circumstances do support, a prevalence of 
vegetation typically adapted for life in saturated soil conditions.
    (2) Where wetlands are adjacent to open water, they generally 
constitute the transition to upland. The margin between wetland and open 
water can best be established by specialists familiar with the local 
environment, particularly where emergent vegetation merges with 
submerged vegetation over a broad area in such places as the lateral 
margins of open water, headwaters, rainwater catch basins, and 
groundwater seeps. The landward margin of wetlands also can best be 
identified by specialists familiar with the local environment when 
vegetation from the two regions merges over a broad area.
    (3) Wetland vegetation consists of plants that require saturated 
soils to survive (obligate wetland plants) as well as plants, including 
certain trees, that gain a competitive advantage over others because 
they can tolerate prolonged wet soil conditions and their competitors 
cannot. In addition to plant populations and communities, wetlands are 
delimited by hydrological and physical characteristics of the 
environment. These characteristics should be considered when information 
about them is needed to supplement information available about 
vegetation, or where wetland vegetation has been removed or is dormant.
    (b) Possible loss of values: The discharge of dredged or fill 
material in wetlands is likely to damage or destroy habitat and 
adversely affect the biological productivity of wetlands ecosystems by 
smothering, by dewatering, by permanently flooding, or by altering 
substrate elevation or periodicity of water movement. The addition of 
dredged or fill material may destroy wetland vegetation or result in 
advancement of succession to dry land species. It may reduce or 
eliminate nutrient exchange by a reduction of the system's productivity, 
or by altering current patterns and velocities. Disruption or 
elimination of the wetland system can degrade water quality by 
obstructing circulation patterns that flush large expanses of wetland 
systems, by interfering with the filtration function of wetlands, or by 
changing the aquifer recharge capability of a wetland. Discharges can 
also change the wetland habitat value for fish and wildlife as discussed 
in subpart D. When disruptions in flow and circulation patterns occur, 
apparently minor loss of wetland acreage may result in major losses 
through secondary impacts. Discharging fill material in wetlands as part 
of municipal, industrial or recreational development may modify the 
capacity of wetlands to retain and store floodwaters and to serve as a 
buffer zone shielding upland areas from wave actions, storm damage and 
erosion.