Section F. Atypical Situations 



71. Methods described In this section should be used only when a deter- 

 mination has already been made in Section D or E that positive indicators of 

 hydrophytic vegetation, hydric soils, and/or wetland hydrology could not be 

 found due to effects of recent human activities or natural events. This sec- 

 tion is applicable to delineations made in the following types of situations: 



a. Unauthorized activities. Unauthorized discharges requiring 

 enforcement actions may result in removal or covering of indi- 

 cators of one or more wetland parameters. Examples Include, 

 but are not limited to: (1) alteration or removal of vegeta- 

 tion; (2) placement of dredged or fill material over hydric 

 soils; and/or (3) construction of levees, drainage systems, or 

 dams that significantly alter the area hydrology. NOTE: This 

 section should not be used for activities that have been previ- 

 ously authorized or those that are exempted from CE regulation. 

 For example, this section is not applicable to areas that have 

 been drained under CE authorization or that did not require CE 

 authorization. Some of these areas may still be wetlands, but 

 procedures described in Section D or E must be 



used in these cases. 



b. Natural events. Naturally occurring events may result in 

 either creation or alteration of wetlands. For example, recent 

 beaver dams may impound water, thereby resulting in a shift of 

 hydrology and vegetation to wetlands. However, hydric soil 

 Indicators may not have developed due to insufficient time 

 having passed to allow their development. Fire, avalanches, 

 volcanic activity, and changing river courses are other exam- 

 ples. NOTE: It is necessary to determine whether alterations 

 to an area have resulted in changes that are now the "normal 

 circumstances . " The relative permanence of the change and 

 whether the area is now functioning as a wetland must be 

 considered. 



c. Man-induced wetlands. Procedures described in Subsection A are 

 ~ for use in delineating wetlands that have been purposely or 



incidentally created by human activities, but in which wetland 

 indicators of one or more parameters are absent. For example, 

 road construction may have resulted in Impoundment of water in 

 an area that previously was nonwetland, thereby effecting 

 hydrophytic vegetation and wetland hydrology in the area. How- 

 ever, the area may lack hydric soil indicators. NOTE: Subsec- 

 tion D is not intended to bring into CE jurisdiction those man- 

 made wetlands that are exempted under CE regulations or policy. 

 It is also important to consider whether the man-induced 

 changes are now the "normal circumstances" for the area. Both 

 the relative permanence of the change and the functioning of 

 the area as a wetland are implied. 



83 



