118 • Wetlands: Their Use and Regulation 



DEFINITIONS 



The Council on Environmental Quality (CEQ) 

 distinguishes between three basic types of impacts 

 in the National Environmental Policy Act (NEPA) 

 regulations:' 



• Cumulative impacts are those impacts on the 

 environment that result from the incremen- 

 tal impact of a development activity when 

 added to other past, present, and reasonably 

 foreseeable future activities. Cumulative im- 

 pacts can result from individually minor, but 

 collectively significant, activities taking place 

 over time.^ 



• Direct effects are caused by specific activities 

 and occur at the same time and place as the 

 activities.' * 



• Indirect, or secondary, effects are caused by 

 the activities and are later in time or farther 

 removed in distance but still reasonably fore- 

 seeable. Indirect effects may include growth- 

 inducing effects and other effects related to in- 

 duced changes in the pattern of land use, pop- 

 ulation density, or growth rate, and related ef- 

 fects on air and water and other natural sys- 

 tems, including ecosystems.* 



Impacts can also be described as permanent or 

 temporary, and short or long term. The former dis- 

 tinction refers to whether or not the wedand restores 

 itself naturally after suffering impacts; the latter in- 

 dicates the length of time an impact takes to mani- 

 fest itself after the activity occurs. An activity may 

 have temporary and permanent impacts, as well 

 as short- and long-term impacts, simultaneously. 



'CFR title 40, pt. 325 to end, July 1, 1982. 

 ^S. 1508.7. 

 'S. 1508.8, 



•The words "effect" and "impact" are used interchangeably in 

 both the CEQ regulations zind this chapter. 

 «S. 1508.8. 



A canad dredged through a wetland area, for in- 

 stance, will immediately damage a wetland by re- 

 moving vegetation and wetland soil; this impact, 

 in most cases, is permanent. The dredging, how- 

 ever, also will cause turbidity — generally a short- 

 term, temporary impact — and slumping of adja- 

 cent wetland areas into the canal — potentially a 

 long-term, permanent impact. 



Two other terms used to describe impacts in this 

 chapter are onsite and offsite. Activities can impact 

 a wetland whether they take place directly on the 

 wetland (onsite) or some place removed from the 

 wetland (offsite). In general, offsite activities will 

 have less immediate impacts than will onsite ac- 

 tivities. Dredging in a wedand wiU remove vegeta- 

 tion and overlying substrata and cause immediate 

 damage. Erosion of fill material disposed in areas 

 adjacent to a wedand may cause gradual accumula- 

 tion of sediment in the wedand over a longer time. 



The term mitigation as used in the NEPA regula- 

 tions includes: 



a) avoiding the impact altogether by not taking 

 a certain (i.e., activity) action or parts of an 

 action; 



b) minimizing impacts by limiting the degree 

 or magnitude of the action and its implemen- 

 tation; 



c) rectifying the impact by repairing, rehabili- 

 tating, or restoring the affected environment; 



d) reducing or eliminating the impact over time 

 by preservation and maintenance operations 

 during the life of the action; and 



e) compensating for the impact by replacing or 

 providing substitute resources or environ- 

 ments.* 



HO CFR, pt. 1508.20. 



