wetlands and nonwetlands, and hydrophytic vegetation and hydric soils may 

 persist for decades following alteration of hydrology that will render an area 

 a nonwetland. The presence of hydric soils and wetland hydrology indicators 

 in addition to vegetation indicators will provide a logical, easily defen- 

 sible, and technical basis for the presence of wetlands. The combined use of 

 indicators for all three parameters will enhance the technical accuracy, con- 

 sistency, and credibility of wetland determinations. Therefore, all three 

 parameters were used in developing the technical guideline for wetlands and 

 all approaches for applying the technical guideline embody the multiparameter 

 concept. 

 Approaches 



20. The approach used for wetland delineations will vary, based pri- 

 marily on the complexity of the area in question. Two basic approaches 

 described in the manual are (a) routine and (b) comprehensive. 



21. Routine approach. The routine approach normally will be used in 

 the vast majority of determinations. The routine approach requires minimal 

 level of effort, using primarily qualitative procedures. This approach can be 

 further subdivided into three levels of required effort, depending on the 

 complexity of the area and the amount and quality of preliminary data avail- 

 able. The following levels of effort may be used for routine determinations: 



a. Level 1 - Onsite inspection unnecessary. (PART IV, Section D, 

 Subsection 1) . 



b. Level 2 - Onsite inspection necessary. (PART IV, Section D, 

 Subsection 2) . 



£. Level 3 - Combination of Levels 1 and 2. (PART IV, Section D, 

 Subsection 3) . 



22. Comprehensive approach. The comprehensive approach requires appli- 

 cation of quantitative procedures for making wetland determinations. It 

 should seldom be necessary, and its use should be restricted to situations in 

 which the wetland is very complex and/or is the subject of likely or pending 

 litigation. Application of the comprehensive approach (PART IV, Section E) 

 requires a greater level of expertise than application of the routine ap- 

 proach, and only experienced field personnel with sufficient training should 

 use this approach. 



Flexibility 



23. Procedures described for both routine and comprehensive wetland 

 determinations have been tested and found to be reliable. However, 



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