Part 510 - General Operating Procedures 



510.90(e) (2) (ii) 



Make certain that the county hydric soil list is current and 

 includes any mapping units with hydr-.j: soil inclusions that 

 were identified during the appeal process. When soil lines 

 are changed, make certain they are recorded, initialed, and 

 dated on the official copy of the soil survey and on any 

 maps included in the appeal files. If spot symbols are 

 used, they should be taken from the published soil survey or 

 the National Map Symbols Handbook, or they may be cross 

 referenced to the Field Office Technical Guide. 



(ii) Hydrology r The seasonal weather 

 conditions and water regime, including field documentation 

 of prior drainage or manipulation if appropriate by the 

 appropriate specialist. It is not sufficient to indicate 

 that the area is wetland without documentation that the area 

 is subject to sufficient flooding, ponding, or saturation to 

 meet the wetland hydrology criteria. For example, if the 

 area floods, cite flood years used for data or cite 

 interviews with local people who attest to the flooding, 

 giving names and dates of interviews. Describe the 

 topography, such as depression, pothole, playa, or 

 floodplain, and give periods of ponding, flooding, or 

 saturation or the combination of these. The engineer's \(- 

 report should mention any factors affecting the flow of 

 surface or subsurface water. 



(iii) Hvdrophvtic vegetation . Unless the 

 area is cropped, documentation should include a list of the 

 dominant species and their relative abundance in order to 

 determine plant prevalence. Photo documentation is very 

 useful. Include documentation of visual or transect 

 determinations: 



(A) visual determination should include 

 a list of the most abundant plant species with their 

 respective indicator status that occur within the hydric 

 soil boundary (or similar area if vegetation has been 

 removed) . Estimate the percent coverage of each, and 

 include enough information to document that the percent 

 coverage was greater for either obligate and facultative wet 

 species, or upland and facultative for upland species. 

 Delineate on the ASCS aerial photo the area that supports or 

 would support a prevalence of hydrophytic vegetation. 



510-70 



(180-V-NFSAM, Second Ed., Amend. 6, May 1991) 



