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Federal Register / Vol. 56, No. 157 / Wednesday, August 14, 1991 / Proposed Rules 



Springs and Seepage Wetlands 



Wetlands occurring in flowing waters 

 from springs and groundwater seepage 

 areas may not exhibit typical hydric soil 

 properties due to oxygen-enriched 

 waters. Springs have permanently 

 flowing waters, while seepage flows 

 may be seasonal. Not all seepage areas, 

 however, are considered wetlands. To 

 qualify as wetland, the follovmg 

 conditions should be met: (1) Seepage 

 flow by oxygen-enriched waters is 

 continuous for at least a 30-day period 

 during the growing season in most years 

 and saturate the soil to the surface, and 

 (2) OBL and/or FACW species 

 predominate or have a prevalence index 

 less than or equal to 2.5. Soils wet for 

 this duration are typically considered to 

 have an aquic moisture regime and are 

 hydric. The outer boundary of these 

 wetlands is estabUshed by the limits of 

 predominance of OBL and/or FACW 

 species. 



Drought-affected Wetlands 



Droughts periodically occiu' in many 

 parts of the country, especially in the 

 semiarid and arid West. During drought, 

 it is quite obvious that water wrill not be 

 observed in many wetlands, especially 

 those higher up on the soU moisture 

 gradient. With the drying of these 

 wetlands over a number of consecutive 

 years, environmental conditions no 

 longer favor the growth of hydrophytic 

 vegetation, so FACU and UPL species 

 become established and often 

 predominate in time. Thus, the plant 

 community composition changes to one 

 that is no longer dominated by 

 hydrophytes. Such communities fail to 

 meet the hydrophytic vegetation 

 criterion, unless treated as harder to 

 identify wetlands. Drought-affected 

 wetlands should be identified by the 

 presence of hydric soils, further refined 

 by clear signs of long-term hydrology as 

 expressed in the soil by: Thick organic 

 surface layers, gleyed layers, low 

 chroma matrices with high chroma 

 mottles, and others Usted as regional 

 wetland hydrology indicators. 

 Additional verification of hydrology 

 may be advisable for some sites and an 

 examination of aerial photographs 

 during the wet part of the growing 

 season in years of normal precipitation 

 (distributions and amount) should reveal 

 signs of wetland hydrology. In addition, 

 landscape position (e.g., depressions 

 and sloughs) may provide additional 

 evidence for recognizing these wetlands 

 during droughts. 



Appendix 7. Disturbed Area Procedures 



Step 1. Determine whether vegetation, 

 soils, and/or hydrology have been 



significantly altered at the site. Proceed 

 to Step 2. 



Step 2. Determine whether the 

 "altered" characteristic met the wetland 

 criterion in question prior to site 

 alteration. Field persormel shall 

 docimient the reasons for determining 

 that the site would have been a wetland 

 but for the disturbance. Review existing 

 information for the area (e.g., aerial 

 photos, NWI maps, soil surveys, 

 hydrologic data, and previous site 

 inspection reports), contact 

 knowledgeable persons familiar v«th the 

 area, and conduct an onsite inspection 

 to build supportive evidence. The 

 strongest evidence involves considering 

 all of the above plus evaluating a nearby 

 reference site (an area similar to the one 

 altered before modification) for field 

 indicators of the three technical criteria 

 for wetland. If a human activity or 

 natural event altered the vegetation, 

 proceed to Step 3; the soils, proceed to 

 Step 4; the hydrology, proceed to Step 5. 



Step 3. Determine whether the 

 hydrophytic vegetation criterion was 

 met prior to distiu'bance: 



(1) Describe the type of alteration. 

 Examine the area and describe the type 

 of alteration that occurred. Look for 

 evidence of selective harvesting, 

 clearcutting, bulldozing, recent 

 conversion to agriculture, or other 

 activities (e.g., burning, discing, the 

 presence of buildings, dams, levees, 

 roads, and parking lots). 



(2) Determine the approximate date 

 when the alteration occiuxed if 

 necessary. Check aerial photographs, 

 examine building permits, consult with 

 local individuals, and review other 

 possible sources of information. 



(3) Describe the effects on the 

 vegetation. Generally describe how the 

 recent activities and events have 

 affected the plant communities. 

 Consider the following: 



(A) Has all or a portion of the area 

 been cleared of vegetation? 



(B) Has only one layer of the plant 

 commimity (e.g., trees) been removed? 



(C) Has selective harvesting resulted 

 in the removal of some species? 



(D) Has the vegetation been burned, 

 mowed, or heavily grazed? 



(E) Has the vegetation been covered 

 by fill, dredged material, or structures? 



(F) Have increased water levels 

 resulted in the death of all or some of 

 the vegetation? 



(4) Determine whether the area had 

 plant communities that met the 

 hydrophytic vegetation criterion. 

 Develop a list of species that previously 

 occurred at the site from existing 

 information, if possible, and determine 

 whether the hydrologic vegetation 



criterion was met. If site-specific data 

 do not exist, then do the follovdng, as 

 appropriate: 



(A) If the vegetation is removed and 

 supportive evidence affirmadvely 

 demonstrates that the hydrophytic 

 vegetation criterion would have been 

 met but for the alteration and no other 

 alterations have been done, then 

 evidence of the elimination of the 

 hydrophytic vegetation together with the 

 presence of hydric soils and evidence of 

 wetiand hydrology will be used to 

 identify wetiands. It may be 

 advantageous to examine a nearby 

 reference site to collect data on the 

 plant conununity to confirm this 

 assumption. (Note: Determination of 

 reg\ilatory jurisdiction for such areas is 

 subject to agency interpretation. For 

 example. Federal wetland regulatory 

 pohcy imder the Clean Water Act, and 

 agricultural program policy under the 

 Food Security Act of 1985, as amended, 

 interprets the relative permanence of 

 distiu'bance to vegetation caused by 

 cropping. Be sure to consult appropriate 

 agency policy in making Federal 

 weUand jurisdictional determinations in 

 such areas.) 



(B) If the area is filled, biuying the 

 vegetation, and no other alterations (i.e., 

 to hydrology or soils) have taken place, 

 then either. (1) Look below the fill layer 

 for hydric soil and indicators of weUand 

 hydrology, plus any signs of hydrophytic 

 vegetation (if not decomposed), or (2) if 

 type of fill (e.g., concrete) precludes 

 examination of soil beneath the fill, then 

 review existing information (e.g., soil 

 survey, weUand maps, and aerial 

 photos) to determine if the area was 

 wetland. If necessary, evaluate a 

 neighboring undisturbed area (reference 

 site) with characteristics (i.e., 

 vegetation, soils, hydrology, and 

 topography) similar to the area in 

 question prior to its alteration. Be sure 

 to record the location and major 

 characteristics (vegetation, soils, 

 hydrology, and topography) of the 

 reference site. Sample the vegetation in 

 this reference area using an appropriate 

 onsite determination method to 

 determine whether hydrophytic 

 vegetation is present. If the hydrophytic 

 vegetation criterion is met at the 

 reference site, then this criterion is 

 presumed to have been met in the 

 altered area. If no indicators of 

 hydrophytic vegetation are found at the 

 reference site, then the original 

 vegetation at the project area is not 

 considered to have met the hydrophytic 

 vegetation criterion. 



(C) If soils and/or hydrology also 

 have been disturbed, then continue 

 Steps 4, 5, and 6 below, as necessary. 



