DRAFT
                  REVISED FEDERAL MANUAL FOR
       IDENTIFYING AND DELINEATING VEGETATED  WETLANDS
                        APRIL 26,  1991
cr>
 j                       HEADQUARTERS LIBRARY
  1                       ENVIRONMENTAL PROTECTION AGENCY
                         WASHINGTON. D.C. 20460

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                        TABLE OF CONTENTS
Part I.
INTRODUCTION
     Purpose
     Organization of the Manual
     Use of the Manual
     Background
     Federal Wetland Definitions
          Section 404 of the Clean Water Act
          Food Security Act of 1985
          Fish and Wildlife Service's Wetland
          Classification System
Page

   1

   1
   1
   1
   2
   5
   5
   6
Part II.
Relationship of Wetlands Identified by this Manual to
"Waters of the United States"
Summary of Federal Definitions

MANDATORY TECHNICAL CRITERIA FOR VEGETATED WETLAND
IDENTIFICATION
     WETLAND HYDROLOGY CRITERION                               10
          Wetland Hydrology Background                         13
          Measuring Wetland Hydrology                          14
          Historical Recorded Hydrologic Data                  15
          Aerial Photographs                                   15
          Field Observations                                   16
               Direct Evidence of Water                        16
               other Signs of Wetland Hydrology                16

     HYDROPHYTIC VEGETATION CRITERION                          18
          Hydrophytic Vegetation Background                    19
          National List of Wetland Plant Species               20
          Dominant Vegetation                                  21

     HYDRIC SOIL CRITERION                                     22
          Hydric Soil Background                               23
          National and State Hydric Soils Lists                23
          County Hydric Soil Map Unit Lists                    24
          Soil Surveys                                         24
          Use of County Hydric Soils Map Units Lists and Soil
          Surveys                                              25
          General Characteristics of Hydric Soils              25
          Organic Soils                                        26
          Hydric Mineral Soils                                 27
          Soil Related Evidence of Significant Saturation      28

     Difficult-to-Identify Wetlands                            31
          Forested Wetlands                                    31
          Streamside/Riparian Wetlands                         3l
          Wet Meadows/Prairie Wetlands                         32

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          Pocosins
          Playas
          Prairie Potholes
          Vernal Pools

Part III. STANDARD METHODS FOR IDENTIFICATION AND DELINEATION
          OF WETLANDS

     Selection of a Method
     Description of Methods
          Offsite Preliminary Determinations
          Onsite Determinations
          Disturbed Area Wetland Determinations
Appendices

Appendix 1.
Appendix 2.
Appendix 3.
Appendix 4.
Appendix 5.
Appendix 6.
Appendix 7.
Appendix 8.
Offsite Preliminary Determination Method
Routine Onsite Determination Method
Intermediate-level Onsite Determination Method
Comprehensive Onsite Determination Method
Descriptions of Difficult-to-Identify Wetlands
Difficult-to-Identify Hydric Soils
Procedures for Difficult-to-Identify Wetlands
Disturbed Area Procedures
                                                  32
                                                  32
                                                  33
                                                  33
34

34
38
38
38
41

43


43
46
52
59
74
82
86
89

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                          FART I.

                        INTRODUCTION
 Purpose
 The purposes  of  this  manual  are:   (1) to provide mandatory
 technical  criteria  for  the identification and delineation of
 wetlands,  (2)  to provide  recommended methods for vegetated
 wetlands identification and  upper  boundary delineation, and  (3)
 to provide sources  of information  to aid in their identification.
 The document  can be used  to  identify jurisdictional wetlands
 subject  to Section  404  of the Clean Water Act and to the
 "Swampbuster"  provision of the Food Security Act of 1985, as
 amended, or to identify vegetated  wetlands in general  for the
 National Wetlands Inventory  and other purposes.  Wetland
 jurisdictional determinations for  regulatory purposes  are based
 on criteria in addition to technical criteria, so consult the
 appropriate regulatory  agency for  its interpretation.  The tern
 "wetland"  as used throughout this  manual refers to vegetated
 wetlands.   This  includes  wetlands  with natural vegetation and
 wetlands where natural  vegetation  has been temporarily disturbed.
 This manual provides  a  single, consistent approach for
 identifying and  delineating  these  wetlands from a multi-agency
 Federal perspective.


 Organization of  the Manual

 This manual is divided  into  three  major parts: Part I  -
 Introduction;  Part  II - Mandatory  Technical Criteria for
 Vegetated  Wetland Identification;  and Part III - Methods for
 Identification and  Delineation of  Vegetated Wetlands.  References,
 a  glossary of  technical terms, and appendices are also included.
Use of the Manual

This manual should be used for the identification and delineation
of vegetated wetlands in the United States. Emphasis for
delineation is on the upper boundary of wetlands (i.e.,
wetland-upland boundary') and not on the lower boundary between
wetlands and other aquatic habitats. The technical criteria for
wetland identification presented in Part II are mandatory, while
the methods presented in Part III are recommended approaches.
Alternative methods are offered to provide users with a selection
of methods that range from office determinations to detailed
field determinations. If the user departs from these methods, the
reasons for doing so should be documented.  If there are any
inconsistencies between Parts I, II, and III, the guidance
provided in Part II has preeminence over guidance provided in the
other parts.

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 Background

 At the Federal  level, four agencies are principally involved with
 wetland  identification and delineation:  Army Corps of Engineers
 (CE), Environmental Protection Agency  (EPA), Fish and Wildlife
 Service  (FWS),  and soil Conservation Service (SCS). The CE and
 EPA  are  responsible for making jurisdictional determinations of
 wetlands regulated under Section 404 of the Clean Water Act
 (formerly known as the Federal Water Pollution Control Act, 33
 U.S.C. 1344).   The CE also makes jurisdictional determinations
 under Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C.
 403).  Under Section 404, the Secretary of the Army, acting
 through  the Chief of Engineers, is authorized to issue permits
 for  the  discharge of dredged or fill material into the waters of
 the  United States, including wetlands. EPA has an important role
 in developing the Section 404(b)(l) Guidelines and defining the
 geographic extent of waters of the Unites States, including
 wetlands.  The  CE also issues permits  for filling, dredging, and
 other construction in certain wetlands under Section 10.  Under
 authority of the Fish and Wildlife Coordination Act, the FWS and
 the  National Marine Fisheries Service  review applications for
 these Federal permits and provide comments to the CE on the
 environmental impacts of proposed work. In addition, the FWS is
 conducting an inventory of the Nation's wetlands and is producing
 a series of National Wetlands Inventory maps for the entire
 country.  While the SCS has been involved in wetland
 identification  since 1956, it has recently become more deeply
 involved in wetland determinations through the "Swampbuster"
provision of the Food Security Act of  1985, and the 1990
amendments.

 Prior to the adoption of the "Federal Manual for Identifying and
 Delineating Jurisdictional Wetlands" by the four agencies in
 1989, each agency had its own procedures for identifying and
delineating wetlands.  The CE and EPA developed technical manuals
 for  identifying and delineating wetlands subject to Section 404
 (Environmental  Laboratory 1987 and Sipple 1988, respectively),
yet  neither manual was a nationally-implemented standard even
within the agencies.  Consequently, wetland identification and
delineation remained inconsistent.  The SCS developed procedures
 for  identifying wetlands for compliance with "Swampbuster" which
were adopted by the agency for national use in 1987 (7 CFR Part
 12).   While it has no formal method for delineating wetland
boundaries, the FWS has established guidelines for identifying
wetlands in the form of its official wetland classification
system report (Cowardin, et al. 1979).  These varied agency
approaches and  lack of standardized methods resulted in
inconsistent determinations of wetland boundaries for the same
type of area.  This created confusion and identified the need for
a single, consistent approach for wetland determinations and
boundary delineations.

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 In early 1988,  the CE and EPA  resumed previous discussions on the
 possibilities of merging their manuals  into a single document and
 establishing it as a  national  standard  within the agencies, since
 both manuals were produced in  support of Section 404 of the Clean
 Water Act.   The FWS and  SCS were  invited to participate, thereby
 creating the Federal  Interagency  Committee for Wetland
 Delineation  (Committee)  with each of the four agencies  (CE, EPA,
 FWS,  and SCS)  represented.

 The four agencies reached agreement on  the technical criteria for
 identifying  and delineating wetlands and merged their methods
 into a single wetland delineation manual, which was published on
 January 10,  1989 as the  "Federal  Manual for Identifying and
 Delineating  Jurisdictional  Wetlands".   This established a
 national standard for wetland  identification and delineation, and
 terminated previous locally implemented approaches that were not,
 in  some cases,  scientifically  based nor consistent.  Further,
 adoption of  the manual in 1989 resulted in some changes in the
 scope of regulatory jurisdiction  in some agency field offices.

 During the following  two years, the 1989 manual was used by the
 agencies for wetland  delineation, chiefly for identifying and
 delineating  wetlands  subject to federal regulations under the
 Clean Water  Act.  Unfortunately,  during this time many
 misconceptions  about  the intent of the  1989 manual,
 misapplication  of the 1989  manual (e.g., classifying any area
 mapped as hydric soil as wetland without considering other
 criteria), and  other  factors created an obvious need to review
 the 1989 manual  and revise  it  accordingly.  From the outset, the
 Committee recognized  that additional clarification and/or changes
 might  be required.

Accordingly,  in  May 1990, the  Committee initiated an evaluation
 of the  1989  manual, which consisted of  several steps:

      1.   Formal  field testing was conducted by the Environmental
          Protection  Agency to evaluate the sampling protocols of
          the 1989  manual  (Sipple and DaVia 1990} ;

      2.   Reviews by  agency field staff using the 1989 manual;

      3.   To afford the  public the opportunity to comment on the
          technical aspects of the 1989 manual, public meetings
          were held in Baton Rouge,  Louisiana, Sacramento,
          California,  St. Paul, Minnesota, and Baltimore,
          Maryland; and

     4.   Written comments  on  the technical aspects of the 1989
          manual were also  accepted subsequent to the meetings to
          give the public ample opportunity to express any
          concerns.  More than 500 letters were received and
          reviewed.

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The  technical comments were reviewed by the Committee and
considered  for  incorporation into a revised manual.  The Agencies
concluded that  while the manual represented a substantial
improvement over pre-existing approaches, several key issues
needed to be re-examined and clarified. Some of the key technical
issues needing  re-examination were: (1) the wetland hydrology
criterion,  (2)  the use of hydric soil for delineating the wetland
boundary,  (3) the assumption that facultative vegetation
indicated wetland hydrology, and (4) the open-ended nature of the
determination process which created opportunities for misuse.

The  wetland hydrology criterion in the 1989 manual included a
series of requirements related to specific soil types (soil
drainage classes).  Looking for water tables at various depths
depending on soil drainage class was confusing, especially since
properties  associated with soil drainage classes are not
standardized across the country.  The National Technical
Committee for Hydric Soils (NTCHS)  criteria for defining hydric
soils were  adopted in the 1989 manual.  The hydric soil criterion
included wetland hydrology requirements to identify those soils
wet  enough  to be hydric.  In adopting the NTCHS hydric soil
criteria, the 1989 manual retained the hydrology requirements
under its hydric soil criterion and also in effect, repeated them
as the wetland  hydrology criterion.  This clearly gave the
impression  of a less than three criteria approach to wetland
identification.

Perhaps the issue that engendered the most concern over potential
misuse of the 1989 manual involved the use of hydric soils for
wetland identification and delineation.  Since the 1989 manual
included wetland hydrology requirements within the hydric soil
criterion,  and  the delineation methods relied on hydric soil
properties  to delineate the wetland boundary, some users got the
impression  that the.1989 manual was not based on three mandatory
criteria, but rather based solely on one criterion - the hydric
soil criterion  (since it, in fact,  embodied the wetland hydrology
criterion).  This,  by itself, was not a significant problem,
since hydrology was still considered.   Some users then
erroneously translated this to mean that any area mapped as a
hydric soil series was a wetland.  However, it was the clear
intent of the agencies that specific soil properties derived
directly from wetland hydrology (e.g., significant soil
saturation) would be used to separate those members of hydric
soil series that were associated with wetlands from those that
were not.  Hydric soil napping units include significant acreage
of phases of these soils that were never wetland or no longer
meet the wetland hydrology requirements of the hydric soil
criterion (i.e., dry phases and drained phases, respectively) as
well as inclusions of nonhydric soils.

By considering  any mapped hydric soil area as wetland, millions

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 of former wetlands (now effectively drained) could be
 misidentified as  wetland.  This grossly exaggerated the extent of
 "jurisdictional wetlands" present in the United States.  While
 the presence  of certain plants were required to separate
 vegetated wetlands from nonvegetated wetlands, they were not used
 to help identify  the upper boundaries, although they can be very
 useful  indicators in certain cases where hydrology has been
 altered or where  soil properties themselves are difficult to
 interpret.  Consequently, by ignoring plant composition on the
 upper end of  the  wetland/upland gradient and by erroneously using
 napped  boundaries of hydric soil units to delineate wetland
 boundaries, errors in judgment were possible.

 The 1989  manual specified three mandatory criteria, but did not
 require the use of various indicators to verify these criteria,
 although  the  interrelationships were presented. This allowed
 individuals to develop  their own indicators or ignore strong
 indicators in determining whether a particular criterion was met.
 Clearly,  the  criteria needed to be intricately linked to a
 limited set of field indicators to prevent their misuse.

 A  series  of meetings of the Committee were held during the period
 of October 1990 through April 1991. Major revisions to the 1989
 manual  were made  to correct the technically-based shortcomings
 addressed above,  reduce misinterpretations and the possibility of
 erroneous wetland determinations, and better explain the manual's
 usage.
Federal Wetland Definitions

Several definitions have been formulated at the Federal level to
define "wetland" for various laws, regulations, and programs.
These definitions are cited below with reference to their guiding
document along with a few comments on their key elements.

Section 404 of the Clean Water Act

The following definition of wetland is the regulatory definition
used by the EPA and CE for administering the Section 404 permit
program:

Those areas that are inundated or saturated by surface or
groundwater at a frequency and duration sufficient to support,
«md that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil
conditions.  Wetlands generally include swamps, marshes, bogs,
and similar areas (EPA, 40 CFR 230.3, December 24, 1980; and CE,
33 CFR 328.3, November 13, 1986).

This definition emphasizes hydrology, vegetation, and saturated
soils.  The Section 404 regulations also deal with other "waters

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 of  the United States" such as open .water areas, mud flats, coral
 reefs, riffle and pool complexes, vegetated shallows, and other
 aquatic habitats.   Both EPA and CE regulations  (cited above)
 implementing this definition were subject to formal rulemaking
 public notice and comment procedures in accordance with the
 Administrative Procedures Act (5 USC 553).

 Food Security Act of 1985 (as amended)

 The following wetland definition is used by the SCS for
 identifying wetlands on agricultural land in assessing farmer
 eligibility for U.S. Department of Agriculture program benefits
 under the  "Swampbuster" provision of this Act:

 Wetlands are defined as areas that have a predominance of hydric
 soils and  that are  inundated or saturated by surface or ground
 water at a frequency and duration sufficient to support, and
 under normal circumstances do support, a prevalence of
 hydrophytic vegetation typically adapted for life in saturated
 soil conditions, except lands in Alaska identified as having a
 high potential for  agricultural development and a predominance of
 permafrost soils.*  (National Food Security Act Manual, 1988 and
 revised editions)

 *Special Note: The  Emergency Wetlands Resources Act of 1986 also
 contains this definition, but without the exception for Alaska.

 This definition specifies hydrology, hydrophytic vegetation, and
 hydric soils.  Any  area that meets the hydric soil criteria
 (defined by the National Technical Committee for Hydric Soils) is
 considered to have  a predominance of hydric soils.  The
 definition also makes a geographic exclusion for Alaska, so that
 wetlands in Alaska  with a high potential for agricultural
 development and a predominance of permafrost soils are exempt
 from the requirements of the Food Security Act.

 Fish and Wildlife Service's Wetland Classification System

 The FWS in cooperation with other Federal agencies, state
 agencies,  and private organizations and individuals developed a
 wetland definition  for conducting an inventory of the Nation's
 wetlands.  This definition was published in the FWS's publication
 "Classification of  Wetlands and Deepwater Habitats of the United
 States0 (Cowardin,  et al. 1979):

 Wetlands are lands  transitional between terrestrial and aquatic
 systems where the water table is usually at or near the surface
 or the land is covered by shallow water.  For purposes of this
 classification wetlands must have one or more of the following
 three attributes:   (1)  at least periodically, the land supports
 predominantly hydrophytes, (2) the substrate is predominantly
undrained hydric soil,  and (3) the substrate is nonsoil and is

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 saturated with water or covered by.shallow water at some time
 during the growing season of  each year.

 This definition includes both vegetated and nonvegetated
 wetlands,  recognizing that some types of wetlands lack vegetation
 (e.g.,  mud flats,  sand flats, rocky shores, gravel beaches, and
 sand bars).   The classification system also defines "deepwater
 habitats"  as  "permanently flooded lands lying below the deepwater
 boundary of wetlands."  Deepwater habitats include estuarine and
 marine  aquatic beds (similar  to "vegetated shallows" of Section
 404}, although aquatic beds in shallow fresh water are considered
 wetlands.   Open waters below  extreme low water at spring tides in
 salt and brackish  tidal areas and usually below 6.6 feet in
 inland  areas  and freshwater tidal areas are also included  in
 deepwater  habitats.

 Relationship  of Wetlands Identified by this Manual to "Haters of
 the  United States"

 This manual is used to identify and delineate vegetated wetlands.
 Figure  1 presents  a generalized landscape continuum from upland
 to open water (deepwater habitat) showing the relationship of the
 various Federal wetland definitions.  Vegetated wetlands as used
 herein  means  areas  that,  under normal circumstances, usually have
 hydrophytic vegetation,  hydric soil, and wetland hydrology.
 Further, this manual  applies  to areas that are vegetated by
 erect,  self-supporting vegetation (e.g., vegetation extending
 above the water's  surface in  aquatic areas or free-standing on
 soil).

Vegetated wetlands  are a subset of areas regulated as "Waters of
 the  United States"  under Section 404 of the Clean Water Act, and
 one  of  the areas regulated  as "special aquatic sites" under the
 Section 404(b)(l) Guidelines promulgated by the Environmental
 Protection Agency.  Other "special aquatic sites" include
mudflats, vegetated shallows, coral reefs, riffle and pool
 complexes, and sanctuaries  and refuges.  Open water areas are
also part of  the "Waters of the United States."

Vegetated wetlands  are also a subset of those areas designated as
wetlands under the  FWS's "Classification of Wetlands and
 Deepwater Habitats  of  the United States."  The FWS definition of
wetland is used  for National Wetlands Inventory and is
nonregulatory  in nature.  The only differences between wetlands
 identified by  FWS and  this  manual are those aquatic areas 6.6
 feet or less  in depth  that  do not contain emergent vegetation, or
are unvegetateoT.  Such areas are identified as wetlands under the
FWS system, but not under the manual.  However, there are few if
any areas covered by the FWS classification system that are not
covered under  Section  404.  For vegetated wetlands, the FWS
classification system  and this manual are essentially identical.
Ninety-four percent of  all  FWS-classified wetlands in the

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 coterminous United states are vegetated.

 The emphasis of this manual  is on the boundary between wetland
 and upland, since that is the area most often in question and
 where determinations and delineations become most difficult.
 However, wetland determinations in lower wetter areas are
 generally easy to make and seldom in question from a regulatory
 standpoint since both wetland and open water are regulated areas.
 Generally, as one moves up slope, it becomes increasingly more
 difficult to determine what  areas are wetlands.  This manual
 recognizes this fact and requires less rigorous investigation in
 obvious wetland situations than in areas which may be
 questionable. In either situation, however, documentation
 supporting a delineation is  required.

 This manual does not change  the existing definitions of wetlands
 used for Section 404 of the  Clean Water Act and the Swampbuster
 provision of the 1985 Food Security Act, as amended, or the FWS
 wetland definition.  The former two definitions are specific to
 vegetated wetlands or wetlands that are vegetated under normal
 circumstances.  These are the wetlands to which the manual
 applies.  This manual provides for the consistent identification
 and delineation of these wetlands in the field.  Because this
 manual was developed to resolve differences in identifying
 wetlands under these definitions, it is limited to vegetated
 wetlands and does not address nonvegetated wetlands.

 Wetland determinations made  through the use of this manual for
 the purposes of determining  Federal wetland jurisdiction at a
 site are subject to modification in accordance with legal and
 policy considerations of the applicable regulatory program.  For
 example, Section 404 regulatory jurisdiction in wetlands is
 limited to areas that are waters of the United States because
 they have a connection with  interstate or foreign commerce.
Another example is the application of Federal wetland
 jurisdiction on cropland which is subject to agency policy-based
 interpretations of such matters as the relative permanence of the
cropping disturbance and its effect on hydrophytic vegetation
and/or wetland hydrology.  Such matters generally are not
 addressed in this manual; rather, the appropriate agency policy
 should be consulted in conjunction with the manual for wetland
determinations in such areas.

 Summary of Federal Definitions

The CE,  EPA, and SCS wetland definitions include only areas that
are vegetated under normal circumstances, while the FWS
definition encompasses both vegetated and nonvegetated areas.
Except for the FWS inclusion of nonvegetated areas and aquatic
beds in shallow water as wetlands and the exemption for Alaska in
the SCS definition, all four wetland definitions are conceptually
the same; they all include three basic elements - hydrology,
vegetation,  and soils - for  identifying wetlands.                »

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                             PART II.

                 MANDATORY TECHNICAL CRITERIA FOR
                VEGETATED WETLANDS IDENTIFICATION

 Wetland hydrology  is  the  driving  force of wetlands,  vegetated
 wetlands occur in  shallow water,  on  permanently  saturated soils,
 or in  areas  subject to periodic inundation or saturation where
 anaerobic conditions  usually develop due to excess water.
 Certain hydrologic conditions called "wetland hydrology"
 therefore drive the formation of  wetlands and continue to.
 maintain them.  Permanent or periodic wetness is the fundamental
 factor that  makes  wetlands different from uplands  (nonwetlands).

 Although wetland hydrology is the dominant force creating
 wetlands,  long-term records for hydrology typically are not
 available for  identifying the presence of wetland? or for
 delineating  their  upper boundaries.  Consequently  other
 indicators sometimes  must be used to determine whether an area
 meets  the wetland  criteria.  It has  been long recognized that
 various plants  and their  adaptations, certain plant communities,.
 specific soil properties, and particular soil types (e.g., peats,
 mucks,  and gleyed  soils)  can be used to help identify wetlands.
 In addition, there are a  number of hydrologic indicators that can
 be used to help identify  wetlands.

 Existing wetland definitions recognize that wetlands are driven
 by wetland hydrology  (permanent or periodic inundation and/or
 soil saturation) and  that characteristic plants  (hydrophytic
 vegetation)  and soils (hydric soils) are identifiable components
 of vegetated wetlands.  This manual  uses these three components
 as criteria  for vegetated wetland identification.  Field staff
 should  examine  sites  for  indicators  of hydrophytic vegetation,
 hydric  soils, and  wetland hydrology  and document the presence or
 absence of indicators to  the extent  practicable.  At sites where
 wetlands  are obvious  due  to the overwhelming evidence provided by
 one indicator  (e.g.,  large stands of undisturbed salt marsh),
 documentation of the  other indicators, while necessary, need not
 be  as  intensive as in areas where wetlands are not so obvious.
 There are, however, many  other cases where, as one moves toward
 the drier portion  of  the  moisture gradient, rigorous examination
 and documentation  of  soil, vegetation, and hydrology
 characteristics is necessary.  The fact that such wetlands are
 difficult  to identify has no bearing on their status as wetlands.

Under natural,  undisturbed conditions, vegetated wetlands
generally  possess  three characteristics: (1) hydrophytic
vegetation,  (2) hydric soils, and (3) wetland hydrology. These
characteristics and their technical  criteria for identification
purposes are described in the following sections. The three
technical  criteria and their verifying characteristics are
                                                                 %
                                9

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 mandatory.   For an  area  to  be  identified as a wetland, all three
 criteria  must  be met  by  positive  identification of the presence
 of one  or more of the indicators  described below for each
 criterion, with two noted exceptions:  wetlands in disturbed
 conditions such that  indicators of one or more of the criteria
 are absent,*  and wetlands that  are difficult to identify because
 natural fluctuations  in  hydrology or climate or other site-
 specific  or  unusual conditions prohibit their identification
 based on  the standard criteria and indicators.  The procedures to
 be used for  identifying  and delineating wetlands in areas that
 potentially  fall within  each of these categories of exceptions
 are included as an  Appendix to this manual.  Representative
 examples  of  difficult-to-identify wetlands are also discussed in
 this manual.   Included with these examples are situations (e.g.,
 pit and mound  topography) encountered in the field that
 complicate the wetland delineation process.

 The three mandatory technical  criteria are presented below.
 Background information for  each criterion is also provided.

 WETLAND HYDROLOGY CRITERION

 An  area has  wetland hydrology  when it is:

     1.   Inundated and/or  saturated at the surface by surface
          water or  ground water for more than 14 consecutive days
          during the  growing season in most years, or

     2.   Periodically flooded by tidal water in most years.

 Areas meeting  this  criterion also are usually inundated or
 saturated for  variable periods during the non-growing season.
 The  term  "inundated and/or  saturated at the surface1* means the
 soil is inundated or  wet enough at the surface to the extent that
 water reaches  the surface in an unlined borehole or can be
 squeezed  or  shaken  from the soil  at the surface. The growing
 season  is the  interval between 3  weeks before the average date of
 the  last  killing frost in the  Spring to 3 weeks after the average
 date of the  first killing frost in the Fall, with exceptions for
 areas experiencing  freezing temperatures throughout the year
 (e.g., montane,  tundra and boreal areas) that nevertheless
 support hydrophytic vegetation.   The term "in most years" means
 that the  condition  would occur more than 50 years out of 100
 years and, therefore,  represents  the prevailing long-term
 hydrologic condition.

While the above  criterion must be met, many times field staff
will not be present to do wetland determinations at the right
 time of year or  for long enough to directly observe more than two
weeks of  inundation and/or saturation.  Accordingly, field
personnel need to use  indicators  of wetland hydrology as a basis
 for professional  judgment on whether the hydrology criterion is

                                10

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met.

An area meets the wetland hydrology criterion above by direct
measurement of inundation and/or soil saturation or tidal
flooding or as documented by one or more of the  following
indicators (also see note on page 13):

     1.   A minimum of 3 years of hydrologic records (e.g.,
          groundwater well observations following the protocol  on
          page 99,  or tide or stream gauge records)  collected
          during years of normal rainfall (amount and monthly
          distribution)  and correlated with long-term hydrologic
          records for the specific geographical  area that
          demonstrates the area meets the wetland hydrology
          criterion;  or

     2.   Examination of aerial photography (preferably early
          spring or wet  part of the growing season)  for a  minimum
          of 5 years reveals evidence of inundation and/or
          saturation in  most years (e.g.,  3 of 5 years or  6  of  10
          years)  and correlated with long-term hydrologic  records
          for the specific geographical areas demonstrate  that
          the area  meets the wetland hydrology criterion;  or

     3.   One or more primary hydrologic indicators below, which,
          when considered with evidence of frequency and duration
          of rainfall or other hydrologic conditions,  provide
          evidence  sufficient to establish that  more than  14
          consecutive days of inundation and/or  saturation at the
          surface during the growing season occurs,  are
          materially  present:

          a.    Surface water inundation;  or

          b.    Observed  free water at the surface in an unlined
               borehole;  or

          c.    water  can be squeezed or shaken from a soil sample
               taken  at  the soil surface;  or

          d.    Oxidized  stains along the channels of living  roots
               (Oxidized rhizospheres);  or

          e.    Sulfidic  material (distinct hydrogen sulfide,
               rotten egg odor)  within  12  inches of the soil
               surface;  or

          f.    Water-stained leaves,  trunks or stems that  are
               grayish or blackish in appearance as a result of
               being  underwater for significant  periods; or

          g.    Specific  plant  morphological adaptation/responses

                               11

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               to prolonged  inundation or saturation:
               pneumatophores, prop roots, hypertrophied
               lenticels, arenchymous tissues, and floating stems
               and leaves of floating-leaved plants growing in
               the area  (may be observed lying flat on the soil),
               and buttressed trunks or steins.

          Always consider the frequency and duration of these
          primary indicators (or of the wetness that created
          them), and whether significant hydrologic modification
          (e.g., drainage) has effectively removed wetland
          hydrology from the site.  Inundation for seven
          consecutive days during the growing season generally
          results in saturation at the surface for a total of
          more than 14 consecutive days. However, certain
          inundated wetlands (e.g., some prairie potholes, playa
          lakes and vernal pools) exhibit anaerobic conditions  at
          the surface but may not have 7 days of saturation at
          the surface following 7 days of inundation. These and
          other exceptions are addressed on page 31 below as
          difficult-to-identify wetlands.

     4.   If none of the indicators in items 1, 2, or 3 above is
          present, one or more of the following secondary
          hydrologic indicators should be used in conjunction
          with collateral information (e.g., maps) that supports
          a wetland hydrology determination:

          a.   Silt marks (waterborne silt deposits) that
               indicate inundation; or

          b.   Drift lines; or

          c.   Surface-scoured areas; or

          d.   Other common plant morphological
               adaptations/responses to hydrology:  shallow root
               systems and adventitious roots.

          These secondary indicators may only be used in
          conjunction with other collateral information that
          indicates wetland hydrology (e.g., regional indicators
          of saturation, hydrologic gauge data, county soil
          surveys, National Wetlands Inventory maps, aerial
          photographs, or reliable persons with local knowledge
          of inundation and/or saturated conditions). This type
          of information may also can be used to support
          determinations based on the primary indicators listed
          above.

NOTE:  IN ADDITION, CERTAIN SEASONALLY-SATURATED WETLANDS MAY
LACK THE ABOVE HYDROLOGIC INDICATORS DURING A PORTION OF THE

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 GROWING SEASON DUE  TO  SEASONAL  DRYNESS OR OTHER NORMAL HYDROLOG1C
 FLUCTUATIONS.   SUCH AREAS ARE LISTED AS DIFFICULT-TO-IDENTIFY
 WETLANDS (See  Page  31).  UNLESS SPECIFICALLY ADDRESSED IN THE
 DIFFICULT-TO-IDENTIFY  OR DISTURBED AREAS SECTIONS OF THE HANUAL,
 AREAS WITHOUT  ANY OF THE ABOVE  HYDROLOGIC INDICATORS ARE
 NONWETLAND.  IN AREAS  OF SUSPECTED SIGNIFICANT HYDROLOGIC
 MODIFICATION,  FOLLOW THE DISTURBED AREA PROCEDURES TO DETERMINE
 IF WETLAND HYDROLOGY STILL EXISTS PAGE 41.

 Wetland Hydrology Background

 The driving  force creating wetlands is "wetland hydrology," that
 is, permanent  or periodic inundation, or soil saturation for a
 significant  period  (two weeks or more) during the growing season.
 Many  wetlands  are found along rivers, lakes, and estuaries where
 flooding is  likely  to  occur, while other wetlands form in
 isolated depressions surrounded by upland where surface water
 collects.  Still others develop on slopes of varying steepness,
 in  surface water drainageways,  or where ground water discharges
 to  the  land  surface in spring or seepage areas. Thus, landscape
 position provides much insight  into whether an area is likely to
 be  subjected to wetland hydrology.

 Permanent or periodic  inundation, or soil saturation at the
 surface,  at  least seasonally, are the driving forces behind
 wetland formation.  The presence of water in the soil for two
 weeks or more  during the growing season typically creates
 anaerobic conditions,  which affect the types of plants that can
 grow  and the types  of  soils that develop.  These conditions hold
 true  for most  wetlands, especially those at the upper end of the
 soil  moisture  gradient.  Anaerobiosis does not necessarily occur
 in  all  wetlands and those where it may not occur include
 vegetated sand bars, seepage areas, springs, and the upper edges
 of  salt marshes.  These exceptions are addressed below as
 difficult-to-identify  wetlands.  Wetlands have at least a
 seasonal  or  periodic abundance  of water.  For example, this water
 may come from  direct precipitation, overbank flooding, surface
 water runoff due to precipitation or snow melt, ground water
 discharge, tidal flooding, irrigation, or other human-induced
 activities.  The frequency and  duration of inundation and soil
 saturation vary widely from permanent flooding or saturation to
 irregular flooding  or  saturation.  Of the three technical
 criteria for wetland identification, wetland hydrology is often
 the least exact and most difficult to establish in the field, due
 largely to annual,  seasonal, and daily fluctuations.

Numerous  factors influence the  wetness of an area, including
precipitation,  stratigraphy, topography, soil permeability, and
plant cover.   The frequency and duration of inundation or soil
saturation are  important in separating wetlands from nonwetlands.
Areas of  lower  elevation in a floodplain or marsh usually have
longer duration of  inundation and saturation and often more

                                13

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 frequent  periods  of  these  conditions than most areas at higher
 levels.   Floodplain  configuration may significantly affect the
 duration  of  inundation by  facilitating rapid runoff or by causing
 poor  drainage.

 Soil  permeability related  to the texture of the soil also
 influences the duration of inundation or soil saturation.  For
 example,  clayey soils absorb water more slowly than sandy or
 loamy soils, and  therefore have slower permeability and remain
 saturated much longer.

 Type  and  amount of plant cover affect both the degree of
 inundation and the duration of saturated soil conditions. Excess
 water drains more slowly in areas of abundant plant cover,
 thereby increasing duration of inundation or soil saturation. On
 the other hand, transpiration rates are higher in areas of
 abundant  plant cover, which may reduce the duration of soil
 saturation.

 To determine whether the wetland hydrology criterion is met, one
 should consider recorded data, aerial photographs, and observed
 field conditions  that provide direct or indirect evidence of
 inundation or soil saturation.  Prolonged saturation often leaves
 evidence  of such  wetness in the soil (e.g., sulfur odor) and
 these properties  are useful for verifying wetland hydrology
 provided  the area's  hydrology has not been significantly modified
 on-site or upstream  in the  watershed.  If the hydrology has been
 significantly disturbed, particular care must be taken in
 assessing the wetland hydrology criterion; refer to disturbed
 area  procedures (p.  41) to  determine whether wetland hydrology
 still  exists.

 Measuring Wetland Hydrology

 In certain instances, especially disturbed situations, it may be
 necessary to determine an  area's hydrology by actively collecting
 on-site hydrologic data from direct measurements or observations.
 The duration and  frequency  of inundation by flooding may be
 established by evaluating  long-term stream or tide gauge data or
 by examining aerial  photos  covering at least a 5-year period and
 comparing results with the wetland hydrology criterion.
 Saturation at the surface may be determined by making
 observations in an unlined borehole and establishing whether or
 not the soil is saturated at the surface for more than 14 days
 during the growing season.  A procedure for this is presented in
 the Disturbed Areas  section of the manual (p. 41). In general, if
 soil  saturation is observed at the surface for more than 14 days
during the growing season wetland hydrology probably exists.
 Interpretation of the above observations, however, must always be
done with consideration of  recent rainfall conditions (e.g.,
within the past few  weeks)  as well as the long-term rainfall
patterns  (e.g.,  abnormally wet or dry periods)  preceding and

                               14

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 during the time  the  hydrologic data were recorded.

 Historical Recorded  Hydrologic Data

 Historical recorded  hydrologic data usually provide both short-
 and long-term  information on the frequency and duration of
 flooding,  but  little or no  information on soil saturation
 periods.   Historical recorded data include stream gauge data,
 lake gauge data, tide gauge data, flood predictions, and .
 historical flood records.  Use of these data is commonly limited
 to  areas adjacent to streams and other similar areas.  Recorded
 data may be available from the following sources: (1) CE district
 offices  (data  for major waterbodies and for site-specific areas
 from planning  and design documents),  (2) U.S. Geological Survey
 (stream and tidal gauge data), (3) National Oceanic and
 Atmospheric Administration  (tidal gauge data), (4) State, county
 and  local  agencies (flood data), (5)  SCS state offices  (small
watershed  projects and water table study data), and  (6) private
 developers or  landowners (site-specific hydrologic data, which
 nay  include water table or groundwater well data).

Aerial Photographs

Aerial photographs may provide direct evidence of inundation or
 soil saturation  at the surface in an  area. Inundation (flooding
or ponding) is best  observed during the early spring in temperate
and boreal  regions when snow and ice  are gone and leaves of
deciduous  trees  and  shrubs are not yet fully developed. This
allows detection of  wet soil conditions that would be obscured by
i:he tree or shrub canopy at full leaf-out. For marshes, this
reason of  photography is also desirable, except in regions
characterized by distinct dry and rainy seasons, such as southern
Florida and California. Wetland hydrology would be best observed
during the  wet season in these latter areas.

It is most  desirable to examine several consecutive years of
oarly spring or  wet  season aerial photographs to document
evidence of wetland  inundation or soil saturation. In this way,
the effects of abnormally dry or wet  springs, for example, may be
ninimized.  in interpreting aerial photographs, it is important to
taow the antecedent  weather conditions.  This will help eliminate
potential misinterpretations caused by abnormally wet or dry
periods.   Contact the U..S.  Weather Service for historical weather
records or  the U.S.  Geological Survey for hydrologic records.
Aerial photographs for agricultural regions of the country are
often available  at county offices of  the Agricultural
Stabilization and Conservation Service.
                                15

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Field Observations

Direct Evidence of Water

At certain tines of the year in wetlands, and in certain types of
wetlands at most tines, wetland hydrology is quite evident, since
surface water or saturated soils (e.g., soggy or wetter
underfoot) may be observed.  The most obvious and revealing
hydrologic indicator nay be sinply observing the areal extent of
inundation. However, both seasonal conditions and recent weather
conditions must be considered when observing an area because they
can affect the presence of surface water on wetland and
nonwetland sites.  In many cases, soils saturated at the surface
are obvious, since the ground surface is soggy or mucky under-
foot.

To observe free water at the surface it may be necessary to dig a
hole and observe the level at which water stands in the hole
after sufficient time has been allowed for water to drain into
the hole.  In some cases, the upper level at which water is
flowing into the hole can be observed by examining the walls of
the hole.  This level may represent the depth to the water table.
In some heavy clay soils, however, water may not rapidly
accumulate in the hole even when the soil is saturated,  when
attempting to observe free water in a bore hole, adequate time
should be allowed for water in the hole to reach equilibrium with
the water table.

Soil saturation at the surface may be detected by a "squeeze
test" or "shake test" which involve taking a surface soil sample
and squeezing or shaking the sample.  If water can be extracted,
the soil is considered saturated at the surface.

When evaluating soil saturation, both the season of the year and
the preceding weather conditions must be considered, since excess
water may not be present during parts of the growing season in
some wetlands due to high evaporation and plant transpiration
rates which effectively lower the water table.  At such times,
other indicators of wetland hydrology may be present.

Other Signs of Wetland Hydrology

It is not necessary to observe inundation or saturation at the
time of field inspection to identify wetland hydrology so long as
indicators are sufficient to demonstrate to field personnel that
the wetland hydrology criterion on page 10 is met.  Other signs
of wetland hydrology may be observed, e.g., oxidized rhizospheres
(root channels)  and water-stained leaves or stems.

Some plants are able to survive saturated soil conditions (i.e.,
a reducing environment) because they can transport oxygen to
their root zone.  Iron oxide concretions (orangish or reddish

                                16

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 brown  in color) may  form along the channels of living roots and
 rhizomes creating oxidized rhizospheres that provide evidence of
 soil saturation  (anaerobic conditions) for a significant period
 during the growing season.  Ephemeral or temporary oxidized
 rhizospheres may develop after abnormally heavy rainfall periods.
 Consequently, oxidized rhizospheres are most meaningful when
 observed with other  wetland indicators especially in undrained
 soils  displaying diagnostic hydric soil properties.

 Forested wetlands that are inundated earlier in the year will
 frequently have trees and shrubs with water-stained trunks or
 stems  if flooded for long periods, or water-stained leaves in
 depressions on the forest floor.  The stems are usually black-
 colored to the normal high water mark.  The leaves are generally
 grayish or blackish  in appearance, darkened from being underwater
 for significant periods.

 Other  signs that may reflect wetland hydrology include water
 marks,  drift lines,  water-borne deposits, surface-scoured areas,
wetland drainage patterns, and certain plant morphological
 adaptations.

     (1)  Water marks are found most commonly on woody vegetation
     or fixed objects (e.g., bridge pillars, buildings, and
     fences) but may also be observed on other vegetation. They
     often occur as  dark stains on bark or other fixed objects.

     (2)  Drift lines are typically found adjacent to streams or
     other sources of water flow in wetlands and often occur in
     tidal marshes.  Evidence consists of deposition of debris in
     a line on the wetland surface or debris entangled in
     aboveground vegetation or other fixed objects.  Debris
     usually consists of remnants of vegetation (branches, stems,
     and leaves), litter, and other water-borne materials often
     deposited more-or less parallel to the direction of water
     flow.   Drift linen provide an indication of the minimum
     portion of the area inundated during a flooding event; the
     maximum level of inundation is generally at a higher
     elevation that  indicated by a drift line.  The drift lines
     in tidal wetlands are often referred to as "wrack
     lines."

     (3)  Water-borne deposits of mineral or organic matter may be
     observed on plants and other objects after inundation.  This
     evidence may remain for a considerable period before it is
     removed by precipitation or subsequent inundation.  Silt
     deposition on vegetation and other objects provides an
     indication of the minimum inundation level.  When the
     deposits are primarily organic (e.g., fine organic material
     and  algae),  the detritus may become encrusted on or slightly
     above  the soil surface after dewatering occurs.  Sediment
     deposits (e.g.,  sandy material)  along streams provide

                               17

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<\f
            evidence of recent overbank flooding.

            (4)  Surface scouring occurs along floodplains where overbank
            flooding erodes sediments (e.g.,  at the bases of trees).
            The  absence of leaf litter from the soil surface is also
            sometimes an indication of surface scouring.   Forested
            wetlands that contain standing waters  for relatively long
            duration will occasionally have areas  of bare or essentially
            bare soil,  sometimes associated with local depressions.

            (5)  Many plants growing in wetlands have developed
            morphological features in response to  inundation or soil
            saturation.   Examples include pneumatophores  (e.g.,  cypress
            knees),  prop roots,  floating stems and leaves,  hypertrophied
            lenticels (oversized stem pore),  aerenchyma (air-filled)
            tissue in roots and stems, buttressed  tree trunks, multiple
            trunks,  adventitious roots,  shallow root systems,
            polymorphic leaves,  inflated leaves, stems or roots.
            Pneumatophores, prop roots,  floating stems and leaves,
            hypertrophied lenticels,  aerenchyma tissue, and buttresssed
            tree trunks develop virtually only in  wetland or aquatic
            environments and therefore are listed  as primary hydrologic
            indicators  in the wetland hydrology criterion.   When these
            features are observed in young plants,  they provide good
            evidence that wetland hydrology exists.   Multiple trunks,
            adventitious roots,  shallow root systems,  polymorphic
            leaves,  inflated leaves,  stems or roots are commonly found
            in many  wetland plants,  yet not exclusive to  them, and
            therefore are listed as secondary hydrologic  indicators  in
            the  wetland hydrology criterion and indicate  wetlands only
            when accompanied by other collateral information that
            indicates wetland hydrology.


      HYDROPHYTIC VEGETATION CRITERION

      An area meets the hydrophytic vegetation criterion when,  under
      normal  circumstances:

            (1)  more than 50 percent of the dominant species from all
      strata  are obligate wetland (OBL),  facultative wetland (FACW),
      and/or  facultative (FAC)  species,  or

            (2)  a frequency analysis of all  species within the community
      yields  a  prevalence index value of less than 3.0 (where OBL =
      1.0,  FACW - 2.0,  FAC » 3.0,  FACU - 4.0,  and UPL -  5.0).

      NOTE: WETLAND TYPES THAT MAY HAVE VEGETATION THAT  DOES NOT MEET
      THIS  CRITERION ARE LISTED AS DIFFICULT-TO-IDENTIFY WETLANDS (SEE
      PAGE  31).   AREAS  WHERE THE VEGETATION HAS BEEN REMOVED WILL
      GENERALLY MEET THE HYDROPHYTIC VEGETATION CRITERIA IF THEY ARE
      CAPABLE OF SUPPORTING SUCH VEGETATION.  (SEE DISTURBED AREAS

                                      18

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 SECTION,  PAGE 41)

 For each  stratum (e.g.,,  tree,  shrub,  and herb)  in the plant
 community,  dominant species are determined by ranking all species
 in descending order of dominance (e.g., areal cover or basal
 area)  and cumulatively totaling species until they exceed 50
 percent of the total dominance measure  (e.g., total areal
 coverage  or total  basal  area for a  sample plot).  All species
 that contribute to exceeding the 50 percent  level are considered
 dominant  species.   Any additional species comprising 20 percent
 or more of the total dominance measure for the  stratum is also
 considered a dominant species.   All dominants,  regardless of
 stratum,  are treated equally in determining  the presence of
 hydrophytic vegetation.   A valid stratum for identifying
 dominants in the plant community must have at least 5 percent
 areal  cover within the observation  area  (e.g.,  plot).

 Hydrophytic Vegetation Background

 The term  "hydrophytic vegetation" describes  plants that live in
 conditions  of excess wetness.   For  purposes  of  this manual,
 hydrophytes are defined,  as macrophytic plant life growing in
 water  or  on submerged substrates, or  in soil or on a substrate
 that is at  least periodically  anaerobic  (deficient in oxygen) as
 a  result  of excessive water content.  All plants growing in
 wetlands  have adapted in one way or another  to  life in
 permanently or periodically inundated or saturated soils.  Some
 plants have developed structural or morphological adaptations to
 inundation  or saturation,  while others have  broad ecological
 tolerances  (Tiner,  1991).   Some of  these features are used as
 indicators  of wetland hydrology in  this manual  (see hydrology
 criterion page 10),  since they are  a  response to inundation
 and/or soil saturation.   Probably all plants growing in wetlands
 possess physiological mechanisms to cope with periodic anaerobic
 soil conditions or  1-ife  in water.   Because they are not
 observable  in the  field,  physiological and reproductive
 adaptations are not included in this  manual.

 Persons making wetland determinations should be able to identify
 at  least  the dominant wetland  plants  in each stratum (layer of
 vegetation)  of a plant community.   Plant identification requires
 the  use of  field guides  or more technical taxonomic manuals (see
Appendix  	 for sample list).   When necessary,  seek help in
 identifying difficult species.   Once  a plant is identified to
genus  and species,  consult the appropriate Federal list of plants
 that occur  in wetlands to determine the "wetland indicator
status" of  the plant (see explanation below).   This information
will be used to help determine whether the hydrophytic vegetation
criterion is met.

One should  also become familiar with the technical literature on
wetlands,  especially for  one's  geographic region.  Sources of
                                                                 ^
                                19

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 available  literature  include: taxonomic plant manuals and field
 guides; scientific  journals dealing with botany, ecology, and
 wetlands in particular; technical government reports on wetlands;
 proceedings of wetland workshops, conferences, and symposia; and
 the  FWS'S  national-  wetland plant database, which contains habitat
 information on about  7,000 plant species.  Appendix 	 presents
 examples of the  first four sources of information.  In addition,
 the  FWS's  National  Wetlands Inventory (NWI) maps provide
 information on locations of hydrophytic plant communities that
 can  be studied in the field to improve one's knowledge of such
 communities in particular regions.

 If all wetland plant  species grew only in wetlands, plants alone
 could be used to identify and delineate wetlands.  However, of
 the  nearly 7,000 vascular plant species which have been found
 growing in U.S.  wetlands (Reed 1988), only about 27 percent are
 "obligate  wetland"  species that nearly always occur in wetlands
 under natural conditions.  This means that the majority of plant
 species growing  in  wetlands also grow in nonwetlands to varying
 degrees. These plants may or may not be hydrophytes depending on
 where they are growing.  This variability in habitat occurrence
 causes certain difficulties in identifying wetlands from a purely
 botanical  standpoint  in many cases. This is a major reason for
 evaluating soils and  hydrology when identifying wetlands.

 National List of Wetland Plant Species

 The  FWS in cooperation with CE, EPA, and SCS has published the
 "National  List of Plant Species That Occur in Wetlands" from a
 review of  the scientific literature and review by selected
 wetland experts  and botanists (Reed 1988).  The list separates
 vascular plants  into  four basic groups,  commonly called "wetland
 indicator  status," based on a plant species' frequency of
 occurrence in wetlands: (1) obligate wetland plants (OBL) that
 occur almost always'(estimated probability >99%) in wetlands
 under natural conditions; (2) facultative wetland plants (FACW)
 that usually occur  in wetlands (estimated probability 67-99%),
 but occasionally are  found in nonwetlands; (3) facultative plants
 (FAC) that are nearly equally likely to occur in wetlands or
 nonwetlands (estimated probability 34-66%); and (4) facultative
 upland plants (FACU)  that usually occur in nonwetlands (estimated
 probability 67-99%),  but occasionally are found in wetlands
 (estimated probability 1-33%).  If a species occurs almost always
 (estimated probability >99%) in nonwetlands under natural
 conditions, it is considered an obligate upland plant (UPL).
These latter plants do not usually appear on the wetland plant
 list; they are listed only in some regions of the country.  If a
species is not on the list, it is presumed to be an obligate
upland plant,  yet be  advised that the list intentionally does not
 include nonvascular plant species (e.g., algae and mosses) or
epiphytic  plants.  These omitted plants should not be considered
 in determining whether the hydrophytic vegetation criterion is

                               20

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 met,  unless  one  has  particular knowledge of their frequency of
 occurrence in wetlands.  Also be sure to check for synonyms in
 plant scientific names,  since the nomenclature used in the list
 varies for some  species  from that used in regional taxonomic
 manuals or commonly  used plant identification field guides.

 The  "National List of Plant Species That Occur in Wetlands" has
 been  subdivided  into regional and state lists.  There is a formal
 procedure to petition the interagency plant review committee for
 making additions, deletions, and changes in indicator status.
 Since the lists  are  periodically updated, the U.S. Fish and
 Wildlife Service should  be consulted to be sure that the most
 current version  is being used for wetland determinations.' The
 appropriate  plant list for a specific geographic region should be
 used  when making a wetland determination and evaluating whether
 the hydrophytic  vegetation criterion is satisfied. (Note; The
 "National List of Plant  Species that Occur in Wetlands" uses a
 plus  (+) sign or a minus (-) sign to signify a higher or lower
 portion of a particular  wetland indicator frequency for the three
 facultative-type indicators; for purposes of identifying
 hydrophytic vegetation according to this manual, however, FACW+,
 FACW-,  FAC+, and FAC- are included as FACW and FAC, respectively,
 in the  hydrophytic vegetation criterion.)

 Dominant Vegetation

 Dominance as used in this manual refers strictly to the spatial
 extent  of a species  that is directly discernable or measurable in
 the field.  When identifying dominant vegetation within a given
 plant community, one should consider dominance within each valid
 stratum.  All dominants  are treated equally in characterizing the
 plant community  to determine whether the hydrophvtie vegetation
 criterion is met.  For each stratum (e.g., tree, shrub, and herb}
 in the  plant community,  dominant species are determined by
 ranking all species.in descending order of dominance (e.g., areal
 cover or basal area) and cumulatively totaling species until they
 exceed  50 percent of the total dominance measure  (e.g., total
 areal coverage or total  basal area for a sample plot).  All
 species that contribute  to exceeding the 50 percent level are
 considered dominant  species, along with any additional species
 comprising 20 percent or more of the total dominance measure for
 the stratum.

Vegetative strata for which dominants should be determined may
 include: (1) tree (>5.0  inches diameter at breast height  (dbh)
 and 20  feet or taller);  (2) sapling (0.4 to <5.0 inches dbh and
 20 feet or taller);  (3)  shrub (usually 3 to 20 feet tall
 including multi-stemmed, bushy shrubs and small trees below 20
 feet tall);  (4)   woody vine; and (5) herb (herbaceous plants
 including graminoids, forbs, ferns, fern allies, herbaceous
vines,  and tree  seedlings).  Bryophytes (mosses, horned
 liverworts, and  true liverworts) should be sampled as a separate
                                                                 *
                                21

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stratum in certain wetlands, including shrub bogs, moss-lichen
wetlands, and wooded swamps where bryophytes are abundant and
represent an important component of the community,  in most other
wetlands, bryophytes should be included within the herb stratum
due to their scarcity.  In order to be counted as a valid
stratum, a stratum must have at least 5 percent areal cover for
the area under evaluation, e.g., 5-foot radius plot for herbs and
30-foot radius plot for woody plants.  This minimum does not
apply to woody vines; use professional judgment to determine
whether they are abundant enough to count as a stratum. Always
document the omission of any such stratum from the final
evaluation regarding the hydrophytic vegetation criterion.

There are many ways to estimate or quantify dominance measures.
Dominant species for each stratum can be determined by estimating
one or more of the following, as appropriate: (1) relative basal
area (trees); (2) areal cover (all strata); or (3) stem density
(all strata).  Direct measurement of tree diameters at breast
height provides data for calculating basal area for determining
dominant tree species. Alternatively, one may wish to perform a
frequency analysis of all species within a given plant community.
These are accepted methods for evaluating plant communities. Part
III of this manual provides recommended approaches for sampling
or analyzing the plant community.


HYDRIC BOIL CRITERION

An area has hydric soil when it has either:

     1.   Soils listed by series in "Hydric Soils of the United
          States" (1987 and amendments), or

     2.   Organic soils (Histosols, except Folists), or

     3.   Mineral soils classifying as Sulfaquents, Kydraquents,
          or Histic subgroups of Aquic suborders, or

     4.   Other soils that meet the National Technical Committee
          for Hydric Soils' criteria for hydric soil.

An area meets the hydric soil criterion when it has one or more
of the following:

     1.   Where soil survey maps are available,  the subject area
          is within:

          a.   a hydric soil map unit identified on the county
               list of hydric soil map units that is verified by
               landscape position and soil morphology against the
               series description of the hydric soil, or

                                                                 »
                               22

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           b.    a soil map unit with hydric  soil  inclusions
                identified on the county list  of  hydric  soil map
                units, and the landscape position of the inclusion
                and the soil  morphology  for  the identified soil
                series as a hydric soil  inclusion are verified,
                or,  if no series is designated, then either:

               1}   the soil,  classified  to the series level, is on
                   the national list of  hydric soils, or

               2)   the soil,  classified  according to "Soil
                   Taxonomy",  is a Histosol  (except Folists),
                   Sulfaquent,  Hydraquent, or  Histic Subgroup  of
                   Aquic Suborders,  or

               3}   regional indicators of significant soil
                   saturation  are materially present; or

      2.  Where  soil  maps are not available,  and the landscape
          position  is likely  to contain hydric soil (e.g.,
          floodplain,  depression,  or seepage  slope), subject  area
          has  either:

          a.   the  soil,  classified to the series level,  is on the
               national list of hydric soils,  or

          b.   the soil,  classified according  to  "Soil Taxonomy",
               is a  Histosol  (except Folists), Sulfaguent,
               Hydraquent,  or  Histic Subgroup  of  Aquic Suborders,
               or

          c.   regional indicators of significant soil saturation
               are materially  present.

Hydric Soil Background

Wetlands typically  possess hydric soils, but  not all areas mapped
as a hydric soil series  are wetlands (e.g., dry  phases  that were
never wetlands and  drained phases that  represent former
wetlands).  Hydric  soils are  defined as soils that are  saturated,
1:1coded, or ponded  long  enough during the growing season to
develop anaerobic conditions  in the upper part (U.S.D.A. Soil
Conservation Service  1987). These soils usually  support
hydrophytic vegetation under  natural (unaltered)  conditions.

National and State  Hydric  Soils Lists

The SCS in cooperation with the National Technical Committee  for
Hydric Soils (NTCHS) has prepared a list of the  Nation's hydric
s.oils (U.S.D.A. Soil Conservation Service 1987).  State  lists  have
also been prepared  for statewide use. The national and  state
lists identify those soil  series that typically  meet the NTCHS
                                                                  1
                                23

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hydric soil criteria according to available soil interpretation
records in SCS's soils database. These lists are periodically
updated, so make sure the list being used is the current one. The
list, while extensive, does not include all series that nay have
hydric members; these soils may be determined as hydric when they
have evidence of wetland hydrology and hydrophytic vegetation.
The lists facilitate use of SCS county soil surveys for
identifying potential wetlands. One roust be careful, however, in
using the soil survey, because a soil map unit of a nonhydric
soil may have inclusions of hydric soil that were not delineated
on the map or vice versa. Also, some map units (e.g., alluvial
land, swamp, tidal marsh, muck and peat) may be hydric soil
areas, but are not on the hydric soils lists because they were
not given a series name at the time of mapping.  These soils meet
the NTCHS criteria for hydric soils.

County Hydric Soil Map Unit Lists

Because of the limitations of the national and state hydric soil
lists, the SCS prepared lists of hydric soil map units for each
county in the United States. These lists may be obtained from
local SCS district offices and are the preferred lists to be used
when using soil survey maps.  The hydric soil map unit lists
identify all map units that are either named by a hydric soil or
that have a potential of having hydric soil inclusions.  The
lists provide the map unit symbol, the name of the hydric soil
part or parts of the map unit, information on the hydric soil
composition of the map unit, and probable landscape position of
hydric soils in the map unit delineation.  The county lists also
include map units named by miscellaneous land types or higher
levels in "Soil Taxonomy" that meet NTCHS hydric soil criteria.

Soil Surveys

The SCS publishes soil surveys for areas where soil mapping is
completed. Soil surveys that meet standards of the National
Cooperative Soil Survey (NCSS) are used to identify areas of
hydric soils. These soil surveys may be published (completed) or
unpublished (on file at local SCS field offices). Published soil
surveys of an area may be obtained from the local SCS field
office or the Agricultural Extension Service office. Unpublished
maps may be obtained from the local SCS district office.

The NCSS maps contain four kinds of map units: (1) consociations,
(2) complexes, (3) associations, and (4) undifferentiated groups.
(Note: Inclusions of unnamed soils may be contained within any
map unit; the inclusions are listed in the description of the
soil map unit in the soil survey report.)  Consociations are soil
map units named for a single kind of soil (taxon) or
miscellaneous area. Seventy-five percent or more of the area is
composed of the taxon for which the map unit is named  (and
similar taxa). When named by a hydric soil, the map unit is

                                24

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 considered a hydric soil  nap unit  for wetland determinations.
 However,  snail areas within these  nap units generally too snail
 to be napped separately (sone areas  are  identified by "wet spot"
 symbols)  nay not be hydric and should be excluded in delineating
 wetlands.

 Complexes and associations are soil  nap  units named by two or
 nore  kinds of soils (taxa)  or miscellaneous areas. If all taxa
 for which these map units are naned  are  hydric, the soil map unit
 nay be considered a hydric soil map  unit for wetland
 determinations.  If only part of the  map  unit is made up of hydric
 soils,  only those portions of the  map unit that are hydric are
 considered in wetland determinations.

 Undifferentiated groups are soil nap units naned by two or nore
 kinds  of  soils or miscellaneous areas. The soils in these map
 units  do  not  always occur together in the sane nap unit but are
 included  together because sone common feature such as steepness
 or  flooding determines use and management. These map units are
 distinguished from the others in that "and" is used as a
 conjunction in the nane,  while dashes are used for conplexes and
 associations.  If all conponents are  hydric, the nap unit nay be
 considered a  hydric soil  nap unit. If one or nore of the soils
 for which  the unit is naned are nonhydric, each area must be
 examined  for  the presence of hydric  soils.

 Use of County Hydric Soils Map Unit  Lists and Soil Surveys

 The county hydric soils nap unit list and soil surveys should be
 used to help  determine if the hydric soil criterion is met in a
 given area. When making a wetland  determination, one should first
 locate the area  of concern on a soil survey map and identify the
 soil nap units for the area.  The county  list of hydric soil nap
 units should  be  consulted to determine whether the soil nap units
 are hydric or potentially hydric.  If hydric soil nap units or map
 units with hydric soil  inclusions  are noted, then one should
 exanine the soil  in the field and  compare its morphology with the
 corresponding hydric soil  description in the soil survey report.
 If  the soil's characteristics natch  those described for hydric
 soil, then the hydric soil  criterion is  net, unless the soil has
 been effectively drained.   If soils  have been significantly
 disturbed,  either mechanically or  hydrologically, refer to the
 disturbed  areas  section on  page 41.  In the absence of site-
 specific information,  hydric soil's also  may be recognized by
 certain soil  properties caused by  wetland hydrology conditions
 that make  soil neet the NTCHS criteria for hydric soils.

General Characteristics of  Hydric  Soils

 Due to their wetness  during the growing  season, hydric soils
usually develop  certain morphological properties that can be
 readily observed  in the field. Anaerobic soil conditions usually
                                                                 *
                                25

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 occur due  to  excessive wetness and they typically lower the soil
 redox potential  causing a chemical reduction of some soil
 components, mainly  iron oxides and manganese oxides. This
 reduction  affects solubility, movement, and aggregation of these
 oxides which  is  reflected in the soil color and other physical
 characteristics  that  are usually indicative of hydric soils.

 Soils are  separated into two major types on the basis of material
 composition:  organic  soil and mineral soil. In general, soils
 with  at  least 16 inches of organic material in the upper part of
 the soil profile and  soils with organic material resting on
 bedrock  are considered organic soils  (Histosols). Soils largely
 composed of sand, silt, and/or clay are mineral soils. For
 technical  definitions, see "Soil Taxonomy", U.S.D.A. Soil Survey
 staff 1975.

 Organic  Soils

 Accumulation  of  organic matter in most organic soils results from
 anaerobic  soil conditions associated with long periods of
 submergence or soil saturation during the growing season. These
 saturated  conditions  impede aerobic decomposition (oxidation) of
 the bulk organic materials such as leaves, stems, and roots, and
 encourage  their  accumulation over time as peat or muck.
 Consequently, most  organic soils are characterized as very pporly
 drained  soils. Organic soils typically form in waterlogged
 depressions,  and peat or muck deposits may range from about 1.5
 feet  to  more  than 30  feet deep. Organic soils also develop in
 low-lying  areas  along coastal waters where tidal flooding is
 frequent.

 Hydric organic soils are subdivided into three groups based on
 the presence  of  identifiable plant material: (1) muck (Saprists)
 in which two-thirds or more of the material is decomposed and
 less  than  one-third of the plant fibers are identifiable; (2)
 peat  (Fibrists)  in which less than one-third of the material is
 decomposed and more than two-thirds of the plant fibers are still
 identifiable; and (3) mucky peat or peaty muck (Hemists) in which
 the ratio  of  decomposed to identifiable plant matter is more
 nearly even (U.S.D.A. Soil Survey Staff 1975). A fourth group of
 organic  soils  (Folists) exists in tropical and boreal mountainous
 areas where precipitation exceeds the evapotranspiration rate,
 but these  soils  are never saturated for more than a few days
 after heavy rains and thus do not develop under hydric
 conditions. All  organic soils, with the exception of the Folists,
 are hydric soils.

Hydric organic soils can be easily recognized as black-colored
muck to  dark brown-colored peat. Distinguishing mucks from peats
based on the  relative degree of decomposition is fairly simple.
 In mucks (Saprists), almost all of the plant remains have been
decomposed beyond recognition. When rubbed, mucks feel greasy and
                                                                 »
                                26

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 leave hands dirty,  in contrast,  the  plant  remains  in peats
 (Fibrists)  show little decomposition and the original constituent
 plants can  be recognized fairly  easily. When the organic matter
 is rubbed between the fingers, most  plants fibers  will remain
 identifiable,  leaving hands relatively clean. Between the
 extremes of mucks and peats,  organic soils with partially
 decomposed  plant fibers (Hemists) can be recognized. In peaty
 mucks up to two-thirds of the plant  fibers can be  destroyed by
 rubbing the materials between the fingers,  while in mucky peats
 up to two-thirds of the plant remains are  still recognizable
 after rubbing.

 Hydric Mineral  Soils

 When  less organic material accumulates in  soil, the soil is
 classified  as mineral soil.   Some mineral  soils may have thick
 organic surface layers (histic epipedons)  due to heavy seasonal
 rainfall or a high  water table,  yet  these  soils are still
 composed largely of mineral matter  (Ponnamperuma 1972). Mineral
 soils that  are  covered with moving  (flooded) or standing (ponded)
 water for significant periods or are saturated for extended
 periods during  the  growing season meet the NTCHS criteria for
 hydric soils and are classified  as hydric  mineral  soils.  Soil
 saturation  may  result from low-lying topographic position,
 groundwater seepage,  or the presence of a  slowly permeable layer
 (e.g.,  clay, confining layer, confining bedrock, or hardpan).

 The duration and depth of soil saturation  are essential criteria
 for identifying hydric soils  and wetlands.  Soil morphological
 features are commonly used to indicate long-term soil moisture
 regimes (Bouma  1983).  Table 	  lists some of the  more commonly
 observed morphological properties associated with  hydric mineral
 soils having a  Typic Subgroup and Aquic Suborder.

 A thick dark surface, layer, grayish  subsurface and subsoil
 colors,  the presence of orange or reddish  brown (iron) and/or
 dark  reddish brown  or black  (manganese) mottles or concretions
 near  the surface, and the wet condition of the soil may help
 identify the hydric character of many mineral soils. The grayish
 subsurface  and  subsoil colors and thick, dark surface layers are
 the best indicators of current wetness, since the  yellow- or
 orange-colored  mottles are very  insoluble  and once formed may
 remain indefinitely as relict mottles of former wetness (Diers
 and Anderson 1984).

 A, histic  epipedon (organic surface layer)  is evidence of a soil
 meeting  the  NTCHS criteria. It is an 8 to  16 inch  organic layer
 it or  near  the  surface of a hydric mineral  soil that is saturated
with water  for  30 consecutive days or more  in roost years. It
contains  a minimum  of  20  percent organic matter when no clay is
present  or  a minimum  of 30 percent organic  matter  when clay
content  is  60 percent  or  greater. Soils with histic epipedons are

                               27

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 inundated or saturated  for sufficient periods to greatly retard
 aerobic decomposition of  organic natter/ and are considered
 hydric soils.  In  general,  a histic epipedon is a thin surface
 layer of peat or  muck if  the soil has not been plowed (U.S.D.A.
 Soil  Survey  Staff -1975).  Histic epipedons are typically
 designated as O-horizons  (Oa, Oe, or Oi surface layers, and in
 some  cases the terms "mucky11 or "peaty" are used as modifiers to
 the mineral  soil  texture  term, e.g., mucky loam.

 Soil-related Evidence of  Significant Saturation

 Identification of some  wetlands and delineation of the upper
 boundary in  many  wetlands  is not readily accomplished without a
 detailed examination of the underlying soil.  Colors in the soil
 are strongly influenced by the frequency and duration of soil
 saturation which  causes reducing conditions. A gleyed layer and a
 low chroma matrix with  high chroma mottles, near the surface are
 common indicators of hydric soils throughout the county. Other
 soil  markers of significant soil saturation vary regionally.
 These signs  include thick  organic surface layers (> 8 inches),
 gleying,  and certain types of mottling. If significant drainage
 or groundwater alteration  has taken place, then it is necessary
 to determine whether the area in question is effectively drained
 and is now nonwetland or  is only partly drained and remains
 wetland despite some hydrologic modification. Guidance for
 determining  whether an  area is effectively drained is presented
 in the section on disturbed areas (p. 41).

 Soils  saturated for prolonged periods during the growing season
 in most years  are usually  gleyed in the saturated zone.  Gleyed
 layers are predominantly gray in color and occasionally greenish
 or bluish gray. In gleyed  soils, the distinctive colors result
 from  a process known as gleization.  Prolonged saturation of
 mineral  soil converts iron from its oxidized (ferric) form to its
 reduced (ferrous) state. These reduced compounds may be
 completely removed from the soil, resulting in gleying (Veneman,
£t al.  1976).  Mineral soils that are always saturated are
 typically uniformly gleyed throughout the saturated area. Soils
gleyed  to the  surface layer are evidence of wetland hydrology and
 anaerobic soil conditions.  These soils often show evidence of
 oxidizing conditions only  along root channels.  Some nonsaturated
 soils  have gray layers  (E-horizons) immediately below the surface
 layer  that are gray for reasons other than saturation, such as
 leaching  due to organic acids (see Spodosols page 83).

Mineral soils  that are alternately saturated and oxidized
 (aerated)  during  the year  are usually mottled in the part of the
soil that  is seasonally wet.  Mottles are spots or blotches of
different  colors  or shades of colors interspersed with the
dominant  (matrix) color.   The abundance, size, and color of the
mottles usually reflect the  hydrology - the duration of the
saturation period, and indicate whether or not the soil is

                                28

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 saturated for long periods.  Mineral  soils  that are predominantly
 grayish with common or many,  distinct  or prominent brown or
 yellow mottles are usually saturated for long periods during the
 growing season and are hydric soils. Soils that are predominantly
 brown or yellow with gray mottles  are  saturated for shorter
 periods and may be hydric depending  on the depth to the gray
 mottles and the color of the overlying layer. Mineral soils that
 are never saturated are usually bright-colored and are not
 mottled;  they are nonhydric  soils  (Tiner and Veneman 1987).
 Realize,  however,  that in some hydric  soils, mottles may not be
 visible due to masking by organic  matter (Parker, et al. 1984).

 It  is important to note that the gleization and mottle formation
 processes are strongly influenced  by the activity of certain soil
 microorganisms.  These microorganisms reduce iron when the soil
 * ivironment is anaerobic,  that is, when virtually no free oxygen
 is  present,  and when the soil contains organic matter. If the
 soil  conditions are such that free oxygen  is present, organic
 matter is absent,  or temperatures  are  too  low  (below 41 degrees
 Fahrenheit)  to sustain microbial activity,  gleization will not
 proceed and mottles will not form, even though the soil may be
 saturated for prolonged periods of time (Diers and Anderson
 1984).

 Soil  colors as discussed above often reveal much about a soil's
 historical  wetness over the  long term.  Scientists and others
 examining the soil can determine the approximate soil color by
 comparing the soil sample with a Munsell soil color chart. The
 standardized Munsell  soil  colors are identified by three
 components:  hue, value,  and  chroma.  The hue is related to one of
 the main  spectral  colors:  red,  yellow,  green, blue, or purple, or
 various mixtures of these principal  colors. The value refers to
 the degree  of lightness,  while the chroma  notation indicates the
 color strength or  purity.  In  the Munsell soil color book, each
 individual  hue has its own page (Figure 	), each of which is
 further subdivided into units for  value (on the vertical axis)
 and chroma  (horizontal axis).  Although theoretically each soil
 zolor represents a unique combination  of hues, values, and
 shromas,  the number of combinations  common in the soil
 environment usually is limited.  Because of this situation and
 the fact  that accurate reproduction  of each soil color is
 expensive,  the Munsell soil color  book contains a limited number
 of combinations of hues, values, and chromas. The color of the
 soil  matrix or a mottle is determined  by comparing a soil sample
with  the  individual color  chips in the soil color book. The
 appropriate  Munsell color  name can be  read from the facing page
 in the  "Munsell Soil  Color Charts" (Kollmorgen Corporation 1975).
Chromas of  2  or less  are considered  low chromas and are often
diagnostic  of  hydric  soils. Low chroma colors include black,
various shades of  gray,  and the darker shades of brown and red.

Gleying (bluish, greenish, or grayish  colors) in or immediately

                                29

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below th* A-horizon is an indication of a markedly reduced hydric
soil and an area that should meet wetland hydrology in the
absence of significant hydrologic modification. Gleying can occur
in both mottled and unaottled soils. Gleyed soil conditions can
be determined by using the gley page of the "Munsell soil Color
Charts" (Kollmorgen Corporation 1975). NOTE:  GLEYED CONDITIONS
NORMALLY EXTEND THROUGHOUT SATURATED SOILS. BEWARE OF SOILS WITH
GRAY SUBSOILS DUE TO PARENT MATERIALS, SOILS WITH GRAY E-HORIZONS
OR ALBIC HORIZONS DUE TO LEACHING AND NOT TO SATURATION; THESE
LATTER SOILS CAN OFTEN BE RECOGNIZED BY BRIGHT-COLORED LAYERS
BELOW THE E-HORIZON. SEE DISCUSSION ON DIFFICULT-TO-IDENTIFY
WETLANDS SECTION Page 31.

Mineral soils that are saturated for substantial periods of the
growing season, but are unsaturated for some time, commonly
develop mottles. Soils that have brightly colored mottles and a
low chroma matrix are indicative of a fluctuating water table.
The following color features in the horizon immediately below the
A-horizon (or E-horizon, albic horizon) provide evidence of soil
saturation sufficient to be hydric soils and should also meet the
wetland hydrology criterion:

      (1)  Matrix chroma of 2 or less in mottled soils, or

      (2)  Matrix chroma of 1 or less in unmottled soils.

      NOTE: MOLLISOLS HAVE VALUE REQUIREMENTS OF 4 OR MORE AS
      WELL AS CHROMA REQUIREMENTS FOR AQUIC SUBORDERS; SEE
      DIFFICULT-TO-IDENTIFY HYDRIC SOILS FOR OTHER EXCEPTIONS.

The chroma requirements above are for soils in a moistened
condition. Colors noted for dry (unmoistened) soils should be
clearly stated as such. The colors of the topsoil (A-horizon) are
often not indicative of the hydrologic situation because
cultivation and soil enrichment affect the original soil color.
Hence, the soil colors below the A-horizon (and E-horizon, if
present) usually must be examined.

NOTE: BEWARE OF HYDRIC SOILS THAT HAVE COLORS OTHER THAN THOSE
DESCRIBED ABOVE; SEE DIFFICULT-TO-IDENTIFY WETLANDS BELOW.

During the oxidation-reduction process, the iron and manganese in
solution in saturated soils are sometimes precipitated as oxides
into concretions or soft masses upon exposure to air as the soil
dries.  Concretions are local concentrations of chemical
compounds (e.g., iron oxide) in the form of a grain or nodule of
varying size, shape, hardness, and color (Buckman and Brady
1969).  Manganese concretions are usually black or dark brown,
while iron concretions are usually yellow, orange or reddish
brown.  In wetlands, these concretions are also usually
accompanied by soil colors as described above.


                                30

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 DIFPICULT-TO-IDENTIFY WETLANDS

 All wetlands have wetland hydrology, hydric soil, and plants
 adapted to those conditions.  However, there are exceptions where
 evidence of all  three mandatory  criteria  is not readily
 observable,  especially in the drier season of the year or during
 droughts.   A procedure for identifying these difficult-to-
 identify wetlands is  in Appendix 7.  Before using the difficult-
 to-identify procedures, the assumption that an area may be a
 difficult-to-identify wetland must be based on strong well
 documented evidence,  such as:  the area is a wetland type that is
 listed in this manual as  a difficult-to-identify wetland, the
 area is in a landscape position  that is highly likely to support
 wetlands (e.g.,  significant depression or drainageway, or
 adjacency or proximity to a verified wetland or other waterbody),
 the area has vegetation that is  known to  be found in wetlands in
 the local  area,  or the area is underlain  by a soil that is known
 to  support wetlands in the local area.  Wetland types that are
 difficult  to identify are listed below and in Appendix 5.  In
 some of the  below-listed  wetlands, such as playas, prairie
 potholes,  vernal  pools, and pocosins it may be difficult to
 identify more than one of the criteria during dry seasons of the
 year or droughts  even though such wetlands would meet the
 criteria if  visited at the optimal time of year for their
 delineation.  Difficult-to-identify wetlands include the
 following  categories:

 Forested Wetlands

 Some (but  not all) forested wetlands may  be difficult-to-
 identify.  They are found in many parts of the country and meet
 the  wetland  hydrology criterion  by inundation and/or saturation
 at the  surface for more than 14  consecutive days during the
 growing season.   They may be difficult to identify because of
 seasonal fluctuations in  the water table  or drought (e.g., red
 maple swamps  in New England), vegetation  communities that have an
 atypical distribution of  plants  (i.e., comprised of plants that
 also occur in uplands (e.g., hemlock swamps), or soils that are
 not  readily  identifiable  as hydric (e.g., red parent material
 soils.   See Appendix  6).   Forested wetlands typically perform
 important  aquatic functions (e.g., water  quality maintenance,
 stream  discharge  regulation, and groundwater recharge).

 Streamside/Riparian Wetlands

 Streamside and riparian areas may support wetlands that are
 difficult-to-identify.  The rise and fall of stream flow may make
hydrology determinations  difficult during dry seasons or drought.
However, stream gage  data may be available to document normal
hydrologic conditions.  Recent deposits of sediment in river
 channels or on floodplains  may make soils difficult to identify
because soils may  not  have  had time to develop typical indicators
                                                                 *
                                31

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 of  saturation.  Streamside and riparian wetlands typically
 perform  important aquatic functions such as water quality
 maintenance by  filtration of  floodwaters and upland runoff,
 streamflow regulation by storing and slowly releasing floodwaters
 and runoff, and providing aquatic habitats for fish and wildlife.

 Wet Meadows/Prairie Wetlands

 Some wet meadow and prairie wetlands are difficult-to-identify.
 These wetlands  may occur near waterways, in depressions or in
 outwashes in drainageways.  They may not exhibit wetland
 hydrology during dry seasons  or drought.  These wetlands may have
 difficult-to-identify vegetation due to the invasion during dry
 periods  by plants usually found in uplands.  These wetlands may
 perform  aquatic functions such as water quality maintenance and
 groundwater recharge.


 Difficult-to-identify wetlands also include the following
 specific types:

 Pocosins

 The  pocosin wetlands of the Southeast contain broadleaved
 evergreen shrub bogs.  Such bogs typically occur in areas
 characterized by highly organic soils and long hydroperiods
 during which inundation may but does not always occur.  The
 largest  areas of pocosin wetlands occur in the outer Coastal
 Plain of North  Carolina.  Although early settlers used the term
 to depict a variety of swamp  vegetation types, pocosin wetlands
 usually  are described as marshy or boggy shrub areas or flatwoods
 with poor drainage where peaty soils typically support scattered
 pines and a dense growty of shrubs, mostly evergreen (Sharitz and
 Gibbons  1982).  Hydrology of pocosins may not be readily apparent
 due  to the thick underlying peaty soils that may dry out rapidly
 after the early part of the growing season due to
evapotranspiration.  Located  on the Coastal Plain, pocosins
perform  important aquatic functions such as storing rainwater and
 regulating its  discharge into nearby estuaries where aquatic life
 is affected by  fluctuations in streamflow and salinity.  Pocosins
 also function to stabilize nutrients, reducing the potential for
 nutrient overloading in nearby estuaries.

 Playas

 Playas occur in many arid and semiarid regions of the world.
Although occurring throughout much of the western United States,
they are concentrated in the  southern Great Plains as either
ephemeral or permanent lakes  or wetlands.  The topography of roost
playa regions is flat to gently rolling and generally devoid of
drainage.  Playa basins collect water primarily in two peak
periods — May  and September  — as a result of regional

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 convectional  storms.  Wetland hydrology is best characterized by
 examining hydrological  indicators over a multi-year period.
 Playa  basins  may have a dense cover of annual or perennial
 vegetation or may be barren, depending on the timing and other
 factors  such  as precipitation and irrigational runoff.  As with
 potholes,  the process of annual drying in playas enables the
 invasion of FAC, FACU,  and UPL plants during dry periods which
 may persist into other  seasons.  Playas typically are important
 waterfowl habitat.  Additional information to assist in playa
 wetland  identification  is in Appendix 5.

 Prairie  Potholes

 Prairie  potholes are glacially-formed depressional wetlands
 located  in the north central United States and southern Canada.
 Many prairie  potholes are seasonally dry but fill with snowmelt
 and rain early in the growing season.  This is because average
 precipitation is far too sparse to meet the demands of
 evaporation and as a result, some potholes are dry for a
 significant portion of  the year.  The process of annual drying in
 potholes enables the invasion of FAC, FACU, or UPL plant species
 during dry periods which may persist into wet seasons.
 Nevertheless, a variety of vegetation characteristic of a
 freshwater marsh can exist in a prairie pothole with submergent
 and floating  plants in  deeper water, bulrushes and cattails
 closer to  shore, and sedges located toward the upland.  The
 drastically fluctuating climate and alteration for farming have
 resulted in highly disturbed conditions that make wetland
 identification difficult.  Potholes are typically known for
 supporting an abundance of resident and migratory waterfowl.
 Additional  information  to assist in prairie pothole wetland
 identification is in Appendix 5.

Vernal Pools

Vernal pools  are natural wetlands are depressional wetlands that
 are covered by shallow  water for variable periods from winter to
 spring,  but may be completely dry at the surface for most of the
 summer and  fall.  They  hold water long enough to allow some
aquatic  organisms (e.g., salamanders and frogs) to grow and
 reproduce  (complete their life cycles), but not long enough to
permit the  development  of a typical pond or marsh ecosystem.
 Since vernal  pools vary considerably in depth and duration of
both from year to year, within a year, or between different
pools, plant  composition is quite dynamic.  Depending on the
seasonal phase of the pool, plants can range from OBL aquatic
plants to  FAC and FACU  species.  Additional information to assist
 in vernal pool wetland  identification is in Appendix 5.
                                33

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                             FART  III.

 STANDARD METHODS  FOR IDENTIFICATION AND DELINEATION OF WETLANDS

 Four basic approaches for  identifying and delineating wetlands
 have been developed  to cover situations ranging from desk-top or
 office  determinations to highly complex field determinations for
 regulatory purposes.  These methods are the recommended approaches
 that have been  successfully  used  to delineate wetlands by the
 four Federal  agencies.  If  situations require different
 approaches, the reasons for  departing from recommended approaches
 should  be documented.  Remember, however, that any method for
 making  a wetland  determination must consider the three technical
 criteria (i.e., hydrophytic  vegetation, hydric soils, and wetland
 hydrology)  listed in Part  II of this manual. These criteria must
 be met  in order to identify  a wetland. Moreover, procedures for
 determining the wetland boundary  must be consistent with those
 used in this  manual.  In applying  all methods, relevant available
 information on  wetlands in the area of concern should be
 collected and reviewed. Table 	  lists primary data sources.


 Selection of  a  Method

 The  wetland delineation methods presented in this manual can be
 grouped into  two  general types: (1) offsite preliminary
 procedures and  (2) onsite  procedures.  The offsite procedures are
 designed for  use  in  the office for preliminary wetland
 determinations, while onsite procedures are developed for use in
 the  field for definitive wetland  determinations. When an onsite
 inspection is unnecessary  or cannot be undertaken for various
 reasons,  available information can be reviewed in the office to
 make a  preliminary wetland determination. If available
 information is  insufficient  to make a preliminary wetland
 determination or  if  a  definitive  wetland determination or wetland
 boundary must be  established, (e.g., for determining whether or
 not  there is  jurisdiction  or the  boundaries of jurisdiction under
 a Federal wetland regulatory program), an onsite inspection
 should  be conducted.   For  determining whether or not an area is
 subject to Clean  Water Act jurisdiction, an onsite inspection is
 usually necessary.   Depending on  the field information needed or
 the  complexity  of the  area,  one of three basic onsite methods may
 be employed:  (1)  routine,  (2) intermediate-level, or (3)
 comprehensive.  Table  	 presents some examples of when to use
 each method.

The  routine method is  designed for areas equal to or less than
 five  acres in size or  larger areas with homogeneous vegetation.
For  areas greater than five  acres in size or other areas of any
 size  that are highly diverse in vegetation, the
 intermediate-level method  or the  comprehensive method should be
applied, as necessary*  The  comprehensive method is applied to
situations requiring detailed documentation of vegetation, soils,

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 and hydrology.   Assessments  of  significantly disturbed sites will
 often require  intermediate-level  or. comprehensive determinations
 as well  as  some  special  procedures. In other cases where natural
 conditions  make  wetland  identification difficult, special
 procedures  for difficult-to-identify wetland determinations have
 been developed.  Wetland delineators should become well
 acquainted  with  these types  of  situations  (e.g., disturbed and
 difficult-to-identify wetlands) and the appropriate procedures.
 In making wetland determinations, one should select the
 appropriate method  for each  individual unit within the area of
 concern  and not  necessarily  employ one method for the entire
 site. Thus, a combination of determination methods may be used
 for a given site.

 Regardless  of the method used,  the desired outcome or final
 product  is  a wetland/nonwetland determination. Depending on one's
 expertise,  available information, and individual or agency
 preference, there are two basic approaches to delineating wetland
 boundaries. The  first approach  involves characterizing plant
 communities in the  area, identifying plant communities meeting
 the hydrophytic  vegetation criterion, examining the soils in
 these areas to confirm that  the hydric soil criterion is met, and
 finally  looking  for evidence of wetland hydrology to verify this
 criterion.  This  approach has been widely used by the CE and EPA
 and to a large extent by the FWS. A second approach involves
 first delineating the approximate boundary of potential hydric
 soils, and  then  verifying the presence of likely hydrophytic
vegetation  and looking for signs of wetland hydrology. This type
of approach has  been employed by the SCS and to a limited extent
by the FWS. Since these  approaches yield the same result, this
manual incorporates both approaches into most of the methods
presented.
                                35

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 Table  1.
  Ita Name
Primary sources of information that may be helpful in
making a wetland determination.
Topographic Maps  (mostly  1:24,000;
Survey  (USGS)
1:63,350  for Alaska)
1-800-USA-MAPS)

National  Wetlands Inventory Maps
Wildlife  Service
(mostly 1:24,000; 1:63,350
1-800-USA-MAPS)
for Alaska)

County Soil Survey Reports
Conservation Service
Offices

reports—local district
National Hydric Soils List

state Hydric Soils List

       Hydric Soil Map Unit List
National Insurance Agency
Management
  Flood Maps             Agency

Local Wetland Maps
agencies

Land Use and Land Cover Maps
(1-8 00 -USA-MAPS)

Aerial Photographs
sources— USGS, other Federal and

private sources

ASCS Compliance Slides
                                  Source

                                  U.S. Geological

                                   (Call


                                  U.S. Fish and

                                   (FWS) (Call



                                   U.S.D.A. Soil
                                   (SCS) District

                                  (Unpublished

                                  offices)

                                  SCS National Office

                                  SCS State Offices

                                  SCS District Offices

                                  Federal Emergency



                                  State and local


                                  USGS


                                  Various

                                  State agencies, and


                                  U.S.D.A.
Agricultural Stabilization and Conservation Service
Satellite Imagery
National List of Plant Species
                                  EOSAT Corporation,
                                  SPOT Corporation,
                                  and others

                                  Government Printing
                                 36

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 Office
 That  Occur  in Wetlands
 Documents
 (Stock No.  024-010-00682-0)

 Regional Lists of Plants that
 Information Occur in Wetlands
22161
National Wetland Plant Database

stream Gauge Data
and USGS

Soil Drainage Guides

Data Name

Environmental Impact Statements
State atgencies
  and Assessments

Published Reports
Local Expertise
consultants, and others

Site-specific Plans and
Engineering Designs
Superintendent of

Washington, DC 20402

National Technical
Service
5285 Port Royal Head
Springfield, VA

(703) 487-4650

FWS

CE District Offices


SCS District Offices

Source

Various Federal and
Federal and States
agencies,
universities, and
others

Universities,
Private developers
                                 37

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 Description  of Methods

 Offsite  Preliminary  Determinations

 When  an  onsite inspection  is not necessary because information on
 hydrology, hydric soils, and hydrophytic vegetation is known or an
 inspection is not possible due to time constraints or other reasons,
 a preliminary wetland determination can be made in the office. This
 approach provides an approximation of the presence of wetland and
 its boundaries based on available information. The accuracy of the
 determination depends on the quality of the information used and on
 one's ability and experience in an area to interpret these data.
 Where reliable, site-specific data have been previously collected,
 the wetland  determination can be reasonably accurate. Where these
 data do  not  exist, more generalized information may be used to make
 a preliminary wetland determination. In either case, however, if a
 more accurate delineation is required, then onsite procedures must
 be employed.  For the purposes of determining whether an area is
 subject  to Federal jurisdiction under the Clean Water Act or other
 Federal  wetland regulatory program, onsite determinations are
 usually  necessary. Regardless of the method used, documentation of
 all three criteria is mandatory.

 Onsite Determinations

 When an  onsite inspection is necessary, always be sure to review
 pertinent background information (e.g., NWI maps, soil surveys, and
 site plans)  before going to the subject site. This information will
be helpful in determining what type of field method should be
 employed. Also, read the sections of this manual that discuss
disturbed (page 41)  and difficult-to-identify (page 31) wetlands
before conducting field work. These situations pose significant
problems for the inexperienced wetland delineator, so learn the
procedures for evaluating these sites. Recommended equipment and
materials for conducting onsite determinations are listed in Table
  •

Figures  1, 2, and 3  show the decision process for making onsite
wetland determinations by the various approaches presented in the
manual.
                                 38

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Table 2.  Recommended equipment and materials for onsite
determinations.
Equipment
Materials
Soil auger, probe, or spade
Sighting compass
Pen or pencil
Penknife
Hand lens
Vegetation sampling frame*
Camera/Film
wetland  Binoculars
Tape measure
Prism or angle gauge
Diameter tape*

Vasculum (for plant collect.)
Names
Calculator*
Dissecting kit
Data sheets and clipboard
Field notebook
Base (topographic) map
Aerial photograph
Nation Wetlands Inventory map
Soil survey or other soil map
Appropriate Federal interagency
  plants list
County hydric soil map unit list
Munsell soil color book
Plant identification field
guides/manuals
National List of Scientific Plant

Flagging tape/wire flags-wooden stakes
Plastic bag (for collecting plants and
  soil samples as needed)
•Needed for comprehensive determination
                                 39

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 For every upcoming  field  inspection, the following pre-inspection
 steps should be undertaken:

     Step 1. Locate the project area on a map  (e.g., U.S. Geological
 Survey topographic  nap or SCS soil survey nap) or on an aerial
 photograph and determine  the limits of the area of concern. Proceed
 to Step  2.

     Step 2. Estinate the size of the subject area. Proceed to Step
 3.

     Step 3. Review existing background information and determine,
 to the extent possible, the site's geomorphological setting (e.g.,
 floodplain, isolated depression, or ridge and swale complex), its
 habitat  or vegetative complexity (i.e., the range of habitat or
 vegetation types),  and its soils. (Note: Depending on available
 information, it may not be possible to determine the habitat
 complexity without  going  on the site; if necessary, do a field
 reconnaissance.)  Proceed  to Step 4.

     Step 4. Determine whether a disturbed condition exists. Examine
 available information and determine whether there is evidence of
 sufficient natural  or human-induced alteration to significantly
 modify all or a portion of the area's vegetation, soils, and/or
 hydrology. If such  disturbance is noted, identify the limits of
 affected areas for  they should be evaluated separately for wetland
 determination purposes (usually after evaluating undisturbed areas).
 The presence of disturbed areas within the subject area should be
 considered when selecting an onsite determination method. (Note: It
may be possible that at any time during this determination, one or
more of the three characteristics may be found to be significantly
 altered. If this happens, follow the disturbed area wetland
determination procedures, as necessary, noted on p. 41).  Proceed to
 Step 5.

     Step 5. Determine the field determination method to be used.
 Considering the size and  complexity of the area and the need for
 quantification, determine whether a routine, intermediate-level, or
 comprehensive field determination method should be used. When the
 area is equal to or less  than five acres in size or is larger and
 appears to be relatively  homogeneous with respect to vegetation,
 soils, and/or hydrology,  use the routine method (see below). When
the area is greater than  five acres in size, or is smaller but
appears to be highly diverse with respect to vegetation, use the
 intermediate-level  method (Appendix 3). When detailed quantification
of plant communities and  more extensive documentation of other
 factors  (soils and  hydrology) are required, use the comprehensive
method regardless of the  wetland's size (Appendix 4). significantly
disturbed sites (e.g., sites that have been filled, hydrologically
modified, cleared of vegetation, or had their soils altered) will
generally require intermediate-level or comprehensive methods. In
                                                               %
                                 40

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 these disturbed  areas,  it  usually will be necessary to follow a set
 of subroutines to determine whether the altered characteristic met
 the applicable criterion prior to its modification; in the case of
 altered wetland  hydrology, it nay be necessary to determine whether
 the area is  effectively drained. Because a large area may include a
 diversity of smaller  areas ranging from simple wetlands to
 vegetatively complex  areas, one may use a combination of the onsite
 determination methods,  as  appropriate.
 Disturbed Area Wetland Determinations

 In the course of  field investigations, one often encounters
 significantly disturbed or altered areas. Disturbed areas include
 situations where  field indicators of one or more of the three
 wetland identification criteria are obliterated or not present due
 to recent change. The following sections discuss these situations
 and present procedures for distinguishing wetlands from nonwetlands.

 Disturbed areas have been altered either recently or in the past in
 some way that makes wetland identification more difficult than it
 would be in the absence of such changes. Disturbed areas include
 both wetlands and nonwetlands that have been modified to varying
 degrees by human  activities (e.g., filling, excavation, clearing,
 damming, and building construction) or by natural events (e.g.,
 avalanches, mudslides, fire, volcanic deposition, and beaver dans).
 Disturbed wetlands include areas subjected to deposition of fill or
 dredged material, removal or other alteration of vegetation,
 conversion to agricultural land and silviculture plantations, and
 construction of levees, channelization and drainage systems, and/or
 dams (e.g., reservoirs and beaver dams) that significantly modify an
 area's hydrology.  In considering the effects of natural events
 (e.g., a wetland  buried by a mudslide), the relative permanence of
 the change and whether the area is still functioning as a wetland
 must be considered..  If natural events have relatively permanently
 disturbed an area to the extent that wetland hydrology is no longer
 present, and therefore hydric soils and hydrophytic vegetation, even
 if still present, would not be expected to persist at the site, the
 area is no longer a wetland.  Detailed investigations of the prior
 condition of such areas is generally inappropriate.

 In cases where recent human activities have caused these changes, it
 may be necessary  to determine the date of the alteration or
 conversion for legal purposes.  If an illegal disturbance is
 suspected, and the pre-disturbance condition must be determined for
 the purposes of wetland regulatory program enforcement purposes,
 then a detailed investigation of the prior and current conditions of
 the disturbed area (i.e., whether the area was and is wetland or
 non-wetland) is appropriate.  However, if an area has been disturbed
 by legal human activities that have effected the relatively
permanent removal of wetland hydrology, hydric soil, or hydrophytic
vegetation, then  the area is non-wetland, and a detailed
                                                                *
                                 41

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investigation of the prior condition of such areas is generally
inappropriate.  In addition, determination of regulatory
jurisdiction for such areas is subject to agency interpretation.
For example. Federal wetland regulatory policy under the Clean water
Act, and agricultural program policy under the Food Security Act of
1985, as amended, interprets the relative permanence of disturbance
to vegetation caused by agricultural cropping.  Be sure to consult
appropriate agency in making Federal wetland jurisdictional
determinations in such areas.

In disturbed wetlands, field indicators for one or more of the three
technical criteria for wetland identification are usually absent.
Where it is necessary to determine whether the "missing"
indicator(s) (especially wetland hydrology) existed prior to
alteration, one should review aerial photographs, existing maps, and
other available information about the site.  This determination may
involve evaluating a nearby reference site (similar to the original
character of the one altered) for indicator(s) of the "altered"
characteristic.

When a significantly disturbed condition is detected during an
onsite determination, and the prior condition of the area must be
determined or it is suspected that the area may still be a wetland,
the following steps should be taken to determine if the "missing"
indicator(s) was present before alteration and whether the criterion
in question was originally met. Be sure to record findings on the
appropriate data form. After completing the necessary steps in
Appendix 4, return to the applicable step of the onsite
determination method being used and continue evaluating the site's
characteristics.
                                 42

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 APPENDIX  l.  Offsite Preliminary Determination Method

 The  following steps are recommended for conducting an offsite
 wetland determination:

     Step 1. Locate the area of interest on a U.S. Geological Survey
 topographic map and delineate the approximate subject area boundary
 on the map. Note whether marsh or swamp symbols or lakes, ponds,
 rivers, and other waterbodies are present within the area. If they
 are, then there is a good likelihood that wetland is present.
 Proceed to Step 2.

     Step 2. Review appropriate National Wetlands Inventory  (NWi)
 maps, State wetland maps, or local wetland maps, where available. If
 these maps designate wetlands in the subject area, there is a high
 probability that wetlands are present unless there is evidence on
 hand that the wetlands have been effectively drained, filled,
 excavated, impounded, or otherwise significantly altered since the
 effective date of the maps. Proceed to Step 3.

     Step 3. Review SCS soil survey maps where available. In the
 area of interest, are there any map units listed on the county list
 of hydric soil map units or are there any soil map units with
 significant hydric soil inclusions? If YES, then at least a portion
 of the project area may be wetland. If this area is also shown as a
wetland on NWI or other wetland maps, then there is a very high
probability that the area is wetland unless it has been recently
altered (check recent aerial photos, Step 4). Areas without hydric
soils or  hydric soil inclusions should in most cases be eliminated
 from further review, but aerial photos still should be examined for
small wetlands to be more certain. This is especially true if
wetlands  have been designated on the National Wetlands Inventory or
other wetland maps. Proceed to Step 4.

     Step  4. Review recent aerial photos of the project area. Before
reviewing  aerial photos, evaluate climatological data to determine
whether the photo year had normal or abnormal (high or low)
precipitation two to three months, for example, prior to the date of
the photo. This will help provide a useful perspective or
frame-of-reference for doing photo interpretation. In some cases,
aerial photos covering a multi-year period (e.g., 5-7 years) should
be reviewed, especially where recent climatic conditions have been
abnormal.

During photo interpretation, look for one or more signs of wetlands.
For example:

      1)   hydrophytic vegetation;
      2)    surface water;
      3)   saturated soils;
      4)    flooded or drowned out crops;
                                                               %
                                 43

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       5)   stressed  crops due  to wetness;
       6)   greener crops in dry years;
       7)   differences  in vegetation patterns due to different
           planting  dates.

 If  signs  of wetland are observed, proceed to Step 5 when
 site-specific  data  are available; if site-specific data are not
 available, proceed  to  Step 6.


 (CAUTION:  Accurate  photo interpretation of certain wetland types
 requires  considerable  expertise. Evergreen forested wetlands,
 seasonally saturated wetlands, and temporarily flooded wetlands, in
 general,  may present considerable difficulty. If not proficient in
 wetland photo  interpretation, then one can rely more on the findings
 of  other  sources, such as NWI maps and soil surveys, or seek help in
 photo  interpretation.)

     Step 5. Review available site-specific information.  In some
 cases, information  on  vegetation, soils, and hydrology for the
 project area has been  collected during previous visits to the area
 by  agency personnel, environmental consultants or others. Moreover,
 individuals or experts having firsthand knowledge of the  project
 site should be contacted for  information whenever possible. Be sure,
 however,  to know the reliability of these sources. After  reviewing
 this information, proceed to Step 6.

     Step 6. Determine whether wetlands exist in the subject area.
 Based  on  a review of existing information, a preliminary
 determination  can be made that the area is likely to be a wetland
 if:

     1) Wetlands are shown on NWI or other wetland maps,  and hydric
 soil map  unit  or a  soil map unit with hydric soil inclusions is
 shown  on  the soil-survey; or

     2) Hydric soil  map unit or soil map unit with hydric soil
 inclusions is  shown  on the soil survey fNote: in the latter case,
 only the  hydric inclusion is being evaluated as wetland.), and

          A) site-specific information, if available, confirms
          hydrophytic  vegetation, hydric soils, and wetland
          hydrology, or

          8) wetlands  are shown in aerial photos.

     If,  after examining the available reference material one is
 still unsure whether the area is likely to be wetland, then a field
 inspection should be conducted, whenever possible.  Alternatively,
more detailed  information on the site's characteristics may be
 sought, to help make the preliminary determination.

                                                               *
                                 44

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The validity of offsite preliminary determinations are dependent on
the availability of information for making a wetland determination,
the quality of this information, and one's ability and experience t
interpret these data. In most cases, therefore, the offsite
procedure yields a preliminary determination.  For more accurate
results, one must conduct an onsite inspection.
to
                                45

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APPENDIX 2.  Routine Onsite Determination Method

For most cases, wetland determinations can be made in the field
without rigorous sampling of vegetation and soils. Two approaches
for routine determinations are presented: (1) hydric soil assessment
procedure, and  (2) plant community assessment procedure. In the
former approach, areas that meet or may meet the hydric soil
criterion are first identified and then dominant vegetation is
visually estimated to determine if hydrophytic vegetation is
obvious. If so, the area is designated as wetland. If not, then the
site must undergo a more rigorous evaluation following one of the
other onsite determination methods presented in the manual. The
second routine  approach requires initial identification of
representative  plant community types in the subject area and then
characterization of vegetation, soils, and hydrology for each type.
After identifying wetland and nonwetland communities, the wetland
boundary is delineated. All pertinent observations on the three
mandatory wetland criteria should be recorded on an appropriate data
sheet; this should be done for all inspections to determine
regulatory -Jurisdiction.


Hydric Soil Assessment Procedure

     Step 1. Identify the approximate limits of areas that may meet
the hydric soil criterion within the area of concern and sketch
limits on an aerial photograph. To help identify these limits use
sources of information such as Agricultural Stabilization and
Conservation slides, soil surveys, NWI maps, and other maps and
photographs. (Note; This step is more convenient to perform offsite,
but may be done onsite.) Proceed to Step 2.

     Step 2. Scan the areas that may meet the hydric soil criterion
and determine if disturbed conditions exist. Are any significantly
disturbed areas present? If YES, identify their limits for they
should be evaluated separately for wetland determination purposes
(usually after evaluating undisturbed areas). Refer to the section
on disturbed areas (p. 41), if necessary, to evaluate the altered
characteristic(s) (vegetation, soils, or hydrology).  If
appropriate, determine whether wetland regulatory policy exempts the
area from Federal regulatory jurisdiction (e.g., regulatory policy
on wetlands converted to cropland.  See Disturbed Areas discussion,
p.85); then return to this method and continue evaluating
characteristics not altered. (Note; Prior experience with disturbed
sites may allow one to easily evaluate an altered characteristic,
such as when vegetation is not present in a farmed wetland due to
cultivation*)- Keep in mind that if at any time during this
determination,  one or more of these three characteristics are found
to have been significantly altered, the disturbed area determination
procedures should be followed. If the area is not significantly
disturbed, proceed to Step 3.


                                 46

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      Step 3.  Scan the areas  that may meet the hydric soil criterion
 and determine if obvious  signs  of wetland hydrology or hydric soil
 are present.  The wetland  hydrology criterion is met for any area or
 portion thereof where it  is  obvious or known that the area is
 frequently inundated or saturated to the surface for a sufficient
 duration during the growing  season in most years. If the above
 condition exists,  the hydric soil criterion is presumed to be met
 for the subject area and  the area is considered wetland. If
 necessary,  confirm the presence of readily identified hydric soil by
 examining the soil for appropriate properties. If the area's
 hydrology has not be significantly disturbed and the soil is organic
 (Histosols, except Folists)  or  is mineral classified as Sulfaquents,
 Hydraquents,  or Histic subgroups of Aquic Suborders, the area is
 also considered wetland.  fNotei The hydrophytic vegetation criterion
 is  presumed to be met under  these conditions, i.e., undrained hydric
 soil, so vegetation does  not need to be examined. Moreover,
 hydrophytic vegetation should be obvious in these situations;
 however you may need to record  dominant species for future
 references) Areas lacking obvious indicators of wetland hydrology or
 readily obvious hydric soils must be further examined, so proceed to
 Step 4.

      Step 4.  Refine the boundary of areas that may meet the hydric
 soil criterion.  Verify the presence of hydric soil within the
 appropriate map units by  digging a number of holes at least 18
 inches  deep along the boundary  (interface) between hydric soil units
 and  nonhydric soil units. Compare soil samples with descriptions in
 the  soil  survey report to see if they are properly mapped. In this
 way,  the  boundary of areas meeting the hydric soil criterion is
 further refined by field  observations. In map units where only part
 of the  unit is  hydric (e.g.,  complexes, associations, and
 inclusions),  locate hydric soil areas on the ground by considering
 landscape position and evaluating soil characteristics for hydric
 soil properties.  (Note; Some hydric soils, especially organic soils,
 have not  been given a series name and are referred to by common
 names,  such as  peat,  muck, swamp, marsh, wet alluvial land, tidal
 marsh,  Sulfaquents,  and Sulfihemists. These areas are also
 considered hydric  soil  map units. Certain hydric soils are mapped
 with nonhydric  soils as an association or complex, while other
 hydric  soils  occur as inclusions in nonhydric map units. Only the
 hydric  soil portion of these map units should be evaluated for the
 hydrophytic vegetation criteria in Step 7.) If the area meets the
 hydric  soil criterion,  proceed to Step 5.

     Step 5.  Consider the following:

     1)  Is the  area presently lacking hydrophytic vegetation or
hydrologic indicators due to annual, seasonal or long-term
 fluctuations  in precipitation, surface water, or ground-water
levels?

     2)  Are hydrophytic vegetation indicators lacking due to
                                                                »
                                 47

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seasonal  fluctuation in temperature  (e.g., seasonality of plant
growth)?

If the answer to either of these questions is YES or uncertain,
proceed to the section on difficult-to-identify wetland discussion
 (p.31). If the answer to both questions is NO, normal conditions are
assumed to be present, so proceed to Step 6.  mote;  In some cases,
normal climatic conditions, such as snow cover or frozen soils, may
prevent an accurate assessment of the wetland criteria; one must use
best professional judgement to determine if delaying the wetland
delineation is appropriate.)

     Step 6. Select representative observation area(s). Identify one
or more observation areas that represent the area(s) meeting the
hydric soil criterion. A representative observation area is one in
which the apparent characteristics (determined visually) best
represent characteristics of the entire community. Mark the
approximate location of the observation area(s) on the aerial photo.
Proceed to Step 7.

     Step 7. Characterize the plant community within the area(s)
meeting the hydric soil criterion. Visually estimate the percent
areal cover of dominant species for the entire plant community. If
dominant species are not obvious, use one of the other onsite
methods. Proceed to Step 8 or to another method, as appropriate.

     Step 8. Record the indicator status of dominant species within
each area meeting the hydric soil criterion. Indicator status is
obtained from the interagency Federal list of plants occurring in
wetlands for the appropriate geographic region. Record information
on an appropriate data form. Proceed to Step 9.

     Step 9. Determine whether wetland is present or additional
analysis is required. If the estimated percent areal cover of OBL
and FACW species (dominants) exceeds that of FACU and UPL species
(dominants), the'area is considered wetland and the
wetland-nonwetland boundary is the line delineated by the limits of
conditions that verify the wetland hydrology criterion (see p. 10).
If not, then the point intercept or other sampling procedures should
be performed to do a more rigorous analysis of site characteristics.


Plant Community Assessment Procedure

     Step 1. Scan the entire project area, if possible, or walk, if
necessary, and identify plant community types present. In
identifying- communities, pay particular attention to changes in
elevation throughout the site. (CAUTION: In highly variable sites,
such as ridge and swale complexes, be sure to stratify properly,
i.e.,  divide the site into homogeneous landforms to evaluate each
landform separately.) If possible, sketch the approximate location
of each plant community on a base map, an aerial photograph of the

                                 48

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 project area,  or a county soil  survey nap and  label each community
 with an appropriate name.  fNote;  For large homogeneous wetlands,
 especially marshes dominated  by herbaceous plants and shrub bogs
 dominated by low-growing shrubs,  it is usually not necessary to wall
 the entire project area.  In these cases, one can often see for long
 distances and many have  organic mucky soils that can be extremely
 difficult to walk on.  Forested  areas, however, will usually require
 a  walk through the entire project area.)

 In examining the project area,  are any significantly disturbed areas
 observed? If YES,  identify their  limits for they should be evaluated
 separately for wetland determination purpose (usually after
 evaluating undisturbed areas).  Refer to the section on disturbed
 areas  (p.41)  to evaluate the  altered characteristic(s)  (i.e.,
 vegetation,  soils,  or  hydrology).  If appropriate, determine whether
 wetland regulatory policy  exempts the area from Federal regulatory
 jurisdiction (e.g.,  regulatory  policy on wetlands converted to
 cropland);  then return to  this  method to continue evaluating
 characteristics not altered.  Keep in mind that if at any time during
 this determination one or  more  of these three  characteristics are
 found  to have  been significantly  altered, the  disturbed area
 procedures  should  be followed.  If the area is  not significantly
 disturbed,  proceed to  Step 2.

     Step 2. Consider  the  following:

     1)  Is  the area presently lacking hydrophytic vegetation or
 hydrologic  indicators  due  to  annual, seasonal  or long-term
 fluctuations in precipitation,  surface water,  or ground-water
 levels?

     2)  Are  hydrophytic vegetation indicators  lacking due to
 seasonal  fluctuations  in temperature (e.g., seasonality of plant
 growth)?

 If the  answer  to either of these  questions is  YES  or uncertain,
 proceed  to the section on  difficult-to-identify wetland
 determinations (p.31). If  the answer to both questions is NO, normal
 conditions are assumed to  be  present, so proceed to Step 3. fNote:
 In some  cases,  normal  climatic  conditions, such as snow cover or
 frozen  soils,  may  prevent  an  accurate assessment of the wetland
 criteria; one  must use best professional judgement to determine if
 delaying the wetland delineation  is appropriate.)

     Step 3. Select  representative observation area(s). Select one
 or more  representative observation areas within each community type.
A representative observation  area is one in which the apparent
characteristics  (determined visually) best represent characteristics
of the entire  community. Mark the approximate  location of the
observation areas  on the base map or photo. Proceed to Step 4.
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      Step  4.  Characterize  each plant community in the project area.
 Within  each plant  community  identified  in Step 1, visually estimate
 the  dominant  plant species for each valid vegetative stratum in the
 representative  observation areas and record them on an appropriate
 data form.  Vegetative  strata may include tree, sapling, shrub, herb,
 woody vine, and bryophyte  strata (see glossary for definitions).
 Make sure  the size of  the  observation area is sufficient to insure a
 representative  assessment  of the plant  community. A separate form
 must be completed  for  each plant community identified for wetland
 determination purposes. After identifying dominants within each
 vegetative stratum, proceed to Step 5.

      Step  5.  Record the indicator status of dominant species in all
 strata.  Indicator  status is obtained from the interagency Federal
 list of plants  occurring in wetlands for the appropriate geographic
 region.  Record  indicator status for all dominant plant species on a
 data form.  Proceed to  Step 6.

      Step  6.  Determine whether the hydrophytic vegetation criterion
 is met.  When  more  than 50  percent of the dominant species in each
 community  type  have an indicator status of OBL, FACW, and/or FAC,
 the  hydrophytic vegetation criteria is met. Complete the vegetation
 section of  the  data form.  Portions of the project area failing this
 test are usually not wetlands, although under certain circumstances
 they may have wetland  hydrology and therefore be wetland (see list
 of difficult-to-identify wetlands on p.31). Proceed to Step 7.

      Step  7.  Determine whether soils must be characterized or
 additional  analysis is needed. Examine vegetative data collected for
 each plant  community (in Steps 5 and 6) and identify any plant
 community where OBL species or OBL and FACW species predominate the
 list of dominant plant species. In the absence of significant
 hydrologic modification, these plant communities are considered
 wetland (i.e.,  the hydric  soil and wetland hydrology criteria are
 presumed to be  met), but it may be advisable to record observations
 of hydric soils and wetland hydrology, if assessing wetlands for
 regulatory purposes; proceed to Steps 9 and 10 and quickly record
 indicators of these criteria. Similarly, plant communities where UPL
 species  or UPL  and FACU species predominate the list of dominants
 are  considered  nonwetland. (CAUTION: Make sure that this plant
 community  is  not a difficult-to-identify wetland, see p. 31.)
 Proceed to Step 11. Plant  communities lacking the above
 characteristics must have  soils closely examined; proceed to Step 8.

      Step 8.  Determine whether the hydric soil criterion is met.
 Locate  the observation area on a county soil survey map, if
possible, and determine the soil map unit delineation for the area.
Using a  soil  auger, probe, or spade, make a hole at least 18 inches
deep  at  the representative location in each plant community type.
Examine  soil  characteristics and compare if possible to soil
descriptions  in the county soil survey report or classify to
Subgroup following  "Soil Taxonomy" (often reguires digging a deeper
                                                                >
                                 50

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 hole),  or look for regional  indicators of significant soil
 saturation  If soil has  been plowed or otherwise altered, which may
 have eliminated these  indicators/ proceed to the section on
 disturbed areas (p.  41).   Complete the soils section on the
 appropriate  data sheet and proceed to Step 9 if conditions satisfy
 the  hydric soil criterion. Areas  having soils that do not meet the
 hydric  soil  criterion  are  nonwetlands. (CAUTION: Become familiar
 with problematic hydric  soils that do not possess good hydric field
 indicators,  such as red  parent material soils, some sandy soils, and
 some floodplain soils, so  that these hydric soils are not
 misidentified  as nonhydric soils; see the difficult-to-identify
 wetlands  discussion on p.31.)

      Step 9. Determine whether the wetland hydrology criterion is
 met. Record  observations and complete the hydrology section on the
 appropriate  data form. If  the wetland hydrolgy criterion is met,
 proceed to Step 10.  If the wetland hydrology criterion is not met,
 the  area  is  nonwetland.  (CAUTION: Seasonally saturated wetland may
 not  appear to  meet  the hydrology  criterion at certain times of the
 growing season;  see  discussion of difficult-to-identify wetlands,
 page 31).

     Step 10.  Make  the wetland determination. Examine data forms for
 each plant community identified in the project area. Each community
 meeting the  hydrophytic vegetation, hydric soil, and wetland
 hydrology criteria  is  considered  wetland. If all communities meet
 these three  criteria,  then the entire project area is a wetland. If
 only a portion of the  project area is wetland, then the
wetland-nonwetland boundary  must  be established. Proceed to Step n.|

     Step 11.  Determine the  wetland-nonwetland boundary. Where a
 base map  or  annotated  photo  was prepared, mark each plant community
 type on the  map or photo with a "W" if wetland or an "N" if
 nonwetland.  Combine  all  "Ww  types into a single mapping unit, if
possible,  and  all."N"  types  into  another mapping unit. On the map or
photo, the wetland boundary  will  be represented by the interface of
these mapping  units. If flagging  the boundary on the ground, the
boundary  is  established by determining the limits of the indicators
that verify  all  three  criteria.
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APPENDIX 3.  intermediate-level Onsite Determination Method

On occasion, a more rigorous sampling method is required than the
routine method to determine whether hydrophytic vegetation is
present at a given site, especially where the boundary between
wetland and nonwetland is gradual or indistinct. This circumstance
requires more intensive sampling of vegetation and soils than
presented in the routine determination method. This method also may
be used for areas greater than five acres in size or other areas
that are highly diverse in vegetation.

The intermediate-level onsite determination method has been
developed to provide for more intensive vegetation sampling than the
routine method. Two optional approaches are presented: (1) quadrat
transect sampling procedure, and (2) vegetation unit sampling
procedure. The former procedure involves establishing transects
within the project area and sampling plant communities along the
transect within sample quadrats, with soils and hydrology also
assessed as needed in each sample plot. In contrast, the vegetation
unit sampling procedure offers a different approach for analyzing
the vegetation. First, vegetation units are designated in the
project area and then a meander survey is conducted in each unit
where visual estimates of percent areal coverage by plant species
are made. Soil and hydrology observations also are made as
necessary. Boundaries between wetland and nonwetland are established
by examining the transitional gradient between them.

The following steps should be completed:

     Step 1. Locate the limits of the project area in the field and
conduct a general reconnaissance of the area. Previously the project
boundary should have been determined on aerial photos or maps. Now
appropriate ground reference points need to be located to insure
that sampling will be conducted in the proper area. In examining the
project area, were any significantly disturbed areas observed? If
YES, identify their limits for they should be evaluated separately
for wetland determination purposes  (usually after evaluating
undisturbed areas). Refer to the section on disturbed areas (p. 41)
to evaluate the altered characteristic(s) (i.e., vegetation, soils,
or hydrology); then return to this method to continue evaluating the
characteristics not altered. Keep in mind that if at any time during
this determination, one or more of these three characteristics is
found to have been significantly altered, the disturbed areas
procedures should be followed. If the area is not significantly
disturbed, proceed with Step 2.

     Step 2. Decide how to analyze plant communities within the
project area: (1) by selecting representative plant communities
(vegetation units), or (2) by sampling along a transect. Discrete
vegetation units may be identified on aerial photographs,
topographic and other maps, and/or by field inspection. These units
                                                                *
                                 52

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 will  be  evaluated  for hydrophytic vegetation and also for hydric
 soils and wetland  hydrology, as necessary, if the vegetation unit
 approach is  selected, proceed to Step 3. An alternative approach is
 to  establish transects  for identifying plant communities, sampling
 vegetation and evaluating other criteria, as appropriate. If the
 transect approach  is chosen, proceed to Step 4.

      Step 3.  Identifying vegetation units for sampling. Vegetation
 units are identified by examining aerial photographs, topographic
 maps,  NWI maps, or other materials or, by direct field inspection.
 All of the different vegetation units present in the project area
 should be identified. The subject area should be traversed and
 different vegetation units specifically located prior to conducting
 the sampling.

 Field inspection may refine previously identified vegetation units,
 as appropriate. It may  be advisable to divide large vegetation units
 into  subunits for  independent analysis. (CAUTION: In highly variable
 terrain, such as ridge  and swale complexes, be sure to stratify
 properly.) Decide  which plant community to sample first and proceed
 to Step  7.

      Step 4. Establish  a baseline for locating sampling transects.
 Select as a baseline one project boundary or a conspicuous feature,
 such  as  road, in the project area. The baseline should be more or  A
 less  parallel to the major watercourse through the area, if presen^F
 or perpendicular to the hydrologic gradient (see Figure 	).
 Determine the approximate baseline length. Proceed to Step 5.

      Step 5. Determine  the minimum number and position of transects.
 Use the  following  to determine the minimum number and position of
 transects (specific site conditions may necessitate changes in
 intervals or additional transects). Divide the baseline length by
 the number of required  transects to establish baseline segments for
 sampling. Establish one transect in each resulting baseline segment
 (see  Figure 1). Use the midpoint of each baseline segment as a
 transect starting  point. For example, if the baseline is 1,200 feet
 in length, three transects would be established: one at 200 feet,
 one at 600 feet, and one at 1,000 feet from the baseline starting
 point. Make sure that all plant community types are included within
 the transects; this may necessitate relocation of one or more
 transect lines or  establishing more transects. Each transect should
 extend perpendicular to the baseline (see Figure 4J. Once positions
 of transect lines  are established, go to the beginning of the first
 transect and proceed to Step 6.

     Step 6. Locate sample plots along the transect. Along each
 transect, sample plots  are established within each plant community
 encountered to assess vegetation, soils, and hydrology. When
 identifying these  sample plots, two approaches may be followed: (1)
walk the entire length  of the transect, taking note of the number,
 type,  and location of plant communities present (flag the location/

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 if  necessary),  and  on  the  way back  to  the baseline,  identify plots
 and perform  sampling,  or  (2) identify  plant communities as the
 transect  is  walked  and sample the plot at that time  ("sample as you
 go11}.  The sample  plot  should be  located so it is representative of
 the plant community type.  When the  plant community type is large and
 covers a  significant distance along the transect, select an area
 that is no closer than 300 feet  to  a perceptible change in plant
 community type; mark the center  of  this area on the  base map or
 photo and flag  the  location in the  field, if necessary. (CAUTION: In
 highly variable terrain, such as ridge and swale complexes, be sure
 to  stratify  properly to ensure best results.) At each plant
 community, proceed  to  Step 7.

      Step 7.  Consider  the  following:

      1) Is the  area presently lacking  hydrophytic vegetation or
 hydrologic indicators  due  to annual, seasonal, or long-term
 fluctuations  in precipitation, surface water, or ground-water
 levels?

      2) Are  hydrophytic vegetation  indicators lacking due to
 seasonal  fluctuations  in temperature (e.g., seasonality of plant
 growth)?

 If  the answer to  either of these questions is YES or uncertain,
 proceed to the  section on  difficult-to-identify wetlands (p.31),
 then return  to this method and continue the wetland  determination.
 If  the answer to  both  questions  is  NO, normal conditions are assumed
 to  be  present, so proceed  to Step 8. (Note: In some  cases, normal
 climatic  conditions, such  as snow cover or frozen soils, may prevent
 an  accurate  assessment of  the wetland  criteria; one  must use best
 professional judgement to  determine if delaying the  wetland
 delineation  is appropriate.)

     Step 8. Characterize  the vegetation of the vegetation unit or
 the  plant community along  the transect.

 If  analyzing vegetation units, meander through the unit making
visual estimates  of the percent  area covered for each species in the
 herb,  shrub, sapling,  woody vine, and  tree strata; alternatively,
 for the tree stratum determine basal area using the  Bitterlich
method (see  Dilworth and Bell 1978; Avery and Burkhart 1983). Then:

      1) Within each stratum determine  and record the cover class of
each species and  its corresponding  midpoint. The cover classes (and
midpoints) are: T - <1% (none);  1 - 1-5% (3.0); 2 »  6-15% (10.5); 3
» 16-25%  (20.5);  4  « 26-50% (38.0); 5  - 51-75% (63.0); 6 « 76-95%
 (85.5); 7 - 96-100%  (98.0).

     2) Rank the  species within  each stratum according to their
midpoints.   (Note;  If  two  or more species have the same midpoints
and the same or essentially the  same recorded percent areal cover,

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 rank them equal;  us*  absolute areal cover values as a tie-breaker
 only if  they are  obviously different.)

      3)  Sum the midpoint values of all species within each stratum.

      4)  Multiply  the  total midpoint values for each stratum by 50
 percent.  (Note: This  number represents the dominance threshold
 number and is used to determine dominant species.)

      5)  Compile the cumulative total of the ranked species in each
 stratum  until 50  percent of the sum of the midpoints (i.e., the
 dominance threshold number), for the herb, woody vine, shrub,
 sapling,  and tree strata (or alternatively basal area for trees) is
 immediately exceeded. All species contributing areal cover or basal
 area  to  the 50 percent threshold are considered dominants, plus any
 additional  species representing 20 percent or more of the total
 cover class midpoint  values for each stratum or the basal area for
 tree  stratum. (Note;  If the threshold is reached by two or more
 equally  ranked species, consider them all dominants, along with any
 higher ranked species. If all species are equally ranked, consider
 them  all  dominants.)

      6)  Record all dominant species on an appropriate data sheet and
 list  indicator status of each. Proceed to Step 9.

 If using the transect approach, sample vegetation in each stratum
 (e.g., tree,  shrub, herb, etc.) occurring in the sample plots using
 the following quadrat sizes: (1) a 5-foot radius for bryophytes and
 herbs, and  (2) a  30-foot radius for trees, saplings, shrubs, and
 woody vines.  Plot size and shape may be changed as necessary to meet
 site  conditions,  but  be sure that it is sufficient to adequately
 characterize the  plant community. Determine dominant species for
 each  stratum by estimating one or more of the following as
 appropriate:  (1)  relative basal area (trees); (2) areal cover
 (trees,  saplings, shrubs, herbs, woody vines, and bryophytes); or
 (3) stem  density  (shrubs, saplings, herbs, and woody vines), when
 estimating  areal  cover, use cover classes T (trace) through 7 and
 use the midpoints of  the cover classes to determine dominants, see
 substeps  1  through 5  above. All plants covering the plot and
 representative of the plant community under evaluation should be
 counted  in  the cover  estimate; plants overhanging from adjacent
 plant communities should not be counted. Record all dominant species
 on an appropriate data sheet and list the indicator status of each.
 Proceed  to  Step 9.

      Step 9.  Determine whether the hydrophytic vegetation criterion
 is met. When more than 50 percent of the dominant species in the
vegetation  unit or sample plot have an indicator status of OBL,
FACW, and/or FAC, hydrophytic vegetation is present. If the
vegetation  fails  to be dominated by these types of species, the unit
or plot is  usually not wetland, but check difficult-to-identify
wetlands  and  disturbed areas discussions for exceptions (pages 31

                                 55

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 and  41,  respectively).  If the hydrophytic vegetation criterion is
 net,  Proceed  to  Step  10 after completing the vegetation section of
 the  data sheet.

      Step 10.  Determine whether soils must be characterized or
 additional analysis is  needed. Examine vegetative data collected for
 the  vegetation unit or  plot  (in Steps 8 and 9) and identify any
 plant community  (units  or plots) where OBL species or OBL and FACW
 species  predominate the list of dominants. In the absence of
 significant hydrologic  modification, these plant communities are
 typically wetland  (i.e., the hydric soil and wetland hydrology
 criteria are  presumed to be met), but it may be adviseable to record
 indicators for the other criteria, especially if making a wetland
 determination for regulatory purposes; proceed to Steps ll and 12 as
 necessary and record appropriate indicators.. Similarly, plant
 communities where UPL species or UPL and FACU species predominate
 the  list of dominants are considered nonwetland. (CAUTION: Make sure
 that  this plant  community is not a difficult-to-identify wetland,
 see  pp.  31).  Proceed to Step 12. Plant communities (e.g., vegetation
 units or plots)  lacking the above characteristics must have soils
 closely  examined; proceed to Step 11.

      Step 11.  Determine whether the hydric soil criterion is met.
 Locate the observation  area on a county soil survey map, if
 possible,  and determine the soil map unit delineation for the area.
 Using a  soil  auger, probe, or spade, make a hole at least 18 inches
 deep  at  the representative location in each plant community type.
 Examine  soil  characteristics and compare if possible to soil
 descriptions  in  the county soil survey report or classify to
 Subgroup following "Soil Taxonomy" (often requires digging a deeper
 hole), or look for regional indicators of significant soil
 saturation.   If  soil has been plowed or otherwise altered, which may
 have  eliminated  these indicators, proceed to the section on
 disturbed areas  (p.41).  Complete the soils section on the
 appropriate data sheet  and proceed to Step 12 if conditions satisfy
 the hydric soil  criterion. Areas having soils that do not meet the
 hydric soil criterion are nonwetlands. (CAUTION: Become familiar
 with  hydric soils that  do not possess good hydric field indicators,
 such  as  red parent material soils, some sandy soils, and some
 floodplain soils, so that these hydric soils are not misidentified
 as nonhydric  soils; see the difficult-to-identify wetlands
 discussion on  p.31).

      Step 12.  Determine whether the wetland hydrology criterion is
 met.   Record observations and complete the hydrology section on the
 appropriate data form.  If the wetland hydrolgy criterion is met,
proceed  to Step  13. If  the wetland hydrology criterion is not net,
 the area  is nonwetland. (CAUTION: Seasonally saturated wetland may
 not appear to  meet the  hydrology criterion at certain times of the
 growing  season;  see discussion of difficult-to-identify wetlands,
page  31).


                                 56

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      Step 13.  Make the wetland determination for the plant
 or vegetation  unit.  Examine  the data f ~~~~?s  for the plant community
 (sample plot)  or vegetation  unit. Wher  r.e  community or unit meets
 the hydrophytic  vegetation,  hydric so;1. and wetland hydrology
 criteria,  the  area is  considered wetla-.i. Complete the summary data
 sheet;  proceed to Step 14 when continuing to sample the transect or
 other vegetation units,  or to Step 15 when  determining, a boundary
 between wetland  and nonwetland plant communities or units.  (Note;
 Before  going on,  double check all data sheets to ensure that the
 forms are completed properly.)

      Step 14.  Sample other plant communities along the transect or
 other vegetation units.  Repeat Steps 6 through 13 for all remaining
 plant communities along the  transect if following transect  approach,
 or  repeat Steps  7 through 13 at the next vegetation unit. When
 sampling is completed  for this transect, proceed to Step 15, or when
 sampling is completed  for all vegetation units, proceed to  Step 16.

      Step 15.  Determine the  wetland-nonwetland boundary point along
 the  transect.  When the transect contains both wetland and nonwetland
 plant communities,  then a boundary must be  established. Proceed
 along the transect from the  wetland plot toward the nonwetland plot.
 Look for the occurrence of UPL and FACU species, the appearance of
 nonhydric  soil types,  subtle changes in hydrologic indicators,
 and/or  slight  changes  in topography. When such features are noted,
 look closely for  evidence of wetland hydrology in the soil  (see p.
 	)  and locate the wetland boundary (i.e.,  the point at which the
 wetland hydrology criterion  is no longer met). Establish sample
 plots on each  side of  the boundary (e.g., within 50 feet) and repeat
 Steps 8  through  13.  If existing plots are within a reasonable
 distance,  additional plots may not be necessary, but always identify
 the  features that were used  to identify the boundary. Data  sheets
 should  be  completed  for each new plot.  Mark the position of the
 wetland boundary  point on the base map or photo and stake or flag
 the  boundary in the  field, as necessary. Continue along the transect
 until the  boundary points between all wetland and nonwetland plots
 have been  established.  (CAUTION: In areas with a high interspersion
 of wetland and nonwetland plant communities, several boundary
 determinations will be required.) When all  wetland determinations
 along this transect have been completed, proceed to Step 17.

     Step  16.  Determine the wetland-nonwetland boundary between
 adjacent vegetation units. Review all completed copies of the data
 sheets  for each vegetation unit. Identify each unit as either
 wetland (W) or nonwetland (N). When adjacent vegetation units
 contain both wetland and nonwetland communities, a boundary must be
 established. Walk the  interface between the two units from  the
wetland  unit toward the nonwetland unit and look for changes in
vegetation, soils, hydrologic indicators, and/or elevation. As a
general  rule,  at  100-foot intervals or whenever changes in  the
 vegetation unit's  characteristics are noted, look for evidence to
 locate the wetland-nonwetland boundary. At  each designated  boundary

                                 57

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 point,  complete data  sheets  for  new observation  areas  immed.iatg.iy
 upslope and downslope of the wetland-nonwetland  boundary (i.e., one
 set  for the wetland unit and one for the nonwetland  unit),  repeat
 Steps  8 through 13  for each  area, and record the distance and
 compass directions  between the boundary points.  Record  evidence of
 wetland hydrology as  close to the boundary as possible,  and record
 the  features that were used  to delineate the boundary. Mark the
 position of the wetland boundary point on the base nap or photo and
 stake  or flag the boundary in the field, as necessary. Based on
 observations along  the interface, identify other of  boundary points
 between each wetland  unit and nonwetland unit. Repeat  this  step for
 all  adjacent vegetation units of wetland and nonwetland. When
 wetland boundary points between  all adjacent wetland and nonwetland
 units  have  been established, proceed to Step 18.

     Step 17.  Sample  other transects and make wetland  determinations
 along  each.  Repeat  Steps 5 through 15 for each remaining transect.
 When wetland boundary points for all transects have  been
 established,  proceed  to Step 18.

     Step 18.  Determine the wetland-nonwetland boundary  for the
 entire  project area.  Examine all completed copies of the data
 sheets,  and  mark the  location of each plant community  type  along the
 transect on  the base  map or photo, when used. (Note: This has
 already been done for the vegetation unit approach.) Identify each
 plant community as  either wetland (W) or nonwetland  (N), if it has
 not been done  previously. If all plant communities are wetlands,
 then the entire project area is wetland. If all  communities are
 nonwetlands,  then the entire project area is nonwetland. If both
wetlands and nonwetlands are present, identify the boundary points
 on the  base  map and connect these points on the  map  by generally
 following contour lines to separate wetlands from nonwetlands.
 Confirm  this boundary by walking the contour lines between  the
transects or vegetation units, as appropriate. Should anomalies be
encountered,  it  will  be necessary to establish short transects in
these areas  to refine the boundary; make any necessary adjustments
to the boundary  on the  base map and/or on the ground. If those areas
are significant  in scope, be sure to record data used for the
boundary determination.  When marking the boundary for subsequent
surveying by engineers,  the boundary points should be flagged or
marked otherwise to facilitate the survey.
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 APPENDIX  4.  Comprehensive Onsite Determination Method

 The comprehensive determination method is the most detailed,
 complex,  and labor-intensive approach of the three recommended types
 of onsite determinations. It is usually reserved for highly
 complicated and/or large project areas, and/or when the
 determination requires rigorous documentation. Due to the latter
 situation, this type of onsite determination may be used for areas
 of any size.

 In applying this method, a team of experts, including a wetland
 ecologist and a soil scientist, is often needed, especially when
 rigorous  documentation of plants and soils are required. It is
 possible, however, for a highly trained wetland boundary specialist
 to singly apply this method.

 Two alternative approaches of the comprehensive onsite determination
 method are presented: (1) quadrat sampling procedure and (2) point
 intercept sampling procedure. The former approach establishes
 quadrats  or sampling areas in the project site along transects,
 while the latter approach involves a frequency analysis of
 vegetation at sampling points along transects. The point intercept
 sampling  procedure requires that the limits of potential hydric
 soils be  established prior to evaluating the vegetation. In many
 cases, soil maps are available to meet this requirement, but in
 other cases a soil scientist may need to inventory the soils
 applying  this method. The quadrat sampling procedure, which
 identifying plant communities along transects and analyzing
vegetation, soils, and hydrology within sample plots (quadrats) ,
be the preferred approach when soil maps are unavailable or the
 individual is more familiar with plant identification.
                                                                 may
Quadrat Sampling Procedure

Prior to implementing this determination procedure, read the
sections of this manual that discuss disturbed area and difficult-
to- identify wetland section (p. 31) ; this information is often
relevant to project areas requiring a comprehensive determination.

     Step 1. Locate the limits of the project area in the field.
Previously, the project boundary should have been determined on
aerial photos or maps. Now appropriate ground reference points need
to be located to ensure that sampling will be conducted in the
proper area. Proceed to Step 2.

     Step 2. Stratify the project area into different plant
community types. Delineate the locations of these types on aerial
photos or base maps and label each community with an appropriate
name. (CAUTION: In highly variable terrain, such as ridge and swale
complexes, be sure to stratify properly to ensure best results.)
                                                               %
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 evaluating  the  subject  area, were  any significantly disturbed areas
 observed? If  YES,  identify their limits  for they should be evaluated
 separately  for  wetland  determination purposes  (usually after
 evaluating  undisturbed  areas). Refer to  the section on disturbed
 areas  (p.85)  to evaluate the altered characteristic(s) (i.e.,
 vegetation, soils,  and/or hydrology); then return to this method to
 continue evaluating the characteristics  not altered. Keep in mind
 that if at  any  time during this determination, it is found that one
 or more or  these three  characteristics have been significantly
 altered, the  disturbed  areas wetland determination procedures should
 be followed.  If the area is not significantly disturbed, proceed to
 Step 3.

     Step 3.  Establish  a baseline  for locating sampling transects.
 Select as a baseline one project boundary or a conspicuous feature,
 such as a road,  in  the  project area. The baseline ideally should be
 more or less  parallel to the major watercourse through the area, if
 present, or perpendicular to the hydrologic gradient (see Figure 1).
 Determine the approximate baseline length and record its origin,
 length, and compass heading in a field notebook. When a limited
 number of transects are planned, a baseline may not be necessary
 provided there  are  sufficient fixed points (e.g., buildings, walls,
 and fences) to  serve as starting points  for the transects. Proceed
 to Step 4.

     Step 4.  Determine  the required number and position of
 transects. The  number of transects necessary to adequately
 characterize  the site will vary due to the area's size and
 complexity of habitats. In general, it is best to divide the
 baseline into a  number  of equal segments and use the mid-point of
 each baseline segment as the transect starting point (see Figure
 „_). For example, if the baseline  is 1,600 feet in length, four
 transects will be established; one at 200 feet, one at 600 feet, one
 at 1,000 feet, and  one  at 1,400 feet from the baseline starting
 point.  Each transect should extend perpendicular to the baseline.

 Use the following as a  guide to determine the minimum number of
 baseline segments:

 *If the baseline exceeds five miles, baseline segments should be 0.5
 mile in length.

Make sure that each plant community type is included in at least one
 transect; if  not, modify the sampling design accordingly by
 relocating one or more  transect lines or by establishing additional
 transects. When the  starting points for  all required transects have
been established, go to the beginning of the first transect and
proceed to Step 5.

     Step 5.  Identify sample plots along the transect. Along each
transect,  sample plots  may be established in two ways: (1) within
each plant community encountered (the plant community transect

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 sampling approach); or (2)  at fixed intervals (the fixed interval
 transect sampling approach);  these plots will be used to assess
 vegetation,  soils, and hvdroloov.
fe*.a*<9«*>>, ««•«!£,*Aiiy apt"* wawuj i  uue
vegetation, soils, and hydrology
 When employing the plant community transect sampling approach,  two
 techniques for identifying sample plots may be followed:  (1)  walk
 the entire length of the transect,  taking note of the number,  type,
 and location of plant communities present (flag the locations,  if
 necessary)  and on the way back to the baseline,  record the length of
 the transect,  identify sample plots and perform sampling;  or  (2)
 identify plant communities as the transect is  walked,  sample  the
 plot at that time ("sample as you go"),  and record the length of the
 transect.

 When conducting the fixed interval  transect sampling approach,
 establish sample plots along each transect using the following as a
 guide:

 The first sample plot should be established at a distance  of  50 feet
 from the baseline.  When obvious nonwetlands occupy a long  segment of
 the transect from the baseline,  begin the first plot in the
 nonwetland  at  approximately 300 feet from the  point where  the
 nonwetland  begins to intergrade into a potential wetland community
 type. Keep  in  mind that additional  plots will  be required  to
 determine the  wetlancl-nonwetland boundary between fixed points. In
 large areas having a mosaic of plant communities,  one transect may
 contain several  wetland boundaries.

 If  obstacles such as a body of water or impenetrable thicket  prevent
 access  through the length of the transect,  access from the opposite
 side of the project area may be necessary to complete the  transect;
 take appropriate compass reading and location  data.  At each sample
 plot  (i.e.,  plant -community or fixed interval  area),  proceed  to step
 6.

     Step 6. Consider the following:

     1)  Is  the area presently lacking hydrophytic vegetation  or
 hydrologic  indicators due to annual,  seasonal  or long-term
 fluctuations in  precipitation,  surface water,  or ground-water
 levels?

     2) Are hydrophytic vegetation  indicators  lacking due  to
 seasonal fluctuations in temperature (e.g.,  seasonality of plant
growth)?

If the answer  to either of these questions  is  YES or uncertain,
proceed to  the section on difficult-to-identify wetland
determinations (p.  31).  If the answer to both  questions is NO,
normal conditions are assumed to be  present. Proceed to Step  7  when
 following the  plant community transect approach.  If following the
 fixed interval approach,  go to the appropriate fixed point along thj

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transect and proceed to Step 8.  (Note: in some cases,  normal
climatic conditions, such as snov cover or  frozen soils, may prevent
an accurate assessment of the wetland criteria; one must use best
professional judgement to determine if delaying the wetland
delineation is appropriate,)


     Step 7. Locate a sample plot in the plant community type
encountered. Choose a representative location along the transect in
this plant community. Select an area that is no closer than 50 feet
from the baseline or from any perceptible change in the plant
community type. Mark the center of the sample plot on  the base map
or photo and flag the point in the field. Additional sample plots
should be established within the plant community at 300-foot
intervals along the transect or sooner if a different  plant
community is encountered. (Note; In large-sized plant  communities, a
sampling interval larger than 300 feet may be appropriate, but try
to use 300-foot intervals first.) Proceed to Step 8.

     Step 8. Lay out the boundary of the sample plot.  A circular
sample plot with a 30-foot radius should usually be established,
however, the size and shape of the plot may be changed to match
local conditions (e.g., narrow ridges and swales) as necessary. At
the flagged center of the plot, use a compass to divide the circular
plot into four equal sampling units at 90*, 180*, 270', and 360'.
Mark the outer points of the plot with flagging. Proceed to Step 9.

     Step 9. Characterize the vegetation and determine dominant
species within the sample plot. Sample the vegetation  in each layer
or stratum (i.e., tree, sapling, shrub, herb, woody vine, and
bryophyte)  within the plot using the following procedures for each
vegetative stratum and enter data on appropriate data  sheet (see
Appendix 	 for examples of data sheet):

1) Herb stratum

     A) Sample this stratum using corresponding approach:

          (1)   Plant community transect sampling approach:

               (a)  Select one of the following designs:

                    (i) Eight (8) - 8" x 20" sample quadrats (two
                    for each sampling unit within the  circular
                    plot); or

                    (ii)  Four (4) - 20" x 20" sample quadrats (one
                    for each sample unit within the plot); or

                    (iii)  Four (4)  - 40" x 40" sample  quadrats (one
                    for each sample unit).


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                    .: Alternate shapes of sample quadrats are
               acceptable provided they are similar in area to
               those listed above.)

           (b)  Randomly toss the quadrat frame into the
               understory of the appropriate sample unit of the
               plot.

           (c)  Record percent areal cover of each plant
               species.

           (d)  Repeat (b) and (c) as required by the sampling
               scheme.

           (e)  Construct a species area curve  (see example,
               Appendix 	) for the plot to determine whether
               the number of quadrats sampled sufficiently
               represent the vegetation in the stratum; the
               number of samples necessary corresponds to the
               point at which the curve levels off
               horizontally; if necessary, sample additional
               quadrats within the plot until the curve levels
               off.

           (f)  For each plant species sampled, determine the
               average percent areal cover by summing the
               percent areal cover for all sample quadrats
               within the plot and dividing by the total number
               of quadrats (see example, Appendix 	}. Proceed
               to substep B below.

     (2)  Fixed interval sampling approach:

           (a) Place one (1) - 40" x 40" sample quadrat centered
          on the transect point.

           (b) Determine percent areal coverage for each
          species. Proceed to substep B below.

B)   Rank plant species by their average percent areal cover,
     beginning with the most abundant species.

C)   Sum the percent cover (fixed interval sampling approach)
     or average percent cover (plant community transect
     sampling approach).

D)   Determine the dominance threshold number - the number at
     which 50 percent of the total dominance measure (i.e.,
     total cover) for the stratum is represented by one or more
     plant species when ranked in descending order of abundance
     (i.e., from most to least abundant).
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     £)   Sum the cover values for the ranked plant species
          beginning with the most abundant until the dominance
          threshold number is immediately exceeded; these species
          contributing to surpassing the threshold  number are
          considered dominants, plus any additional species
          representing 20 percent or more of the total cover of the
          stratum; denote dominant species with an asterisk on the
          appropriate data form.
     F)   Designate the indicator status of each dominant.

2) Bryophyte stratum (mosses, horned liverworts, and true
liverworts): Bryophytes may be sampled as a separate stratum in
certain wetlands, such as shrub bogs, moss-lichen wetlands, and the
wetter wooded swamps, where they are abundant and represent an
important component of the plant community. If treated as a separate
stratum, follow the same procedures as listed for herb stratum. In
many wetlands, however, bryophytes are not abundant and should be
included as part of the herb stratum.

3} Shrub stratum (woody plants usually between 3 and 20 feet tall,
including multi-stemmed, bushy shrubs and small trees below 20
feet):

     A)   Determine the percent areal cover of shrub species within
          the entire plot by walking through the plot, listing all
          shrub species and estimating the percent areal cover of
          each species.

     B)   Indicate the appropriate cover class (T and 1 through 7)
          and its corresponding midpoints (shown in parentheses) for
          each species: T - <1% cover (None); 1 - 1-5% (3.0); 2 =
          6-15% (10.5); 3 - 16-25% (20.5); 4 - 26-50% (38.0); 5 -
          51-75% (63.0); 6 - 76-95% (85.5); 7 • 96-100% (98.0).

     C)   Rank shrub species according to their midpoints, from
          highest to lowest midpoint;

     D)   Sum the midpoint values of all shrub species.

     E)   Determine the dominance threshold number - the number at
          which 50 percent of the total dominance measure (i.e.,
          cover class midpoints)  for the stratum is represented by
          one or more plant species when ranked in descending order.

     F)   Sum the midpoint values for the ranked shrub species,
          beginning with the most abundant, until the dominance
          threshold number is immediately exceeded; these species
          are considered dominants, plus any additional species
          representing 20 percent or more of the total midpoint
          values of the stratum;  identify dominant species (e.g.,
          with an asterisk)  on the appropriate data form.


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     6)   Designate the indicator status of each dominant.

4} Sapling stratum (young or small trees greater than or equal to 20"
feet tall and with a diameter at breast height less than 5 inches):
Follow the same procedures as listed for the shrub stratum or the
tree stratum (i.e., plot sampling technique), whichever is
preferred.

5) Woody vine stratum  (climbing or twining woody plants): Follow the
same procedures as listed for the shrub stratum.

6) Tree stratum (woody plants greater than or equal to 20 feet tall
and with a diameter at breast height equal to or greater than 5
inches): Determine the basal area of the trees by individual and by
species within the 30-foot radius sample plot. Basal area for
individual trees can be calculated by measuring diameter at breast
height (dbh)  with a diameter tape and converting diameter to basal
area using the formula A - £d2/4 (where A - basal area, jj « 3.1416,
and d * dbh).

Do the following steps:

     A) Locate and mark, if necessary, a sample unit (plot) with a
     radius of 30 feet, or change the shape of the plot to match
     topography, or increase size of plot based on species area
     curve assessment. fNotc; A larger sampling unit may be required
     when trees are large and widely spaced.)

     B) Identify each tree within the plot, measure its dbh (using a
     diameter tape),  compute its basal area, then record data on the
     data form.  (fiflifi: Compute basal area using the formula A =
     fid2/4,  where A - basal area, fi - 3.1416, and d - dbh. To
     expedite this calculation, use a hand calculator into which the
     following conversion factor is stored * 0.005454 for diameter
     data in inches or 0.78535 in feet. Basal area in square feet of
     an individual tree can be obtained by squaring the tree
     diameter and multiplying by the stored conversion factor.)

     C) Calculate the total basal area for each tree species by
     summing the basal area values of all individual trees of each
     species.

     D) Rank species according to their total basal area, in
     descending order from the largest basal area to the smallest.

     £} Calculate the total basal area value of all trees in the
     plot by summing the total basal area for all species.

     F)  Determine the dominant trees species; dominant species are
     those species (when ranked in descending order and cumulatively
     totaled) that immediately exceed 50 percent of the total basal
     area value  for the plot, plus any additional species comprising^
                                                               v
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     20 percent or more of the total basal area of the plot; record
     the dominant species on the appropriate data form.

     G) Designate the indicator status of each dominant  (i.e., OBL,
     FACW, PAC, FACU, or UPL) .

After determining the dominants for each stratum, proceed to step
10.
     Step 10. Determine whether the hydrophytic vegetation criterion
is met. When more than 50 percent of the dominant species in the
sample plot have an indicator status of OBL, FACW, and/or FAC,
hydrophytic vegetation is present. Complete the vegetation section
of the summary data sheet. If the vegetation fails to be dominated
by these types of species, the plot is usually not a wetland,
however, it may constitute hydrophytic vegetation under certain
circumstances (see disturbed areas discussion, on pp. 41, and the
list of difficult-to-identify wetlands on pp. 31). If hydrophytic
vegetation is present, proceed to Step 11. If the hydrophytic
vegetation criterion is not met, then the area is nonwetland.

     Step 11. Determine whether the hydric soil criterion is met.
Locate the observation area on a county soil survey map, if
possible, and determine the soil map unit delineation for the area.
Using a soil auger, probe, or spade, make a hole at least 18 inches
deep at the representative location in each plant community type.
Examine soil characteristics and compare if possible to soil
descriptions in the county soil survey report or classify to
Subgroup following "Soil Taxonomy" (often requires digging a deeper
hole), or look for regional indicators of significant soil
saturation (Appendix 	). If soil has been plowed or otherwise
altered, which may have eliminated these indicators, proceed to the
section on disturbed areas (p.41).  Complete the soils section on
the appropriate data sheet and proceed to Step 9 if conditions
satisfy the hydric soil criterion. Areas having soils that do not
meet the hydric soil criterion are nonwetlands.  (CAUTION: Become
familiar with hydric soils that do not possess good hydric field
indicators, such as red parent material soils, some sandy soils, and
some floodplain soils, so that these hydric soils are not
misidentified as nonhydric soils; see the difficult-to-identify
wetlands discussion on p. 31.)

     Step 12. Determine whether the wetland hydrology criterion is
met. Record observations and complete the hydrology section on the
appropriate data form. If the wetland hydrolgy criterion is met,
proceed to Step 13. If the wetland hydrology criterion is not met,
the area is nonwetland. (CAUTION: Seasonally saturated wetland may
not appear to meet the hydrology criterion at certain times of the
growing season; see discussion of difficult-to-identify wetlands,
page 31).

     Step 13. Make the wetland determination for the sample plot.
Examine the data forms for the plot. When the plot meets the

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 hydrophytic vegetation,  hydric  soil, and wetland hydrology criteria,
 it is considered wetland.  Complete the summary data sheet; proceed
 to Step 14  when continuing to sample transects, or to Step 15 when
 determining a boundary between  wetland and nonwetland sample plots.
 (Note:  Double check all  data sheets to ensure that they are
 completed properly before  going to another plot.)

      Step 14.  Take other samples along the transect. Repeat Steps 5
 through 13,  as appropriate. When sampling is completed for this
 transect proceed to Step 15.

      Step 15.  Determine  the wetland-nonwetland boundary point along
 the transect.  When the transect contains both wetland and nonwetland
 plots,  then a boundary must be  established. Proceed along the
 transect from the wetland  plot  toward the nonwetland plot. Look  for
 the occurrence of UPL  and  FACU  species, the appearance of nonhydric
 soil types,  subtle changes in hydrologic indicators, and/or slight
 changes in  topography. When such features are noted, evaluate the
 three criteria and locate  the wetland-nonwetland boundary  (i.e., the
 point at which one of  the  three wetland hydrology criterion is no
 longer  met;  make sure, however, that this area does not qualify  as a
 problem area wetland.). Establish new sample plots on each side of
 the boundary (e.g.,  within 50 feet) and repeat Steps 8 through 12.
 If  existing  plots are  within a  reasonable distance of the boundary,
 additional plots may not be necessary, but always document the
 features that were used  to identify the boundary. Data sheets
 be  completed for each  plot. Mark the position of the wetland
 boundary point on the  base map  or photo and place a surveyor flag or
 stake at the boundary  point in  the field, as necessary. Continue
 along the transect until the boundary points between all wetland and
 nonwetland plots have  been established. (CAUTION: In areas with  a
 high interspersion of  wetland and nonwetland plant communities,
 several  boundary determinations will be required.) When all wetland
 determinations along this  transect have been completed, proceed  to
 Step 16.

      Step 16.  Sample other transects and make wetland determinations
 along each.   Repeat Steps 5 through 15 for each remaining transect.
 When wetland boundary  points for all transects have been
 established, proceed to  Step 17.

      Step 17.  Determine  the wetland-nonwetland boundary for the
 entire project area. Examine all completed copies of the data sheets
 and  mark the  location  of each plot on the base map or photo.
 Identify each  plot as  either wetland (W) or nonwetland (N) on the
map  or photo.  If  all plots are  wetlands, then the entire project
 area  is  wetland.  If all  plots are nonwetlands, then the entire
project  area is  nonwetland. If  both wetland and nonwetland plots are
present,  identify  the  boundary  points on the base map or on the
ground,  and connect these  points on the map by generally following
 contour  lines  to  separate  wetlands from nonwetlands. Confirm this
boundary on the ground by  walking the contour lines between the ^  A

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 transects.  Should anomalies  be  encountered,  it will be  necessary to
 establish  short  transects  in these areas to  refine the  boundary,
 apply Step 15, and make  any  necessary adjustments to the boundary on
 the  base map  and/or  on the ground. It may be worthwhile to place
 surveyor flags or stakes at  these boundary points, especially when
 marking the boundary for subsequent surveying by engineers.


 Point Intercept  Sampling Procedure

 The  point  intercept  sampling procedure is a  frequency analysis of
 vegetation used  in areas that may meet the hydric soil  and wetland
 hydrology  criteria.  It involves first identifying areas that may
 meet the hydric  soil and wetland hydrology criteria within the area
 of concern and then  refining the boundaries  of areas that may meet
 the  hydric soil  criterion  for further examination. Transects are
 then established for analyzing vegetation and determining whether
 hydrophytic vegetation criterion is met by calculating  a prevalence
 index. Sample worksheets and a sample problem using this method are
 presented  in  Appendices    .  respectively.

      Step  1.  Identify the  approximate limits of areas that may meet
 the  hydric  soil  criterion  within the area of concern and sketch
 limits on  an  aerial  photograph. To help identify these  limits use
 sources of  information such  as Agricultural  Stabilization and
 Conservation  Service slides, soil surveys, NWI maps, and other maps
 and  photographs.  (Note:  This step is more convenient to perform
 offsite, but  may be  done onsite; some modification of study area
 lines may be  required after  seeing the site  in the field}. Areas
 that may meet the hydric soil criterion should be stratified into
 areas of similar soils and similar vegetation lifeforms (e.g.,
 forested wetland,  shrub  wetland, and emergent wetland)  for further
 analysis. Proceed to Step  2.

     Step 2.  Scan the areas  that may meet the hydric soil criterion
 and  determine if disturbed conditions exist. Are any significantly
 disturbed areas  present? If  YES, identify their limits  for they
 should be evaluated  separately for wetland determination purposes
 (usually after evaluating  undisturbed areas). Refer to  the section
 on disturbed  areas (p.41), if necessary, to  evaluate the altered
 characteristic(s)  (vegetation, soils, or hydrology), then return to
 this method and  continue evaluating characteristics not altered.
 (Note: Prior  experience  with disturbed sites may allow  one to easily
 evaluate an altered  characteristic, such as  when vegetation is not
 present in  a  farmed  wetland  due to cultivation.) Keep in mind that
 if at any time during this determination one or more of these three
 characteristics  is found to  have been significantly altered, the
 disturbed area wetland determination procedures should  be followed.
 If the area is not significantly disturbed,  proceed to  Step 3.

     Step 3.  Scan  the areas  that may meet the hydric soil criterion
and determine if obvious signs of wetland hydrology or  hydric soil
                                                               %
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 are present.  The wetland hydrology  criterion  is met for any area or
 portion thereof where,  it is  obvious or known that the area is
 frequently inundated or saturated to the surface during the growi
 season.  If the above condition  exists, the hydric soil criterion is
 presumed to be net for  the subject  area and the area is considered
 wetland.  If necessary (e.g.,  for a  regulatory jurisdiction
 delineation) ,  confirm the presence  of readily identified hydric soil
 by examining  the soil for appropriate properties and take note of
 dominant plants which should  easily meet the  hydrophytic vegetation
 criterion.  If the area's hydrology  has not been significantly
 modified and  the soil is organic  (Histosols,  except Folists) or is
 mineral  classified as Sulfaquents,  Hydraquents, or Histic Subgroups
 of Aquic Suborders according  to "Soil Taxonomy", then the area is
 also considered wetland.  fNote; The hydrophytic vegetation criterion
 is presumed to be met under these conditions, since the wetland
 hydrology and  hydric soil criteria  are met, so vegetation may not
 need to  be  examined,  except for regulatory purposes. Regardless,
 hydrophytic vegetation  should be fairly obvious in these
 situations.) Areas lacking obvious  indicators of wetland hydrology
 must be  further examined,  so  proceed to step  4.

      Step 4. Refine the boundary of areas that meet the hydric soil
 criterion.  Verify the presence  of hydric soil within the appropriate
 map units by digging a  number of holes at least 18 inches deep along
 the boundary  (interface)  between hydric soil  units and nonhydric
 soil units. Compare soil  samples with descriptions in the soil
 survey report  to see if they  are properly mapped, and look for soi
 properties  caused by wetland  hydrology (see Appendix _ ). In this
 way,  the  boundary of areas meeting  the hydric soil criterion is
 further refined by field  observations. In map units where only part
 of  the unit is hydric (e.g.,  complexes, associations, and
 inclusions) , locate hydric soil areas on the  ground by considering
 landscape position and  evaluating soil characteristics of the hydric
 soil  portion or for properties  caused by wetland hydrology. fNote;
 Some  hydric soils,  especially organic soils,  have not been given a
 series name and are referred  to by  common names, such as peat, muck,
 swamp, marsh,  wet alluvial land, tidal marsh, Sulfaquents, and
 Sulfihemists;  these areas are also  considered hydric soil map units
 and  should  appear on the  county lists of hydric soil map units.
 Certain hydric soils  are  mapped with nonhydric soils as an
 association or complex, while other hydric soils occur as inclusions
 in  nonhydric soil  map units.  Only the hydric  soil portion of these
 map  units should be evaluated for hydrophytic vegetation.) In areas
 where hydric soils are  not easily located by  landscape position and
 soil  characteristics  (morphology) ,  a soil scientist should be
 consulted.  (CAUTION:  Become familiar with hydric soils that do not
possess good hydric field indicators, such as red parent material
 soils, some sandy  soils,  and  some floodplains soils, so that these
hydric soils are not  misidentified  as nonhydric soils, see section
on difficult-to-identify  wetlands,  p. 31.) (Note; If the project
area does not  have a  soil  map,  hydric soil areas must be determined
 in the field to  use the point intercept sampling method. Consider
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 landscape position, such as depressions, drainageways, floodplains,
 and seepage slopes, and either classify the soil or look for field
 indicators of hydric soil, then delineate the hydric soil areas
 accordingly. If the boundary of the hydric soil area cannot be
 readily delineated, one should use the quadrat sampling procedure
 (page 	)

 After establishing the boundary of the area in question, proceed to
 Step 5.

     Step 5. Consider the following:

     1) Is the area presently lacking hydrophytic vegetation or
 hydrologic indicators due to annual, seasonal, or long-term
 fluctuations in precipitation, surface water, or ground water
 levels?

     2) Are hydrophytic vegetation indicators lacking due to
 seasonal fluctuations in temperature (e.g., seasonality of plant
 growth)?

 If the answer to either of these questions is YES or uncertain,
 proceed to the section on problem area wetland determinations  (p.
  ). If the answer to both questions is NO, normal conditions are
 assumed to be present. Proceed to Step 6. (Note: In some cases,
 normal climatic conditions, such as snow cover or frozen soils, may
 prevent an accurate assessment of the wetland criteria; one must use
 best professional judgement to determine if delaying the wetland
 delineation is appropriate.)

     Step 6. Determine random starting points and random directions
 for three 200-foot line transects in each area that meets or nay
meet the hydric soil criterion. (Note; More than three transects may
be required depending on the standard error obtained for the three
transects.) There are many ways to determine random starting points
and random transect direction. The following procedures are
 suggested:

     1) Starting point - Starting points for the transects are
 selected randomly along the perimeter of the area to be examined.
 Determine the approximate perimeter length and select three random
numbers (from a table for generating random numbers or other
suitable method); these random numbers indicate the position of the
starting points for the three transects; pick a point along the
perimeter to begin pacing off the distance to the starting points.

     2) Transect direction - At a starting point, spin a pencil or
similar pointed object in the air and let it fall to the ground. The
direction that the pencil is pointing indicates the direction of the
transect.  Proceed to Step 7.

     Step 7. Lay out the transect in the established direction. If

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 the transect crossas the hydric soil boundary  (into the nonhydric
 soil area), bend the line back into the hydric soil area by randomj
 selecting  a new direction for the transect following the procedure
 suggested  above, Mark the approximate location of the transect on a
 base nap or aerial photo. Proceed to Step 8.

     Step  8. Record plant data (e.g., species name, indicator group,
 and number of occurrences) at interval points along the transect.
 Only individual plants with stems located in the subject area (i.e.,
 soil type) should be recorded. At the starting point and at each
 point on 2-foot intervals along the transect, record all individual
 plants that would intersect an imaginary vertical line extending
 through the point. Count each individual plant only once per sample
 point; each individual of a single species counts as a separate
 plant for  the tally (e.g., three individuals of red maple count as
 three hits for red maple at that single point). If this imaginary
 line has no plants intersecting it (either above or below the sample
 point), record nothing. Identify each plant observed to species  (or
 other taxonomic category if species cannot be  identified), enter
 species name on the Prevalence Index Worksheet, and record all
 occurrences of each species along the transect. For each species
 listed, identify its indicator group from the appropriate regional
 list of plant species that occur in wetlands (i.e., OBL, FACW, FAC,
 FACU, and  UPL; see pp. ). Plant species not recorded on the lists
 are assumed to be upland species.  If no regional indicator status
 and only one national indicator status is assigned, apply the
 national indicator status to the species. If no regional indicator/
 status is  assigned and more than one national indicator status is
 assigned,  do not use the species to calculate a prevalence index. If
 the plant  species is on the list and no regional or national
 indicator  status is assigned, do not use the species to calculate
the prevalence index. For a transect to be valid for a prevalence
 calculation, at least 80 percent of the occurrences must be plants
that have  been identified and placed in an indicator group. Get help
 in plant identification if necessary. Unidentified plants or plants
without indicator status are recorded but are not used to calculate
the prevalence index. Proceed to Step 9.

     Step  9. Calculate the total frequency of occurrences for each
species (or other taxonomic category), for each indicator group of
plants, and for all plant species observed, and enter on the
Prevalence Index Worksheet. The frequency of occurrences of a plant
species equals the number of times it occurs at the sampling points
along the  transect.. Proceed to Step 10.
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      Step 10.  Calculate the prevalence  index  for  the transect  using
 the following  formula:

                   IFo + 2Ffv +  3Ff  +  4Ffu  + SFu
 Pli -          ,          Fo + Ffw + Ff  + Ffu  + Fu

 where

 Pli  * Prevalence  Index for transect  i;
 Fo   - Frequency of occurrence  of obligate wetland  (OBL)  species;
 Ffw  * Frequency of occurrence  of facultative wetland (FACW)
 species;
 Ff   - Frequency of occurrence  of facultative (FAC)  species;
 Ffu  - Frequency of occurrence  of facultative upland (FACU) species;
 Fu   - Frequency of occurrence  of upland  (UPL) species.
 After calculating  and recording the prevalence index for  this
 transect,  proceed  to Step 11.

      Step 11.  Repeat Steps 5 through  10 for two other transects.
 After completing the three transects, proceed to  Step 12.

      Step 12.  Calculate a mean  prevalence  index for  the three
 transects. To  be considered wetland,  a hydric soil area usually must
 have  a mean prevalence  index (PIM)  of less than 3.0.  A minimum of
 three transects are required in each  delineated area of hydric soil,
 but enough transects are required so  that  the standard error for PIM
 does  not  exceed 0.20 percent.

 Compute the mean prevalence index for the  three transects by using
 the following  formula:

           PIM  - PIT
                N
 where

           PIM  - mean prevalence index for  transects;
           PIT  - sum of  prevalence index values for all transects;
           N -  total number of transects.

 After computing the mean prevalence index  for the three transects,
 proceed to Step 13.

      Step 13.  Calculate the standard  deviation (s) for the
 prevalence index using  the following  formula:

        (PI1-PIM)2  + CPI2-PIMJ2  + (PI3-PIMJ2
                    N-l

fNote; See formulas in Steps 8 and 10 for symbol definitions.)

After performing this calculation, proceed to Step  14.

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     St«p  14. Calculate the standard error (sx) of the mean
prevalence index using the following formula:
          sx
where

          s • standard deviation for the Prevalence Index
          N - total number of transects
(Note: The sx cannot exceed 0.20. If sx exceeds 0.20, one or more
additional transects are required. Repeat Steps 6 through 14, as
necessary, for each additional transect.) When sx for all transects
does not exceed 0.20, proceed to Step 15.

     Step 15. Record final mean prevalence index value for each
hydric soil map unit and make a wetland determination. All areas
having a mean prevalence index of less than 3.0 meet the hydrophytic
vegetation criterion (see p. 18).  If the community has a prevalence
index equal to or greater than 3.0, it is usually not hydrophytic
vegetation except under certain circumstances; consult the section
on difficult-to-identify  wetlands (p.31) for these exceptions.
Proceed to Step 16.

     Step 16.  Determine whether the wetland hydrology criterion is
met. Record observations and complete the hydrology section on the
appropriate data form. If the wetland hydrolgy criterion is met,
then the area is considered a wetland. If the area has been
hydrologically disturbed, one must determine whether the area is
effectively drained before making a wetland determination; this type
of area should have been identified in Step 2 (see disturbed areas
discussion, page 41). If the area is effectively drained, it is
considered nonwetlartd; if it is not, the wetland hydrology driterion
is met and the area is considered a wetland. (CAUTION: Seasonally
saturated wetland may not appear to meet the hydrology criterion at
certain times of the growing season; see discussion of difficult-to-
identify wetlands, page 31).

     Step 17.  Delineate the wetland boundary. After identifying the
wetland, delineate the boundary by refining the limits of the area
that meets the all three criteria (including any problem area
wetlands). Mark the boundaries with flagging tape, if necessary.
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APPENDIX 5.  Descriptions of Difficult-to-Identify Wetlands.

Prairie Potholes.

     Potholes are glacially-formed depressions that are capable of
     storing water (Eisenlohr 1972).  They are generally located in
     the north central United States  and southern Canada.  Although
     potholes nay occur in forested areas,  the majority occur in the
     prairie region where they are subject to arid or semi-arid
     climatic conditions. Most potholes are small, generally less
     than an acre in size.

     Pothole soils are generally poorly drained,  slowly permeable
     soils capable of ponding water.  Precipitation is the  basic
     source of water in potholes. Runoff from the drainage area is
     highly variable, but it is the key in determining if  and how
     long ponding will occur.  Precipitation in the pothole region
     varies appreciably from year to  year.  Average precipitation is
     far too small to meet the demands of evaporation and  as a
     result most potholes are dry for a significant portion of the
     year,  containing water for only  a short period generally early
     in the growing season. In years  of drought,  potholes  may not
     pond water at all. However in most years, seasonal
     replenishment can be expected (Eisenlohr 1972).

     In certain areas, the vast majority of potholes  are farmed,
     either occasionally or every year,  depending upon the duration
     of ponding. Many potholes have been either partially  or totally
     drained to enhance agricultural  production.  The  drastically
     fluctuating climate and alteration for farming have resulted in
     highly disturbed conditions that make wetland identification
     difficult. Aerial photographs, ASCS compliance slides,  and
     other offsite information that depict long-term  conditions are
     often better indicators of wetland conditions than onsite
     indicators reflecting only a single point in time.

     Plant communities in potholes are usually disturbed,  either
     naturally or due to farming, and many do not exhibit  vegetation
     typical of more stable wetlands. The process of  annual drying
     (drawdown) in potholes enables the invasion of FAC, FACU,  or
     UPL plant species during dry periods which may persist into the
     wet seasons. Stewart and Kantrud (1971)  have recognized this
     condition in describing vegetation phases in their
     classification of wetlands for the Prairie Pothole Region.  The
     phases are as follows:

          For nohcropland areas:

          Drawdown bare soil phase. As surface water  in the open
          water phase gradually recedes and disappears, expanses of
          bare mud flats, which often become dry, are exposed.
          Ordinarily,  this phase is of short duration, but in
                                                                *
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Plavas.
           intermittent-alkali zones and occasionally in the more
           saline deep marsh zones, it nay persist for considerable
           periods.

           Natural drawdown emergent phase. Undisturbed areas with
           emergent drawdown vegetation are considered to be in this
           phase. Thin growth is composed mostly of annual plants,
           including many forbs, that germinate on the exposed mud or
           bare soil of the drawdown bare soil phase. After the
           drawdown emergents become established, surface water is
           occasionally restored by heavy summer rains.
           Characteristic plant species of this phase include:
           Eleocharis acicularis (terrestrial form), Rumex maritimus,
           Kochia scoparia, Xanthium italicum, Chenopodium rubrun,
           and Senecio congestus.

           For cropland area1

           Cropland drawdown   ase. Tilled pothole bottoms with
           drawdown vegetatii  characterize this phase. The plants
           include many coarse, introduced annual weeds and grasses
           that normally develop on exposed mud flats during the
           growing season. These species appear as overwinter
           emergents whenever surface water is restored by summer
           rains. Characteristic plant species include: Agropyron
           repens, Echinochloa crusgalli, Polygonum lapathifolium,
          Veronica peregrina, Hordeum jubatum, Plagiobothrys
           scopulorum, Xanthium italicum, Bidens frondosa, Seteria
          glauca, Polygonum convolvulus, Agropyron smithii, Brassica
           kaber, Descruainia sophia, Androsace occidentalis, Ellisia
          nyctelea, Erigeron canadensis, and Iva xanthifolia.

          Cropland' tillage phase. In this phase, tilled bottom soils
           are dominated by annual field weeds, characteristic of
           fallow or neglected low cropland. Tilled dry pothole
          bottoms devoid of vegetation are also considered to be in
          this phase. Planted small grain or row crops are often
          present.
     Playas occur in many arid or semiarid regions of the world.
     Although occurring throughout much of the western United
     States, they are concentrated in the southern Great Plains as
     either ephemeral or permanent lakes or wetlands (Nelson et. al.
     1983) . The topography of most playa regions is flat to gently
     rolling and generally devoid of drainage. Runoff from the
     surrounding terrain is collected into playa basins, where water
     is evaporated rapidly. Playas range in size from several
     hundred acres to only a few acres, with the majority being less
     than 10 acres.
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     Surface soils of playas are generally clays that form a highly
     impermeable seal and increase their water-holding capacity. The
     playa soils are typically Vertisols. In the southern Great
     Plains, playa soils are listed as Randall, Lipan, or Ness
     clays, Stegall silty clay loams, Lofton clay loams, or may be
     uncharacterized occurring as inclusions within nonhydric soil
     map units. Soils of playas are generally distinguishable from
     surrounding upland soils because of their contrasting darker
     color (Reed 1930}.

     The hydrology of playas involves rapid accumulation of natural
     runoff during late spring, with a gradual loss by evaporation
     and seepage through the summer except where basins have been
     excavated to concentrate water. The hydrology is influenced by
     agricultural practices, including basin modification for water
     collection and retention and grazing in the watershed. Water
     reaching the playa is derived primarily from precipitation and
     runoff within the basin watershed.

     Playa basins are dry most of the time. The basins collect water
     primarily in two peak periods - May and September -as a result
     of regional convectional storms common throughout the region.
     Water collection in the basins is generally representative of
     seasonal or long-term extremes and not average annual
     conditions. As a result, wetland hydrology is best
     characterized by examining hydrological indicators over a
     multi-year period rather than relying on hydrological
     conditions that may be present at any point in time.

     The hydrology of most playa wetlands seldom allows a stable
     flora to develop. Playa basins may have a dense cover of annual
     or perennial vegetation or may be barren, depending on the
     timing, intensity and amount of precipitation and irrigation
     runoff, the extent of grazing, and the size of the playas. As
     with potholes, the process of annual drying (drawdown) in
     playas enables the invasion of FAC, FACU, and UPL plants during
     dry periods which may persist into other seasons. Playa basins
     may show vegetative zonation in concentric bands from the basin
     center to the perimeter in response to decreasing water depths
     or soil moisture levels. However, such zonation is not typical
     of all playa basins; small playas that collect limited runoff
     may support prairie vegetation (primarily FACU and UPL species}
     or may be cultivated. Cultivated basins often contain either
     the living plants or remnants of smartweeds (Polygonum spp.),
     ragweeds (Ambrosia spp.), or other invading annuals. Some playa
     basins are large enough to have an open expanse of deep water
     that may support aquatic plant communities.
Vernal Pools.
     Vernal pools are depressional areas covered by shallow water
     for variable periods from winter to spring, but may be
                                                              %

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 completely dry for most  of the summer and fall.  Small pools
 may drain completely  several times during the rainy season a
 some pools may not retain any water during drought years.

 An understanding  of the  natural history of the plants that
 occur in  the  transitional areas from pool to typically
 terrestrial habitat is useful in delineating these wetlands.
 Zedler (1987)  provides an excellent overview of vernal pools
 which is  briefly  summarized below.

 Vernal pools  are  wide-ranging in size (from 10 feet wide to 10
 acres)  but are always shallow (less than 6 inches to 2 feet
 deep).  Depth and duration of saturation and inundation are
 more important in defining a vernal pool than size.  Soils with
 confining layers,  either nearly impermeable clay layers or
 iron-silica cemented  hardpans, often have a  seasonally perched
 water table which favors the development of vernal pool.
 Microrelief on the soils typically is hummocky, with pits
 (depressions)  and mounds.  Individual vernal pools are often
 interconnected by a series of swales and tributaries,  winter
 rainfall  perches  on the  confining layer, until removed by
 evapotranspiration in the spring.  A cemented hardpan or nearly
 impermeable clay  subsoil layer, the pit and mound microrelief,
 and  presence  of swales are strong indicators of vernal pools.

 Vernal  pools  hold water  long enough to allow some strictly
 aquatic organisms to  grow and reproduce (complete their life
 cycles),  but  not  long enough to permit the development of a
 typical pond  or marsh ecosystem.  Changes in a vernal pool
 during  the season are so dramatic that it is in some ways more
 appropriate to consider  it to be sequence of ecosystem (a
 cyclical  wetland)  rather than a single static type.  Vernal
 pool  development  can  be  broken into four phases:  (l) wetting
 phase,  (2)  aquatic phase, (3) drying phase, and (4) drought
 phase.  The first rains  stimulate the germination of dormant
 seeds and the  growth  of  perennial plants (wetting phase).  When
 the  cumulative rainfall  is sufficient to saturate the soils,
 aquatic plants and animals proliferate (aquatic phase).
 Nonaquatic plants are subjected to stress at this time.  As the
 pool  levels begin to  recede (drying phase), the high soil
 moisture  insures  that plant growth continues after standing
 water is  gone.  Eventually, the plants succumb to drought and
 turn brown, with  drying  cracks appearing in the soil (drought
 phase).

 Plant species  characteristic of vernal pools are endemic to
vernal pools,  or  occur in vernal pools but are common in other
 aquatic habitats  or associated with vernal pools (see Tables
 6A-D in Zedler, 1987).   Non-pool species can tolerate the
 limited periods of  standing water that exist toward the pool
margins.
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     Since vernal pools typically vary considerably in depth and
     duration or both from year to year, within a year, or between
     different pools, plant composition is quite dynamic.  FAC, FACU
     and UPL species often invade the pool basins in dry years, as
     they do in .other seasonally variable wetlands.  Lack of
     hydrophytic plant species also nay be indicative of recent
     disturbances such as off-road vehicle activities, farming, or
     grazing.  In delineating these wetlands, it is important to be
     aware not only of the "pool" but of the vernal pool complex
     (pool, basin, swales, tributaries), parts of which may have
     shorter and more variable periods of inundation.  •

Other Seasonally Variable Wetlands.

In many regions (especially in arid and semiarid regions and areas
with distinct wet and dry seasons), depressional areas occur that
may have evidence of all three wetland criteria during the wetter
portion of the growing season, but normally lack evidence of wetland
hydrology and/or hydrophytic vegetation during the drier portion of
the growing season. In addition, some of these areas lack hydric
soil properties. Seasonal changes in plant species dominance may
create problems for recognizing these wet during dry periods.  While
OBL and FACW plant species are normallly dominant during the wetter
portion of the growing season, FACU and UPL species (usually
annuals) may be dominant during the drier portion of the growing
season and during and for some time after droughts. Examples of
seasonally variable wetlands are pothole wetlands in the upper
Midwest, playa wetlands in the Southwest, and vernal pools along the
West Coast; these are discussed above. Become familiar with the
ecology of these and similar types of wetlands (see Appendix    for
readings). Also, be particularly aware of drought conditions that
permit invasion of UPL species (even perennials).

Vegetated River Bars and Adjacent Flats. Along western streams in
arid and semiarid parts of the country, some river bars and flats
may be vegetated by FACU species while others may be colonized by
wetter species. If these areas are frequently inundated and/or
saturated sufficient to meet the wetland hydrology criterion, they
are wetlands. They may be subject to flooding more than once during
the growing season, depending on rainfall patterns. The soils often
do not reflect the characteristic morphological properties of hydric
soils,  however, and thereby pose delineation problems.


Difficult-to-Identify Wetland Situations

Certain situations encountered in the field make wetland
identification and delineation difficult. These situations are
discussed below along with guidance on how to handle them.
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 Navlv created wetlands.  These  wetlands  include manmade  (artificial
 wetlands,  beaver-created wetlands,  and  other wetlands that have
 recently formed due to natural processes. Artificial wetlands may be
 purposely or accidentally created  (e.g., road impoundments,
 undersized culverts,  irrigation, and  seepage from earth-dammed
 impoundments)  by human activities.  Many of these areas will have
 evidence of wetland hydrology  and  hydrophytic vegetation. The area
 should lack typical morphological  properties of hydric soils, since
 the soils have just recently been  inundated and/or saturated. Since
 all of these wetlands are newly established, evidence of one or more
 of  the wetland identification  criteria  nay not be present. One must
 always consider the relative permanency of the wetter conditions.
 For example,  if a beaver has recently blocked a road culvert that
 has now caused flooding  of nonwetland (e.g., upland forest or
 field),  it is  quite possible that  the blockage will soon be removed.
 In  this case,  the action is considered  nonpermanent and the area is
 not considered wetland.  If, however,  hydrophytic vegetation has
 colonized  the  area,  the  hydrology  is  considered more or less
 permanently altered and  the area is considered wetland. Temporary
 roads  may  impede the  natural flow  of  water and impound water for
 some time.  Yet,  since the road is  only  temporary, the effect is also
 temporary,  so  the area is not  considered wetland, unless, of course,
 it  was wetland prior  to  the road construction.

 Wetlands on glacial till or in rockv  areas.

 Sloping wetlands occur in glaciated areas where soils cover
 relatively impermeable glacial till or  where layers of glacial till
 have different hydraulic conditions that permit groundwater seepage.
 Such areas are seldom, if ever, flooded, but downslope groundwater
 movement keeps the soils saturated  for  a sufficient portion of the
 growing  season to produce anaerobic and reducing soil conditions.
 This promotes  the development  of hydric soils and hydrophytic
 vegetation.  Evidence  of  wetland hydrology may be lacking during the
 drier  portion  of the  growing season.  Hydric soil properties also may
 be difficult to observe  because certain areas are so rocky that it
 is difficult to examine  soil characteristics within 18 inches.

 Wetland-nonwetland mosaics, in numerous areas, including northern
 glaciated  regions and the coastal plain, the local topography may be
 pockmarked with a complex of "pits" (depressions) and "mounds"
 (knolls).  The  pits may. be wet  enough  to be classified as wetland,
 whereas  the mounds are usually nonwetland. (Note: in some areas, the
 shallow  mounds are also  wetland.  When  this is true, the entire area
 is wetland.) The iriterspersion of wet pits and dry mounds may make
 the  delineation of the wetland boundary difficult when the pits are
 too  small  to separate from the mounds.  Of course, any area should
be mapped within practical  limits.  When it is not practicable to
 separate the wet pits from the dry  mounds, it is recommended that
 the  wetland-nonwetland boundary be  delineated by assessing the
 percent  of  the area covered by the  wetland pits in an area of
 similar  pit-mound relief.  At least  two  random transects should be
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 established to determine the percent of pits vs. mounds. Based on
 the  assessment at  two-foot  intervals along each transect, the
 percent  of wetland vs. upland points can be established for the
 area.  Consult the  appropriate regulatory agency to learn what ratio
 they want to consider  "wetland"  for regulatory purposes. One should
 also note in his or her field report that this protocol was used and
 give an  estimated  size range for the wetland pits (e.g., 3-5*
 diameter) as well  as a brief narrative description of the site.

 Cyclical wetlands. While the hydrology of all wetlands varies
 annually, the hydrology of  certain wetlands may naturally fluctuate
 in a cyclical patterns of a series of consecutive wet years followed
 by a series of dry years. During the wet periods, hydrophytic
 vegetation and wetland hydrology are present, yet during the dry
 periods, the hydrology does not  appear to meet the wetland hydrology
 criterion and FACU and UPL  plant species often become established
 and  may  predominate under these  temporal drier conditions. Despite
 the  lack of periodic flooding or saturated soils for a multi-year
 period,  these area should still  be considered wetland, since in the
 long run, wetland  characteristics prevail. Specific examples of
 cyclic wetlands include Alaska's black spruce-permafrost wetlands
 (see Alaska in regional list above), groundwater wetlands of the
 Cimmaron Terrace of Oklahoma and Kansas, and wetlands in coastal and
 West Texas (see Midwest regional list above). Other cyclical
 wetlands are associated with drought-prone areas such as southern
 California and the arid and semi-arid regions of the country.


 Vegetated Flats. Vegetated  flats are characterized by a marked
 seasonal periodicity in plant growth. They are dominated by annual
 OBL  species, such  as wild rice (Zizania aquatica), and/or perennial
 OBL  species, such  as spatterdock (Nuphar luteum), that have
 nonpersistent vegetative parts (i.e., leaves and stems breakdown
 rapidly  during the winter,  providing no evidence of the plant on the
 wetland  surface at the beginning of the next growing season). During
 winter and early spring, these areas lack vegetative cover and
 resemble mud flats; therefore, they do not appear to qualify as
 wetlands. But during the growing season the vegetation becomes
 increasingly evident, qualifying the area as wetland. In evaluating
 these areas, which occur both in coastal and interior parts of the
 country  (e.g., regularly flooded freshwater tidal marshes and
 exposed  shores of  lakes or  reservoirs during drawdowns due to
 natural  fluctuations or human actions), one must consider the tine
 of year  of the field observation and the seasonality of the
vegetation.  Again, one must become familiar with the ecology of
these wetland types (see Appendix 	 for readings).

Interdunal swale wet;lands.  Along the U.S. coastline, seasonally wet
swales supporting  hydrophytic vegetation are located within sand
dune complexes on  barrier islands and beaches. Some of these swales
are  inundated or saturated  to the surface for considerable periods
during the growing season,  while others are wet for only the early
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 part of the  season.  In  some  cases, swales may be flooded irregularly
 by the  tides. These  wetlands have sandy soils that generally lack  A
 evidence of  hydric soil properties. In addition, evidence of wetlanW
 hydrology may be  absent during the drier part of the growing season.
 Consequently, these  wetlands may be difficult to identify.

 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 following 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 established
 by the  limits of  predominance of OBL and/or FACW species.

 Drought-affected  Wetlands.   Droughts periodically occur in many
 parts of the country, especially in the semiarid and arid West.
 During  drought, it is quite  obvious that water will not be observed
 in many wetlands, especially those higher up on the soil 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 problem area wetlands which
 is  the  case.  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 listed 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.
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 APPENDIX C.  Difficult-To-Identify Hydric  Soils

 Some hydric  soils are soils lacking  diagnostic  hydric  soil
 properties or soils that nay look like  hydric soils  in terns of soil
 color,  but whose color is not the result  of  excess wetness.
 Presumably,  the area in question  has been located on a soil survey
 nap that identified it as a hydric component of a nap  unit on the
 county  list  of hydric soil map units or if no maps are available,
 soil properties (matrix colors) that appear  to  contradict landscape
 position (e.g.,  red-colored soils in obvious depressions or gray-
 colored soils in obvious uplands)  have  been  observed.  Problem area
 soils are discussed in the following subsection.

 To determine whether the area in  question is wetland,  emphasis will
 be placed on vegetation and signs of hydrology, yet  always consider
 landscape position in assessing the  likelihood  of wetland in these
 situations.

 Seven types  of these hydric soils are recognized and discussed
 below.

 Hydric  Entisols  tfloodolain and sandv soils!. Entisols are usually
 young or recently formed soils that  have  little or no  evidence of
 pedogenically developed horizons  (U.S.D.A. Soil Survey Staff 1975).
 These soils  are  typical of floodplains  throughout the  U.S., but are
 also found in glacial outwash plains, along  tidal waters, and in
 other areas.  They  include sandy soils of  riverine islands, bars, and
 banks and finer-textured soils of floodplain terraces.  Wet entisols
 have an aquic or peraquic moisture regime and are considered hydric
 soils,  unless effectively drained. Some Entisols are easily
 recognized as hydric soils such as the  Sulfaquents of  tidal salt
 marshes and  Hydraquents,  whereas  others pose problems  because they
 do  not  possess typical  hydric soil field  indicators. Wet sandy
 Entisols (with loamy fine sand and coarser textures  in horizons
vithin  20 inches of the surface)  may lack sufficient organic matter
 and clay to  develop hydric soil colors. When these soils have a hue
 between 10YR and 10Y and distinct or prominent  mottles present, a
 chroma  of 3  or less is  permitted  to  identify the soil  as hydric
 (i.e.,  an aquic  moisture regime).  Also, hydrologic data showing that
 the soil is  flooded or  ponded enough to be wetland are sufficient to
 verify  these soils  as hydric.  Sandy  Entisols must have positive
 indicators of hydrology (see  positive indicators for sandy soils for
 your region)  in  the upper 6  inches and  have  colors of  the loamy fine
 sand or coarser  Aquents.  Soils that  key to the  aerie suborder or
 have  colors  of the  aerie suborder within  12  inches are not
 considered hydric soils.  Other Entisols are  considered hydric if
 they  classify in the aquic suborder  and have the colors as listed
 for  soils  that are  finer than loamy  fine  sand in some  or all layers
 to  a depth of 12 inches.  Soils that  key to the  aerie subgroup or
have  aerie colors above  12  inches  as listed  for Aquent subgroups are
not hydric.

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 Hydric Mollisols  fppairie and steppe soils!. Mollisols are dark
 colored, base-rich  soils. They are common in the central part of the
 conterminous U.S. from eastern Illinois to Montana and south to
 Texas.  Natural vegetation is mainly tall and mid grass prairies and
 short  grass steppes. These soils typically have deep, dark-colored
 surface (mollic epipedons) and subsurface layers that have color
 values of  less than 4 moist and commonly have chromas of 2 or less.
 The  low chroma colors of Mollisols are not necessarily due to
 wetness of periods  of saturation. They are rich in organic matter
 due  largely to the  vegetation (deep roots) and reworking of the soil
 and  organic matter  by earthworms, ants, moles, and rodents. The low
 chroma colors of Mollisols are not necessarily due to prolonged
 saturation, so be particularly careful in making wetland
 determinations in these soils. Many Great Groups of aquic Mollisols
 do not have aerie subgroups. Therefore, if a Mollisol is classified
 as an  Aguoll, special care is needed to determine if it is hydric.
 There  are  two suborders of Mollisols that have aquic moisture
 regimes: Albolls and Aquolls. Albolls have an albic horizon that
 separates  the surface layer from an argillie or natric horizon. The
 albic  horizon must  have chromas of 2 or less or the albic, argillic,
 or natric  horizons  must have characteristics associated with wetness
 such as mottles, iron-manganese concretions larger than 2 mm or
 both. All  Albolls are considered hydric soils. Aquolls exhibiting
 regional hydrology  characteristics for Mollisols in the upper part
 are considered hydric.

 Hydric Oxisols. These soils are highly weathered, reddish,
 yellowish, or grayish soils of tropical and subtropical regions.
 They are mixtures of quartz, kaolin, free oxides, and organic
 matter. For the most part, they are nearly featureless soils without
 clearly distinguishable horizons. Oxisols normally occur on stable
 surfaces and weathering has proceeded to great depths. To be hydric,
 these normally red-colored soils are required to have chromas 2 or
 less immediately below the surface layer, or if there are distinct
 or prominent mottles, the chroma is 3 or less. They also qualify as
 hydric  if  they have continuous plinthite within 12 inches of the
 surface.

Hydric Spodosols (evergreen forest soils!. These soils, usually
 associated with coniferous forests, are common in northern temperate
 and boreal regions  of the U.S. and along the Gulf-Atlantic Coastal
 Plain. Spodosols have a gray eluvial E-horizon overlying a
diagnostic spodic horizon of accumulated (sometimes weakly cemented)
 organic matter, aluminum, and iron (U.S.D.A. Soil Survey staff
 1975). A process called podzolization is responsible for creating
these two  soil layers. Organic acids from the leaf litter on the
soil surface are moved downward through the soil with rainfall,
cleaning the sand grains in the first horizon (the E-horizon) then
coating the sand grains with organic matter and iron oxides in the
second layer (the spodic horizon). Certain vegetation produce
organic acids that  speed podzolization including eastern hemlock

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 (Tsuga canadensis), spruces  (Picea spp.), pine  (Pinus spp.), larches
 (Larix spp.)/ and  oaks  (Quercus spp.)  (Buol, et al. 1980). The E-
 horizon or Albic horizon by definition has a chroma of 3 or less and
 is often mistaken  for a gleyed layer by the novice. These Spodosols
 must have one of the positive regional hydrology indicators and meet
 the color requirement for Aguods listed in "Soil Taxonomy." Hydric
 Spodosols that have a thick  (more than 12 inches) sandy epipedon are
 extremely difficult to identify especially in the Gulf-Atlantic
 Coastal Plain. These soils must also meet the color requirements for
 the Aguod suborder and meet one of the regional hydrology indicators
 for sandy soils.


 Hvdric Vertisols (shrink and swell soils). These soils are dark-
 colored clayey soils that are extensive in the Great Plains, in the
 southern U.S., and in parts of California. They develop wide, deep
 cracks when dry and swell shut, when wet. Many Vertisols exhibit
 gilgai microtopography with swells and swales or mounds and hollows.
 The morphology of  these soils may be distinctly different on the
 mound and in the hollow. They commonly have thick dark-colored
 surface layers because of the churning action created by the
 shrinking and swelling clays. During wet periods, they are very
 slowly permeable and may pond water on the surface of the micro-
 hollows, but in dry periods they are rapidly permeable with water
 travelling along the deep cracks to lower layers. These soils must
 meet one of the regional hydrology indicators for Vertisols to
 qualify as hydric.

 Hydric soils derived from red parent material. Hydric mineral soils
 derived from red parent materials (e.g., weathered clays, Triassic
 sandstones, and Triassic shales) may lack the low chroma colors
 characteristic of  most hydric mineral soils. In these soils, the hue
 is redder than 10YR because of parent materials that remain red
 after citrate-dithionite extraction, so the low chroma requirement
 for hydric soil is waived (U.S.O.A. Soil Conservation Service 1982).
 Red soils are most common along the Gulf-Atlantic Coastal Plain
 (Ultisols), but are also found in the Midwest and parts of the
 Southwest and West (Alfisols), in the tropics, and in glacial areas
 where older landscapes of red shales and sandstones have been
 exposed. In southern New England, red parent material hydric soils
 are derived from reddish sandstone, shale, conglomerate, or basalt.
 These soils include the following series: Meno  (Aerie Haplaquepts),
 Wilbraham (Aquic Dystrochrepts), Lim (Aerie Fluvaquents), and Bash
 (Fluvaquentic Dystrochrepts). In the absence of diagnostic hydric
 soil properties, more weight must be placed on the vegetation and
 hydrology. Follow  procedures for identifying wetlands in problem
 area soils at the  beginning of this subsection.

Hydric soils derived from low chroma parent materials. Soils derived
 from slate and phyllite produce low chroma colors due to this parent
material. In southern New England, nonhydric soils having                I
predominantly low  chroma colors include the following series:            I

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Newport, Nassau, Dutches*, Bernards ton, Pittstown, Dummerston,
Taconic, Macomber, Lakesboro, and Fullan. A few series derived from/
these materials are hydric, including Stissing, Brayton, and
Mansfield, with the first two including nonhydric members as well.
Due to the difficulty of using soil colors as indicators of wetness,
more weight must be placed on vegetation and hydrology. Follow
procedures for identifying wetlands in problem area soils at the
beginning of this subsection.
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APPENDIX 7. Procedures for Difficult-to-Identify Wetlands

Difficult-to-identify wetlands are to be identified using the
procedures below.  These procedures should only be used in
accordance with the guidance for difficult-to-identify wetlands on
Page 31.

1.   What is the reason for the difficulty in wetland
identification/delineation?  (Identify only one of the parameters as
the basis for this difficulty):

     If vegetation is the criterion for which a positive indicator
was not identifiable, go to 2a.  If soils,  go to 2b.  If hydrology,
go to 2c.


     2a.  Is the plant community growing on a soil that meets the
          hydric soil criterion on page 22?

          If no, the area is non-wetland.

          If yes, document the reasons for this conclusion and go to
          3a.


     3a.  Are one or more of the following conditions satisfied?:

               *    hydrologic records or aerial photography
                    combined with hydrologic records (items l and 2
                    on page 11)  document wetland hydrology; or

               *    one or more primary hydrologic indicators (item
                    3 on page 11)  is documented to have been found
                    at the site; or

               *    one or more secondary hydrologic indicators are
                    materially present and supported by
                    corroborative information as described in item 4
                    on page 12 (e.g.,  regional indicators of
                    saturation,  hydrologic gauge data,  NWI maps).

               If no, the area is non-wetland.

               If yes, the area is a wetland; document the reasons
               for this conclusion.   The upper boundary of these
               wetlands is established by the limits of the
               combination of the wetland hydrology indicators
               present and hydric soil.

     2b.   Does the soil support a plant community that meets the
          hydrophytic vegetation criterion on page 18?
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      If no,  th« area is non-wetland.

      If yes,  document the reasons  for this  conclusion and go
      to 3b.
      3b.   Are one or more  of  the  following conditions
           satisfied:

           *     hydrologic  records or aerial photography
                combined  with  hydrologic  records  (items 1 and 2
                on page 11) document wetland hydrology; or

           *     one or more primary hydrologic  indicators  (iten
                3  on page 11)  is documented; or

           *     one or more secondary hydrologic  indicators  are
                materially  present and supported  by
                corroborative  information as described in item 4
                on page 12  (e.g.,  regional indicators of
                saturation, hydrologic gauge data, NWI naps)?

           If  no,  the  area  is  non-wetland.

           If  yes,  the area is a wetland; document the reasons
           for this conclusion.  The upper boundary of these
           wetlands is established by the limits  of the
           combination of the  wetland hydrology indicators
           present and hydrophytic vegetation.

2c.  Is the plant community growing on a soil  that meets the
hydric soil criterion on page 22  ?

     If no, the area  is  non-wetland.

     If yes,  document the  reasons  for this conclusion and go to
     3c.
     3c.  Does the area demonstrate a regional indicator of
     saturation  (see Appendix -)

          If no, go to 5c.

          If yes, go to 4c.

     4c.  Does the area support a plant community that meets
the hydrophytic vegetation criterion on page 18 ?

     If no, the area is non-wetland.
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If yes, the area is a wetland.  Document the reasons for
this conclusion.  The upper boundary of this wetland is
established by the limits of the combination of
hydrophytic vegetation, hydric soils, and the regional
indicators of saturation present.


5c.  Does the percent cover of obligate wetland (OBL)  and
     facultative wetland (FACW)  species in all strata
     except the tree stratum exceed that of the
     facultative upland (FACU) and upland (UPL) species in
     the all strata except the tree stratum or does the
     plant community have a mean prevalence index of less
     than 3.0?

          If no, the area is non-wetland.

          If yes, the area is wetland; document the
          reasons for this conclusion.  The upper boundary
          of this wetland is established by the limits of
          the combination of the wetland vegetation as
          described in this step and hydric soils.
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APPENDIX t.  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. 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 with 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 disturbance:

     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 occurred
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 community (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

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          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 hydrophytic vegetation criterion
was met. If site-specific data do not exist, then do the following,
as appropriate:

          A) If the vegetation is removed and no other alterations
          are done, then the presence of hydric soils and evidence
          of wetland hydrology will be used to identify wetlands.
          If such evidence is found, conditions are assumed to be
          sufficient to support hydrophytic vegetation. It nay be
          advantageous to examine a nearby reference site to collect
          data on the plant community to confirm this assumption.
          (Note; Determination of regulatory jurisdiction for such
          areas is subject to agency interpretation.  For example,
          Federal wetland regulatory policy under the Clean water
          Act, and agricultural program policy under the Food
          Security Act of 1985, as amended, interprets the relative
          permanence of disturbance to vegetation caused by
          cropping.  Be sure to consult appropriate agency in making
          Federal wetland jurisdictional determinations in such
          areas.)

          B) If the area is filled, burying 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 wetland 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,  wetland 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,

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          then continue Steps 4,  5,  and 6 below,  as necessary.
          Otherwise, return to the applicable step of the onsite
          determination method being used.

     Step 4. Determine whether or not hydric soils previously
occurred:

     1}   Describe the type of alteration.  Examine the area and
          describe the type of alteration that occurred.  Look  for
          evidence of:

          A) Deposition of dredged or fill  material - In  many  cases
          the presence of fill material will be obvious.  If so, it
          will be necessary to dig a hole to reach the original soil
          (sometimes several feet deep).  Fill material will usually
          be a different color or texture than the original soil
          (except when fill material has been obtained from similar
          areas onsite). Look for decomposing vegetation  between
          soil layers and the presence of buried organic  or hydric
          mineral soil layers. In rare cases, excessive deposition
          of sediments may be due to catastrophic conditions,  e.g.,
          mud slides and volcanic eruptions. Floodplain environments
          are subjected to periodic sedimentation, but this is a
          more normal occurrence  and does not constitute  a
          significant disturbance for purposes of this manual.

          B) Presence of nonwoody debris at the surface - This can
          only be applied in areas where the original soils do not
          contain rocks. Nonwoody debris includes items such as
          rocks,  bricks, and concrete fragments.

          C) Subsurface plowing - Has the area recently been plowed
          below the A-horizon or  to depths  of greater than 10
          inches? '

          D) Removal of surface layers - Has the surface  soil  layer
          been removed by scraping or natural landslides? Look for
          bare soil surfaces with exposed plant roots or  scrape
          scars on the surface.

          E) Presence of manmade  structures - Are buildings,  dams,
          levees, roads,, or parking lots present?

     2}    Determine the approximate date when the alteration
          occurred, if necessary.  Check aerial photographs, examine
          building permits,  consult with local individuals, and
          review other possible sources of  information.

     3)    Describe the effects on soils.  Consider the following:

          A)  Has  the soil been buried? If so, record the  depth of
          fill material  and determine whether the original soil,was

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     left intact or disturbed. (Note: The presence of a typical
     sequence of soil horizons or layers in the buried soil is
     an indication that the soil is still intact; check
     description in the soil survey report.)
     B) Has the soil been nixed at a depth below the A-horizon
     or greater than 12 inches? If so, it will be necessary to
     examine the soil at a depth immediately below the plow
     layer or disturbed zone.

     C) Has the soil been sufficiently altered to change the
     soil phase? Describe these changes. If a hydric soil has
     been drained to some extent, refer to Step 5 below to
     determine whether soil is effectively drained or is still
     hydric.

4)   Characterize the soils that previously existed at the
     disturbed site. Obtain all possible evidence that may be
     used to characterize soils that previously occurred on the
     area. Consider the following potential sources of
     information:

     A) Soil surveys - In many cases, recent soil surveys are
     available.  If so, determine the soils that were mapped for
     the area. If all soils are hydric soils, it is presumed
     that the entire area had hydric soils prior to alteration.
     Consult aerial photos to refine hydric soil boundaries,
     especially for soil nap units with hydric soil inclusions.

     B) Buried soils - When fill material has been placed over
     the original soil without physically disturbing the soil,
     examine and characterize the buried soils. Dig a hole
     through the fill material until the original soil is
     encountered. Determine the point at which the original
     soil material begins. Remove 18 inches of the original
     soil front the hole and follow standard procedures for
     determining whether the hydric soil criterion is met (see
     p. 	). (Hfitfi: When the fill material is a thick layer,
     it might be necessary to use a backhoe or posthole digger
     to excavate the soil pit.) If USGS topographic maps
     indicate distinct variation in the area's topography, this
     procedure must be applied in each portion of the area that
     originally had a different surface elevation.

     C) Deeply plowed soils or removed surface layers - If soil
     surface layers are removed,  redistributed or deeply plowed
     (excluding normal plowing),  vegetation will not be
     present, so review existing information (e.g., soil
     surveys, wetland maps, and aerial photos), identify a
     nearby reference site that is similar to disturbed area
     prior to its alteration, evaluate for indicators of
     hydrophytic vegetation, hydric soils,  and wetland
     hydrology and make wetland or nonwetland determination, as

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          appropriate.

     5}   Determine whether hydric soils were present at the project
          area prior to alteration. Examine the available data and
          determine whether evidence of hydric soils were formerly
          present. If no evidence of hydric soils is found, the
          original soils are considered nonhydric soils. If evidence
          of hydric soils is found, the hydric soil criterion has
          been met. Continue to Step 5 if hydrology also was
          altered. Otherwise, record decision and return to the
          applicable step of the onsite determination method being
          used.

     Step 5.  Determine whether wetland hydrology existed prior to
alteration and whether wetland hydrology still exists (i.e., is the
area effectively drained?). To determine whether wetland hydrology
still occurs, proceed to Step 6. To determine whether wetland
hydrology existed prior to the alteration:

     1)   Describe the type of alteration. Examine the area and
          describe the type of alteration that occurred. Look for
          evidence of:

          A) dams - Has recent construction of a dam or some natural
          event (e.g., beaver activity or landslide) caused the area
          to become increasingly wetter or drier? (Note: This
          activity could have occurred at a considerable distance
          from the site in question, so be aware of and consider the
          impacts of major dams in the watershed above the project
          area.)

          B) levees,, dikes, and similar structures - Have levees or
          dikes been recently constructed that prevent the area from
          periodic overbank flooding?

          C) ditches or drain tiles - Have ditches or drain tiles
          been recently constructed causing the area to drain more
          rapidly?

          D) channelization * Have feeder streams recently been
          channelized sufficiently to alter the frequency and/or
          duration of inundation?

          E) filling of channels and/or depressions (land-leveling)
          - Have natural channels or depressions been recently
          filled?

          F) diversion of water - Has an upstream drainage pattern
          been altered that results in water being diverted from the
          area?

          G) groundwater withdrawal - Has prolonged and intensive

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     pumping of groundwater for irrigation or other purposes
     significantly lowered the water table and/or altered
     drainage patterns?

2)   Determine the approximate date when the alteration
     occurred, if necessary. Check aerial photographs, consult
     with local individuals, and review other possible sources
     of information.

3)   Describe the effects of the alteration on the area's
     hydrology. Consider the following and generally describe
     how the observed alteration affected the project area:

     A) Is the area more frequently or less frequently
     inundated than prior to alteration? To what degree and
     why?

     B) Is the duration of inundation and soil saturation
     different than prior to alteration? How much different and
     why?

4)   Characterize the hydrology that previously existed at the
     area. Obtain and record all possible evidence that may be
     useful for characterizing the previous hydrology. Consider
     the following:

     A) stream or tidal gauge data - If a stream or tidal
     gauging station is located near the area, it may be
     possible to calculate elevations representing the upper
     limit of wetland hydrology based on duration of
     inundation.  Consult SCS district offices, hydrologists
     from the local  CE district offices or other agencies for
     assistance.  If  fill material  has not been placed on the
     area, survey this elevation from the nearest USGS
     benchmark.  If fill material has been placed on the area,
     compare the calculated elevation with elevations shown on
     a  USGS topographic map or any other survey map that
     predates site alteration.

     B) field hydrologic indicators onsite or in a neighboring
     reference area  - Certain field indicators of wetland
     hydrology may still be present.  Look for water marks on
     trees or other  structures,  drift lines,  and debris
     deposits (see pp.  17-19 for additional hydrology
     indicators).  If adjacent undisturbed areas are in the same
     topographic position,  have the same soils (check soil
     survey map),  and are similarly influenced by the same
     sources of inundation,  look for wetland hydrology
     indicators in these areas.

     C)  aerial  photographs  - Examine aerial photographs and
     determine  whether the  area has been inundated or saturated
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           during the growing season. Consider the time of the year
           that  the  aerial photographs were taken and use only
           photographs taken prior to site alteration.

           D)  historical records - Examine historical records for
           evidence  that the area has been periodically inundated.
           Obtain copies of any such information.

           E)  National Flood Insurance Agency flood maps - Determine
           the previous frequency of inundation of the area from
           national  floods maps (if available).

           F)  local  government officials or other knowledgeable
           individuals - Contact individuals who might have knowledge
           that  the  area was periodically inundated or saturated.

If sufficient data  on hydrology that existed prior to site
alteration are  not  available to determine whether wetland hydrology
was previously  present, then use the other wetland identification
criteria  (i.e.,  hydrophytic vegetation and hydric soils) to make a
wetland determination.

     5)    Determine whether wetland hydrology previously occurred.
           Examine available data. If hydrology was significantly
           altered recently (e.g., since Clean Water Act), was
           wetland hydrology present prior to the alteration? If the
           vegetation and soils have not been disturbed, use site
           characteristics - vegetation, soils, and field evidence oJ
           wetland hydrology - to identify wetland.  If vegetation
           and soil  are removed, then review existing information
           (e.g., soil surveys, wetland maps, and aerial photos),
           following procedures in Step 6, substep 3. If no evidence
           of  wetland hydrology is found, the original hydrology of
           the area  is not considered to meet the wetland hydrology
           criterion. If evidence of wetland hydrology is found, the
           area  used to meet the wetland hydrology criterion. Record
           decision  and return to the applicable step of the onsite
           determination method being used.

     Step  6.  Determine whether wetland hydrology still exists. Many
wetlands have a  single ditch running through them, while others may
have an extensive network of ditches. A single ditch through a
wetland nay not  be  sufficient to effectively drain it; in other
words, the wetland  hydrology criterion still may be met under these
circumstances. Undoubtedly, when ditches or drain tiles are
observed,  questions as to the extent of drainage arise, especially
if the ditches or drain tiles are part of a more elaborate stream
channelization or other drainage project. In these cases and other
situations where the hydrology of an area has been significantly
altered (e.g., dams, levees, groundwater withdrawals, and water
diversions),  one must determine whether wetland hydrology still
exists. If it is present, the area is not effectively drained. If

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wetland hydrology is not present, the area is not a wetland.  To
determine whether wetland hydrology still exists:

      1) Describe the type or nature of the alteration. Look for
evidence of:

          A) dans;
          B) levees, dikes, and similar structures;
          C) ditches;
          D) channelization;
          E) filling of channels and/or depressions;
          F) diversion of water; and
          G) groundwater withdrawal.

(See Step 5 above for discussion of these factors.)

     2) Determine the approximate date when the alteration occurred,
if necessary. Check aerial photographs, consult with local
officials, and review other possible sources of information.

     3) Characterize the hydrology that presently exists at the
area. When evaluating agricultural land to determine the presence or
absence of wetland, it is recognized that such lands are generally
disturbed and must be viewed in that context. Wetland hydrology is
often altered on agricultural lands, so the mere presence of soils
meeting the hydric soil criterion is not sufficient to determine
that wetlands are present. Due to the common hydrologic and
vegetative modifications on agricultural lands, indicators of
wetland hydrology,  together with soil-related properties, are the
most reliable means of wetland identification. The following
procedure is designed to provide technical guidance for determining
whether an area subject to some degree of hydrologic modification
still meets the wetland hydrology criterion. In general, the
hydrology of most such areas can be evaluated by reviewing existing
site-specific information, examining aerial photographs, or
conducting onsite inspections to look for evidence of wetland
hydrology (substeps A-F). More rigorous assessment (substep G) may
be done less commonly where despite the lack of wetland hydrology
evidence one has a strong suspicion that wetland hydrology still
exists. The reason for doing this more detailed assessment should be
documented.  CAUTION: WHEN THE HYDROLOGY OF AN AREA HAS BEEN
SIGNIFICANTLY ALTERED, SOIL CHARACTERISTICS RESULTING FROM WETLAND
HYDROLOGY CANNOT BE USED TO VERIFY WETLAND HYDROLOGY SINCE THEY
PERSIST AFTER WETLAND HYDROLOGY HAS BEEN ELIMINATED.)  Figure 	
shows the sequence of substeps
required to evaluate whether the wetland hydrology criteria is net.

     A) Review existing site-specific hydrologic information to see
     if data support the wetland hydrology criterion. If such data
     are unavailable or inconclusive, proceed to step 2.

     B) Examine aerial photographs (preferably early spring or wet

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 growing  season)  for  several recent years  (e.g., a minimum of 5
 years  is recommended), look for signs of  inundation or
 prolonged soil saturation, and consider these observations in
 the context of long-term hydrology,  fflqfre; Large-scale aerial
 photographs,  1:24,000 and larger, are preferred.)  Be sure to
 Know the prevailing  environmental conditions for all dates of
 photography.  Try to  avoid abnormally wet  or dry dates for they
 may lead to erroneous conclusions about wetland hydrology. You
 are attempting to assess conditions during normal rainfall
 years. If the area is wet more years than not during normal
 rainfall years (e.g., 3 of 5 years or 6 or 10 years), then the
 wetland  hydrology criterion is presumed to be met. If the area
 shows  no indication  of wetness during normal rainfall years or
 shows  such signs in  only a few years (e.g., 1 of 5 years or 3
 of 10  years), then the wetland hydrology  criterion is presumed
 not to be met. !Cf conditions are between  the two mentioned
 above  (e.g.,  2 of 5  years or 4-5 of 10 years), proceed to
 substep  C.  mote:   Only those areas showing signs of wetness
 should be considered to meet the wetland  hydrology criterion.)

 C) Examine additional aerial photos, National Wetland Inventory
 maps/  or other information for indication of wetland or signs
 of wetland hydrology. If other information, coupled with the
 previous information is substep B, indicates that the area is
 wet more often than  not (e.g., 3 of 5 years or 6 of 10 years),
 or indicates  that the area is wet half of the time (e.g., 3 of
 6 years  or 5  of  10 years), then the wetland hydrology criterion,
 is presumed to be met. If other information, coupled with the
 previous  information in substep 2, provides indication that the
 area is  wet less often than not (e.g., 2  of 5 years or 4 of 1C
 years),  then  the wetland hydrology criterion is presumed not to
 be met.  If it is perceived after reviewing additional
 information that wetland hydrology is still inconclusive,
 proceed  to substep D.

 D) Inspect the «ite  for direct evidence of inundation or
prolonged  soil saturation or other field  evidence of wetland
hydrology  (excluding soil properties resulting from long-term
 hydrology) to determine whether the wetland hydrology criterion
 is met.  Ideally,  such inspection should be done during the
 early  or wet  part of the growing season during a normal
 rainfall  year. Avoid periods after heavy  rainfall or
 immediately after more normal rainfalls.  After conducting the
 onsite inspection, if necessary, proceed  to substep E in areas
where vegetation has not been removed or  cultivated or to
 substep G  in  cultivated areas to perform  a more rigorous
assessment of vegetation and/or hydrology and document your
reason for doing so.

E) Inspect the site,  on the ground to assess changes in the
plant community.  If  OBL or OBL and             FACW plant
 species  (especially  in the herb stratum)  are dominant or

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scattered throughout the site and UPL species are absent or not
dominant, the area is considered to meet the wetland hydrology
criterion and remains wetland. If UPL species predominate one
or more strata  (i.e., they represent more than 50 percent of
the dominants in a given stratum) and no OBL species are
present, then the area is considered effectively drained and is
no longer wetland. (Note; Make sure that the UPL species are
materially present and dominate a valid stratum, see p. 	).
If the vegetation differs from the above situations, then the
vegetation at this site should be compared if possible with a
nearby undisturbed reference area, so proceed to substep F; if
it is not possible to evaluate a reference site and the area is
ditched, channelized or tile-drained, go to substep G.

F) Locate a nearby undisturbed reference site with vegetation,
soils, hydrology, and topography similar to the subject area
prior to its alteration, examine the vegetation (following an
appropriate onsite delineation method), and compare it with the
vegetation at the project site. If the vegetation is similar
(i.e., has the same dominants or the subject area has different
dominants with the same indicator status or wetter as the
reference site), then the area is considered to be wetland —
the wetland hydrology criterion is presumed to be satisfied, if
the vegetation has changed to where FACU and UPL species or UPL
species alone predominate and OBL species are absent, then the
area is considered effectively drained and is nonwetlahd. If
the vegetation is different than indicated above,  additional
work is required — go to substep 6.

G) Select one of the following approaches to further assess the
area's hydrology:

     (1)  Determine the "zone of influence" of the drainage
          structure and its effect on the water table using
          existing SCS soil drainage guides, the ellipse
          equation, or similar drainage model (SCS soil
          drainage guides and the ellipse equation relate only
          to water table and do not address surface water), and
          determine the effect of the drainage structure on
          surface water (ponding and flooding). Factors to
          consider when analyzing the effect of the drainage
          structure on surface water are: (a) the type of
          drainage system (e.g.,  size, spacing, depth, grade,
          and outlet conditions); (b) surface inlets; (c)
          condition of the drainage system; (d) how surface
          water is removed; and (e)  soil type as it related to
        ~  runoff. An example using the ellipse equation to
          calculate the zone of influence is given in Appendix
          	l or,

     (2)  Conduct detailed ground water studies, making direct
          observations of inundation and soils saturation

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throughout the area in question.   Data should be
collected in the following manner:

     (a)   Depth of Wells.   Well should be placed
     within 24 inches of the soil surface or to the
     top of the restrictive horizon,  if shallower.

     (b)   Annual Observation Period..   Observations
     should be made during the expected high water
     table period including both the  nongrowing and
     growing seasons;  the recommended period of
     observation will vary regionally.  At a minimum,
     the period should encompass a three month period
     during the wettest part of the growing season
     and include the month before the start of the
     growing season if the wettest part is in the
     Spring.

     (c)   Frequency of Observation.  During the
     observation periods,  the wells should be
     observed a minimum of two times  per week at a
     regular interval not to exceed four days between
     observations; for soils with anticipated rapid
     fluctuations of the water table  (e.g., sandy
     soils) , a one or two day observation interval  is
     recommended .
     (d)   Length of Study.   A minimum of three
     observation periods,  each having at least 90% of
     average yearly precipitation and at least 90% cf
     normal  monthly distribution.   Also, the year
     prior to the water table study must have had 90%
     of the  monthly and annual precipitation.  The
     observation study may cease after the minimum
     consecutive time period required for meeting the
     wetland hydrology criterion.   fNote;  Data from
     any year that does not have 90% of average
     precipitation cannot  be counted toward the
     three-year study duration unless it can be
     adequately justified  in a specific case.)
     Precipitation information should be locally
     derived (not necessarily site-specific) from the
     nearest NOAA-approved weather station or other
     available sources of  technically valid
     information (e.g., university branch stations or
     research sites,  media weather stations, uses
     stations,  state agency stations, etc.).  These
     precipitation stations must be located within 25
     miles of the monitored water table study.  If
     this is not possible,  consult appropriate
     regulatory agency for alternatives.  Appendix
         contains information on the installation of
     *^^^*™

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delineating the wetland.
                    ground-water observation wells.
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