EPA and Hardrock Mining: A Source Book for Industry in the Northwest and Alaska

January 2003

APPENDIX I

WETLANDS
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Appendix I: Wetlands

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TABLE OF CONTENTS

1.0 PURPOSE AND GOALS OF THE APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1

2.0 TERMINOLOGY AND ISSUES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1

2.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1

2.2 Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-3

2.2.1 Wetland Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-3

2.2.2 Local, State, and Federal Regulatory Considerations . . . . . . . . . . . . . . . . I-3

2.2.3 404(b)(1) Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-4

2.2.4 Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-4

3.0 AFFECTED ENVIRONMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-5

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-5

3.2 Wetland Inventory and Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-5

3.3 Wetland Determination and Delineation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-6

3.3.1 Delineation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-6

3.3.1.1 Hydrophytic Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-7

3.3.1.2 Hydric Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-7

3.3.1.3 Wetland Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-8

3.3.2 Delineation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-8

3.3.2.1 Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-8

3.3.2.2 Comprehensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-10

3.4 Describing Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-10

3.4.1 Cowardin System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-11

3.4.2 Alaska Vegetation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-12

3.4.3 Function Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-12

3.4.3.1 Wetland Evaluation Technique (WET) . . . . . . . . . . . . . . . . . . I-13

3.4.3.2 Hydrogeomorphic Method (HGM) . . . . . . . . . . . . . . . . . . . . . I-13

4.0 IMPACT ASSESSMENT AND COMPENSATORY MITIGATION . . . . . . . . . . . . . I-14

4.1 Impact Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-14

4.1.1 Direct and Indirect Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-14

4.1.2 Cumulative Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-15

4.2 Compensatory Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-16

5.0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-18

6.0 CONTACTS AND OTHER INFORMATION SOURCES . . . . . . . . . . . . . . . . . . . . . I-20
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TABLE OF CONTENTS

(continued)

LIST OF FIGURES 

I-1. Routine wetland determination for areas 5 acres or less and with relatively 

homogeneous vegetation, soils, and hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-9

I-2. Routine wetland determination for assessment areas greater than 5 acres and/or 

with complex vegetation, soils, and hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-11

TABLE

I-1. Example of Direct Impacts Table for Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-16
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1.0 PURPOSE AND GOALS OF THE APPENDIX

Wetlands constitute an important resource, in terms of impact assessment. Any project or

activity with the potential to impact wetlands should fully characterize this resource as part of

establishing baseline conditions and consider potential permit requirements in project planning. 

Accurately describing existing wetland conditions at a site and identifying sources of potential

impacts should facilitate the development of alternatives and mitigation, including avoidance,

minimization, and as necessary, compensation.

The purpose of this appendix is to provide guidance on determining data needs,

identifying data gaps, collecting necessary baseline information and conducting an impact

analysis for wetland resources. The subsequent sections discuss wetland terminology and issues;

characterization of the affected environment; and impact analysis. A list of reference materials

and contacts are provided in the final section. This appendix does not address in detail, the

Clean Water Act Section 404 permitting process, a topic discussed in the main body of the

source document.

2.0 TERMINOLOGY AND ISSUES

2.1 Terminology

Terminology surrounding wetland science is often confusing. Ambiguity results from the

wide variety of disciplines (e.g., plant ecology, wildlife biology, soil science, and hydrology)

involved as well as the fact that the terminology often has both regulatory and ecological

connotations. The list of definitions that follows is based on terminology that is generally accepted

in the wetland science community. The key point is that wetland, is a general term that applies to

a type of feature or habitat occurring within the landscape; while jurisdictional wetland applies to

specific wetlands under jurisdiction of the U.S. Army Corps of Engineers (COE), U.S.

Environmental Protection Agency (EPA), and some state and local governments. To the untrained

observer, the mere presence of certain features, such as standing water or aquatic vegetation, might

warrant classification of an area as a wetland; however, these areas may or may not meet the

regulatory definition of jurisdictional wetlands as defined below. All jurisdictional wetlands are

wetlands while all wetlands are not jurisdictional. All discussions of wetlands in this Appendix refer

to jurisdictional wetlands or other Waters of the United States.

Jurisdictional wetlands are wetlands that occur within jurisdiction of the COE and EPA

authority under Section 404 of the Clean Water Act. Under normal circumstances, wetlands

exhibit three criteria: hydrophytic vegetation; hydric soils; and wetland hydrology that must be

identified in accordance with the COE 1987 Wetlands Delineation Manual (1987 Manual). 

Plants that grow in undrained hydric soils are referred to as hydrophytes or hydrophytic

vegetation. These plants tolerate varying degrees of soil saturation or inundation and some

species even continue to grow partially submerged. Undrained hydric soils are oxygen depleted

soils, a condition attributable to the prolonged presence of water in the soil. Wetland hydrology
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is found where water saturates or inundates soils for an extended period during the plant growing

season. “Atypical” or “problem” areas may still be classified as jurisdictional wetlands despite

the absence of one or more of the aforementioned criteria. 

A professional wetland scientist can be retained to make wetland determinations and to

conduct wetland delineations as per the 1987 Manual. Wetland determinations only denote

whether or not the land being assessed is a wetland. A wetland delineation defines the physical

boundary of a wetland once it has been determined that one exists on the property. It should be

noted that only the COE and EPA have regulatory authority to make jurisdictional

determinations. 

Waters of the United States is a regulatory phase that defines the limits of jurisdiction for the

COE under the Clean Water Act. The term generally applies to ‘navigable waters’ and watercourses

that possess a ‘bed and bank,’ including those that may be intermittent or ephemeral. Jurisdictional

wetlands are considered a type of Waters of the United States and the Clean Water Act defines

wetlands as “...those areas that are inundated or saturated by surface or ground water at a frequency

and duration sufficient to support, and that under normal circumstances do support, a prevalence of

vegetation typically adapted for life in saturated soil conditions” (33 CFR Section 328.3). Where

a question exists as to the designation of a Water of the United States, the local COE district office

should be contacted for their interpretation.

Wetland functions. Wetlands may provide habitat for threatened or endangered species as

well as numerous other plant, wildlife, and fish species. Wetlands may perform other functions,

in addition to providing habitat, including: shoreline stabilization; storage of flood waters; and

filtration of sediments, nutrients, and toxic chemicals from water; and serving as recharge and

discharge areas for ground water. Destruction of wetlands specifically can result in higher

downstream water treatment costs and the potential for property damage from increased

flooding.

Wetland Values. Although often used in conjunction with “function,” wetland “value”

refers to wetland attributes determined to be valuable to society. Examples of wetland values

include education, recreation, esthetics, tribal harvest areas, scientific study, contribution to the

economy and other social/cultural attributes.

Navigable waters of the United States are those waters that are subject to the ebb and flow

of the tide and/or are presently used, or have been used in the past, or may be susceptible for use

to transport interstate or foreign commerce (33 CFR § 328.3). A determination of navigability,

once made, applies laterally over the entire surface of the waterbody, and is not extinguished by

later actions or events which impede or destroy navigable capacity (33 CFR § 328.3).

The USFWS’s National Wetland Inventory (NWI) is a federal classification system for the

nation’s wetlands and deepwater habitats (USFWS, 1998). USFWS publishes NWI maps for

many areas of the country. NWI maps identify wetland and deepwater habitat and are often

superimposed on U.S. Geological Survey (USGS) maps of various scales. USFWS produces

these maps through interpretation of remote sensing data (i.e., aerial photography) and limited

field investigations. NWI maps occasionally miss certain types of wetlands (e.g., forested
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wetlands) and in other cases these maps include water bodies (e.g., wastewater treatment

lagoons) not under COE jurisdiction (Rolband, 1995; Stolt and Baker, 1995). Therefore, NWI

maps should not be used as the only source of information to determine if an area contains

wetlands.

Riparian is a term that refers to “plant communities contiguous to and affected by surface

and subsurface hydrologic features of perennial or intermittent lotic and lentic water bodies

(rivers, streams, lakes, or drainage ways). Riparian areas have one or both of the following

characteristics: 1) distinctly different vegetative species than adjacent areas, and 2) species

similar to adjacent areas but exhibiting more vigorous or robust growth forms. Riparian areas

are usually transitional between wetland and upland” (USFWS, 1997). Riparian areas also often

include wetlands. 

2.2 Issues

There are a number of issues that should be kept in mind when undertaking an assessment

of wetlands. Four issues presented in this appendix are particularly relevant to mine projects: (1)

wetland boundaries may vary over time; (2) local, state, and federal regulatory considerations;

(3) 404(b)(1) Guidelines; and (4) compensatory mitigation.

2.2.1 Wetland Boundaries 

Wetlands often occur as transitional zones between upland and aquatic habitats. Hydric

soils persist over a relatively long period and, therefore may indicate that an area may still be a

wetland even after it has been successfully drained. Hydrology, on the other hand, may vary

significantly over both the short- (seasonally) and long-term (annually or longer), which is why

one must rely on a “normal year” (i.e., 30 year period) cycle. Vegetation, depending on form

(i.e., tree, shrub, or forb), may or may not reflect long-term conditions at the site because plants

respond relatively quickly to changes in hydrology. Any mapping effort should, ideally,

consider the conditions of a site over multiple seasons and preferably multiple years rather than

relying solely on site conditions at a particular instant in time. Also, the easiest and most reliable

time to delineate a wetland boundary is during the wettest period of the growing season.

2.2.2 Local, State, and Federal Regulatory Considerations 

The need to conserve wetlands, and the benefits they provide, is reflected in the potential 

protections afforded jurisdictional wetlands established under the Clean Water Act and crosscutting federal environmental statutes. Beyond federal requirements, some state and local

governments may require permits for projects that may impact aquatic habitat and/or wetlands;

or sometimes place additional restrictions on projects that could impact wetland habitat (e.g.,

setbacks or buffer zones around wetlands and other Waters of the United States). Therefore,

once wetlands have been identified in a project area, early consultation with state, federal, local

planning offices, and resource agencies can help to clarify all issues and concerns. 

Communications with interested agencies will help to focus data collection efforts and may

improve the options for avoiding impacts through project design and mitigation. 
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2.2.3 404(b)(1) Guidelines 

The regulatory requirements of permitting under Section 404 of the Clean Water Act are

presented in the body of the source document. However, a brief acknowledgment of the

404(b)(1) Guidelines (Guidelines) may shed additional light on the subject of permitting and

environmental impact analysis. Prior to issuance of a permit by the COE for unavoidable

impacts to wetlands and other Waters of the United States, the Guidelines require the proponent

to demonstrate that the selected project alternative is the least environmentally damaging

practicable alternative. Often, the preferred alternative selected from the environmental impact

analysis of the National Environmental Policy Act (NEPA) process, is not the least

environmentally damaging practicable alternative because NEPA does not have the same

requirement as the Guidelines. It is therefore important to avoid and/or minimize all impacts to

wetlands to the fullest extent possible.

2.2.4 Mitigation 

A Memorandum of Agreement (MOA), dated February 6, 1990, between the COE and the

Environmental Protection Agency establishes the policy and procedure in determining the type

and level of mitigation necessary to comply with Section 404(b)(1) Guidelines. The MOA sets

‘no net loss’ of wetland functions and values as a national goal and defines the types of

mitigation, for practical purposes as minimization and compensatory. Although compensatory

mitigation is often the focus of project proponents, from a regulatory perspective, avoidance and

minimization should be the focus of any project with the potential to impact wetlands and other

Waters of the United States. Due to their importance, avoidance and minimization are discussed

here as they apply to the early stages of project planning and design. Compensatory mitigation

will be discussed in Section 4.1 along with other aspects of impact assessment.

Avoidance addresses the portion of the Guidelines which states that no permit shall be

issued if there is a practicable alternative to the proposed discharge which would have less

adverse impact to the aquatic ecosystem including wetlands. The minimization aspect of the

MOA addresses the requirement that all appropriate and practicable steps taken which minimize

the potential adverse impacts of the discharge. Avoidance and minimization would typically be

implemented during early phases of project design through such things as alternative siting of

roads and infrastructure; minimizing the footprint of facilities that encroach on wetlands; and

reducing or eliminating the amount of fill for stream and wetland crossings (e.g. using bridges

instead of culverts where feasible).

A project description submitted as part of an environmental impact assessment or permit

application should clearly demonstrate how avoidance and minimization have been addressed. 

Realize that avoidance and minimization are part of an iterative process that will begin at the

earliest conceptual stages and continue through final designs. A pre-application meeting with

the COE may facilitate the permit process by identifying less damaging alternatives. Optimizing

avoidance and minimization may also be achieved by working with the COE, EPA and any other

interested agencies once the basic design criteria have been developed. Failure to consider
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compliance with the Guidelines may result in project delays later in the permitting process or

outright permit denial.

3.0 AFFECTED ENVIRONMENT

3.1 Introduction

Descriptions of the affected environment, as required in National Environmental Policy

Act (NEPA) documentation, may require: (1) an initial inventory and classification; (2) a

jurisdictional delineation; and (3) a functional assessment of wetland resources within the project

area. Prior to any assessment of the wetland resource, however, the affected environment to be

described must be established. Defining the affected environment and assessing wetland

resources within this environment are discussed below.

The first step in describing the affected environment is to establish the study area or

region of influence (ROI) in terms of the proposed action and potential direct and indirect effects

to wetland resources. For wetlands, the ROI typically extends beyond the footprint of the

proposed ground disturbance. A larger ROI ensures that potential indirect effects to wetland

hydrology, water quality, and other functions are considered, including potential affects to downgradient areas that may occur as a result of the wetland impacts. 

Once the ROI is established, an initial inventory and classification of wetlands and other

Waters of the United States is typically performed to determine the general nature and extent of

these resources within the ROI and to facilitate impact avoidance and minimization through

project design. Following refinement of alternatives, a delineation of wetlands within the ROI is

conducted to provide a comparison of the effects of each alternative. A functional assessment of

wetlands is also conducted to facilitate the comparison of effects between alternatives and

between pre- and post-project conditions.

The remainder of this section presents additional information on inventory, classification,

delineation, and functional assessment of wetlands and how they relate to describing the affected

environment. 

3.2 Wetland Inventory and Mapping

Due to the typical large size of ROIs and the numerous and conceptual nature of project

alternatives early stage in the review process, the initial inventory and classification of wetlands

is generally performed by use of existing information (e.g., NWI maps, aerial photography, local

and/or regional soil surveys). NWI maps are an effective starting point for inventorying and

classifying potential wetlands. Aerial photography and satellite imagery (collectively referred to

as remote sensing products) are interpretive tools, often used in conjunction with NWI maps, for

identifying the location of wetlands in the field. Remote sensing products can be obtained from

a variety of different sources including US Forest Service, USGS, COE, USDA Farm Services
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Agency, USDA Natural Resource Conservation Service, state departments of transportation or

natural resources, and private contractors.

Depending on the season and type of remote sensing products available, wetlands are

often best identified using color infrared (CIR) aerial photography. However, wetlands can also

be identified using panchromatic photography. When using remote sensing images it is helpful

to obtain coverage for the same area over a period of years and seasons as the vegetation

boundaries of wetlands may vary due to seasonal hydrologic changes. Where the use of a

stereoscope is possible, photography should be ordered as stereo pairs in the largest scale

available to enhance the ability to locate wetlands on the photographs. Wetlands observed on

aerial photographs should be checked against the NWI maps recognizing that some wetlands

appearing on NWI maps may not be evident in available aerial photography and vice versa.

Soil surveys and hydric soil lists obtained from the USDA Natural Resources

Conservation Service can also be used to identify potential wetland areas. A soil survey map in

conjunction with aerial photographs can be used to identify areas exhibiting hydric soil and

hydrophytic vegetation respectively.

Once potential wetlands are identified using NWI maps and/or interpretation of remote

sensing images and other resources, a field survey should be conducted to ground truth the

information and other potential locations (e.g. topographic depressions and seeps) should be

investigated during the field survey. Specific boundaries and NWI classification categories (e.g.

PSSb) should be verified (or determined) in the field and a list of dominant plant species

generated. A brief assessment of wetland functions (see below) may also be completed at this

time. The data collected may then be used to draft descriptions of the resource.

A geographic information system (GIS) or other means may be used to add wetland

locations to other mapped features of the project area. Attributes (descriptors) may be assigned

to the different wetland ‘polygons’ occurring on the map. The locations and characteristics of

these mapped wetlands may then be used as part of the description of the affected environment,

for impact assessment, and for planning purposes. The usefulness of GIS, however, is limited by

two factors. First, since wetland boundaries and conditions can change over the years, the GIS

data represent only a snapshot in time. Second, the GIS is only as accurate as the input data (i.e.,

field surveys, NWI maps, or photo interpretation). Acknowledging its limitations, GIS is useful

for generating approximate acreages by type of wetland, potential impact, or other descriptor.

3.3 Wetland Determination and Delineation

3.3.1 Delineation Criteria. 

The COE of Engineers Wetlands Delineation Manual (1987 Manual) (Environmental

Laboratory, 1987) defines how the three criteria – hydrophytic vegetation, hydric soils, and

wetland hydrology – are used to delineate wetlands. Under normal circumstances, wetlands

possess at least one positive wetland indicator for each of these parameters, for purposes of the

CWA. The 1987 Manual identifies a number of indicators available for each parameter. This
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section presents an overall summary of the three criteria and some of their indicators; however,

the reader is referred to the 1987 Manual for complete details. Wetland delineations may not

necessarily be conducted for all wetlands within a study area. Due to practical matters and costs

associated with intensive sampling, delineations may be focused only on wetlands that could be

impacted by a proposed disturbance. Regardless of the jurisdictional status and whether or not a

wetland boundary is established, there are other characteristics used to describe wetlands within

a discussion of the affected environment. Other methods for describing wetland resources are

discussed in Section 3.4.

Both EPA and COE accept the 1987 Manual as the standard document for wetland

delineation, as of this writing. The reader should be aware that several manuals spelling out

specific methodologies for wetland identification and delineation have been written or proposed

which might someday replace the 1987 Manual if the federal government determine they are an

acceptable substitute. Consultation with the COE or other relevant federal agency will help

ensure that delineations are completed using the appropriate manual and techniques.

3.3.1.1 Hydrophytic Vegetation 

The delineation process considers all of the dominant plant species occurring at a site

when determining the presence or absence of hydrophytic vegetation. Hydrophytic vegetation

refers to plants that are adapted to growing in anaerobic soil conditions, or those conditions that

typically exist under prolonged soil inundation or saturation. The delineation process requires

identifying the dominant plants occurring at a site and determining their ‘indicator status.’ The

indicator status is established in USFWS’s National List of Plant Species that Occur in Wetlands

(USFWS, 1988) and reflects the likelihood of a plant species occurring in wetlands. A site

supports hydrophytic vegetation if more than 50 percent of the dominant plant species present at

the site are more likely to occur in wetlands than in uplands. Other indicators include visual

observations of plants growing in inundated/saturated conditions, morphological adaptations,

physiological adaptations, and technical literature (Environmental Laboratory, 1987).

3.3.1.2 Hydric Soils 

Soils exposed to prolonged periods of anaerobic conditions, such as those created by

saturation or inundation, develop distinct characteristics. These characteristics result in

particular soils being classified as hydric under US Department of Agriculture Soil Conservation

Service (now Natural Resources Conservation Service [NRCS]) nomenclature. Hydric soil lists

for particular areas are available through the NRCS. These lists identify hydric soils (or those

with hydric inclusions) within a particular soil survey. Since all hydric soils within an area may

not be mapped, or mapped at too small a scale to be useful, field studies are recommended to

determine the presence of hydric soils. Common field indicators of hydric soil include a dark

color or chroma, gleying (gray colors), and the presence of colored mottling or iron and

manganese concretions (Environmental Laboratory, 1987).
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3.3.1.3 Wetland Hydrology

The term ‘wetland hydrology’ applies to characteristics that demonstrate or imply a site is

periodically inundated or the soils are saturated to the surface for an extended period during the

growing season. Indicators of wetland hydrology often appear through the characteristics of the

site’s vegetation and soils – vegetation adapted to saturated conditions and soils exhibiting

hydric indicators. However, direct indicators of wetland hydrology include recorded data (e.g.

gauging stations, floodplain maps) and field data (e.g. visual observations, watermarks, drift

lines) (Environmental Laboratory, 1987). The reader is referred to Appendix A, Hydrology, for

a discussion of hydrological analyses and methodology.

3.3.2 Delineation Methods 

The 1987 Manual establishes three approaches to completing a wetland delineation. The first,

onsite inspection unnecessary, may be used when sufficient information is available about the

site to make a wetland determination. This approach is usually not used, as all the necessary

information is seldom available. The other two methods, which are typically employed, are the

routine onsite and comprehensive determinations (Environmental Laboratory, 1987). 

3.3.2.1 Routine

The routine onsite approach to delineating wetlands begins with a review of existing data

including US Geological Survey (USGS) quadrangle maps, NWI maps, soil surveys, gauge data,

and aerial photography. Resource management agencies (local, state, or federal) may also be

sources for additional information on a particular area. The site must also be evaluated to

determine whether an ‘atypical situation’ exists, that is, have vegetation, soils, and/or hydrology

been altered by recent human-activity (e.g., land clearing, farming, water diversions, filling,

diking/ditching, etc.) or natural conditions changing the area from having wetland characteristics

to non-wetland characteristics. An atypical situation requires the completion of additional

analytical procedures, which will not be summarized here (see Section F of the 1987 Manual). 

There are two procedures for field delineation depending on the size and complexity of the

assessment area. The delineation process for areas five acres or less and thought to be relatively

homogeneous with respect to vegetation, soils, and hydrologic regime, involves sketching

locations of individual plant communities on a map and characterizing each community type by

establishing sample points in representative locations (see Figure I-1). Sampling involves

collecting data for vegetation, soils, and hydrology and completing a data form for each sample

point. Dominant plant species are identified and their indicator status determined to establish 

whether the site is dominated by (more than 50 percent) hydrophytic vegetation. Soil pits are

excavated to determine if soils exhibit hydric characteristics. Soil pits are also used to

demonstrate the presence of and if present, depth to saturated soil. This observation can also be

used in support of a wetland hydrology determination. Sample locations demonstrating positive

results for all three criteria are considered wetlands. After sample points have been established

in each plant community, boundaries must be established between upland and wetland

communities. Where boundaries between the vegetation types are unclear, additional sample
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points are completed to ascertain the absolute boundary. A map is then completed depicting the

locations of wetlands within the study area. From a practical standpoint, the boundaries should

be staked or flagged and surveyed in order to have adequate location data for use in permitting

and when detailed project designs are being drafted (Environmental Laboratory, 1987).

Areas greater than five acres require the establishment of a baseline and transects to frame

the sampling regime (see Figure I-2). The length of the baseline, number of transects, and

spacing of transects depend upon the size of the study area. Each community type must be

sampled within at least one transect. Under this approach, sampling occurs within each plant

community along each transect, and a data form is completed for each sample location. 

Boundaries between uplands and wetlands are established as described in the preceding

paragraph (Environmental Laboratory, 1987).

Figure I-1. Routine wetland determination for areas 5

 acres or less and with relatively homogeneous 

 vegetation, soils and hydrology
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Appendix I: Wetlands

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3.3.2.2 Comprehensive 

The comprehensive approach is used for complex projects or when a project requires more

documentation than would typically be necessary. A comprehensive study may be undertaken

for example, where there is a likelihood of litigation at some point in the future or where a

wetland may be suspected of providing habitat for threatened or endangered species. Under the

comprehensive method, the preliminary work is completed as in a routine survey. The

vegetation must be characterized to determine the number and location of plant communities that

need to be sampled. A baseline and transects are then established, based on the size of the area. 

Sample data are collected on a different form than that used in routine delineations. In this case,

the information is recorded in greater detail and includes species composition and density data

for the different vegetation layers (trees, saplings/shrubs, grasses/forbs, and woody vines). 

Vegetation data are then summarized on a second data form in making a determination on the

presence/absence of hydrophytic vegetation. Soils and hydrology data are recorded similarly to

the process used in the routine approach. Boundaries between wetland communities and nonwetland communities are determined by observing distinct changes in vegetation or topography,

or completing additional sampling points. Boundaries between transects may be developed

based on surveying a contour between sample points across transects or again conducting

additional sampling (Environmental Laboratory, 1987).

The results of wetland delineations should be summarized in a report that includes a map

and copies of the data forms. The report may then be used to support a Section 404 permit

application and/or environmental impact analysis.

3.4 Describing Wetlands 

Wetlands represent a transitional zone between uplands and aquatic habitats and tend to

occupy a relatively small percentage of the landscape (Mitsch and Gosselink, 1993). However,

in some areas, such as portions of Alaska and within floodplains, wetlands may encompass large

areas. Different classification schemes may be used to describe wetland resources in each of

these cases. The so-called Cowardin system is one method of classifying wetlands and

deepwater habitats; this method is used to describe wetlands on NWI maps (see Section 2.0). In

some cases, vegetation classification schemes, such as The Alaska Vegetation Classification

(Viereck et al., 1992), may be more appropriate than the Cowardin system. For example, in

Alaska, the Alaska Vegetation Classification is tailored to local conditions and plant species and

therefore allows the user to be more specific in the description of wetland resources. Other

descriptors, in addition to a classification scheme, include wetland functions (see below). The

descriptions that result from gathering this information provide a basis for comparing the types

of 

wetlands present and will aid in assessing the potential impacts (Section 4.0). The approaches to

classifying and describing a project’s wetlands will be discussed in more detail below. Note that

all wetlands, regardless of jurisdictional status should be described. 
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Appendix I: Wetlands

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Figure I-2. Routine wetland determination for assessment areas greater than 5 acres 

 and/or with complex vegetation, soils and hydrology 

3.4.1 Cowardin System 

The Cowardin classification scheme characterizes both wetlands and deepwater habitats

using a hierarchical approach (Cowardin et al., 1979). The Cowardin scheme does not include

nor should it be used to determine jurisdictional status of wetlands and other waters of the United

States. Indeed, the Cowardin classification scheme does not use the same definition for wetlands

as used by the COE and EPA in accordance with the CWA. Under this classification scheme,

systems represent the first tier followed by subsystems, classes, and subclasses. Dominance type

and modifier constitute the lowest tiers of the scheme. Each successive tier provides a greater

level of detail for individual wetlands. Classifying wetlands using the Cowardin system

facilitates comparisons with wetlands exhibiting similar characteristics both within and outside

the project area.
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Cowardin’s scheme includes three freshwater ‘systems’ – palustrine, lacustrine, and

riverine. Palustrine systems are commonly referred to as marshes, swamps or bogs. They

encompass all non-tidal wetlands and tidal area wetlands where ocean-derived salinity is below

0.5% that are dominated by trees, shrubs, and persistent emergents. Lacustrine systems include

lakes and reservoirs. Lacustrine systems are generally larger than 20 acres in size; situated in a

topographic depression or dammed river channel; and lack trees, shrubs, and persistent

emergents. If smaller than 20 acres, lacustrine systems are generally defined by depth. Riverine

systems include wetlands and deepwater habitats that are contained within a channel. Riverine

systems exclude wetlands dominated by trees, shrubs, or persistent emergent, which would be

considered palustrine. Classes within each system describe the substrate or dominant life form

of the plant species within an individual wetland. Examples of classes include forested, scrubshrub, aquatic bed, and unconsolidated bottom. Dominance type refers to the plant species that

dominate an individual wetland. A modifier may provide insight to the individual wetland’s

hydrology (e.g. excavated, diked, and beaver). An example of a willow thicket classified under

the Cowardin system would be a willow-dominated palustrine scrub-shrub (PSS). A beaver

pond could be described as a palustrine aquatic bed (PAB) with a beaver modifier (PABb). 

3.4.2 Alaska Vegetation System 

The Alaska Vegetation System also uses a hierarchical approach to classification but

applies to vegetation communities rather than wetlands in particular (Viereck et al., 1992). This

system identifies plant communities with wetland characteristics to a limited extent in its second

and third tiers and more so in its fourth tier. The first two tiers (Levels I and II) describe the life

form of the dominant community. Level I consists of Forest, Shrub, and Herbaceous; Level 2

includes descriptors of these life forms – such as broadleaf or needleleaf; tall or low scrub; and

graminoid or forb communities. Level III describes the degree of canopy closure and, in some

cases whether it occurs in wet areas. Levels IV and V describe the dominant species and the

associated vegetation, respectively. Examples of descriptions based on the Alaska Vegetation

System include Closed (canopy) Sitka Spruce Forest and Open Tall Alder-Willow Shrub. Using

this classification as a basis for the description of the environment can include vegetation in

general and also wetlands, particularly where wetlands encompass a large portion of the project

area. The Cowardin system may be applied on top of the plant associations described using the

Alaska classification system. For example, an Open (canopy) Tall Alder-Willow Shrub

vegetation community that occurs in wet conditions would be consistent with Cowardin’s

Palustrine Scrub-Shrub class.

Where wetlands cover a large portion of the landscape, a routine delineation may be

undertaken using these vegetation units as the basis for the delineation. Since this method could

potentially over- or under-represent the extent of wetlands at a site, an agreement should be

reached with the COE and lead agency if this approach is proposed. The COE will require that a

field delineation be performed for all wetlands potentially impacted by the project.

3.4.3 Function Assessment 
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Appendix I: Wetlands

1 Functional attributes include: groundwater recharge and discharge; flood storage and desynchronization; shoreline anchoring

and dissipation of erosive forces; sediment trapping; nutrient trapping and removal; food chain support; habitat for fisheries and

wildlife; active and passive recreation; and heritage value (FHWA, 1983).

I-13 January 2003

Wetland functions are physical, biological or chemical processes that occur in wetlands. 

Examples of wetland functions include but are not limited to, fish and wildlife habitat,

groundwater recharge/discharge, or flood storage. Wetland functions, as physical, biological,

and/or chemical processes or conditions, are not always easily quantifiable and are often

described qualitatively. Wetland functional assessment provides a basis for comparing wetlands,

a necessary component of wetland analysis. A common, early approach to assessing wetland

functions is the Federal Highway Administration’s (FHWA) Wetland Evaluation Technique

(WET) or some modification thereof. The Hydrogeomorphic (HGM) method is a quantitative

approach to wetland functional assessment currently under development. HGM assesses the

functional level for individual wetlands within different wetland ‘classes’ wetlands. Analyses

completed using HGM are not directly comparable with WET analyses. These two methods or

modifications thereof, are the typical methods used to assess and describe wetland function;

however, there is no required method for describing wetland function.

3.4.3.1 Wetland Evaluation Technique (WET)

The FHWA method for wetland functional assessment, WET, provides a procedure for

converting typical wetland field observations (e.g., wildlife, plant species, recreation) into

preliminary statements regarding the wetlands probable functional value (FHWA, 1983a). WET

rates a broad range of functional attributes and values on a scale of high, moderate, and low

(Mitsch and Gosselink, 1993).1 Each wetland function is rated on three attributes: social

significance; effectiveness; and opportunity (Mitsch and Gosselink, 1993; FHWA, 1983b). 

Social significance assesses the societal value of a wetland in terms of economic value, strategic

location, or special designation (Mitsch and Gosselink, 1993). Effectiveness relates to the

wetland’s capacity to carry out a function because of its physical, chemical, or biological

characteristics (Mitsch and Gosselink, 1993). The degree to which a wetland functions at its

level of capability is assessed for the opportunity rating (Mitsch and Gosselink, 1993). WET has

some limitations including its limited transferability from site-specific to landscape level

analysis (Mitsch and Gosselink, 1993) and comparability with analyses completed using other

techniques. The WET manual often uses the terms function and value inter-changeably. See

Section 2.1 for a discussion of these terms.

3.4.3.2 Hydrogeomorphic Method (HGM) 

HGM represents a new approach for evaluating wetland function. The HGM approach

focuses on comparisons among wetlands with similar characteristics (i.e., within the same

wetland class) and includes methods for assessing human induced changes to wetland functions

(Brinson, 1996; Brinson, 1993). HGM uses indicators from the literature and field

measurements in describing measurable properties of a particular function within a particular

wetland class. These measurements and models are calibrated on regional reference wetlands

and then used to develop an index of functionality for each wetland function. This information
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Appendix I: Wetlands

I-14 January 2003

can be used not only to describe the extent to which a particular wetland is performing specific

functions but also to establish mitigation goals, evaluate the mitigation potential for different

sites, and monitor progress of mitigation activities (Rheinhardt et al., 1997).

HGM focuses on comparing wetlands within particular classes (e.g. depressional or

riverine) rather than trying to compare characteristics across classes. For example, a fish habitat

may be rated for riverine wetlands but might not be considered at all for certain types of seasonal

wetlands within the depressional class. The HGM approach is still in development but may be

available for broader use within the foreseeable future.

4.0 IMPACT ASSESSMENT AND COMPENSATORY MITIGATION

4.1 Impact Assessment

Impact assessment is the description of impacts to wetland resources from all aspects of

mine construction, operation, and closure. While there are many sources of impacts that may

occur to wetlands, the two general categories of impacts are direct and indirect. Direct impacts

result from a discrete action and occur at a particular point in time and at a particular location. 

Filling a wetland to construct a road would be considered a direct impact. Indirect impacts on

the other hand, result at a time or location removed from the point of disturbance. The change in

species composition of downstream wetlands over a period of years in response to changes in

hydrology upstream would be considered an indirect impact. 

4.1.1 Direct and Indirect Impacts 

A number of mining-related activities may result in direct or indirect impacts to wetlands. 

These activities include exploration, geotechnical drilling, construction and operation of

facilities; excavation, heap leaching, surface water diversions; withdrawal of groundwater; and

accidental and permitted discharges. The results of these types of activities include direct

wetland loss through filling or draining; changes to the hydrologic regime with subsequent

changes in flora and fauna; habitat fragmentation due to human encroachment; and changes in

sedimentation patterns. Identifying, attributing, and describing the short- and long-term range of

environmental impacts to individual resources is the key to impact assessment. 

Impact assessment relates to a wide range of questions and while many would be

applicable to most projects others will depend on the specific conditions related to each

individual project. Some of the relevant questions include: 

• How many acres of wetlands will be directly and/or indirectly impacted by fill

activities?

• To what extent will changes in surface water flows affect wetlands within (and

outside) the project area?

• Will groundwater withdrawals influence wetlands and if so, to what extent?

• Will sediment loading to particular wetlands be increased?
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• To what degree would mining-related activities affect habitat values? 

• To what degree would mining-related activities affect water quality (i.e.,

temperature, toxins, etc.) within wetlands?

Descriptions of potential impacts to wetlands are usually presented in terms of absolute

loss (acres filled or drained) and in loss of function. The former analysis is quantitative and

relatively straight forward and tends to only address direct impacts while the latter is

significantly more complicated but necessary to adequately address indirect impacts. For

example, wetlands tend to be greater than the sum of their parts and, thus, a 1:1 relationship does

not necessarily exist between wetland acreage and functions. Therefore, filling 50 percent of a

wetland may have either a greater or lesser effect on the functions demonstrated by the wetland

than simply halving them. This situation needs to be considered in describing potential impacts

to wetland functions. Likewise, the loss of all or part of a wetland can impact the functions of

other wetlands and other aquatic areas, and even nonwetland areas, beyond its boundary.

The most practical approach to determining the extent of impacts to wetlands is to assess

each type of activity that could cause impacts. This ‘checklist’ should go from the obvious to the

subtle. Obvious items include calculating the number of wetland acres that will be filled to

construct and operate the various facilities and determining of the extent to which surface water

diversions and groundwater withdrawals will affect wetlands. Less obvious items might include

determining the affect of human encroachment on habitat values, assessing the potential for

long-term changes to the local hydrology; and projecting the results of permitted discharges over

the long-term. The duration of wetland impacts should also be considered and discussed. Some

impacts may only occur during construction (e.g., noise from construction equipment), while

others could continue throughout the life of the project or longer. For example, fill used to

construct a wetland crossing may only be needed during mining operations and could be

removed upon closure. Such an impact would be considered temporary compared to a wetland

permanently buried under a waste rock dump. For example, impacts to a forested wetland would

likely require more time to recover than impacts to an emergent marsh. This aspect also requires

consideration during the mitigation process.

Ultimately, the analysis should summarize the impacts that are anticipated by class or

category of wetland. The direct impacts may be presented in tabular form, similar to that

presented in Table I-1. Indirect impacts should be clearly described and include the type of

wetland impacted, size of impact area, description of functions to be impacted, and the source of

the potential impact. All of the discussions should indicate whether the impacts would be

temporary (e.g., noise during summer construction), short-term (e.g., mowing of herbaceous

vegetation), long-term (e.g., sedimentation from erosion of exposed soil), or permanent (e.g.,

wetlands buried by construction of buildings).

4.1.2 Cumulative Impacts 

Aspects of the direct and indirect impact analyses should also be considered and described

in terms of a cumulative impact analysis. Cumulative impacts are defined as the sum of all

individual impacts occurring over time and space, including those of the foreseeable future
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(EPA, 1992). Proposed changes to the nationwide permitting process by the COE resulted in

part, because of cumulative impacts to small isolated wetlands, through permitted and

unpermitted activities. In their rationale for proposing these changes, the COE stresses that the

“only

Table I-1. Example of Direct Impacts Table for Wetlands

Wetland

Class1

Acres

Within Study Area Short-Term Impacts Long-Term Impacts

Jurisdictional NonJurisdictionalJurisdictional NonJurisdictionalJurisdictional NonJurisdictionalTotal

Impacts

Palustrine

Aquatic

Bed

12.3 0.6 1.4 0 1.4 0 12.9

Palustrine

Emergent

28.8 0 2.3 N/A 1.5 N/A 28.8

Palustrine

Forested

4.2 3.5 0 1.5 0 1.5 7.7

Palustrine

ScrubShrub

12.8 0 3.2 N/A 2.4 N/A 12.8

Total 58.1 4.1 6.9 1.5 5.3 1.5 62.2

1

Cowardin et al. 1979.

technically sound approach” to cumulative impact assessment is on a watershed basis (Federal

Register, 1998).

A cumulative impact analysis should consider impacts to the resource in the context of

what other projects have occurred or could foreseeably occur in the area. For example, a

proposed action could result in the loss of half of the forested wetlands in a study area. The

cumulative impact analysis may indicate that a different project, also in the planning stages or

already occurring/completed, would also cause the loss of a large portion of the same forested

wetland. In this case, the cumulative impact may be much more significant that the impact

caused by either project individually. Cumulative impacts to wetlands may be addressed by

considering the extent of impacts on wetland classes and function within a particular area – the

boundaries may include a drainage basin, watershed, or some other land management unit. The

boundaries of the cumulative impact area and the sources of potential cumulative impacts are

typically identified in conjunction with the lead agency at the beginning of the actual

environmental impact assessment process. 

4.2 Compensatory Mitigation
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Section 2.2 introduced the concept of mitigation in terms of the Guidelines and the

COE/EPA MOA. Within this framework, mitigation usually refers to avoidance, minimization,

and compensatory mitigation. The two former terms were discussed previously while this

section focuses on the latter. Compensatory mitigation refers to the restoration, enhancement, or

creation of wetlands to restore or replace functions of unavoidable and/or accidental wetland

impacts by a particular project. No net loss of resource value requires that an ecological

assessment of wetland functions and wetland delineation be performed as mentioned previously. 

A description of wetland functions and delineation of boundaries identifies resources that could

be impacted and catalogues what will need to be replaced if compensatory mitigation is required. 

Compensatory mitigation is an important component of impact assessment. After an

applicant demonstrates avoidance and minimization of impacts to the extent practicable, some

type of compensatory mitigation will generally be required in order to obtain CWA 404

authorization from the COE.

Compensatory mitigation requirements vary by location and are determined by the COE

on an individual project basis, usually in conjunction with public comment. The extent of

mitigation often relates to the size of the project, nature of impacted wetlands, and the degree

and amount of wetland impacts expected. The relative level of success or failure (i.e., level of

risk and temporal rate of replacement) of mitigation efforts to replace impacted functions are

also considerations in determining required mitigation. Some districts require compensatory

mitigation in excess of a one for one ratio (loss to replacement) other areas (such as Alaska),

may not necessarily require any compensatory mitigation. 

Frequently, the preferred approach to mitigation is termed on site, in kind mitigation,

which equates to replacing the specific characteristics of an impacted wetland within the project

area. Off site, in kind mitigation may be an alternative when no on site options are available or

practicable. Likewise, on site, out of kind may also be possible, particularly when the functions

and values of such an undertaking would surpass those of the impacted wetland and where inkind is not practicable and/or desirable based on identified regional or watershed wetland

functional priorities. Off site, out of kind mitigation is generally the last choice when other

options are unavailable or regionally less desirable. The success of mitigation projects often

relates directly to the type of mitigation undertaken. Restoration tends to be more predictable

than wetland creation as some wetland characteristics already exist (or existed) at the site. 

Establishing an adequate hydrologic regime is one of the keys to successful wetland mitigation;

this can be a difficult task for wetland creation projects, but relatively much easier for wetland

restoration. Enhancement of degraded wetlands is often a more practical approach than creation

because again, the site presumable already possesses some wetland characteristics. A qualified

professional, with experience in designing and implementing wetland mitigation projects, should

be consulted prior to the development of any mitigation plan. Likewise it is often important to

confer with the regulatory and resource agencies through a pre-application consultation process

before finalizing mitigation plans/design.
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5.0 REFERENCES

Brinson, M.M., 1993. A Hydrogeomorphic Classification for Wetlands, U.S. Army COE of

Engineers Waterways Experiment Station, Vicksburg, MS, Technical Report WRP-DE-4. 

Brinson, M.M., 1996. Assessing Wetland Functions Using HGM, National Wetland Newsletter,

pp. 10-16.

Cowardin, L.M., Carter, V., Golet, F.C., and LaRoe, E.T., 1979. Classification of Wetlands and

Deepwater Habitats of the United States, U.S. Fish & Wildlife Service Publication No.

FWS/OBS-79/31 (December 1979), http://www.nwi.fws.gov/classman.html.

Environmental Laboratory, 1987. COE of Engineers Wetlands Delineation Manual, U.S. Army

COE of Engineers Waterways Experiment Station, Vicksburg, MS, Wetland Research

Program Technical Report Y-87-1. 

Federal Register. 1980. “40 CFR Part 230: Section 404 (b) (1), Guidelines for Specification of

Disposal Sites for Dredged or Fill Material,” U.S. Govt. Printing Office, Wash., DC,

45(249), 85, 352-85, 353.

Federal Register. 1982. “Title 33: Navigation and Navigable Waters; Chap. 2. Regulatory

Programs of the Corps of Engineers,” U.S. Govt. Printing Office, Wash., DC, 47 (138),

31, 810.

Federal Register, 1998. Proposal to Issue and Modify Nationwide Permits; Notice, Department

of Defense, Department of Army, COE of Engineers, July 1, 1998. 36039-36078.

Lyon, John G. 1993. Wetland Identification and Delineation. Lewis Publishers, Ann Arbor,

Michigan.

Mitsch, W.J., and Gosselink, J.G., 1993. Wetlands, 2nd edition, Van Nostrand Reinhold, New

York, NY.

Rolband, M., 1995. A Comparison of Wetland Areas in Northern Virginia: National Wetland

Inventory Maps Versus Field Delineated Wetlands Under the 1987 Manual, Wetland

Journal, vol. 7, no. 1, pp. 10-14.

Rheinhardt, R.D., Brinson, M.M., and Farley, P.M., 1997. Applying Wetland Reference Data to

Functional Assessment, Mitigation, and Restoration, Wetlands, vol. 17, no. 2, pp. 195-

215.

Stolt, M.F. and Baker, J.C., 1995. Evaluation of National Wetland Inventory Maps to Inventory

Wetlands in the Southern Blue Ridge of Virginia, Wetlands, vol. 15, no. 4, pp. 346-353.
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Appendix I: Wetlands

I-19 January 2003

U.S. Army Corps of Engineers, and U.S. Environmental Protection Agency, 1990. 

Memorandum of Agreement Between the Environmental Protection Agency and the

Department of the Army Concerning the Determination of Mitigation Under the Clean

Water Act Section 404(b)(1) Guidelines). 

U.S. Dept. of Agriculture, Soil Conservation Service. 1975. Soil Taxonomy, Agricultural

Handbook No. 436. U.S. Govt. Printing Office, Wash., DC.

U.S. Dept. of Agriculture, Soil Conservation Service. 1983. “List of Soils With Actual or High

Potential for Hydric Conditions,” USDA-SCS Natl. Bulletin No. 430-3-10, Wash., DC.

U.S. Dept. of Agriculture, Soil Conservation Service. 1991. “Hydric Soils of the United States,”

Misc. Publ. 1491, Wash., DC.

U.S. Department of Transportation, Federal Highway Administration, 1983a. A Method for

Wetland Functional Assessment, Volume 1, Report No. FHWA-IP-82-23, March 1983.

U.S. Department of Transportation, Federal Highway Administration, 1983b. A Method for

Wetland Functional Assessment, Volume 2, Report No. FHWA-IP-82-24, March 1983.

U.S. Environmental Protection Agency, 1992. A Synoptic Approach to Cumulative Impact

Assessment: A Proposed Methodology, Report prepared by S.G. Leibowitz, B.

Abbruzzese, P.R. Adams, L.E. Hughes, and J.T. Irish for the U.S. Environmental

Protection Agency, Environmental Research Laboratory, Corvallis, OR, EPA/600/R92/167.

U.S. Fish and Wildlife Service, 1988. National List of Plant Species that Occur in Wetlands: 

1988 National Summary, Report prepared by P.B. Reed, Jr. for the National Wetlands

Inventory, U.S. Fish and Wildlife Service, Department of the Interior, Washington, DC,

Biological Report 88(24). 

U.S. Fish and Wildlife Service, 1998. “NWI Overview.” http://www.nwi.fws.gov/overiew.htm,

November 20, 199). 

U.S. Fish and Wildlife Service, 1997. A System for Mapping Riparian Areas In The Western

United States, USFWS National Wetlands Inventory, Washington, D.C., December 1997,

http://www.nwi.fws.gov/riparian.htm, November 12, 1998.

Viereck, L.A., Dyrness, C.T., Batten,A.R., and Wenzlick, K.J., 1992. The Alaska Vegetation

Classification, USDA Forest Service, Pacific Northwest Research Station, General

Technical Report PNW-GTR-286.
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6.0 CONTACTS AND OTHER INFORMATION SOURCES

Code of Federal Regulations - http://law.house.gov/4.htm

Natural Resources Conservation Service (http://www.nrcs.usda.gov/) – information available

through Web page or state and district offices.

Society of Wetland Scientists - http://www.sws.org/

U.S. Army COE of Engineers (http://www.usace.army.mil/) Note that Sacramento District

(http://www.spk.usace.army.mil/cespk-co/regulatory/) has information specifically related to

jurisdictional wetland delineations and 404 permitting:

U.S. Environmental Protection Agency, Office of Water (http://www.epa.gov/owow/wetlands/)

provides information on wetlands as well as a wetland Hotline Number: 1-800-832-7828, email

to wetlands-hotline@epamail.epa.gov

U.S. Fish and Wildlife Service (http://www.fws.gov/) – provide National Wetland Inventory

maps; may be a source for information regarding potential mitigation opportunities. 

USFWS NWI maps are available as paper copies, mylar overlays, and occasionally as digital

layers. The USFWS NWI homepage (http://www.nwi.fws.gov) contains information on NWI

products, available maps, and ordering information.

USFWS endangered species home page-http://www.fws.gov/~r9endspp

U.S. Geological Survey’s EROS data center (http://edcwww.cr.usgs.gov/eros-home.html) serves

as a clearinghouse for aerial photography compiled by federal agencies and allows on-line

searches by location.