Groundwater-Dependent 

Ecosystems: Level I 

Inventory Field Guide

Inventory Methods for 

Assessment and Planning

United States Department of Agriculture

Forest Service

Gen. Tech. Report WO-86a

March 2012
Groundwater-Dependent 

Ecosystems: Level I 

Inventory Field Guide

Inventory Methods for 

Assessment and Planning

United States Department of Agriculture

Forest Service

Gen. Tech. Report WO-86a

March 2012
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GDE: Level I iii Inventory Field Guide

Contributors

This field guide was developed under the direction of the 

Groundwater-Dependent Ecosystems (GDE) Protocol Development 

Core Team with primary contributions from Marc Coles-Ritchie 

of Management & Engineering Technologies International, Inc. 

(METI, Inc.) and Joe Gurrieri (Forest Service, an agency of the 

U.S. Department of Agriculture). Chris Carlson (Forest Service) 

and Steve Solem (METI, Inc.) provided essential edits and guidance in the field guide development process. Other members of 

the Core Team, who provided detailed edits and recommendations at multiple stages of the field guide development, were 

(of the Forest Service unless otherwise noted): Allison Aldous 

(The Nature Conservancy), Devendra Amatya, Trish Carroll, 

Kate Dwire, Mark Gonzalez (Bureau of Land Management, U.S. 

Department of the Interior), and Barry Johnston.

The GDE Protocol Development Steering Team provided valuable guidance at multiple stages of the process. That team was 

made up the following individuals (of the Forest Service unless 

otherwise noted): Leslie Bach (The Nature Conservancy), Chris 

Carlson (team leader), Tony Crump, Tony Erba, Russ Lafayette, 

Bill LeVere, Dan Neary, Mike Nevill, Andy Rorick, Linda Spencer, 

Cynthia Tait, and Richard Ullrich. Luke Boehnke created the 

figures, including invertebrate illustrations in appendix 11.

Reviews and comments were also provided by members of 

Technical Advisory Teams for the GDE Protocol Development 

project.

Pilot testing of this field guide involved dedicated individuals 

from the following units: Black Hills and Nebraska National 

Forests (Rocky Mountain Region); the Spring Mountains National 

Recreation Area (on the Humboldt-Toiyabe National Forest) 

(Intermountain Region); Inyo National Forest (Pacific Southwest 

Region); the Malheur, Wallowa-Whitman, and Umatilla National 

Forests (Pacific Northwest Region); Francis Marion and Sumter 

National Forest (Southern Region), White Mountain National Forest (Eastern Region); and the Fraser Experimental Forest (Rocky 

Mountain Research Station).
GDE: Level I iv Inventory Field Guide

Acknowledgments

This field guide is a product of a partnership between The 

Nature Conservancy, Oregon Chapter, and the Forest Service 

to improve the awareness and management of groundwaterdependent ecosystems. 

Support for development of this field guide was provided by 

Anne Zimmermann, Director of Watershed, Fish, Wildlife, Air, and 

Rare Plants and Tony Ferguson, Former Director of Minerals and 

Geology Management. Joel Holtrop, Former Deputy Chief for 

National Forest System, provided encouragement and support 

along with the Information Resources Decision Board in providing project funding. Operational support was provided by Patrice 

Janiga, Ecosystem Management Coordination (EMC) Information 

Assets Portfolio Manager; Mindy Martin, EMC Contracting 

Officer’s Representative; and Jody Rose, Intermountain Region 

Webmaster. The project team members and leadership provided 

by METI, Inc., were essential for successful project management 

and development of the field guide.
GDE: Level I v Inventory Field Guide

Foundations

Many questions in the “Pre-Field Survey” and “Field Survey” 

portions of this field guide are based on the Forest Service Site 

General: Field Guide (USDA Forest Service 2009). Attributes that 

are required in Site General are noted as such.

Much of this field guide has been influenced by the foundational 

work of others in the fields of spring and wetland science as 

represented in the following protocols:

• Field and Laboratory Operations Report for the Oregon 

Wetlands Study (Magee et al. 1995).

• Terrestrial Springs Ecosystems Inventory Protocols (Stevens 

et al. 2006).

• National Park Service Mojave Inventory and Monitoring Network Spring Survey Protocols: Level I and Level II (Sada and 

Pohlmann 2006 draft). 

• Groundwater and Biodiversity Conservation: A Methods Guide 

for Integrating Groundwater Needs of Ecosystems and Species 

Into Conservation Plans in the Pacific Northwest (Brown et al. 

2007).

• Interim Protocol, Ground-Water Resource Inventory and Monitoring Protocol, Level I Spring Ecosystem Inventory (Gurrieri 

2007 draft).

• Assessing Proper Functioning Condition for Fen Areas in the 

Sierra Nevada and Southern Cascade Ranges in California: A 

User Guide (Weixelman and Cooper 2009).

• Study Plan: Sampling of the Polygons Photointerpreted for 

Possible Fens on the Grand Mesa-Uncompahgre-Gunnison 

National Forest, Colorado (Johnston et al. 2009 draft).
GDE: Level I vi Inventory Field Guide
GDE: Level I vii Inventory Field Guide

Contents

Introduction .................................................................................. 1

Business Requirements Addressed by This Field Guide ..... 2

Relationships Between Business Requirements and 

Field Guide Levels................................................................ 5

Targeted GDEs..................................................................... 8

Limitations on Use.............................................................. 15

Using the Level I Field Guide...................................................... 17

Skills and Time Required.................................................... 19

When To Sample................................................................ 20

Preventing Damage to Sites............................................... 22

Pre-Field Survey Activities (in office).......................................... 23

Site Information.................................................................. 23

Geographic Information ..................................................... 26

Mapping ............................................................................. 29

Route.................................................................................. 31

Other Information About the Site ....................................... 32

Field Survey Activities ................................................................ 35

Survey Information ............................................................. 35

Georeferencing................................................................... 40

Geologic Setting................................................................. 42

Images................................................................................ 48

Unusual Sites ..................................................................... 52

Vegetation .......................................................................... 52

Soil ..................................................................................... 55

Hydrology........................................................................... 64

Aquatic and Terrestrial Fauna ............................................ 76

Natural and Anthropogenic Disturbance............................ 77

Management Indicator Tool ............................................... 82
GDE: Level I viii Inventory Field Guide

Post-Field Survey Activities (in office) ...................................... 105

Obtain or Verify Data........................................................ 105

Laboratory Analyses......................................................... 105

Implement Data Management and Interpretation 

Procedures....................................................................... 106

Validate and Confirm Management Indicator Tool 

Entries .............................................................................. 106

Analyze and Evaluate Collected Information.................... 106

Glossary ................................................................................... 107

References ............................................................................... 115

Appendix 1. Order of Data Collection ...................................... 119

Appendix 2. Job Hazard Analysis ............................................ 121

Appendix 3. Field Forms .......................................................... 129

Appendix 4. Site Protection Guidelines.................................... 141

Appendix 5. Groundwater-Dependent Ecological Systems 

Described in NatureServe ........................................................ 143

Appendix 6. Equipment List..................................................... 147

Appendix 7. Secondary Lithology ............................................ 151

Appendix 8. Landform.............................................................. 161

Appendix 9. Plant Labels ......................................................... 165

Appendix 10. Measurement of Discharge at Springs and 

Wetlands .................................................................................. 167

Appendix 11. Identification of Freshwater Invertebrates ......... 181
GDE: Level I 1 Inventory Field Guide

Introduction

This Level I inventory field guide describes a national protocol 

to supply data used in project identification and planning. Data 

collected through this field guide serve as the basis for the assessment of project and activity effects on, and the identification 

of project-level design and mitigation measures for, a specific set 

of groundwater-dependent ecosystem (GDE) types.

This Level I field guide includes procedures for collecting a 

narrower array of data attributes and less detail for some data 

attributes than the companion Level II field guide (GTR-WO-86b). 

This Level I field guide is intended to document the location, size, 

and basic characteristics of a site during a relatively short 2-hour 

site visit by a trained field crew. The Level II field guide is intended 

to more comprehensively characterize the vegetation, hydrology, 

geology, and soils of GDE sites and typically would require 4 to 

8 hours at the field site by a crew of specialists.

If inventory or monitoring of specific species or communities is 

the goal, then a more detailed and/or targeted set of methods 

should be used.

Specific examples of what this field guide is designed to be used 

for include the following:

• Determining the location and extent of GDEs within an area 

(as long as appropriate site selection process is used).

• Qualitatively characterizing GDEs within an area (as long as 

appropriate site selection process is used).

• Determining if GDEs may be affected by proposed actions or 

activities.

If the objective is to monitor certain conditions of a GDE, then it 

will be necessary to develop and use a more detailed and sitespecific Level III protocol. This Level I field guide, however, can 

be used as a starting point for the development of a site-specific 

Level III protocol that will meet the management needs of a 

particular situation. Assistance with the development of Level III 

protocols is available from the National Groundwater Technical 

Team.
GDE: Level I 2 Inventory Field Guide

Business Requirements Addressed 

by This Field Guide

Pressure on National Forest System (NFS) lands to supply the 

water, minerals, and energy needed to meet societal needs is 

intensifying. In addition, wildland fire management, hazardous fuels 

reduction, invasive species control, livestock grazing, mineral 

extraction, road and trail management, and ecological restoration 

activities also affect GDEs. Accurate and consistent information 

regarding GDEs and their condition is critical to making decisions 

about and implementing a wide variety of mission responsibilities 

of the Forest Service, an agency of the U.S. Department of Agriculture (USDA). This Level I field guide is designed to collect accurate and consistent information regarding the location of GDEs 

and their condition. Data collected are essential to informed 

decisionmaking associated with the agency’s mission responsibilities supported by broad- and mid-scale assessments and land 

and resource management planning. The Level II GDE field guide 

should be used to collect data needed to inform project-level 

decisions and activity administration affecting GDEs.

Effective resource management requires a clear understanding of 

the underlying business requirements for practicing conservation. 

In some instances, policy and direction limit management’s ability to 

respond to identified needs; in others, they create an affirmative 

obligation for the agency to take action to conserve or protect 

resources and public safety. Business requirements stem from 

two primary sources: (1) regulatory and policy requirements, and 

(2) management questions and concerns associated with land 

and resource management plans and ongoing or proposed 

projects/activities (see table 1).

Across the NFS, legal requirements and management issues are 

highly variable, so it is difficult to define a discrete set of business 

requirements applicable to all NFS lands. In several instances, 

laws and regulations provide the opportunity for States and tribes 

to establish additional requirements (these could be statutory or 

rule based) for the protection of resources associated with GDEs. 

This situation creates an even more complex set of management 

requirements. This Level I field guide, therefore, is designed to allow for local additions within an established national framework.

Information used to identify management requirements was 

gleaned from the Forest Service Directives System. Forest Service Manual (FSM) 2880 and the “zero chapters” of FSMs 1900, 

1940, and 2500 were the primary sources consulted.
GDE: Level I 3 Inventory Field Guide

Management requirements Management questions

•	 Laws—Establish Forest Service

authority and procedural

requirements for managing GDEs.

•	 Regulations—Establish the

processes and policy for

conducting land and resource

management activities affecting

GDEs.

•	 Executive Orders and 

Presidential Directives—Specify

procedures and requirements

applicable to all Government

agencies for the management

and protection of GDEs and

associated resources.

•	 Departmental policy—

Establishes procedures and

policies for USDA agencies

responsible for or potentially

affecting GDE resources.

•	 Agency policy—Establishes

agency-specific procedures for

regulatory requirements if not

addressed directly through other

means.

Table 1.—Business requirement sources.

•	 Land management plans—

Establish desired outcomes

(goals and objectives), standards

and guidelines, and monitoring

requirements. Plans include:

§ Ecological context—Are

ecological systems functioning

and disturbance processes

operating within the natural or

desired range of variation? Are

human pressures or changes

in ecological systems inducing

changes to the ecological

context in which species

reside?

§ Species context—Are habitat

relationships or ecological

factors affected by management creating risk to species

persistence?

•	 Resource or area plans—

Refine interpretations and

requirements for specific

resources or areas.

•	 Monitoring—Includes:

§ Implementation—Are

projects and activities being

implemented as designed?

§ Effectiveness—Are mitigation

measures, best practices,

and design features effective

in mitigating anticipated

impacts?

§ Validation—Are conservation

actions achieving desired

outcomes?
GDE: Level I 4 Inventory Field Guide

Management requirements applicable to inventory and monitoring of GDEs fall into three groups:

1. GDE resource management—The importance of GDEs, and 

their ability to sustain both ecological systems and species 

dependent on groundwater resources, is evident in most 

national forests and grasslands. The collection of requirements related to the management of water and water uses, 

and the conservation of threatened, endangered, and sensitive species that rely upon these areas, is further evidence of 

their importance. Protection, conservation, and restoration of 

GDEs are often key aspects of decisionmaking on NFS lands 

and a foundation for many land management plans. Inventory 

and monitoring of GDEs are described in FSM 2880.

Because of the State-by-State variability associated with 

water rights and uses within the NFS, no attempt has been 

made to summarize such requirements that apply below the 

national level as part of this effort. Readers are encouraged to 

consult FSM 2540 and appropriate regional and forest supplements to that chapter to review those requirements.

2. Planning and environmental compliance—Policy and 

procedures for land management planning and environmental 

compliance activities are outlined in FSM 1920 and 1950, 

respectively. Depending on the “vintage” of the land and 

resource management plan for an NFS administrative unit, 

different requirements apply. Field users are encouraged to 

consult their appropriate land management plans and the 

National Environmental Policy Act (NEPA) decision documents 

associated with individual uses, activities, and authorizations 

to determine specific design and monitoring requirements.

3. Resource information management—Forest Service Natural 

Resource Manager (NRM) resource information systems, 

such as NRM-Natural Resource Information System (NRIS), 

NRM-Infrastructure (INFRA), and NRM-Automated Lands 

Program (ALP), provide agencywide data systems that comply 

with departmental and agency requirements. NRM applications must be used to store GDE data collected under this 

Level I field guide. NRM applications also provide standard 

analysis and evaluation tools supported by the data collection 

methods described in this field guide.
GDE: Level I 5 Inventory Field Guide

Management requirements applicable to GDE inventory and 

monitoring can be summarized into the following general points:

• Support an affirmative agency obligation to protect, conserve, and restore waters, watersheds, and listed wildlife and 

plant species and their habitats, and to conserve biological 

diversity.

• Assess and disclose environmental effects associated with 

ongoing and proposed actions and activities, including using 

monitoring data to identify needed adjustments to management practices.

• Use the best available information and science to support 

agency decisionmaking. Collect and maintain resource data 

with known data standards and data quality for use in agency 

decisionmaking processes. Provide for information security.

A detailed review of more than 100 statutes and policies that 

establish management requirements addressed by this effort is 

documented in Groundwater Dependent Ecosystems Inventory 

and Monitoring Business Requirements Analysis (v5.2, January 

30, 2010) and is available for review at http://www.fs.fed.us/

geology/groundwater.html.

Relationships Between Business Requirements 

and Field Guide Levels

Because of the variety of situations encountered on NFS lands, it 

is essential to develop a field guide “package” consisting of integrated modules or components that can be matched to a local 

unit’s business requirements and needs. Using different inventory 

and monitoring “intensity levels,” which herein correspond to 

field guide levels, supports this functionality.

A relationship exists between the types of management requirements and questions being addressed and the data needed to 

address those questions. The amount of effort or “intensity” of 

inventory and monitoring can be categorized into three levels. 

Table 2 describes the level of effort and focus of these levels.
GDE: Level I 6 Inventory Field Guide

Inventory and 

monitoring 

intensity level

Description

Level I Conducted to characterize GDEs qualitatively within an

administrative unit or management area. GDE location 

and extent are spatially referenced. Serves as the

basis for determining when GDEs may be affected by

proposed actions or activities or landscape scale change.

Level II Serves as the foundation for assessment of project and 

activity effects and identification of design measures.

Describes major attributes including the following:

hydrogeologic setting, aquatic habitat, aquatic and

wetland flora and fauna, and site-affecting disturbances.

Can be used to determine ecological significance of the

GDE and associated resources. Can also be used as a

foundation for designing a long-term monitoring plan.

Level III Usually conducted in relation to monitoring a major

activity or set of activities affecting GDEs and their

characteristics. Compiles highly quantitative information

that describes spatial and temporal variation in physiochemical characteristics of GDEs. Often used in the 

administration of projects or activities and, therefore,

is highly site specific.

Table 2.—Descriptions of GDE inventory and monitoring intensity levels.

To provide flexibility and ensure appropriate use of the GDE field 

guides, the relationship between business requirements (why 

data are collected) and inventory and monitoring field guides 

(how data are collected) must be clearly described and understood. The relationship between business requirements and GDE 

inventory and monitoring field guide (intensity) levels is illustrated 

in figure 1.

The number of management questions considered and the level 

of detail needed to address these questions increases with the 

inventory and monitoring intensity level. Each of the boxes in 

figure 1 represents a grouping of management requirements. The 

level of detail and resolution for data elements needed to support 

the business requirements increases from Level I to Level III. For 

example, the types of information collected in Level I for vegetation would be more general than those collected in Level II, which 

would likely be more general than those collected in Level III, 

depending on the particular management requirements for which 
GDE: Level I 7 Inventory Field Guide Figure 1.—General relationships between GDE business requirements and field guide levels.

the Level III protocol was developed. Specific management 

questions have been identified and associated with business 

requirements as part of the GDE Business Requirements Analysis.
GDE: Level I 8 Inventory Field Guide

Targeted GDEs

Although many different types of GDEs exist, not all are targeted 

for this field guide. GDEs are ecosystems that are supported by 

groundwater, which include springs and seeps, cave and karst 

systems, phreatophytic ecosystems, and, in many cases, rivers, 

wetlands, and lakes. This field guide was developed to focus on a 

subset of nonmarine GDEs, specifically springs and groundwaterdependent wetlands (such as fens) as illustrated in figure 2. Figure 2.—Diagram of GDE types, with the highlighted types (in box on left) representing those for which this field guide was designed.
GDE: Level I 9 Inventory Field Guide

Although this field guide is not intended specifically for other 

types of GDEs (lakes and ponds, streams and hyporheic zones, 

riparian areas, phreatophytic systems, or marine systems), parts 

of this field guide could be used to inventory or monitor these 

systems as well.

In general, where groundwater intersects the ground surface, 

plants and animals that are supported by access to that 

groundwater will occur, hence the term “groundwater-dependent 

ecosystems.” In some cases, groundwater emerges at a point 

location, usually called a spring or seep, depending on the 

quantity of water available. Herein the term “spring” will be used 

to include both springs and seeps. Springs are always GDEs. In 

the case of wetlands supported by groundwater, often there is 

not a single point where the groundwater flows or emerges at 

the surface; rather, it usually emerges in a more diffuse manner 

across a large area. In some wetlands, however, springs emerge 

within the wetland, or a complex of wetlands and springs is 

present across an area. In many cases, groundwater-dependent 

wetlands, such as fens, are simply springs covered by unconsolidated material (such as glacial deposits, pumice, colluvium) that 

become saturated to the surface. Because an indistinct boundary 

exists between springs and wetlands dependent on groundwater 

discharge, a single field guide was developed for these systems. 

Groundwater emerging at the ground surface is the common 

thread that links these features and their associated ecosystems. 

It is important to recognize that some wetlands are not supported 

by groundwater, but are formed from water that originates exclusively from precipitation and associated surface runoff. Such 

wetlands are called “ombrogenous” hydrological systems (National Wetlands Working Group 1997). The meaning of the term 

ombrogenous is “rain fed” according to Mitsch and Gosselink 

(2007). Ombrogenous wetlands are not the focus of this field 

guide, although the field guide may have components that could 

be used to evaluate ombrogenous wetlands. 

This field guide is intended for those wetlands that are supported 

by groundwater that has come in contact with mineral soils or 

bedrock. Such wetlands are called “minerogenous” hydrological 

systems (National Wetlands Working Group 1997) or “minerotrophic peatlands” (Mitsch and Gosselink 2007). Minerogenous wetland systems are normally situated at positions in the landscape 

lower than adjacent terrain, such that water and transported 

mineral elements are introduced by groundwater. 
GDE: Level I 10 Inventory Field Guide

Minerogenous hydrological systems have a strong linkage with 

the physical and chemical nature of the geological environment and generally involve the regional groundwater system. 

They are not restricted by local climatic conditions because 

the groundwater source is generally sufficient to maintain soil 

saturation and, therefore, wetland processes. By contrast, 

ombrogenous hydrological systems (or ombrotrophic peatlands, 

as described by Mitsch and Gosselink (2007)) are not dependent 

on groundwater and are highly restricted geographically because 

of local climatic conditions. In arid and semiarid regions, many 

wetlands are supported by groundwater. In humid regions, 

distinction of groundwater support of wetlands becomes more 

difficult. Nevertheless, many wetlands in humid regions are highly 

groundwater dependent.

Because it is not always easy to verify a wetland’s dependence 

on groundwater, a site-specific assessment is necessary. One 

source of information to help determine groundwater dependence is a publication by The Nature Conservancy (Brown et al. 

2007), which includes decision trees for determining groundwater 

dependence, such as the one for wetlands, which is adapted for 

this Level I field guide in box 1. 

In summary, this Level I field guide is intended for the inventory 

and monitoring of a subset of GDEs, specifically springs and 

groundwater-dependent wetlands (described in table 3). The 

primary basis for determining which systems to include in the 

GDE field guide is hydrology, specifically the primary water source. 

This field guide provides a very general classification of wetlands 

to indicate which types of wetlands are covered (fig. 2 and table 3). 
GDE: Level I 11 Inventory Field Guide

Box 1

Decision Tree for Identifying Groundwater-Dependent Wetlands

(based on Brown et al. 2007, with modifications for this field guide)

Answer the questions in sequence. A bold answer indicates likely groundwater dependence, and subsequent questions need not be answered.

1.	 Is the wetland seasonal?

Yes—Low likelihood of groundwater dependence

No—Go to next question

2.	 Does the wetland occur in one of these landscape settings:

(a) slope break, (b) intersection of a confined aquifer with a slope,

(c) stratigraphic change, or (d) along a fault?

Yes—High likelihood of groundwater dependence

No—Go to next question

3.	 Is the wetland associated with a spring or seep?

Yes—High likelihood of groundwater dependence

No—Go to next question

4.	 Does the wetland have signs of surface inflow?

No—High likelihood of groundwater dependence

Yes—Go to next question

5.	 Are the wetland soils organic, muck, or peat?

Yes—High likelihood of groundwater dependence

No—Go to next question

6.	 Is the wetland saturated even after surface inputs become dry and

during extended periods with no precipitation?

Yes—

Are the wetland soils clay, hardpan, or impermeable?

No—High likelihood of groundwater dependence

Yes—Low likelihood of groundwater dependence

No—Low likelihood of groundwater dependence
GDE: Level I 12 Inventory Field Guide Characteristics Springs Peatlands, including fens (groundwater dependent) Other wetlands (groundwater dependent) Hydrology Completely groundwater dependent Minerotrophic; always groundwater dependent Minerotrophic; depend on groundwater, precipitation, and sometimes stream inflow Water table position At ground surface or, for artesian, a piezometric surface above the ground surface At or slightly below surface, or piezometric surface above the ground Above or below ground surface; can fluctuate dramatically; can have periodic standing water Soils and peat or muck depths Mostly mineral soils; sometimes a small accumulation of peat Accumulation of peat or muck up to several meters; little or no mineral soil within plant-rooting zone for fens Usually little or no peat or muck accumulation; sometimes wood-rich peat Redox conditionsa Oxic to anoxic depending on geochemistry and residence time of water in aquifer Anoxic slightly below the surface, leading to the accumulation of peat or muck Temporary soil anoxia during times of high water table or standing water Water movement within GDEs Standing or flowing water Slow to imperceptible flow on surface Periodic standing or flowing water Table 3.—Important GDE characteristics and the GDE types covered by this field guide.

a Redox (short for REDuction-OXidation) conditions describe a key chemical characteristic in hydrologic systems that controls the 

availability of many elements and the propensity of the system to support the accumulation of organic matter, such as peat and muck. At the ground surface, redox conditions are often controlled by the availability of oxygen.
GDE: Level I 13 Inventory Field Guide Characteristics Springs Peatlands, including fens (groundwater dependent) Other wetlands (groundwater dependent) Table 3.—Important GDE characteristics and the GDE types covered by this field guide. (continued) Water chemistry Highly variable; from acidic to basic, temperatures vary, can be thermal, can be saline Minerotrophic, acidic (poor fens) to basic (rich fens); can be iron rich or calcareous Highly variable, from acidic to basic Vegetation Graminoids, forbs, shrubs, bryophytes, and trees; variable amount of wetland vegetation Bryophytes, graminoids, and low shrubs; lichens; sometimes trees; always wetland vegetation Tall woody plants and forbs (swamps) or emergent graminoids and floating aquatic macrophytes (marshes); mostly wetland vegetation
GDE: Level I 14 Inventory Field Guide

Springs

Springs are GDEs where groundwater discharges at the ground 

surface, often through complex subsurface flow paths (Stevens 

and Meretsky 2008). Where a spring emerges from the ground, 

there are communities of plants and animals that depend on that 

water. There are many different types of springs. Spring-type 

descriptions in this field guide are from Springer and Stevens 

(2009). Most spring types—such as outflows from caves, helocrenes, hypocrenes, hillslope springs, limnocrenes, fountains, 

and rheocrenes—can be characterized using this field guide. 

Wetlands Dependent on Groundwater (including 

peatlands)

The Level I field guide recognizes that a variety of wetland types 

are dependent on groundwater, with many different regional 

characteristics, classifications, and names. It also affirms that 

groundwater dependence spans a continuum from completely 

groundwater dependent to not dependent, with varying levels 

of dependence between these end members. In this field guide, 

however, there is no need to distinguish among these different 

types of groundwater-dependent wetlands. For the purposes 

of this sampling field guide, all are considered GDE wetlands, 

including fens, marshes, swamps, wet meadows, and depressional wetlands. 

This field guide, however, does distinguish in some ways 

between fens (i.e., wetlands that have accumulations of peat 

or muck) and groundwater-dependent wetlands that do not 

have peat or muck accumulations. Peat and muck are partially 

decayed plant material that accumulates under saturated conditions where there is little oxygen to facilitate decomposition.

Some names for wetland types apply both to sites dependent 

on groundwater and to others that are maintained by surface 

water. The surface-water supported wetlands, regardless of their 

name, are not the focus of this field guide, although the methods 

described here may be useful to characterize some of them. 

Another way to evaluate these types of wetlands is with the 

criteria for wetland delineation used by the U.S. Army Corps of 

Engineers (1987).
GDE: Level I 15 Inventory Field Guide

Limitations on Use

This field guide is not intended to be used for evaluating some 

specific nonmarine GDEs:

• Groundwater-dependent lakes and associated riparian areas.

• Base-flow streams and associated riparian areas. 

Because of the distinct characteristics of those systems, it is not 

practical to include them in this field guide. It is expected that 

other field guides will address those systems, although they may 

not focus on groundwater conditions and processes. The Forest 

Service is also developing a guide to characterize and monitor 

riparian areas.

In addition, some wetland systems that look similar to GDEs, but 

are not dependent on groundwater, are not specifically targeted 

by this field guide:

• Bogs.

• Insurgences and sinkholes in karst areas.

• Pocosins—a type of bog in the Southeastern United States 

(described in Richardson 2003).

• Carolina Bays of the southeastern U.S. Coastal Plain 

(described in Sharitz 2003).

• Other wetlands not supported by groundwater.

Because of the similarities between these systems and GDEs, 

this GDE field guide may have some utility for inventorying and 

monitoring certain components of those systems.

GDE types that would be difficult to sample with this (and 

perhaps any) field guide include geysers, gushets, and hanging 

gardens. This field guide is not designed for underground 

sampling (e.g., in caves), although it would be appropriate to use 

for sampling the surface outflow from caves. Springs that include 

large open water areas (large exposure springs and large limnocrenes) could involve substantial safety concerns and would be 

difficult to comprehensively sample with this field guide. They 

require limnological sampling techniques, which are beyond the 

scope of this field guide. 

Settings where this field guide has not been tested include tropical, subtropical, arctic, subarctic, tundra, and permafrost areas, 

which are beyond the scope of this field guide.
GDE: Level I 16 Inventory Field Guide
GDE: Level I 17 Inventory Field Guide

Using the Level I Field Guide

The Level I field guide describes specific procedures for field 

data collection for select GDEs; however, a number of important 

activities precede and follow field data collection. In fact, only 

about one-half of the expected total cost for implementing this 

field guide is associated with field data collection. The remainder 

comes from establishing the objectives; selecting an appropriate 

inventory or monitoring design; training; providing quality assurance and control; providing project administration and data entry; 

and, most importantly, analyzing and evaluating the information 

collected. Significant cost savings associated with field data collection can be obtained by spending time “data mining” before 

the field activities.

The recommended sequence of activities for implementing this 

field guide is represented in figure 3 and described in this section 

and in appendix 1.

Figure 3.—Recommended approach for successfully using this field guide. 

Study design

Pre-field survey activities

Field survey activities

Post-field survey activities
GDE: Level I 18 Inventory Field Guide

1. Study design—Developed by user (not described in detail in 

this field guide).

a. Identify management questions and set inventory and 

monitoring objectives.

b. Determine the area of interest and selection of sites—

systematic, stratified, or random design, etc.

c. Create the sampling and remeasurement schedule.

d. Identify the relationship to other inventory and monitoring 

programs and data.

e. Coordinate with other agencies, tribes, States, and Forest 

Service units.

f. Develop quality assurance and control procedures, including training and data management.

2. Pre-field survey activities—

a. Gather and review background information about sites, 

which is obtained in the office with focus on existing maps 

and remote sensing data (data mining).

b. Establish field logistics and plan for site access, including 

travel and access restrictions. Conduct a Job Hazard 

Analysis, or JHA (appendix 2).

c. Interpret available map and remote sensing images.

3. Field survey activities—

a. Use the “Field Survey Activities” part of this field guide to 

conduct data collection. Data can be collected on paper 

field forms (see appendix 3) or with a field data recorder 

(personal data assistant or personal data recorder).

b. Apply Management Indicator Tool (on site).

4. Post-field survey activities—

a. Obtain or verify data based on location information 

obtained in the field. 

b. Gather laboratory analyses of samples and specimens.
GDE: Level I 19 Inventory Field Guide

c. Implement data management and interpretation procedures.

d. Validate and confirm Management Indicator Tool entries.

e. Analyze and evaluate collected information (not described 

in detail in this field guide).

Skills and Time Required

A broad set of skills is necessary to conduct the sampling 

outlined in this field guide, which means that several specialists 

will be needed to collect good-quality data. The skills required 

are summarized in the following list:

• Office. 

§ Geographic Information System (GIS), map interpretation.

§ Data acquisition—from data warehouses, etc. (which will 

likely take a number of days to accomplish).

§ Logistics—transportation, equipment, access, safety, etc.

§ Data entry.

• Field—Botany.

§ Understanding of basic wetland plant ecology.

§ Familiarity with regional flora and proficiency in identifying 

common wetland plant species. Capable of sight recognition of dominant species to the level of genus and species, 

provided plants are at the proper phenological stage, or 

capable of sight recognition of dominant species to the 

family, and proficiency in keying in the field.

§ Ability to collect and press plant specimens so that they 

will be suitable for later identification or verification.

• Field—Animals.

§ Familiarity with quantitative and qualitative methods of 

sampling for aquatic macroinvertebrates.
GDE: Level I 20 Inventory Field Guide

• Field—Hydrology/Hydrogeology.

§ Ability to measure flows and water quality. 

§ Ability to describe the hydrogeologic setting of the feature, 

including aquifers, rock types, geologic structures, and 

groundwater flow system. 

§ If monitoring wells or piezometers are to be installed, the 

ability to install, survey, and monitor them.

• Field—Soils. 

§ Ability to describe the soils at a site (by augering soil cores, 

digging pit, or other means).

§ Ability to determine soil texture by feel.

§ Familiarity with standard soil nomenclature, soil stratigraphy, soil morphology, and USDA Natural Resources 

Conservation Service (NRCS) soil taxonomy.

§ Ability to interpret soil features, particularly hydric soil 

features, and infer soil processes within a landform setting.

With a team of a few (probably two or three) people who have 

the skills previously outlined, it is anticipated that the field data 

collection described in this field guide will take about 2 hours to 

complete.

When To Sample 

No time is ideal for sampling all the attributes described in this 

field guide. The pros and cons to sampling at different times of 

the year are summarized here.

Winter

• Hydrology—Good time to determine base flow; very difficult 

to sample water table in deep snow or when ground is frozen. 

(In some settings, groundwater discharge prevents ground 

from freezing.)

• Soil—Very difficult to sample soils in deep snow or when 

ground is frozen. (In some settings, groundwater discharge 

prevents the ground from freezing.)

• Vegetation—Very difficult to identify plants and to quantify 

their abundance.
GDE: Level I 21 Inventory Field Guide

• Miscellaneous—Might be difficult to access some sites 

(because of snow). In warmer settings, winter might be a time 

to avoid excessive heat; there would probably be less disturbance to the site, such as trampling, as a result of field guide 

implementation. Winter use by herbivores can be observed.

Early in Growing Season

• Hydrology—Hydrology might be highly influenced by weather 

events (such as snowmelt, high runoff, or rain), and water 

chemistry measurements may be biased by spring runoff.

• Soil—Soil can generally be sampled. 

• Vegetation—Difficult to identify plants and to quantify their 

abundance.

• Miscellaneous—Access may be a problem for some sites.

Middle of Growing Season

• Hydrology—Good time to measure water table, although flow 

and water table could be influenced by weather events (such 

as rain).

• Soil—Good time to do soil sampling. 

• Vegetation—Good time to identify plants and to quantify their 

abundance. 

• Miscellaneous—Most sites are accessible. Livestock use can 

be observed.

Late in Growing Season

• Hydrology—Good time for determining groundwater influence, 

although water tables may be lower than they are in midseason, 

making some water chemistry measurements difficult.

• Soil—Good time for sampling whole soil profiles. 

• Vegetation—In general, a good time to identify most plants, 

but some plants may have reached senescence, making 

identification difficult.

• Miscellaneous—Good time for observing or measuring effects 

of use by herbivores.
GDE: Level I 22 Inventory Field Guide

The weather conditions always need to be recorded and considered when evaluating the data. For example, rain can alter pH 

and conductivity and raise the water table.

Preventing Damage to Sites

Springs, fens, and other GDE wetlands are relatively uncommon 

on the landscape in most areas and are also vulnerable to 

impacts from activities associated with data collection. Small 

GDE sites are particularly vulnerable because the impacts are 

concentrated over a small area. Appendix 4, Site Protection 

Guidelines, outlines specific suggestions for minimizing damage 

to the plants, soils, and hydrologic processes of these valuable 

ecosystems.
GDE: Level I 23 Inventory Field Guide

Pre-Field Survey Activities (in office) 

This section explains what information should be gathered or 

acquired in the office before going out to the field. This information can be compiled in the office using existing data in Forest 

Service NRM applications and through map and remote sensing 

(including photo) interpretation. Some of this information might 

be updated after the site visit, when field-determined coordinates 

for the site can be plotted on the map.

Obtain information necessary to address some of the Management Indicator Tool statements before going to the site. Review 

the applicable land resource management plan to determine 

whether the plan recognizes and provides direction for conservation and protection of the site. Identify whether any management 

activities have taken or are currently taking place at the site. Also, 

identify if any authorized uses are located at the site and the 

terms and conditions of those authorizations.

Site Information

Site Identification

Description—The site identification (ID) is a unique identifier for 

each GDE site. It is useful for managing the data in the field and 

in a database. The same site ID should be used for different sampling events at the same site (such as monitoring over time).

Source—The site ID may be obtained from the NRM-INFRA 

Database or the NRM-NRIS Water Rights and Uses database. 

Units may have created their own site IDs in the past. If multiple 

site IDs exist, then choose the one that best represents the site 

and meets the management needs for which the field guide is 

being implemented (e.g., if the field guide implementation is being 

done to assess effects from water withdrawals, then select the 

existing NRM-NRIS Water Rights and Uses site ID). If no site ID 

exists (or it is unknown), then create a site ID. It is highly recommended that the numbers for the region, forest, and district form 

the beginning of the site ID (as recommended in Site General). An 

example would be “040213 Johnson’s Spring.” Some site IDs may 

be only numeric and descriptive text would be in the site name 

(see the following description). If the site ID contains descriptive 

text, then the site name may include some of the same text.
GDE: Level I 24 Inventory Field Guide

Site Name 

Description—The site name is a descriptive name for the site, 

such as the common name of a spring or wetland. A portion or the 

entire text of the site name might also be contained in the site ID.

Source—The site name can be obtained from the following:

• Maps—

§ U.S. Geological Survey (USGS) quadrangle map (these 

names are also listed in the USGS Geographic Names 

Information System). 

§ Forest Service primary base series maps, which are the 

Forest Service version of the USGS quad.

• Management plans, such as a forest plan, project plan, or 

allotment plan, or existing authorizations that specify the site 

by name.

• If no site name exists in the sources previously listed, create 

a descriptive name that is representative—and respectful— 

of the site. It is helpful if this name is unique.

Project Name

Description—The project name is a descriptive term for the field 

guide implementation effort. A project can be a data collection 

activity containing multiple data collection sites guided by a 

specific purpose. Multiple sites can be within the same project. 

(This is a required field in Site General.)

Source—The project team will create this name. 

Purpose 

Description—The purpose describes the reason the site is being 

sampled. A list of values is included from Site General. (This is a 

required field in Site General.) 

Source—Select one or more purposes from the following list:

q Area assessment.

q Analysis for recreation impacts—human or stock.

q Threatened and endangered species animal habitat analysis.

q Big game habitat evaluation.
GDE: Level I 25 Inventory Field Guide

q Ecosystem analysis.

q New ecosystem classification or successional analysis.

q Ecological unit inventory plot.

q Existing vegetation map unit.

q Fire effects or fire history plus fuels.

q Forest plan revision.

q Previous habitat type classification data.

q Integrated multiresource inventory/monitoring.

q Invasive plants inventory.

q Mining claim examination.

q Mining or oil/gas rehabilitation monitoring.

q Threatened and endangered plant species habitat analysis.

q Correlation with permanent timber management plot.

q Range allotment inventory.

q Correlation with regeneration exam/stake rows.

q Range monitoring (i.e., reading, trend, utilization).

q Resource Natural Area and special interest area analysis.

q Research plots.

q Correlation/verification for spectral data/Landsat.

q Correlation with stand exam.

q Correlation with soil survey.

q Vegetation inventory.

q Watershed analysis.

q Wilderness ecology inventory/monitoring.

q General wildlife habitat.

q Watershed inventory.

q Watershed monitoring.

q Operating mine monitoring.

q Oil/gas development.

q GDE inventory or monitoring.

q NEPA.

q Administrative study site.

q Research.

q Water uses and needs inventory.

q State adjudication.

q Determination of waters of the United States.

q Other:________________.
GDE: Level I 26 Inventory Field Guide

Geographic Information

State

Description—The U.S. State(s), possession(s), or territory where 

the site is located.

Source—Forest Service NRM-ALP database.

County

Description—The county or counties in which the site is located. 

Source—Forest Service NRM-ALP database.

Land Status

Description—The land status where the site is located. (This 

is called “ownership” in Site General and is a required field.) 

Options include Forest Service; U.S. Department of the Interior 

(USDI) agencies, such as U.S. Fish and Wildlife Service and 

Bureau of Land Management; county government; etc. 

Source—Forest Service NRM-ALP database.

Note: It is also useful to determine if the entire site and immediate 

area are under the jurisdiction and management of the Forest 

Service. A related piece of information is whether any activities or 

management on lands outside Forest Service jurisdiction are affecting this site. (This information will be necessary to answer questions 

in the Management Indicator Tool, which is toward the end of this 

document.)

Forest Service Region

Description—The Forest Service region(s) in which the site is 

located. This field is required when land status is Forest Service.

Source—Forest Service NRM-ALP database.

National Forest, Grassland, or Prairie

Description—The NFS unit(s) in which the site is located. This 

field is required when land status is Forest Service. (This is called 

“Proclaimed National Forest/Grassland” in Site General.) 

Source—Forest Service NRM-ALP database.
GDE: Level I 27 Inventory Field Guide

Forest Service Ranger District

Description—The ranger district(s) in which the site is located. 

This field is required when land status is Forest Service. 

Source—Forest Service NRM-ALP database.

Grazing Allotment Number

Description—The grazing allotment number. This is useful for 

projects that are focused on grazing issues.

Source—Forest Service NRM-INFRA database.

Grazing Allotment Name

Description—The grazing allotment name. This is useful for 

projects that are focused on grazing issues.

Source—Forest Service NRM-INFRA database.

NRM-INFRA Reference Number 

Description—The NRM-INFRA database reference number 

has been assigned to physical structures or development. (If 

development occurs at the site, it should be recorded in the 

Forest Service NRM-INFRA database that records all structures, 

infrastructure investments, and use authorizations on NFS lands.)

Source—Forest Service NRM-INFRA database.

Water Right Number and Status

Description—This number is assigned to a water source by a 

State. The water right status is a determination of the validity 

of the water right that allows the holder to use it in the manner 

represented or prescribed. This is useful for projects that are 

focused on water rights issues. 

Source—Forest Service NRM-NRIS Water Rights and Uses 

database.

Note: It would be useful to determine if there are any outstanding 

claims for water rights by others for this site. (This information will 

be necessary to complete the Management Indicator Tool, which is 

described later in this field guide.)
GDE: Level I 28 Inventory Field Guide

Watershed(s) Hydrologic Unit Code(s)

Description—The hydrologic unit code (HUC) is a system for 

distinguishing and naming watersheds and subwatersheds (in 

multiple size classes) across the United States. Each hydrologic 

unit is identified by a unique hydrologic unit code consisting of 

2 to 12 digits based on the 4 levels of classification in the hydrologic unit system. We recommend that the 6th-level (12-digit) 

HUC (the subwatershed level) be recorded for each GDE site. 

Multiple HUCs should be recorded if the site is in more than one 

6th-level HUC. 

Source—The HUC can be derived spatially if you have good 

location information (such as Universal Transverse Mercator 

[UTM] coordinates or latitude/longitude). The following USGS 

Web site describes and delineates HUCs: http://water.usgs.gov/

GIS/huc.html.

Ecological Unit

Description—“Ecological units are areas of relatively stable 

environments that depict the inherent properties of their ecosystem elements” (Winthers et al. 2005, p. 51). Ecological units are 

divided into hierarchical levels that include section, subsection, 

landtype association (LTA), landtype (LT), or landtype phase (LTP). 

Source—Section and subsection maps can be obtained from 

the ECOMAP 2007 Web site at http://svinetfc4.fs.fed.us/

clearinghouse/other_resources/ecosubregions.html.

Alternatively, NRM-NRIS feature classes for these map units can 

be loaded from the Corporate Data Warehouse directly into an 

ArcMap project by following the directions at http://fsweb.nris.

fs.fed.us/products/Inventory_Mapping/.

LTA, LT, or LTP feature classes can be used if available. If the 

administrative unit does not have LTs or LTPs, and the region 

does not have LTAs already in the NRM-NRIS database, then the 

default is to use the EcoMap Subsection. This can be derived 

spatially if you have good location information (such as UTM 

coordinates or latitude/longitude). 

Ecological System 

Description—NatureServe (2011) provides conservation status, 

taxonomy, distribution, and life history information for more than 
GDE: Level I 29 Inventory Field Guide

70,000 plants, animals, and ecological communities and systems 

in the United States and Canada. Although GDEs are not explicitly identified in the database, a query of ecological systems using 

terms such as groundwater, seepage, fen, or spring will identify 

most of the GDEs in the inventory area. Examples of GDEs in 

NatureServe include Rocky Mountain Subalpine-Montane Fen 

and Piedmont Seepage Wetland. A list of GDEs from the NatureServe database is presented in appendix 5. 

NatureServe has developed internationally standardized classifications for terrestrial ecosystems—mid-scale ecological units 

useful for standardized conservation assessments of habitat 

diversity and landscape conditions. Each system encompasses 

complexes of plant communities influenced by similar physical 

environments and dynamic ecological processes, including 

dependence on groundwater. 

Source—The NatureServe Explorer Web site is available at 

http://www.natureserve.org/getData/USecologyData.jsp.

Local Feature-Type Name

Description—This local name is used to describe the type of 

feature being sampled. In some cases, this name can be found 

in the NatureServe list. Some common type names are cienega, 

fen, peatland, swamp, and wet meadow.

This local name can be helpful in understanding the type of site 

and the meaning of regional terms for springs and wetlands.

Mapping

This section describes maps and map sources necessary 

to locate and describe the site. A list of useful geologic map 

resources follows:

• Overview of USGS geology products and work—

http://geology.usgs.gov/.

http://pubs.usgs.gov/of/2005/1305/.

• Link to National Geologic Maps Database Web site for 

downloading by State, etc.—

http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html.
GDE: Level I 30 Inventory Field Guide

• Link to State geological surveys—

http://www.stategeologists.org/.

Metadata for State geologic data has been standardized over 

select Western States: Arizona, California, Idaho, Nevada, Oregon, 

Utah, and Washington.

For the Pacific Northwest, the major bedrock lithologic units can 

be obtained from a digital map on this USGS Web site: 

http://geo-nsdi.er.usgs.gov/metadata/open-file/95-680/

metadata.faq.html.

USGS Quad

Find the primary USGS topographic quad map where the site 

is located. The USGS system includes quadrangle boundaries 

for the United States available in the 1:250,000, 1:100,000, and 

1:24,000 scales nationally. The USGS quad can be derived 

spatially once a Global Positioning System (GPS) location is 

established for the site. 

Magnetic Declination

Record the bearing that should be used to adjust for local 

magnetic declination.

Geologic Map Name 

Record the source for geologic mapping. 

Geologic Map Unit 

Determine the geologic unit at the site from the geologic map. 

This unit will be recorded in NRM-NRIS database. It is important 

for establishing the hydrogeologic setting. This can be derived 

spatially once a GPS location is established for the site and a 

digital geologic layer is obtained.

Land Resource Regions

The Land Resource Region and Major Land Resource Area of the 

NRCS can be obtained from the following Web site:

http://soils.usda.gov/survey/geography/mlra/index.html.
GDE: Level I 31 Inventory Field Guide

Soil Map Name and Unit 

This is the soil map unit or the soils classification from the Terrestrial Ecological Unit Inventory (TEUI) map. This can be derived 

spatially once a GPS location is established for the site and a 

digital soil layer is obtained. It is useful to record the year the 

map was published and the taxonomic unit(s) of the map unit.

Route

Coordinates

Determine or estimate UTM coordinates or latitude/longitude 

before the site visit to help with the field crew arrival at the site. 

Update or confirm the coordinates during the field survey.

Location—Driving Route

Provide driving directions from the nearest town to the site (if 

the site is beside a road) or to a place where a vehicle is parked 

before walking to the site (e.g., a trailhead).

Location—Hiking Route

Provide hiking directions from a location where a vehicle is 

parked to the site. Give precise access directions beginning with 

a landmark (e.g., a named point on the topographic map, a major 

highway, marked trailhead) readily locatable on a 7.5-minute 

topographic map as the starting point. Use clear sentences that 

will be understandable to someone who is unfamiliar with the 

area and who has only your directions to follow. Give distances 

and use compass directions (true north, not magnetic north). 

When possible, provide a GPS path and the ArcMap project 

name where data are stored for use in Trimble or other GPS 

data logger. Avoid ambiguous words such as “above,” “near,” 

beyond,” “on the back side of,” or “past.” If site locations lack 

major landmark features as guides, use township, range, and 

section information from topographic maps. Although the 

sample sites may not be permanently marked, others may want 

to relocate them for long-term monitoring purposes. Careful 

documentation of the access route and obvious landmarks are, 

therefore, important. 
GDE: Level I 32 Inventory Field Guide

Location—Other

If appropriate, provide directions for other means of accessing 

the site, such as by boat or aircraft.

Other Information About the Site

Preliminary GDE Type

Before the site visit, what is the GDE type assumed to be? Select 

one or more from the following list:

• Spring/Wetland Type (modified from Springer and Stevens 

2009)—

§ Cave—Groundwater emerges in or from a cave; common 

in karst terrain.

§ Exposure—Groundwater is exposed at the land surface 

but does not have surface inflow or outflow; occurs in karst 

(sinkholes) and lava flows but could form in other types of 

vertical conduits into an aquifer.

§ Fountain—Cool artesian spring that is forced above the 

land surface by stratigraphic head-driven pressure or 

carbon dioxide (CO2).

§ Geyser—Intermittent geothermal spring that emerges 

explosively and usually erratically.

§ Gushet—Discrete source of flow pouring from cliff faces; 

typically emerges from perched, unconfined aquifers, often 

with dissolution enhancement along fractures; exhibits thin 

sheets of water flowing over rock faces.

§ Hanging garden or wet wall—Spring that emerges along 

geologic contacts or fractures and seeps, drips, or pours 

onto underlying walls; typically emerges from perched, 

unconfined aquifers in aeolian sandstone units.

§ Helocrene—Spring that emerges diffusely from lowgradient wetlands; often indistinct or multiple sources 

seeping from shallow, unconfined aquifers (may include 

fens and cienegas).
GDE: Level I 33 Inventory Field Guide

§ Hillslope—Spring and/or wetland on a hillslope (generally 

20- to 60-degree slope); often with indistinct or multiple 

sources of groundwater.

§ Hypocrene—A buried spring where groundwater levels 

come near, but do not reach, the surface in arid regions, 

typically due to very low discharge and high evaporation 

or transpiration. In humid regions, these features may be 

equivalent to shallow groundwater areas including wet 

meadows.

§ Limnocrene—Groundwater emerges in pool(s).

§ Mound—Spring that emerges from a mineralized mound, 

(usually carbonate) frequently at magmatic or fault systems. May also include springs issuing from peat mounds. 

§ Rheocrene—Flowing spring that emerges directly into one 

or more stream channels. Spring-fed streams are also 

referred to as springbrooks or spring runs.

§ Other/unknown (describe in notes).

• Note which sources were used to make preliminary GDE type 

determination:

q USGS map.

q National Wetlands Inventory.

q Forest maps.

q Other map.

q Previous forest inventories (vegetation or hydrologic).

q TEUI/aquatic ecological unit inventory.

q Photo.

q Personal account.

q Other:________________.
GDE: Level I 34 Inventory Field Guide

Archeological, Paleontological, Cultural, or Historic 

Sites or Use

Research records for cultural resources or historic use (e.g., 

archaeological or paleontological sites) at sites to be inventoried. 

This will help limit damage to important cultural resources.

Available Data

Seek out and list other sources of data that are available about 

the site.
GDE: Level I 35 Inventory Field Guide

Field Survey Activities

Appendix 6 lists equipment needed to implement this field guide. 

Field forms are in appendix 3. Metric units of measure are highly 

recommended to facilitate data summarization. Disturb the site as 

little as possible while collecting data, as described in appendix 4 

(Site Protection Guidelines). 

Survey Information

Survey Date

Record the calendar month, day, and year the site was visited. 

(This is a required field in Site General.)

Time

Record the time of day for the start and end of the field data 

collection.

Examiners

Record the first and last names of the crew that is doing the field 

data collection. (This is a required field in Site General.)

Weather

Weather can be important when interpreting water chemistry and 

water level information; for example, rain can alter the pH and 

conductivity measurements and raise the water table.

Record evidence of precipitation (rain or snowfall) during the 

sampling visit or evidence of recent rain or snowfall.

q Recent rain.

q Rain during survey.

q Snowfall, hail, or sleet during survey.

q Snow on ground.

q No current/recent precipitation.
GDE: Level I 36 Inventory Field Guide

Air Temperature 

Record the daytime air temperature at the time of the visit. 

Area of GDE 

For very small sites, see box 2 before proceeding.

Description—This is a measure of the area or size of the GDE 

site. A GDE site generally has distinctive vegetation that is present 

because of the elevated water table. In some settings, such as 

drier regions, a very clear boundary may exist, which is evident 

from different vegetation or topographic differences, between the 

GDE and the uplands. In other settings, a more gradual transition 

from wetland to upland will occur, with significant zones of transition 

that include both wetland and upland plant species and very little 

change in slope. In such cases, the determination of the boundary 

of the wetland is somewhat subjective, and must be based, 

ultimately, on either a judgment call or detailed sampling. The 

following guides will help determine the extent of the GDE.

Hydrology—Water on the surface of the ground, or saturated 

ground (not from recent precipitation), can be an indication that 

the area is part of the GDE, although the absence of water does 

not preclude it from being part of the GDE.

Vegetation—The GDE will typically have obligate, facultative wet, 

and facultative wetland species, as distinguished by the Wetland 

Indicator Status of the U.S. Fish and Wildlife Service (1988). The 

edge of the GDE will generally be associated with a transition from 

those wetland species to more upland species. The presence of 

bryophytes could be indicative of a GDE wetland, although the 

absence of bryophytes does not indicate that it is not part of the GDE.

Landform—A change in slope (from flatter to steeper) can be 

associated with the edge of the GDE. 

Peat or muck—The presence of peat or muck can indicate a 

GDE wetland. A boundary, with peat or muck on one side and no 

peat or muck on the other, could be an indication of the edge of 

the GDE. The absence of peat or muck does not preclude it from 

being within the GDE.

Spring—A spring will include an orifice, where water emerges, 

and possibly a pool and/or channel. Include the orifice and emergence zone, which generally includes obligate and facultative 

wetland plant species, as distinguished by the Wetland Indicator 
GDE: Level I 37 Inventory Field Guide

Status of the U.S. Fish and Wildlife Service (1988), which are 

supported by the groundwater discharge or shallow water table. 

A key question in the application of this field guide is how much 

of an associated spring brook should be included in the site area. 

The response can be an arbitrary choice, based on a set run-out 

distance; a subjective decision, based on how far the riparian 

zone appears to be strongly influenced by the spring; or a more 

objective decision, such as one used in western arid regions, 

which considers the downstream boundary of the spring to be 

the point where the spring brook water temperature changes 

by 2 degrees Celsius. Pros and cons accompany each of these 

alternatives. In this field guide, 20 meters of the run-out stream, 

or spring brook, are included in the site area for sampling. If it is 

desirable to inventory (or monitor) a longer distance of a spring 

brook, then a stream and/or riparian protocol should be used to 

collect the data, which would then be considered as a separate 

(although companion) set of data from those collected from the 

spring as a part of this field guide.

How to measure and record—If possible, walk around the 

perimeter of the GDE when measuring or estimating size (to 

avoid excessive trampling). Determine the size of the GDE site 

(including all the spring and wetland features present) by one of 

the following methods (listed in order of highest to lowest recommendation): 

1. GPS traverse of GDE edge. (Most GPS units have a feature 

that allows the operator to walk around the edge of the unit 

and determine the area.) 

2. Measure the average width and length (for rectangular sites) 

or diameter (for round sites) using a tape (such as a 100-meter 

tape) or a rangefinder. Pacing with a known pace-length may 

also be done, although it is less accurate.

3. Estimate the size using topographic maps, orthophotos (GIS), 

satellite images (GIS or Google Earth), or aerial photos. 

4. For larger features, where it might not be practical to walk the 

perimeter, it may be possible to sketch the perimeter in the 

GPS/data recorder (if using a unit that allows this type of GIS 

entry), using an image in the background. This measurement 

would require a GPS unit that uses software such as ArcPad, 

which allows the technician to sketch GIS features on the 

screen with aerial images as a background.
GDE: Level I 38 Inventory Field Guide

5. Estimate the area using the following classes (last resort):

q < 2 m2

.

q 2 to 10 m2

.

q 10 to 100 m2

.

q 100 to 1,000 m2

.

q 0.1 to 0.5 ha.

q 0.5 to 1 ha.

q 1 to 10 ha.

q 10 to 100 ha.

q > 100 ha.

Note for Very Small Sites

Very small sites are vulnerable to damage from disturbance caused by the

crew collecting data. Follow these guidelines for sampling very small sites (see

appendix 4):

•	 Walk outside of the GDE site as much as possible.

•	 Record vegetation information from outside the GDE if possible.

•	 Take photos and draw the site sketch from outside the site.

•	 Consider skipping soil core and water table measurements.

•	 Do water measurements carefully.

•	 Make only one trip (or very few) in/across the GDE for measurements.

Box 2

Reference Point

Description—A reference point is a spatial location or point on 

the ground that can be documented with GPS and plotted on 

a map. This point is valuable for plotting the site on a map and 

relocating a site for future sampling visits.

How to measure and record—For springs, the reference point 

should be the spring source (sometimes referred to as the spring 
GDE: Level I 39 Inventory Field Guide

orifice). For wetlands that are relatively small, the reference point 

could be the center of the wetland or the wettest part of the wetland. For larger GDEs, the reference point could be the center of 

the site or some distinguishing feature within the GDE. 

At the reference point, record the latitude and longitude coordinates (see Georeferencing section) that will enable someone to 

return to or near that location. Also record specific information 

or features that can be used to relocate the exact position of 

the reference point, ideally including a monumented tree, stake, 

fence, large boulder, or the distance and direction from some 

permanent feature such as a road or stream crossing. 

Indicate where the reference point is on the site sketch (see 

Images section).

Slope

Description—The general incline of the site.

How to measure and record—Record the ratio of vertical rise 

to horizontal distance for the site expressed as percent. This is 

taken either at an average point on the site or as an average for 

a site.

Aspect

Description—The general direction that the landscape faces. 

How to measure and record—Record the azimuth that the landscape faces at the center of the site or the majority of the site. 

Azimuth will be recorded from true north in degrees, 0 to 360. 

Relative Area of GDE

Description—The percent of the area covered in general categories of GDE settings (complexes of springs, wetlands, open 

water, and other settings).

How to measure and record—Estimate the percent of the area 

within the GDE site that is covered by the following settings 

(must sum to 100 percent).

• Spring emergence.

• Channel (such as spring brook or other channel).
GDE: Level I 40 Inventory Field Guide

• Wetland/riparian.

• Open water (standing, not generally flowing).

• Other or unknown.

Georeferencing

Horizontal Datum

Description—This is the GPS datum used to record the location 

information in the field.

How to measure and record—Record the datum for the projection at the “reference point.” 

q North American Datum of 1927 (NAD-27).

q North American Datum of 1983 (NAD-83) (recommended).

q World Geodetic System of 1972 (WGS-72).

q World Geodetic System of 1984 (WGS-84).

GPS Equipment

Description—The make and model of the GPS equipment.

How to measure and record—Record the make and model of 

the GPS equipment used and the approximate GPS accuracy. 

Universal Transverse Mercator Coordinates 

(from GPS) 

UTM zone—This is the zone for the UTM projection. It can be 

obtained from quad maps or from GPS devices. UTM zone coordinates measure in meters east and north from two perpendicular 

reference baselines. 

Easting—This is the distance in meters, east or west, from the 

central meridian of the UTM zone, which is designated at a value 

of 500,000 meters. 

Northing—This is the distance in meters north from the equator 

from the UTM zone origin, which is designated as a value of zero 

meters. (This field guide addresses only north latitudes.)
GDE: Level I 41 Inventory Field Guide

Latitude and Longitude (from GPS)

Record the latitude and longitude at the reference point. This 

may be recorded either in degrees, minutes, and seconds, or in 

decimal degrees.

• Latitude—degrees:

(Range 0 to 90) The latitude degrees of the site as measured 

by GPS. (Default: north latitude.)

• Minutes:

(Range 0 to 59) The latitude minutes of the site as measured 

by GPS. (Default: north latitude.)

• Seconds:

(Range 0 to 59.99) The latitude seconds of the site as measured 

by GPS. (Default: north latitude.)

• Longitude—degrees:

(Range 0 to 180) The longitude degrees of the site as measured 

by GPS. (Default: west longitude.)

• Minutes:

(Range 0 to 59) The longitude minutes of the site as measured 

by GPS. (Default: west longitude.)

• Seconds:

(Range 0 to 59.99) The longitude seconds of the site as 

measured by GPS. (Default: west longitude.)

• Latitude decimal degree:

Latitude in a degree value. Consists of the latitude in degrees 

to at least 6 decimal places.

• Longitude decimal degree:

Longitude in a degree value. Consists of the longitude in 

degrees to at least 6 decimal places.

Elevation

Description—The elevation of the site.

How to measure and record—Record the elevation with a GPS 

unit at the reference point. Substantial error in GPS measurements 

may exist, but these data are adequate to characterize site 

elevation. For more accurate elevations, estimate them from a 

10-meter Digital Elevation Model. Record to within ± 3 meters.
GDE: Level I 42 Inventory Field Guide

Note how elevation was determined. 

q GPS unit.

q Topographic map (if necessary, interpolate between two 

contour intervals).

q Other:________________.

Geologic Setting

Evidence of Groundwater

Record the evidence that this ecosystem is groundwater supported. 

Use the decision tree in box 1 to help with this determination. 

Multiple answers are allowed.

q Flow from a spring source, contact, joint, or fault—indicating 

spring. 

q Peat or muck accumulation significant.

q Standing water.

q Wetland vegetation.

q Other:________________.

GDE Type

Description—A general categorization of the GDE types at the 

site.

How to measure and record—Record the primary (dominant) 

GDE type and secondary GDE types present at the site. Only one 

primary type is recorded, but multiple secondary types can be 

recorded.

• Spring/Wetland Type (modified from Springer and Stevens 

2009):

§ Cave—Groundwater emerges in or from a cave; common 

in karst terrain.

§ Exposure—Groundwater is exposed at the land surface 

but does not have surface inflow or outflow; occurs in karst 

(sinkholes) and lava flows but could form in other types of 

vertical conduits into an aquifer.
GDE: Level I 43 Inventory Field Guide

§ Fountain—Cool artesian spring that is forced above the 

land surface by stratigraphic head-driven pressure or CO2.

§ Geyser—Intermittent geothermal spring that emerges 

explosively and usually erratically.

§ Gushet—Discrete source of flow pouring from cliff faces; 

typically emerge from perched, unconfined aquifers, often 

with dissolution enhancement along fractures; exhibit thin 

sheets of water flowing over rock faces.

§ Hanging garden or wet wall—Spring that emerges along 

geologic contacts or fractures and seeps, drips, or pours 

onto underlying walls; typically emerge from perched, 

unconfined aquifers in aeolian sandstone units.

§ Helocrene—Spring that emerges diffusely from lowgradient wetlands; often indistinct or multiple sources 

seeping from shallow, unconfined aquifers (may include 

fens and cienegas).

§ Hillslope—Spring and/or wetland on a hillslope (generally 

20- to 60-degree slope); often with indistinct or multiple 

sources of groundwater.

§ Hypocrene—A buried spring where groundwater levels 

come near, but do not reach, the surface in arid regions, 

typically due to very low discharge and high evaporation 

or transpiration. In humid regions these features may be 

equivalent to shallow groundwater areas including wet 

meadows.

§ Limnocrene—Groundwater emerges in pool(s).

§ Mound—Spring that emerges from a mineralized mound, 

(usually carbonate) frequently at magmatic or fault systems. May also include springs issuing from peat mounds. 

§ Rheocrene—Flowing spring that emerges directly into one 

or more stream channels. Spring-fed streams are also 

referred to as springbrooks or spring runs.

§ Other/unknown (describe in notes).
GDE: Level I 44 Inventory Field Guide

Geologic Structure Type

Description—The geologic structure type is the kind of structure 

that may be controlling the flow of groundwater to the GDE, such 

as a geologic contact or fault plane. Many GDEs occur on geologic structures because they can create preferential pathways 

for the flow of groundwater. This is helpful for understanding the 

hydrogeologic setting of the site and from where groundwater is 

sourced.

How to measure and record—Record the type of geologic structure (preferential groundwater flow path) that is discharging water 

to the site. Observe the geologic units and geologic structure and 

compare that to a geologic map. Record your conclusions based 

on the following list: 

q Bedding—Planar surfaces that visibly separate layers of 

stratified rock.

q Contact—Planar surfaces that separate different rock units.

q Fault—Fracture or a zone of fractures along which there 

has been displacement.

q Fracture—Fracturing in rock, without displacement.

q Lineation—Any linear structure on the ground surface (in 

general, identified on aerial photography).

q Conduit—Tubular opening, common in karst terrain.

q Unknown.

Indicate source of conclusion:

q Observation.

q Geologic map.

q Other:________________.

Surficial Material 

Description—This is the kind of unconsolidated material occurring at the surface. Many GDEs, particularly fens, develop 

on unconsolidated surficial materials. The type of material can 

influence the water chemistry and ecology.
GDE: Level I 45 Inventory Field Guide

How to measure and record—Record the kind of material occurring at the surface. Surficial materials are defined as nonlithified, 

unconsolidated sediments. They are materials produced by 

weathering, sediment deposition, biological accumulation, and 

human and volcanic activity. They include residual materials 

weathered from rock in situ; transported materials composed of 

mineral, rock, and organic fragments deposited by water, wind, 

ice, gravity, or any combination of these agents; accumulated 

materials of biological origin; materials moved and deposited 

by human actions; and unconsolidated pyroclastic sediments. 

Record the primary surficial material; secondary surficial materials may also be recorded.

q Alluvium—An unconsolidated accumulation of streamdeposited sediments, including sands, silts, clays, or gravels.

q Colluvium—Soil material and rock fragments moved downhill by creep, slide, slough, or local wash and deposited at 

the base of steep slopes.

q Eolian deposit—Wind-deposited sediments.

q Glacial deposit—Includes unsorted and unstratified till, 

including moraines, which are generally exposed in the 

uplands; and glacial meltwater deposits of sorted and 

stratified deltaic, stream, and lake sediments.

q Human-caused or constructed—Natural and manmade 

materials that have been artificially emplaced.

q Lacustrine sediments—Sediments deposited in lakes.

q Landslide deposit—Sediment deposited by downslope 

movement of a sorted or poorly sorted mass of soil or rock 

of mixed grain sizes, including rock falls, slumps, mud 

flows, debris flows, and earth flows.

q Marl—A friable deposit consisting of clay and calcium 

carbonate.

q Residuum—Weathered bedrock.

q Talus deposit—An accumulation of angular rock debris 

at the base of a cliff or steep slope that was produced by 

physical weathering.

q Volcanic unconsolidated material—Ash or mudflow.
GDE: Level I 46 Inventory Field Guide

q Rock—Bedrock with no surficial material present.

q Tufa or travertine deposits—Travertine is a sedimentary 

rock, formed by the precipitation of carbonate minerals 

from solution in ground and surface waters, or geothermally heated hot springs. Similar, but extremely porous, 

deposits formed from ambient temperature water are 

known as tufa.

q Other/unknown.

Lithology, Primary (groundwater source aquifer)

Description—Primary lithology describes the geologic materials 

such as bedrock or other surficial materials under a site. The 

groundwater source aquifer refers to the aquifer from which the 

groundwater is emanating. The primary lithology is generally 

the groundwater source aquifer. Primary lithology is useful for 

understanding the groundwater flow patterns. The location and 

hydrology of GDEs are controlled by the geology, and the type 

of rock can influence the water chemistry and ecology of the 

feature.

How to measure and record—If evidence in the field exists, then 

record one of the following primary lithology descriptors. If no 

evidence in the field exists, then answer this question in the office 

using the electronic resources listed in the “Mapping” section. If 

the groundwater emerges from a talus or other unconsolidated 

material at the base of a slope, then try to determine the upgradient 

geologic unit from which the groundwater is originating. The 

important bedrock lithology or geologic unit is the one supporting 

the aquifer that supplies water to the feature.

q Igneous extrusive.

q Igneous intrusive.

q Sedimentary.

q Metamorphic.

q Undifferentiated—Rocks for which finer age divisions are 

not specified on the map, small areas of rocks of different 

ages are too close together to be shown at the scale of the 

map, or the exact age relationships of the rocks in a given 

area may not yet have been determined.
GDE: Level I 47 Inventory Field Guide

q Unconsolidated—Loose sediment, lacking cohesion or 

cement.

q Unknown.

q Other:________________.

Indicate whether the primary lithology (noted previously) is also 

the groundwater source aquifer.

q Yes.

q No.

q Unknown.

Level of certainty for groundwater source aquifer—

q Known—Based on site investigation.

q Assumed—Based on professional opinion.

q Unknown—Needs further investigation.

Lithology, Secondary

Description—This is a finer scale description of the lithology 

of rock units occurring at the site and is tiered to the primary 

lithology of the aquifer from which the groundwater is emanating, 

or the original rock type that weathered to form the parent or 

surficial material. 

How to measure and record—If evidence in the field exists, 

record the secondary lithology (tiered to the primary lithology) 

from the list in appendix 7, which is from Site General (USDA 

Forest Service 2009).

Landforms

Description—The location of many GDEs is related to the local 

geomorphologic history and existing landforms. GDEs may 

develop within, or adjacent to, certain types of landforms (e.g., 

at the toe of slumps and on stream terraces). 

How to measure and record—Use a geologic map, air photo 

interpretation, satellite imagery, or field observations to select 

a “process/landform” from the list in appendix 8, which is from 

Haskins et al. (1998). Record the primary landform; secondary 

landforms may also be recorded.
GDE: Level I 48 Inventory Field Guide

Images

Photos 

Description—Photos of the site are taken and stored electronically. Photos help to visualize the site, to compare one site to 

another, and to record change over time.

How to measure and record—A brief description of methods for 

photo point monitoring is presented here, while more detailed 

instructions can be found in the Forest Service, Pacific Northwest 

Research Station publication Photo Point Monitoring Handbook

(Hall 2001). One photo can represent multiple points, as long as 

they are all noted.

Note: Photo points can be captured in a GPS and marked as such. 

The digital image can be stored with that point location and viewed 

by simply clicking on a point within a GIS project file.

Instructions for photos—

• Record the distance from camera to photo point (so that 

the same distance can be used in the future when the photo 

points are repeated)—

§ There are two ways to achieve this:

 Always take photos a set distance from an object in the 

photo, such as a measuring staff (or folding 2-meter 

board).

or

 For each photo, record the distance from the camera to 

an object in the photo, such as a measuring staff.

• Height of camera—

§ Always take the photo at a height of 1.5 meters above the 

ground.

• Light and time of day—

§ If possible, take photos in the middle of the day rather than 

early in the morning or late in the afternoon.

§ If possible, do not take photos looking into the sun.
GDE: Level I 49 Inventory Field Guide

• Photo identification board/card/sheet— 

§ In each photo (top corner is recommended) include something (board, card, or sheet) with the following information 

written on it:

 Site ID.

 Photo number.

 Date.

• Note the following on a photo form:

§ Info from photo identification card (Site ID, photo number, 

date).

§ What is in the photographed scene. 

§ Distance from camera to object in photo.

§ Orientation of camera (compass bearing).

§ Time of day.

§ Weather.

• To improve comparability for rephotography, take photos as 

close as possible to the time and date of the previous photos.

Take photos for the following locations (some photos may serve 

more than one purpose, as long as each is noted): 

q Reference point (defined previously).

q Center of site.

q Water measurement locations.

q Soil core locations.

q Spring source (if applicable).

q For springs with outflow channels—

§ Looking downstream, standing at/near source.

§ Looking upstream (or uphill), standing at/near source.

q Overview, from a hill (if possible).
GDE: Level I 50 Inventory Field Guide

Site Sketch Map

Description—This is a hand sketch of the site that includes 

sample locations, important features, etc. The sketch map is 

useful for understanding the site and to facilitate relocating the 

site on return visits. The sketch is also useful where GDE sites 

may be close to one another and map/GPS coordinates weakly 

describe the relative location of sample sites. 

How to measure and record—Draw a sketch (hand-drawn map 

or electronic) of the site (see example in figure 4). One way to do 

this is to use an aerial photo to trace the boundary of the GDE 

onto a blank page that then becomes the sketch of the site. 

Graph paper is useful for drawing the sketch map, using the lines 

as known distances. The items in the following list should be 

captured and documented on the sketch map for each site. 

q Reference point (described previously).

q Approximate locations/dimensions of major geomorphic 

surfaces.

q Springs—

§ Spring source. 

§ Channel locations.

§ Structures including spring boxes, troughs, and pipelines.

§ Pool location, if limnocrene.

q Areas of standing water (indicate deepest part).

q Location of measurements—

§ Soil holes.

§ Water table measurement locations.

§ Wells/piezometers.

§ Water quality samples.

q Structures or other man-made features, such as roads, in or 

adjacent to GDE.

q Indication of north (true recommended, or magnetic).
GDE: Level I 51 Inventory Field Guide

q Indication of scale.

q Boundaries of GDE, or the delineation of the area sampled if 

only a portion of the site was sampled (the site was divided).

Figure 4.—Site sketch map example.
GDE: Level I 52 Inventory Field Guide

Unusual Sites

At sites on walls, such as gushets and hanging gardens, record 

whatever information can be observed from a safe distance. 

Other suggestions include—

• Take pictures.

• Use binoculars.

• Use a range finder.

Vegetation

Only very general information about vegetation is recorded in this 

Level I field guide. If quantitative data about vegetation is desired 

then the Level II field guide should be used.

Surrounding Vegetation

Description—This is a general description of the vegetation 

(generally upland) immediately surrounding the groundwater 

dependent ecosystem, as forested, shrubland, or herbaceous.

How to measure and record—Indicate the type of vegetation 

that is in the area immediately surrounding the GDE site using the 

following list of physiognomic orders from the National Vegetation Classification Standards (NVCS) as described in Brohman 

and Bryant (2005).

• Tree dominated—Areas where tree life form (see growth 

habit at NRCS PLANTS database at http://plants.usda.gov/) 

has at least 10 percent cover in the uppermost strata during 

the peak growing season.

• Shrub dominated—Areas where shrub and/or subshrub life 

forms are at least 10 percent cover in the uppermost strata.

• Herbaceous/nonvascular dominated—Areas where herbaceous and/or nonvascular life forms are at least 10 percent 

cover in the uppermost strata.

• No dominant vegetation type—Areas where vegetation 

cover is at least 1 percent, but the area does not classify as 

tree, shrub, or order herbaceous/nonvascular dominated.
GDE: Level I 53 Inventory Field Guide

• Nonvegetated—Nonvegetated order usually associated with 

open water or land-use-dominated, human-modified land, 

such as heavy industrial, commercial, and transportation 

facilities. 

Dominant Life Form

Description—This is a ranking of the life forms with the greatest 

canopy cover in the GDE site. The cover for a life form is the total 

area covered by all species of that life form. 

How to measure and record—Rank the dominant life forms of 

plants rooted in the GDE using the categories listed below. It is 

appropriate to rank two life forms with the same number if they 

have the same (approximate) amount of cover.

Rank (1 is greatest and 5 is least):

_____ Tree.

_____ Shrub and subshrub.

_____ Graminoid.

_____ Forb/herb.

_____ Bryophyte.

_____ Aquatic plants (submerged or floating).

_____ Unknown.

Dominant Species 

Description—This is a list of the dominant species within each 

life form. The dominant species within a life form is the species 

with the greatest canopy cover in that life form.

How to measure and record—Record the dominant plant species for each life form in the GDE. Record scientific names (such 

as Picea engelmannii) or symbols (such as PIEN) that are listed in 

the NRCS PLANTS database at http://plants.usda.gov/. 

Species of Interest

Description—This is a list of species present at the site that are 

of interest for management, such as invasive species, rare species, 

or species that are specific to GDEs or a subset of GDEs such 

as a calciophyle, which is a plant that grows well in high-calcium 

settings. A regional list of invasive species would be helpful, as 

would a guide to identifying these species.
GDE: Level I 54 Inventory Field Guide

How to measure and record—List any species of interest (SOI) 

that are present at the site. In particular, look for invasive species, rare species, and species that are found primarily in GDEs 

or in a certain type of GDE.

Bryophytes

Description—This is a very general measure of the abundance 

of byrophytes (mosses, liverworts, and hornworts) at the site. 

Bryophytes can be important components of wetlands in terms 

of ecosystem functioning and as indicators of condition. 

How to measure and record—Record the general abundance of 

bryophytes using the classes listed below:

q None.

q Minor component.

q Common component.

q Very abundant.

Plant Specimens 

Description—Plant specimens are useful for identifying unknown 

species, confirming species identifications, providing vouchers, 

and helping with the training of future field technicians.

How to measure and record—If one of the dominant species 

is not known, then a specimen should be collected. Specific 

instructions for plant specimen collection are—

• Use the 1 in 20 rule as a guide: if fewer than 20 individuals are 

present at the site, do not collect the plant; instead, describe 

the plant, the setting, and take a photo.

• Collect as much of the plant as is reasonable, including—

§ Flowers or fruits. 

§ Belowground parts, to show whether it has a caudex, tap 

root, rhizomes, etc. Clean dirt from the roots. 

§ For woody plants, collect a portion of a branch with leaves 

and flowers/fruits/cones. 

§ Two pieces (stems or branches). 
GDE: Level I 55 Inventory Field Guide

• Complete a label (appendix 9) for each specimen with the 

following: plant (or unknown number), collection number, date, 

site name, project/unit, collector, answers to questions about 

the plant.

• Envelopes work well for small plants and seeds.

• Press the specimen in a plant press as soon as possible, with 

the label included. 

• Air out specimens so they do not get moldy. 

• List all collected specimens on a sheet or notebook.

• Make sure that any other data collectors at the site use the 

same unknown numbers for the same plants.

An experienced botanist should identify these specimens later, 

and that identification can be entered into the database in place 

of “unknown.”

Soil

Refer to the soils map to get an idea of the range of expected 

soils and whether the mapped soils are consistent with the soils 

observed at the site. 

A single soil sample is taken to get a general idea of the amount 

of organic material and wetland soil features present. This sample 

is generally taken from the center of the site.

These soil sampling methods are generalized from USDA NRCS 

(2006) and Schoeneberger et al. (2002) and are intended to give a 

general characterization of the soils and focus mainly on the level 

and duration of saturation. Information on the soil profile gives an 

indication of the amount of peat development and peat texture, 

the degree of water table fluctuation, and some indication of the 

underlying aquifer materials. This field guide is not intended for 

soil mapping purposes or to generate rigorous characterizations 

of soil profiles for the entire wetland site. Methods here should 

not be used when regulatory or jurisdictional requirements must 

be met.

There are various ways to take soil samples, such as with a soil 

shovel (sharpshooter), an auger (to extract a core), or a soil push 

probe. A technique that minimizes disturbances is recommended. 
GDE: Level I 56 Inventory Field Guide

If an auger is used, soil texture should influence the size of auger 

to be used. Water table elevations may also be recorded in the 

soil holes and these locations would also be logical locations for 

piezometers or minipiezometers should long-term water table 

monitoring be necessary (see Hydrology section). The depth of 

the soil sample should be about 50 centimeters to 1 meter, if 

possible. Advancement of the hole can stop when a total of 40 

centimeters of organic soil is measured. 

Wet soils and standing water are more difficult for soil sampling, 

but in many instances, it can be accomplished if the water is 

not too deep. Sampling soils at springs is not necessary if only 

a mineral substrate exists; however, if organic soil exists at a 

spring, then soil information should be recorded. The following 

list describes some reasons why soils information might not be 

collected:

• Small site, where sampling is considered too destructive. 

• Threatened, endangered, or sensitive plant or animal species 

present at the site.

• Gravel, cobble, or boulder substrate.

• Deep water.

• Frozen ground.

An Equipment List for soil data collection is in appendix 6.

Location of Soil Sample 

Description—This is the location within the site where soil 

information is collected.

How to measure and record—Record the location of the soil 

sample as one of the following:

q Center of site.

q Other:________________.

q Not taken because of (circle one): sensitive site, rocky substrate, deep water, or frozen ground.
GDE: Level I 57 Inventory Field Guide

Method of Extracting Soil

Description—This is the method or tool used to extract and 

observe soil. When analyzing soil information for the site, this will 

provide the level of reliability in the data collection effort.

How to measure and record—Record one of the following for 

each hole or core:

• Core/auger.

• Push probe.

• Shovel. 

• Other:_________.

Depth of Peat or Muck 

Description—Organic soils develop under saturated (waterlogged) conditions that prevent decomposition. Histosols, histic 

epipedon, and the presence of fibric soil material (peat), hemic 

soil material (mucky peat), and sapric soil material (muck) are 

considered the maximum expression of anaerobiosis and are 

interpreted as indicators of extremely long-term saturation. 

Organic soil materials have organic carbon content (by weight) of 

12 to 18 percent or more, depending on the clay content of the 

soil. Laboratory analysis of organic carbon content can be done 

if needed to respond to specific management questions.

How to measure and record—Record the depth where the 

peat, mucky peat, and muck layers begin and end in the first 80 

centimeters. The definitions for the different organic layers to 

record are listed below:

1. Peat (fibric)—Undecomposed or weakly decomposed organic 

material; plant remains are distinct and identifiable; yields clear 

to weakly turbid water; no peat escapes between fingers. 

2. Mucky peat (hemic)—Moderately to well-decomposed organic 

material; plant remains recognizable but may be rather indistinct and difficult to identify; yields strongly turbid to muddy 

water; amount of peat escaping between fingers ranges from 

none up to one-third; residue is pasty. 

3. Muck (sapric)—Strongly to completely decomposed organic 

material; plant remains indistinct to unrecognizable; amounts 
GDE: Level I 58 Inventory Field Guide

ranging from about one-half to all escape between fingers; 

any residue is almost entirely resistant remains, such as root 

fibers and wood.

Depth to the Mineral Layer

Description—This is a measure of the depth to the first dominantly mineral layer below any organic layer that may be present. 

If there exists a significant organic layer, such as peat, then the 

mineral layer would be below that. If there is a small or nonexistent organic layer, then this depth will be shallow.

How to measure and record—Measure the depth from the 

surface to the first mineral layer (would be zero if no organic layer 

exists).

Texture of Mineral Layer

Description—Texture describes the mineral particle sizes and 

proportions in a sediment, such as clay, silt, and sand.

How to measure and record—Conduct a tactile evaluation of the 

soil texture of the first underlying mineral layer.

Color of Mineral Layer 

Description—Color is useful to understand the composition of the 

soil and gives clues about the conditions the soil is subjected to.

How to measure and record—Describe the color of the first 

underlying mineral layer, using the Munsell color system chart.

Redoximorphic Features

Description—The type and location of redoximorphic features 

within the soil profile are used to interpret the degree of water 

saturation. Redoximorphic features, a result of iron (Fe) and 

manganese (Mn) oxidation and reduction, are not expected in 

organic soils, thus, there is no need to record redoximorphic 

features in histosols (40 centimeters or more of the upper 80 

centimeters is organic soil); mineral soils having a histic epipedon 

(surface horizons of 20 centimeters or more thick of organic soil 

material and underlain by mineral soil material with a chroma of 

2 or less); or mineral soils having peat, mucky peat, muck, or a 

mucky modified soil texture within 12 inches of the surface.
GDE: Level I 59 Inventory Field Guide

For all other soils, redoximorphic features can indicate the 

duration of saturation. Under long duration (many weeks to 

months) of water saturation and reduction, Fe oxide depletion 

features occupy the entire groundmass. The Fe oxide-depleted 

groundmass appears greyer or lighter in color. Short duration of 

water saturation or rapid fluctuation of water tables results in Fe/

Mn oxide nodules and coatings.

How to measure and record—Record the presence and depth 

of the following features:

• Redoximorphic concentrations—Redox concentrations 

include soft masses, pore linings, nodules, and concretions 

(see glossary for definitions). 

• Redoximorphic depletions—Bodies of low chroma (2 or 

less) having value of 4 or more where Fe/Mn oxides have 

been stripped or where both Fe/Mn oxides and clay have 

been stripped, see glossary for definitions. Soils having an 

abundance of gleyed material are saturated for long duration 

resulting in thorough reduction of iron to Fe+2 (ferrous iron). 

It is the presence of ferrous iron that is responsible for the 

greenish colors of gley. An absence of iron concentrations 

within a gleyed zone indicates a stable reducing environment 

and that periodic, or seasonal, fluctuation of soil saturation 

does not occur at that depth.

• Reduced matrices—A soil matrix that has low chroma and 

high value, but in which the color changes in hue or chroma 

when the soil is exposed to air. The color change should 

occur within 30 minutes.

• Presence of bog iron—A large scale redoximorphic feature 

observed in areas where groundwater rich in reduced Fe 

moves to a more oxidizing environment.

Note: In soils derived from dark parent materials (value 4 or less, 

chroma 2 or less), redoximorphic features may be difficult if not 

impossible to recognize in the field.

Hydrogen Sulfide Odor

Description—A “rotten-egg smell” indicates that sulfate is being 

reduced, and therefore the soil is anaerobic. In most hydric soils, 

the hydrogen sulfidic odor occurs only when the soil is saturated 

and anaerobic.
GDE: Level I 60 Inventory Field Guide

How to measure and record—Record whether or not the odor is 

detected as the hole is dug and the soil is removed.

Reaction To Dilute HCL

Description—A carbonate reaction can help identify systems 

supported by calcareous aquifers. This is a measure that is useful 

for identifying rich fens.

How to measure and record—Acid is applied directly to the 

soil specimen. A positive reaction confirms the presence of 

carbonates. The carbonates may be primary, secondary, or 

both. Carbonates including dolomite in soil can be inherited from 

parent material and occur in the fraction less than 2 millimeters 

in size. The specimen can be placed in a spot plate and given 

time (1 to 2 minutes) to react. Dolomitic carbonates react slowly; 

the reaction can be easily overlooked. Carbonates may occur 

in specific locations, such as along faces of peds. A number of 

specimens and locations should be tested. Dolomitic carbonates 

or specimens with a low content of carbonates may be more 

easily recognized with acid concentrations greater than 1 meter.

Depth of Hole

Description—This is the maximum depth of the hole that was 

dug for soils data collection.

How to measure and record—Measure the depth of the pit or 

borehole from the surface to the bottom of the hole.

Fen Characteristics

Description—This is a search for areas with fen characteristics 

within the site. Fens are groundwater-influenced peatlands with 

high water tables. The consistently high water table creates anaerobic conditions that slow decomposition, which leads to the 

development of peat or muck, which is plant material in various 

stages of decomposition (Mitsch and Gosselink 2007).

For purposes of this field guide, we are first looking for areas with 

accumulations of peat or muck (supported by groundwater), which 

we call “fen characteristics,” and secondarily whether the soil meets 

the U.S. Fish and Wildlife Service’s (1999) definition of a fen. 

In some areas of the United States, fens have special designation 

and protection (USFWS 1999), and the Forest Service may wish 
GDE: Level I 61 Inventory Field Guide

to categorize wetlands as fen or nonfen wetlands. Common 

criteria and the U.S. Fish and Wildlife Service’s (1999) definition 

used to classify a wetland as a fen are (1) the wetland is primarily 

supported by groundwater, and (2) the wetland has organic 

soils meeting the USDA NRCS (2010) definition of a histosol or a 

histic epipedon in at least some part of the contiguous wetland 

(see box 3). USDA NRCS (2010) also states the following: “It is 

a general rule that a soil is classified as an organic soil (histosol 

or histel) if more than one-half of the upper 80 centimeters (32 

inches) of the soil is organic or if organic soil material of any 

thickness rests on rock or on fragmental material having interstices filled with organic materials.”

How to measure and record—If a fen (groundwater-influenced 

peatland) was encountered during the systematic sampling, 

then record “yes” to the following fen characteristics question 

and use the soils data to determine if it meets the U.S. Fish and 

Wildlife Service’s (1999) definition of a fen; no further searching is 

necessary. 

If fen characteristics have not been observed during the site visit, 

then do a fen search by systematically walking through the site. 

The objective is not to find all fen areas at the site, but to determine if any fen areas exist at the site. While doing the search, pay 

particular attention to the wettest areas, where groundwater is at 

or near the surface for extended periods. Specific characteristics 

sometimes (but not always) associated with fens are—

• Wet or soggy conditions.

• Abundant mosses. 

• Soft or spongy surface that bounces or shakes when walked 

on.

• Herbaceous vegetation of obligate wetland species (defined in 

the Glossary under “wetland indicator status”).

§ A list of fen indicator species or “peat forming” species would 

be helpful, but they do not exist for all areas. One example 

of a fen indicator species list for California (Region 5) is in 

appendix B of Weixelman and Cooper (2009).

• Pattern of string and flark microtopography (hummock ridges 

and hollows).
GDE: Level I 62 Inventory Field Guide

If some of the previous characteristics are encountered in a 

particular area of a site, then evaluate the soil in that area as a 

target site (using methods described in this Soils section) to look 

for peat or muck. Record whether or not fen characteristics were 

observed. 

Yes, fen characteristics were observed at the site, which 

include—

• Groundwater influenced.

• High water table.

• Peat or muck present.

No, fen characteristics were not observed at the site.

• In addition to the absence of the previous characteristics 

of fens, other clues indicating that it is probably not a fen 

include redoximorphic features or rock (cobble or larger) 

on ground surface. Areas influenced by beaver activity may 

appear like a fen, but may not actually be a fen.

Also answer whether the sites has soil that meets the USDA 

NRCS (2010) definitions of a histosol or histic epipedon:

q Yes, histosol or histic epipedon observed at the site.

q No, histosol or histic epipedon not observed at the site.

Classifying Organic Soils

The “Keys to Soil Taxonomy” (USDA NRCS 2010) requires that

histosols have organic soil materials that meet one or more of the

following:

1. Overlie cindery, fragmental, or pumiceous materials and/or fill their

interstices and directly below these materials have a densic, lithic,

or paralithic contact.

2. When added with the underlying cindery, fragmental, or pumiceous materials, total 40 centimeters (cm) or more between the

soil surface and a depth of 50 cm.

3. Constitute two-thirds or more of the total thickness of the soil to

a densic, lithic, or paralithic contact and have no mineral horizons

or have mineral horizons with a total thickness of 10 cm or less.

Box 3
GDE: Level I 63 Inventory Field Guide

Box 3 (continued)

4. Are saturated with water for 30 days or more per year in normal

years (or are artificially drained), have an upper boundary within

40 cm of the soil surface, and have a total thickness of either—

a.	 60 cm or more if three-fourths or more of their volume consists

of moss fibers or if their bulk density, moist, is less than 0.1 g/

cm3.

b.	 40 cm or more if they consist either of sapric or hemic

materials, or of fibric materials with less than three-fourths (by

volume) moss fibers and a bulk density, moist, of 0.1 g/cm3 or

more.

5.	 Are 80 percent or more, by volume, from the soil surface to a

depth of 50 cm or to a glacic layer or a densic, lithic, or paralithic

contact, whichever is shallowest.

The “Keys to Soil Taxonomy” (USDA NRCS 2010) defines a histic 

epipedon as a layer (one or more horizons) that is characterized by

saturation (for 30 days or more, cumulative) and reduction for some

time during normal years (or is artificially drained) and either:

1. 	Consists of organic soil material that—

a.	 Is 20 to 60 cm thick and either contains 75 percent or more

(by volume) Sphagnum fibers or has a bulk density, moist, of

less than 0.1.

b.	 Is 20 to 40 cm thick.

2.	 Is an Ap horizon that, when mixed to a depth of 25 cm, has an

organic-carbon content (by weight) of—

a.	 16 percent or more if the mineral fraction contains 60 percent

or more clay.

b.	 8 percent or more if the mineral fraction contains no clay.

c.	 8 + (clay percentage divided by 7.5) percent or more if the

mineral fraction contains less than 60 percent clay.

Most histic epipedons consist of organic soil material. Item 2 provides for a histic epipedon that is an Ap horizon consisting of mineral

soil material. A histic epipedon consisting of mineral soil material can

also be part of a mollic or umbric epipedon.
GDE: Level I 64 Inventory Field Guide

Hydrology

An Equipment List for hydrologic data collection is in appendix 6.

Water Table

In general, water table measurements will be done at wetlands 

and not at springs, although exceptions do occur. Water table 

data will be collected at one point, which may be in the boreholes 

created during soil sampling, or other locations. 

Note: One-time water table measurements give only a general 

idea of the water table for a site. Multiple measurements during 

the season using piezometers would provide information about 

the variability (or seasonality) of the water table. Methods to collect 

more detailed groundwater data are described in separate technical 

notes, which can be found on the Minerals and Geology page on 

the Forest Service Web site: http://www.fs.fed.us/geology. 

• Groundwater Monitoring Well Installation in Wetlands. 

• Groundwater Level Measurements.

• Analysis of Groundwater Level Data.

Location of Water Table Measurements

Description—The location within a wetland where a water table 

depth measurement is taken will be at either an unbiased or 

targeted location. In general, wells or piezometers are required 

for meaningful, long-term water table monitoring.

How to measure and record—Establish locations using one of 

these methods:

• Randomly chosen point (unbiased).

• Center of site (unbiased).

• Other (targeted):________________.

Source of Water Table Measurements

Description—This indicates the source of the water table depth 

measurement or where it was taken in a wetland. This helps with 

interpreting the water table data.
GDE: Level I 65 Inventory Field Guide

How to measure and record—If wells are installed, the water 

table measurements should be taken from the wells rather than 

from the soil core boreholes. Note which of the following sources 

was used:

• Soil core borehole.

• Depression. 

• Well/piezometer.

• Other:________________.

Hole Depth

Description—This is the maximum depth of the hole where the 

water table data are collected. If the soil hole is used, then this 

will be the same value entered for the soil hole depth.

How to measure and record—Measure the depth of the pit or 

borehole from the surface to the bottom of the hole.

Water Table Depth

Description—This attribute helps to establish the depth to water 

below the ground surface in wetlands. It would probably not be 

measured at springs that do not have an associated wetland, 

because the water table or piezometric surface at a spring is by 

definition at the surface.

This attribute helps provide an understanding of conditions that 

influence plant species, particularly wetland plant species that 

are highly dependent on a shallow water table for survival. Small 

changes in water table depth can cause changes in wetland plant 

community composition.

How to measure and record—Groundwater depth (centimeter) 

is measured in the borehole from the soil core or by augering a 

hole. The appropriate depth of a hole is somewhat site specific, 

but would typically be a 0.5 to 1 meter or to the bottom of the 

peat (where applicable). Be aware that once the hole penetrates 

below the bottom of a peat layer, the water level may rise in 

the borehole, indicating artesian conditions. Peat layers are 

occasionally confining units and can sometimes “float” on the 

underlying aquifer. Therefore, in those situations, the water level 

measured in a hole would represent the piezometric surface of 

the hydrogeologic unit underlying the peat, which frequently 
GDE: Level I 66 Inventory Field Guide

exhibit strong upward vertical hydraulic gradients. To get the 

true water table elevation within the peat, the borehole must not 

penetrate through the base of the peat.

Before measuring water table depth, allow time for water in holes 

to equilibrate (at least 30 minutes, but preferably a few hours). 

Water table measurement could be taken just prior to refilling the 

boreholes at the end of the field day, which would provide time 

for the water in the hole to equilibrate with the water table. 

If water is at or above the surface, then it is not necessary to auger 

a hole or measure water table depth. The water table would be at 

the surface or at a depth of zero.

Steps to measure water table depth:

• Auger a hole approximately 0.5 to 1 meter in depth. A hole 

can also be dug using a sharpshooter shovel although this 

creates more disturbance to the wetland. 

• Allow the water level in the hole to equilibrate. Monitor the 

water level depth to determine when the water level has 

stabilized.

• Lay a shovel or similar object across the top of the soil pit 

opening and measure from the bottom of this object. Record 

the distance to water. 

• For standing water, record zero, which indicates the water is 

at or above the ground surface.

If no water remains in the hole, even after waiting for a period of 

time, then record it as “dry.”

Water Table Type

Description—This describes the type of water table that exists 

at the site based on observations made while measuring the 

water table depth. This information gives insight into the vertical 

gradients in the underlying aquifer.

How to measure and record—Choose the term that best describes this site, based on the water table measurements taken 

previously.

• Apparent—Water level stabilized in a fresh unlined borehole.

• Artesian—The static level within a cased borehole where 

water rises above an impermeable layer (e.g., peat layer) 
GDE: Level I 67 Inventory Field Guide

due to a positive hydrostatic head or where water discharges 

from an unlined borehole.

• Ponding—Standing water on top of the soil.

• Unknown.

• Other:__________.

Flow

Flow Patterns for Site

Description—This indicates whether the inflow and outflow are 

surface water, groundwater, or a combination of the two. This 

helps to characterize the overall water budget of the wetland. The 

water budget of wetlands varies in the dependence on groundwater inflow/outflow or surface water inflow/outflow. 

How to measure and record—

Inflow (select one):

• Dominated by groundwater inflow.

• Dominated by surface water inflow and/or precipitation.

• Substantial amounts of both groundwater and surface water 

inflow.

Outflow (select one):

• Dominated by groundwater outflow.

• Dominated by surface water outflow.

• Substantial amounts of both groundwater and surface water 

outflow.

• Dominated by evapotranspiration.

Occurrence of Surface Water

Describe the occurrence of surface water at the site using one of 

the following categories (may select multiple):

• No standing or flowing water visible.

• Patches of standing water.

• Extensive standing water.

• Flowing water in channels.
GDE: Level I 68 Inventory Field Guide

Flow Instrument

Record the name of the instrument used to measure flow (or 

discharge). The instrument will vary depending on the site type; 

therefore, multiple options are presented in appendix 10.

Flow Method

Record the method used to measure flow (or discharge). The 

method will vary depending on the site type; therefore, multiple 

options are presented in appendix 10.

Flow Rate

Description—This is a measure of the discharge from the aquifer 

to the surface. This attribute is more important for springs than 

wetlands supplied by diffuse discharge. The flow of a spring is 

important for both ecological reasons and human uses of the 

spring water. In many cases, the flow of a spring correlates with 

the ecological functions and values of the spring habitat.

Where to measure flow—If measuring a single channel, measure 

discharge as close as possible to the spring source. In some 

situations, there will not be a single distinct channel where flow 

can be measured, in which case follow these guidelines:

• If there are multiple channels, and if they all converge to 

a single channel, measure discharge in the single channel 

as close as possible to the confluence of all of the multiple 

channels.

• If there are multiple channels that do not converge, then 

measure flow in as many channels as possible. Record each 

measure with an explanation that it is different (completely or 

partially) than other measures of flow at the site.

• For hanging gardens and wet walls, if possible, take a flow 

measurement at the base of the wall where flow coalesces 

into a channel. If this is not possible, photo documentation of 

the wetted area of rock face is an option.

• If flow is very diffuse (as in a sloped wetland or seep), then 

flow measurements may not be possible.

How to measure and record—Flow measurement applies mainly 

to springs, but can be applied to wetlands that have flowing 

water, such as in an inflow, an outflow, or distinct channels.
GDE: Level I 69 Inventory Field Guide

Measure the quantity of water discharging from the GDE with one 

of the methods listed in appendix 10, which also describes the 

measurement methods. Flow should be measured and recorded 

multiple times (three times is recommended) at the same location 

to increase accuracy. Multiple measures at different locations 

might also be necessary to capture the totality of flow. Record 

and store all flow measurements (in the field and in the database) 

to allow for accurate analysis of flow for the site. 

Also record an estimate of the percent of the surface discharge 

that was captured. 

For limnocrenes that do not have outflow, the static head change 

method is used. For limnocrenes that have an outflow, use one of 

the other measurement techniques described previously. 

If flow was not measured, then explain why by selecting one of 

these options:

q Diffuse outflow.

q No outflow.

q Not a spring. 

q Spring is dry.

q Other:________________.

Note: It may be difficult to estimate the discharge of springs and 

wetlands that (1) are small, (2) have water that is shallow and broadly 

or unevenly spread over a wide area, or (3) have limited moving 

water. Discharge often changes throughout the day (because of 

evapotranspiration), seasonally, or annually, which decreases the 

effectiveness of single measurements to precisely quantify long-term 

discharge characteristics. Highly quantitative discharge measurement 

would be a component of a Level III survey. 

Record notes on flow—Make notes on evidence of recent high 

discharges, such as high water marks, oriented vegetation, or 

debris on or above the channel or floodplain.

Spring Channel Characteristics

For sites that have spring brooks or outflow channels, record 

information for the following questions.
GDE: Level I 70 Inventory Field Guide

Hydroperiod 

Description—This describes the temporal flow characteristics 

of a spring. This information is valuable for assessing the importance of the spring for habitat for aquatic organisms. Perennial 

springs are frequently of higher value for aquatic and terrestrial 

species than are ephemeral springs.

How to measure and record—Estimate the hydroperiod of the 

spring. If the field visit takes place in the dry season and the 

spring is flowing, it is likely perennial.

q Perennial (must have continuous flow at time of visit).

q Intermittent (visible evidence of flow, known to flow at certain 

times of the year).

q Not determined.

Length of Outflow Stream

Description—This is an estimate of the length of the spring brook 

up to a maximum of 20 meters down gradient. Twenty meters is 

an arbitrary cut-off that has been established because at some 

distance downstream, the spring brook changes from a springspecific habitat to a lotic habitat because of cumulative changes 

in flow, temperature, and water quality. The spring brook serves 

as a habitat for many spring-specific species (crenobiontic species), 

so its length is of interest for understanding aquatic biology. 

How to measure and record—Record the distance of the spring 

brook to the downstream limit of surface flow from (1) the source 

(orifice) of a spring (that does not have a wetland between the 

spring and the outflow channel), (2) the point where water coalesces 

into a channel for diffuse springs and discharge wetlands, (3) the 

outflow from a limnocrene, or (4) the downgradient edge of a 

wetland. 

q < 5 meters

q 5 to 10 meters

q 10 to 15 meters

q 15 to 20 meters

q > 20 meters
GDE: Level I 71 Inventory Field Guide

What Happens to Stream Outflow

Description—This is a general description of what happens to 

the spring brook or stream downstream of the sampling area.

How to measure and record—If flow continues beyond 20 

meters (downstream of the site), then also note what happens to 

the flow after the 20 meters using the following options: 

•	 Disappears into the ground.

•	 Continues as far as can be seen.

•	 Flows into another stream.

•	 Some flow is diverted. 

•	 Becomes intermittent.

•	 Other:________________.

Water Quality

Some core field-derived water quality parameters are included to 

help characterize the site. These are the following: temperature, 

specific conductance, pH, and either oxidation/reduction potential (ORP) or dissolved oxygen (DO). In addition, water samples 

may be collected for laboratory analysis of a wider range of water 

quality parameters, if they are needed to address the management requirements for the field guide implementation. 

Detailed instructions for collecting water samples from wells and 

surface waters and analyzing those samples, along with quality 

assurance/quality control procedures can be found in the USGS 

National Field Manual for the Collection of Water-Quality Data 

(National Field Manual). The National Field Manual provides 

guidelines and standard procedures for USGS and other Government agency personnel who collect samples used to assess the 

quality of the Nation’s surface-water and groundwater resources. 

Each chapter of the National Field Manual is published separately 

and revised periodically. Newly published and revised chapters 

are posted on the USGS Web page “National Field Manual for 

the Collection of Water-Quality Data,” http://water.usgs.gov/owq/

FieldManual/.

If there are wells, the water quality samples should be taken from 

the wells with a bailer or pump. For springs or discharge areas 

within wetlands, water quality measurements should always 
GDE: Level I 72 Inventory Field Guide

be taken at the source. Water in wetlands may be ponded or 

flowing. In either case, targeted samples should be collected 

from an area that has sufficient depth, is within the wetland, and 

away from inlets (natural or anthropogenic) because inlets may 

influence the composition of the water sample. In summary, 

water quality sampling should be done at one of the following 

locations, which are listed in order of preference:

• Wells in wetlands (if present) and at the source (orifice) of 

springs. 

• Where flowing water exists in wetlands.

• Standing surface water. 

• Holes created by the soil sampling.

§ Time is needed for water to equilibrate.

§ Temperature may be the only attribute that can be accurately measured in a borehole because the other water 

quality attributes (conductivity, pH, DO and/or ORP) may 

be affected by the digging process. 

Location of Water Quality Measurements

Description—The location within a wetland or spring where a 

water sample or measurement is collected.

How to measure and record—Surface water quality sampling 

should be completed before collecting data for other indicators 

to avoid degrading the water while completing other sampling 

tasks. Use flagging if necessary to keep crew members clear of 

the water sampling location until the water has been sampled. 

The location of the water quality measurement is either an 

unbiased location or a targeted location.

• Unbiased—

§ Randomly chosen point.

§ Center of site.

• Targeted location—

§ Spring source (recommended for springs).

§ Down gradient from spring source.

§ Stream exiting wetland.
GDE: Level I 73 Inventory Field Guide

§ Standing water (includes pools).

§ Hole (dug or augered; including soil sample hole).

§ Well/piezometer.

§ Other:________________.

Time of Water Quality Measurements

Description—This is the time of day that the sample or measurement was collected. This information will help with the interpretation of the data because many water quality parameters fluctuate 

diurnally because of temperature changes, evapotranspiration, 

and photosynthesis. 

How to measure and record—Record the time of day that the 

sample or measurement was taken.

Temperature of Water

Description—This is the temperature of the groundwater 

discharging at the spring or wetland. Water temperature is an 

important factor structuring aquatic communities, and it may give 

insight into the source of the groundwater. The temperature of 

water discharging from a spring is particularly meaningful. The 

temperature of water discharging to the surface of a wetland 

is not an accurate measure of groundwater temperature, but it 

provides general evidence about the temperature of the groundwater. Extreme temperature values might be an indication that 

more careful work is needed.

How to measure and record—One way to measure water 

temperature is with an electronic device that also measures 

dissolved oxygen or conductivity. Calibration is not necessary 

for temperature measurements using a high-quality device. 

Record in degrees Celsius. Expected ranges of values are 4 to 60 

degrees Celsius. For springs unaffected by geothermal heating, 

the water temperature is generally close to the average annual 

temperature of the recharge area.

Water pH

Description—pH is the measure of hydrogen ion activity, which 

indicates the acidity or alkalinity of water. It is measured on a 

scale from 0 to 14, with a pH of 7 indicating neutral conditions. 

Smaller numbers indicate acidic conditions; larger numbers 
GDE: Level I 74 Inventory Field Guide

indicate basic conditions. The pH typically responds to hydrologic disturbance in wetlands; therefore, pH can be an indicator 

of disturbance. The pH is also important in classifying wetland 

sites (Cowardin et al. 1979), and defining rich and poor fens. 

Aquatic fauna and flora are also sensitive to pH conditions. The 

pH of rain is about 5.6, but can range from 5.6 to about 4.5.

How to measure and record—Measure the pH of the water 

using a hand-held field meter. The meter should be kept clean, 

with fresh batteries, and calibrated at least daily, following the 

manufacture’s recommendation. pH probes generally have a 

limited lifetime, and a backup probe should always be carried. 

A backup meter is highly recommended. Record in standard pH 

units. The expected range of pH values is 4.0 to 8.0.

Specific Conductance of Water

Description—Specific conductance (also called electrical 

conductance, or conductivity) is the measure of the ability of 

an aqueous solution to carry an electrical current. This ability 

is dependent on the amount of dissolved ions in the solution, 

and is, therefore, an indicator of total dissolved solids in the 

solution. Conductivity provides insight into water sources and it 

is an indicator of conditions important to aquatic life because of 

requirements to maintain osmoregulatory balance. Conductivity typically responds to hydrologic disturbance in wetlands. 

Conductance is also important in classification of wetland sites 

(Cowardin et al. 1979).

How to measure—Measure conductivity using a field meter. The 

meter should be kept clean, with fresh batteries, and calibrated 

periodically following the manufacture’s recommendation. Most 

high-quality meters do not require frequent calibration. Record in 

microsiemens/centimeter (mS/cm). Expected ranges of values are 

10 to 5,000 mS/cm.

Oxidation-Reduction Potential or ORP (DO is an Alternative)

Description—Oxidation-reduction (redox) reactions (reactions 

involving electron transfer) mediate the behavior of both inorganic and organic chemical constituents by affecting solubility, 

reactivity, and bioavailability. This data will help provide information about the biogeochemistry of wetlands, which is controlled 

largely by oxidation-reduction reactions. Expected values for 

redox potential (also called Eh) range from -300 millivolts (mV) to 
GDE: Level I 75 Inventory Field Guide

+700 mV (see figure 5). Redox potential is significantly affected 

by the oxygen content of the soil and porewater. In oxidized 

systems where aerobic organisms function, the Eh range is very 

narrow, approximately +700 mV to about +300 mV. Below values 

of +300 mV, facultative anaerobes (primarily bacteria) function 

down to about 0 mV. Below this range, obligate anaerobes 

function. In wetland (waterlogged or flooded) soils, Eh can be 

anywhere along the entire scale. Where oxygen is present in 

wetland soil, the Eh can be as high as in a drained soil, but where 

oxygen is not present, Eh can be very low (-250 to -300 mV) 

(U.S. EPA 2008). The Eh-pH diagram in figure 6 can be used to 

interpret the ORP measurements. 

Figure 5.—Range of ORP values for wetlands.

Figure 6.—Distribution of Eh-pH values in natural aqueous environments. 

Zone A is acidic mine drainage, B is rain, C is stream water, D is ocean water, 

E is groundwater, F is bog water, G is anaerobic wetlands (redrawn from 

Langmuir 1996 and Baas-Becking et al. 1960).
GDE: Level I 76 Inventory Field Guide

Note: Measured ORP values have to be converted to Eh to be able 

to use the Eh-pH diagram in figure 6. Converting ORP measurements 

to Eh depends on the type of ORP electrode used. The electrode 

manufacturer typically provides conversion factors for various 

temperatures.

How to measure and record—Measure the ORP of the water 

using a hand-held field meter that has been calibrated using 

Zobell solution. ORP in water is measured in wells, springs, and 

standing or flowing water. The meter should be kept clean, with 

fresh batteries, and calibrated daily following the manufacturer’s 

recommendation. Record in mV.

Dissolved Oxygen or DO (alternative to ORP) 

Description—This is a measure of the amount of DO in the 

groundwater discharging at a spring or wetland. DO at a spring 

gives insight into the source of the groundwater discharging and 

the residence time in the aquifer. In a wetland, DO is a function of 

the biogeochemical processes taking place. 

Because fish and other aquatic organisms cannot survive without 

oxygen, DO is an important water quality parameter for surface 

water systems. Cold water holds more oxygen than warm water. 

Pure water at 4 degrees Celsius (40 degrees Fahrenheit) can 

hold about 13.2 milligrams per liter (mg/L) DO at 100 percent 

saturation, while pure water at 25 degrees Celsius (77 degrees 

Fahrenheit) can hold only 8.4 mg/L at 100 percent saturation. 

Water with a high concentration of dissolved minerals cannot 

hold as much DO as pure water. 

How to measure and record—Measure DO using a field meter. 

The meter should be kept clean, with fresh batteries, and calibrated at least daily following the manufacture’s recommendation. If there are weather fronts moving through the area, it may 

be necessary to calibrate before each measurement. Record DO 

in mg/L. Expected ranges of values for DO are 0 to 13 mg/L.

Aquatic and Terrestrial Fauna

Description—Springs and wetlands can provide important 

habitat for aquatic and terrestrial fauna, which can be important 

for management and restoration. Aquatic macroinvertebrates, in 

particular, are useful bioindicators because some taxa are sensitive to disturbance while others are tolerant. 
GDE: Level I 77 Inventory Field Guide

How to measure and record—Record the important taxonomic 

groups of animals observed at the site. Important taxonomic 

groups that occur in GDEs are those with species that have the 

greatest implication for management. These can include threatened and endangered species, sensitive species, spring-specific 

species (spring snails), fish, amphibians, reptiles, invertebrates, 

and mammals. A substantial amount of training is needed to 

identify many of these species, but identifying most groups of 

animals, and many nonnative species, may be accomplished with 

minimal training. Appendix 11 (Identification of Freshwater Invertebrates) provides representative drawings of groups of aquatic 

macroinvertebrates that may be found in springs and other GDEs 

and a “Key to Macroinvertebrate Life in the River.” For Level I 

surveys, the presence or absence of important species or groups 

is an important goal. 

Voshell (2002) is a useful publication for identifying freshwater 

invertebrates that can be used by a minimally trained person for 

a Level I survey. In addition, many State agencies and universities host Web sites with macroinvertebrate identification keys.

Species of Interest

List any known invasive species that are present. Invasive species could include zebra mussel, red-rimmed melania, or New 

Zealand mud snail. See USGS’ Nonindigenous Aquatic Species 

(http://nas.er.usgs.gov/) for lists and information on invasive 

freshwater mollusks and crustaceans. 

List any rare or sensitive species that are present.

List any GDE-specific species that are present and explain 

interest.

Natural and Anthropogenic Disturbance

Record any disturbances observed at the site. This can provide 

managers with information on activities or structures that may 

be detrimentally affecting the structure and function of the site. 

It can be helpful to make notes about disturbances observed.

Hydrologic Alteration

Description—This is a list of activities or structures that have 

altered the natural hydrologic function of the system. This can 
GDE: Level I 78 Inventory Field Guide

provide managers with information on activities or structures that 

may be having a detrimental effect on the hydrologic function of 

the feature. Multiple answers are allowed.

How to measure and record—

q Water diversion—Water permanently diverted away from 

spring habitat (ditch, pipeline, spring box, or other form of 

dewatering).

q Water diversion—Water eventually returns to spring habitat.

q Upgradient extraction of surface water or groundwater 

(prespring emergence).

q Downgradient capture of surface water or groundwater 

(post-spring emergence).

q Extraction of water within a wetland.

q Extraction of water at spring source.

q Regulated water flow by impoundment/dam.

q Pollution.

q Flooding.

q Wells.

q Other:________________.

q None observed.

Volume and Percent Diverted

Record the volume and percentage (to nearest 10 percent) of 

water being diverted (noted previously) at the time of inspection. 

Indicate whether this was a visual estimate or a measurement 

(e.g., flow meter). Inspect flow upstream and downstream of 

diversion, as well as water in the conveyance, if possible, to 

determine percentage being diverted. 

Soil Alteration

Description—This is a list of the major types of soil alteration 

found at the site. Multiple answers are allowed.
GDE: Level I 79 Inventory Field Guide

How to measure and record—

q Channel erosion.

q Compaction.

q Debris flow.

q Deposition.

q Displacement of soil.

q Erosion (general).

q Evaporate deposition.

q Excavation. 

q Ground disturbance (general).

q Gully erosion.

q Mass wasting.

q Mining.

q Pedestals or hummocks (created by people or animals).

q Pedestals (small-scale, rain-splash induced).

q Pipes.

q Rill erosion.

q Ruts (from vehicle tread).

q Sheet erosion.

q Slump.

q Splash erosion/soil crust.

q Wind erosion.

q Soil mixing/churning.

q Soil removal (peat mining).

q Trails (by people or animals).

q None observed.

q Other:________________.
GDE: Level I 80 Inventory Field Guide

Structures

Description—This is a list of the kinds of structures present at 

the site. Multiple answers are allowed.

How to measure and record—

q Buried utility corridors.

q Enclosure (such as spring house, spring box, or concrete 

enclosure).

q Erosion control structure.

q Exclosure fence.

q Oil and gas well.

q Pipeline.

q Point source pollution.

q Power lines.

q Road (includes construction and maintenance).

q None observed.

q Other:________________.

Recreation Effects

Description—This is a list of recreational activities in evidence at 

the site. Multiple answers are allowed.

How to measure and record—

q Camp sites.

q Tracks or trails by vehicles (all-terrain vehicle [ATV], 4-wheel 

drive, etc.).

q None observed.

q Other:________________.
GDE: Level I 81 Inventory Field Guide

Animal Effects

Description—This is a list of animal-related impacts to the site. 

This includes impacts from both domestic and wild animals. 

Multiple answers are allowed.

How to measure and record—

q Beaver activity.

q Feral animals.

q Grazing or browsing (by ungulates).

§ Wild animals.

§ Livestock.

q Trails by animals and people.

q Trampling (by ungulates, native or nonnative).

q None observed.

q Other:________________.

Miscellaneous

Description—These are potential disturbances that do not fit 

in the categories described previously. Multiple answers are 

allowed.

How to measure and record—

q Fire.

q Tree cutting (timber harvest or other).

q Refuse disposal.

q None observed. 

q Other.

Archeological, Paleontological, Cultural, or Historic 

Sites or Use

Description—This is a list of any archeological, paleontological, 

cultural, or historic sites or other human use of the site. Many 
GDE: Level I 82 Inventory Field Guide

springs in arid regions have a long history of use by Native 

Americans and others. Some have spiritual values associated 

with them. Some fens have preserved remains of extinct animals. 

Knowledge of sensitive sites will limit inadvertent damage to 

these resources.

How to measure and record—Record evidence of archeological, 

paleontological, and cultural resources or historic use (e.g., 

archaeological, paleontological, historic sites).

Management Indicator Tool

Responses to the Management Indicator Tool statements are 

used to identify potential need for management action based 

upon observations and information collected during the field 

guide implementation. This information may be useful for prioritizing sites needing additional monitoring or other management 

actions. The tool should be completed at the site, using a field 

crew consensus approach, and conclusions validated or confirmed later in the office based on a review of the data collected 

and other records or information available at the office (e.g., land 

status records, land and resource management plans). Some of 

the statements, particularly “Administrative Context,” may require 

review of records before the field visit.

This tool uses “true” or “false” answers, which by definition 

require interpretation by the field team and have undefined 

cutoffs. Make the best judgment possible and include comments 

and explanations where uncertainty or mitigating factors entered 

into the assessment. In particular, provide comments for all 

responses of False (No), Does not apply, or Unable to assess.

False answers indicate issues of concern that might pose problems for the long-term functioning of the GDE or when observed 

at multiple sites indicate a need for management attention. 

There is no summary scoring system based on the results of 

this tool. It is up to the specialist involved in data collection and 

the decisionmaker responsible for management to interpret the 

inventory results.

The following other resources were used for assessing management needs and to develop portions of the Management Indicator 

Tool.
GDE: Level I 83 Inventory Field Guide

Assessing proper functioning condition for fen areas in the Sierra 

Nevada and Southern Cascade ranges in California: a user guide

(Weixelman and Cooper 2009). 

A user guide to assessing proper functioning condition and the 

supporting science for lentic areas (Prichard 2003). 

Springs ecosystem assessment protocol xcoring criteria (Stevens 

and Springer in development). 

Following are the 25 management indicator statements to address.

Aquifer functionality: No evidence suggests that 

the aquifer supplying groundwater to the site is 

being affected by groundwater withdrawal or loss of 

recharge.

GDEs exist where groundwater reaches the earth’s surface, often 

through complex and lengthy geologic flow paths. The consistent 

supply of groundwater maintains flows in springs and high water 

tables in wetlands. This supply of groundwater is essential to 

maintain the GDE and, in many cases, unique plant and animal 

communities. This statement asks whether activities exist that 

interrupt or deplete this supply—reducing flows in springs or 

lowering water tables in wetlands.

Examples

This indicator would be answered “Yes” in the following circumstances:

• No evidence suggests that groundwater extraction is 

adversely affecting the site. 

• Evidence of soil saturation exists, or standing water is apparent. 

• Plants that are obligate wetland and/or facultative wetland 

species are abundant at the site, taking into consideration the 

setting and site potential.

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances:

• Groundwater extraction, such as pumping wells or mining that 

intersects the water table, damages aquifer functionality.
GDE: Level I 84 Inventory Field Guide

• There is depletion of recharge to the aquifer through paving, 

soil compaction, vegetation manipulation, etc. 

• Soil saturation in a wetland, or flow of a spring, is less than 

in the past. One indicator of this could be where upland and 

facultative upland plant species are encroaching into areas 

formerly dominated by obligate wetland and facultative 

wetland species, indicating a loss of groundwater. Another 

indicator could be if hydric soils are present beyond the 

current extent of the GDE, suggesting that the GDE has 

decreased in size.

The only definitive way to detect aquifer functionality issues is 

through installation and monitoring of piezometers in wetlands 

and frequent monitoring of flow in springs.

Watershed functionality: Within the watershed, no 

evidence suggests upstream/upgradient hydrologic 

alteration that could adversely affect the GDE site.

The focus of this statement is on surface water, although groundwater and surface water are connected in most watersheds and 

activities affecting one of these resources can potentially affect 

the other. The watershed that is the focus of this statement 

would generally be a 6th-level (12 digit) watershed hydrologic 

unit code. The condition of the surrounding uplands can greatly 

affect the condition of a GDE. Changes in upland condition can 

influence the magnitude, timing, or duration of overland flow 

events, which could result in erosion or deposition of sediment 

in the GDE. The purpose of this indicator is to determine if activities within the watershed have adversely affected the feature. 

Although a correlation can exist, the focus here is on whether the 

uplands are contributing to degradation of the GDE, and not on 

the condition of the uplands.

Examples

This indicator would be answered “Yes” in the following circumstances:

• The site is receiving a normal range of surface flows, even if 

disturbance exists within its watershed. 

• None of the adverse effects in the following list are observed.
GDE: Level I 85 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• Upslope road ditches and cross drainage structures were 

installed in a manner that concentrates overland flows and 

shallow groundwater away from the site, causing desiccation 

of soils. 

• Flow has been added from a diversion, and excessive erosion 

or deposition is taking place as a result of this increased flow.

• Trail development has intercepted, diverted, or concentrated 

overland flows initiating a headcut that is draining the site.

• Upslope road ditches, culverts, etc., are failing or in need of 

repair.

Water quality: Changes in water quality (surface or 

subsurface) are not affecting the GDE site.

GDEs are complex biogeochemical systems where water, 

nutrients, sediments, microclimate, and biota interact as part of 

the natural processes. The ecology of a GDE is affected by the 

quality of the water supporting the site. Changes in water quality 

can have detrimental effects on the flora and fauna. GDEs are 

susceptible to pollution from a number of activities. Pollutants 

may be toxic, which may harm or eliminate aquatic life. Inputs of 

nutrients (e.g., nitrogen, phosphorus) can increase the growth of 

aquatic vegetation and bacterial abundance and lower dissolved 

oxygen concentrations. These effects may cause intolerant 

macroinvertebrate communities to be replaced by communities 

that associated with impaired aquatic systems.

The geology of some watersheds naturally yields constituents 

(salts, iron, nutrients, calcium carbonates, etc.) that can inhibit 

growth for certain plant species. Examples of GDEs that have 

naturally limiting water quality conditions that favor some flora 

and fauna over others are thermal springs, travertine/tufa depositing springs, low pH springs, iron fens, and calcareous fens. 

Understanding the geology, soils, and water source is important 

to be able to accurately assess the causes of the water quality 

data. In some cases, unusual water chemistry values could be 

natural and, in other cases, they could be because of management activities. 
GDE: Level I 86 Inventory Field Guide

Examples

This indicator would be answered “Yes” in the following circumstances:

• Water quality is within the expected range of variability. 

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances:

• Data collected indicate poor water quality (requires knowledge 

of expected range of variability for the site). 

• Sources of pollution such as mining waste or tailings, landfills, 

herbicides, pesticides, or accidental spills of hazardous 

chemicals and waste along roads exist.

• There has been excessive use by nonnative ungulates (such 

as wild horses and burros, cattle, and sheep) or native 

ungulates that have (1) deposited fecal matter and increased 

nutrients in the water or (2) damaged vegetation, allowing 

increased amounts of sediment and nutrients to enter the 

aquatic system. 

• Sewage disposal on site, or sewage from off-site septic 

systems or lagoons has allowed pollutants to leach into the 

groundwater and move to springs along a hydraulic gradient. 

• In some cases, excessive algae may be an indicator of nutrient loading in the water. 

• Vegetation shows signs of stress from chemicals in the water.

Foul smells or discolored water should be further investigated to 

determine whether a water quality problem exists, or whether the 

foul smell is from natural anaerobic conditions and the discoloration is from a natural accumulation of organic matter. 

If a problem is identified, water samples should be collected and 

analyzed and the results compared against relevant water quality 

criteria.
GDE: Level I 87 Inventory Field Guide

Landform stability: No evidence indicates humancaused mass movement or other surface disturbance 

affecting the GDE site stability.

In general, stable landforms are at a state of equilibrium with 

physical conditions and processes that affect a site such as 

climate, slope, soil, soil moisture, and geology. Anthropogenic 

disturbances in the watershed, including the GDE, can cause 

instability in landforms. The intent of this indicator is to identify 

activities or causes of landform instability at the GDE site. 

Natural mass wasting can occur where groundwater discharges 

on a slope because geologic materials become saturated with 

water, the angle of repose is reduced to a very small value, and 

the material tends to flow like a fluid. This is because groundwater reduces grain-to-grain frictional contact. As a result, some 

discharge wetlands are associated with slope failures that are 

natural, but they could also be partially the result of management 

activities.

Examples

This indicator would be answered “Yes” in the following circumstances:

• Only natural mass movement, such as slumping, occurs.

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances: 

• Excessive sediment deposition has occurred.

• Stream channel alteration has occurred, beyond what is 

natural.

• Streambank erosion or a headcut is affecting site stability.

• Slope failure has occurred from unnatural causes.

• A road cut or failing infrastructure (such as retaining walls, log 

cribs) is causing slope instability.
GDE: Level I 88 Inventory Field Guide

Runout channel: The channel, if present, is functioning 

naturally and is not entrenched, eroded, or otherwise 

substantially altered.

Runout channels from springs or wetlands support flora and 

fauna that are an important and often unique part of the biodiversity of a site, therefore the condition of the runout channel is 

important to assess. Changes in channel and bank morphology 

or substrate composition can alter habitat.

Runout channels are groundwater-fed streams that emerge 

from spring orifices (referred to as spring brooks or spring runs) 

or within groundwater-fed wetlands. Surface drainage areas to 

these springs can be very small, often much smaller than the 

recharge area of the springs. The major differences in controls 

on the channel morphology found between the spring-dominated 

and runoff-dominated channels are the discharge regime and 

the sediment input (Griffiths et al. 2008). The hydrology unique to 

spring-dominated channels and the lack of fine-grained sediment 

input combine to create the observed differences. Channels 

downstream of springs are typically straight, or, if sinuous, they 

are without regularity to the pattern. Bars are absent or poorly 

defined, but islands or downed timber is common in the channel. 

Springflow-dominated channels are a special habitat of running 

waters because of the relatively uniform temperature and the 

deoxygenated groundwater contribution to the stream (Springer 

and Stevens 2009). Springflow-dominated systems may be sufficiently stable habitats to allow for evolutionary microadaptation 

and, ultimately, speciation (McCabe 1998). 

Examples

This indicator would be answered “Yes” in the following circumstances:

• The runout channel is functioning naturally.

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances:

• Bank morphology has been changed by ungulate trampling, 

vehicles, or other activities.

• Channel morphology has been changed by excavation, 

ditching, or redirection.
GDE: Level I 89 Inventory Field Guide

• The channel is entrenched.

• Erosion of streambanks is beyond the natural range that 

would be expected at the site.

Soil integrity: Soils are intact and functional. For 

example, saturation is sufficient to maintain hydric 

soils, if present; there is not excessive erosion or 

deposition.

The purpose of this indicator is to evaluate the condition of the 

soil and to determine if the soil has been affected by excessive 

disturbance. Management activities can alter the soil and the 

hydrologic conditions that affect the soil. In the case of wetlands, 

intact hydric soils are a useful indicator that the duration and 

frequency of saturation has been sufficient to maintain wetland 

soil characteristics. Soil saturation creates anaerobic conditions, 

which leads to the reduction, translocation, and accumulation of 

iron, manganese, sulfur, and carbon compounds (redoximorphic 

features). Saturation also slows decomposition of plant material, 

which can lead to the accumulation of peat (over long-term periods). 

This soil integrity indicator is intended to assess whether such 

hydric soils are being maintained in those areas where hydric 

soils would be expected. In the case of springs without hydric 

soils, the intent is to determine if soil disturbance (erosion, 

deposition, compaction, etc.) has occurred. 

Examples

This indicator would be answered “Yes” in the following circumstances:

• Hydric soils are present and soil saturation is close to the 

ground surface.

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances:

• Soil compaction or erosion because of livestock, vehicles, or 

other sources.

• Desiccated peat or oxidized organic matter is observed at the 

site.
GDE: Level I 90 Inventory Field Guide

• Peat soils are churned because of livestock hoof action. (This 

refers to the stirring of the peat layer that causes organic 

matter to be mixed into the underlying mineral layer. The soil 

structure is altered and is massive or platy.)

• Pedestals created by hoof shear, hoof compaction, and 

disruption of root systems.

• Post holes/puddling that result from logging equipment, 

recreational vehicles, livestock, and wildlife.

Vegetation composition: The site includes anticipated 

cover of plant species associated with the site 

environment, and no evidence suggests that upland 

species are replacing hydric species.

Vegetation composition is an expression of environmental 

conditions and management activities. The abundance of plant 

species will respond to changes in hydrologic conditions at a 

GDE. In some cases, certain species disappear altogether from a 

site because of changes in water table or spring flow. Vegetation 

composition can also change because of disturbances and 

management activities. The relatively consistent availability of 

water at GDEs supports hydric plants, which are generally more 

abundant at GDEs than in the surrounding uplands.

Examples

This indicator would be answered “Yes” in the following circumstances:

• Expected vegetation for the setting and environment is present, which would generally include OBL or FACW species of 

the Wetland Indicator Status (USFWS 1988). Primarily native 

species.

This indicator would be answered “No” in the following circumstances:

• Wetland vegetation seems to have been greatly reduced or 

eliminated. 

• Overstory of wetland woody species but a lack of wetland 

understory species, suggesting recent hydrologic changes 

(because herbaceous vegetation is generally more responsive 

to changes in hydrology than woody species). 
GDE: Level I 91 Inventory Field Guide

• Evidence suggesting that upland species have increased. 

• Dominance by nonnative or invasive plants.

Vegetation condition: Vegetation exhibits seasonally 

appropriate health and vigor.

This statement is intended to evaluate the health or vigor of 

the vegetation, based on a visual assessment. The condition of 

vegetation can be adversely affected by management activities.

Examples

This indicator would be answered “Yes” in the following circumstances:

• Sites that have dense, robust vegetation growth that is 

healthy-looking in terms of leaf color, size, and shape. 

This indicator would be answered “No” in the following circumstances:

• Sites that have discolored, decadent, weakened, or unusually 

sparse vegetation.

• Evidence of severe grazing or browsing by livestock and/or 

native ungulates, such as hedged plants.

Threatened, endangered, and sensitive species; 

SOI/SOC; or focal floral species. Anticipated floral 

species are present (will vary by ecological region 

and will require some baseline information).

Some GDEs support threatened, endangered, or sensitive species; 

SOI/species of concern (SOC); or focal floral species. The intent 

of this indicator is to identify sites that support these important 

plant species. 

GDEs can be floristically diverse, supporting a large number of 

rare and uncommon vascular plant species and bryophytes. 

GDEs can be unique habitats that support a higher level of biodiversity than the surrounding landscape. An array of plant species 

is known to be endemic to, or inhabit, these locations.
GDE: Level I 92 Inventory Field Guide

Examples

This indicator would be answered “Yes” in the following circumstances:

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal floral species were observed at a site whether or not 

they had been identified at the site before. 

• No threatened, endangered, or sensitive species; SOI/SOC; or 

focal floral species were observed and none were anticipated.

This indicator would be answered “No” in the following circumstances:

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal floral species were not observed at a site but had been 

documented at the site previously.

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal floral species were expected to be at the site but were 

not observed.

Faunal species: Anticipated aquatic and terrestrial 

faunal species associated with the site environment 

are present. 

Some GDEs have habitats that support aquatic and terrestrial 

faunal species. The intent of this indicator is to identify sites that 

support important animal species. 

Wetlands support many different types of animals, including 

invertebrates, fish, amphibians, reptiles, birds, and mammals. 

Because of the transitional nature of wetlands, both aquatic 

and terrestrial animals live in wetlands. Wetlands provide food 

sources, protection from weather and predators, resting sites, 

reproductive sites, and molting grounds for wildlife (Cooper 

1989). Wetlands provide this habitat function for many species 

of fish and wildlife, including some that are threatened or endangered. Many species of animals that are not typically considered 

to be wetland species also use wetlands.
GDE: Level I 93 Inventory Field Guide

Examples

This indicator would be answered “Yes” in the following circumstances:

• Anticipated faunal species were observed at a site, whether or 

not they had been identified at the site before. 

• No faunal species were anticipated, and none were observed. 

This indicator would be answered “No” in the following circumstances:

• Anticipated faunal species were not observed at a site but 

they had been documented at the site previously. 

• Faunal species were anticipated to be at the site but they 

were not observed.

Threatened, endangered, or sensitive species; SOI/

SOC; or focal faunal species: Anticipated faunal species are present (will vary by ecological region and will 

require some baseline information).

GDEs can be unique habitats that support a higher level of biodiversity than the surrounding landscape. An array of threatened, 

endangered, or sensitive species; SOI/SOC; or focal faunal 

species is known to be endemic to, or use, GDEs. The intent of 

this indicator is to identify sites that support important animal 

species. 

Examples

This indicator would be answered “Yes” in the following circumstances:

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal faunal species were observed, whether or not they had 

been identified at the site before. 

• No threatened, endangered, or sensitive species; SOI/SOC; 

or focal faunal species were anticipated, and none were 

observed. 
GDE: Level I 94 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal faunal species were not observed but had been documented at the site previously.

• Threatened, endangered, or sensitive species; SOI/SOC; or 

focal faunal species were expected to be at the site but were 

not observed.

Invasive species: Invasive floral and faunal species are 

not established at the site.

Invasive plant and animal species have a detrimental effect 

on the ecological functioning of GDEs. This statement asks if 

invasive animal or plant species have become established at 

the site. It is useful to know where invasive species have been 

established, so that controls can be implemented. Identifying the 

occurrence of invasive species before they infest a site is useful 

information.

Various characteristics of invasive species allow them to displace 

native vegetation at sites that have been disturbed by water impoundments, excessive grazing, recreation, and other activities. 

By displacing native vegetation, they reduce habitat that formerly 

provided critical nesting, feeding, and spawning habitat for wildlife species. A number of nonnative vertebrates and invertebrates 

have been introduced into springs in Western North America, and 

in some cases, populations of native aquatic species have either 

been reduced or extirpated as a result. 

Some plant species that are considered to be invasive in springs 

or wetlands, at least in some States, include purple loosestrife, 

tamarisk, common reed, reed canarygrass, and many others. 

Invasive animals could include the zebra mussel and many 

others.

Examples

This indicator would be answered “Yes” in the following circumstances:

• No invasive species (or very few individuals) were observed at 

the site.
GDE: Level I 95 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

•	 Invasive animal or plant species are established at the site.

Lists of invasive plants can be obtained for States and many 

counties or on line at http://plants.usda.gov/java/noxiousDriver.

Flow regulation: Flow regulation is not adversely 

affecting the site.

Alteration of surface or subsurface flow patterns may affect the 

functionality of a site. This statement is intended to determine if 

flow regulation has occurred at the site, which can have significant effects on the biota. For areas where wetland vegetation is 

important, a change in flow patterns may mean a change in vegetation type (wetland species to upland species), creating a site 

unable to function properly. For others, it may mean a decrease 

in extent of wetland or complete wetland loss.

Effects of diversion are similar to the consequences of a drought 

that causes springs and wetlands to become drier. In general, 

species richness declines as diversion increases, and functional 

shifts in the structure of aquatic and wetland communities occur. 

As diversion increases, intolerant aquatic taxa (e.g., mayflies, 

caddisflies, crenobiontics) are replaced by tolerant taxa (e.g., 

midges, beetles, corixids), and nonnative and upland vegetation 

becomes more abundant. 

Examples

This indicator would be answered “Yes” in the following circumstances:

•	 No flow regulation exists at the site.

•	 Flow regulation structures are stable, accommodate flows, 

and do not adversely affect the ecology of the site.

•	 Diversions remove very small amounts of water and have 

minimal effects on ecology.

This indicator would be answered “No” in the following circumstances:

•	 There exists channelization or redirection of flow, delivery 

of water through pipes and concrete channels to tanks and 
GDE: Level I 96 Inventory Field Guide

reservoirs, excavation and installation of spring boxes, ditching 

wetlands to drain them, or impounding spring sources. (These 

structures are designed to capture and divert water for uses 

such as livestock watering, domestic use, or irrigation.)

• Flow diversion is causing the area of wetland vegetation and 

soils to contract.

Construction and road effects: Construction, reconstruction, or maintenance of physical improvements, 

including roads, are not adversely affecting the site. 

Roads can cause negative ecological effects to ecosystems, 

plants, and wildlife. The effects of road construction and operation 

on wetlands and springs include negative effects from changes 

to the chemistry and biology of the local area to changes in hydrology that go beyond the immediate area of the road. Loss of 

wildlife habitat, loss of species, and biodiversity are other consequences of such changes. In addition, roads are barriers that can 

cause habitat fragmentation and edge effects, which may affect 

some plant and animal species. Roads are also corridors that can 

facilitate the spread of invasive species.

Examples

This indicator would be answered “Yes” in the following circumstances:

• No evidence suggests that construction or roads are affecting 

the GDE.

This indicator would be answered “No” in the following circumstances:

• Within the site, roads have caused trampling, soil compaction, 

erosion, disturbance (because of noise or motion), pollution, 

nutrient loading, or introduction of invasive plant species.

• Road is channelizing runoff and delivering sediment to the 

site. 

• Physical improvements, such as buildings, latrines, water 

development structures, piping, and parking lots, are affecting 

the site.

• Stormwater runoff from a road or parking lot is entering a 

wetland. 
GDE: Level I 97 Inventory Field Guide

Fencing effects: Protection fencing and exclosures 

are appropriate and functional.

Fences are sometimes used to exclude animals or people from 

spring or wetland sites to prevent damage to vegetation, alteration 

of sediment flux, or adverse affects on water quality. Proper placement and maintenance of fences is required to meet conservation 

objectives. This indicator assesses if the fences are appropriately 

designed, located, and maintained, and if they are working as 

intended.

Examples

This indicator would be answered “Yes” in the following circumstances:

• Fencing was properly designed and is functioning to exclude 

whatever it was intended to exclude, such as livestock, wild 

animals, vehicles, and recreation use.

This indicator would be answered “No” in the following circumstances:

• Fence is down, damaged, or broken.

• Fence was not designed or constructed in a manner that 

effectively protects the ecologically valuable portions of the 

site.

Herbivore effects: Herbivory is not adversely affecting 

the site.

This indicator documents whether grazing or browsing by native 

or nonnative animals is adversely affecting the site. This refers to 

effects from animals such as cattle, sheep, horses, burros, elk, 

deer, or moose. 

Many springs and wetlands have been altered by grazing and 

trampling of livestock, as well as other nonnative and native 

ungulates. Excessive grazing in GDEs can damage or alter vegetation, lead to increased water temperature, cause soil erosion 

(including streambank erosion), and add sediment and nutrients 

to aquatic systems. Those changes can damage habitat for wildlife, fish, and other aquatic fauna, such as macroinvertebrates.
GDE: Level I 98 Inventory Field Guide

Examples

This indicator would be answered “Yes” in the following circumstances:

• No evidence indicates adverse effects from grazing or 

browsing by native or nonnative ungulates.

This indicator would be answered “No” in the following circumstances:

• Native or nonnative ungulates have caused excessive removal 

of vegetation, abnormally low height (including hedging of 

shrubs) or cover of vegetation, or major changes in species 

composition. 

• Native or nonnative ungulates’ hoof action has caused trampling of vegetation, soil erosion, or other ground disturbance.

Recreational effects: Recreational uses, including 

trails, are not adversely affecting the site.

Recreational activities can negatively affect GDEs. Off-road 

vehicle use is increasing on NFS lands and has damaged many 

wetland and spring habitats. Sada (2001) documented how 

trampling by recreationists affected the abundance and distribution of spring-dwelling mollusks. The effects on springs is similar 

to those caused by excessive livestock and wildlife activity in 

riparian and aquatic systems, where it has degraded riparian 

vegetation and increased water temperature, the amount of fine 

substrates, and nutrient loading (Fleischner 1994, Kauffman and 

Krueger 1984). 

Examples

This indicator would be answered “Yes” in the following circumstances:

• None of the adverse effects in the following list are observed.

This indicator would be answered “No” in the following circumstances:

• Camping, hiking, and associated refuse have adversely 

affected the site.

• Recreation use along a spring brook has caused decreased 

vegetation height or cover (through trampling or other damage).
GDE: Level I 99 Inventory Field Guide

• Vehicles have caused erosion, soil compaction, damage to 

vegetation, or other adverse effects.

• Other recreational activities (trails, horseback riding, etc.) have 

adversely affected the site.

Other disturbance effects: Wildland fire, insect, disease, wind throw, avalanches, or other disturbances 

are not adversely affecting the site.

This indicator documents adverse effects from disturbances 

not captured in other statements, such as fire, blow down, pest 

infestation, disease, and avalanches. 

Examples

This indicator would be answered “Yes” in the following circumstances:

• None of the adverse effects in the following list have had a 

significant adverse affect on the site.

This indicator would be answered “No” in the following circumstances:

• Significant amounts of dead or dying vegetation (particularly 

trees and shrubs) from insect infestation, disease, or wildfire 

are found in the site.

• Evidence suggests that blow down, pest infestation, disease, 

avalanches, debris flow, or other natural disturbances have 

had a significant adverse affect on the site.

Cultural values: Archaeological, historical, or tribal 

values will not affect inventory, restoration, use, or 

management of this site.

Many springs, particularly in the Southwestern United States, 

have cultural and or historical significance that could require 

consultation with tribes or State historic preservation offices.

Examples

This indicator would be answered “Yes” in the following circumstances:

• No evidence indicating archaeological, historical, or tribal 

resources at the site.
GDE: Level I 100 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• Archaeological, historical, or tribal resources could be affected 

by inventory, restoration, use, or management of the site.

• Site sacredness is recognized by tribes or nontribal agencies.

• Site has potential for National Register of Historic Places

status.

• Artifacts, petroglyphs, ruins, water works, or dwelling sites are 

present.

Land ownership: The entire site and immediate area 

are under the jurisdiction and management of the 

Forest Service.

This indicator simply documents that the site is managed by the 

Forest Service and, thus, the land manager has the authority to 

control undesirable or unauthorized activities at the site.

Examples

This indicator would be answered “Yes” in the following circumstances:

• Entire site is within Forest Service jurisdiction.

This indicator would be answered “No” in the following circumstances:

• Part, or all, of the site is not within Forest Service jurisdiction.

Other landowner actions: Activities or management 

on lands outside Forest Service jurisdiction are not 

adversely affecting the site.

This indicator documents whether the site is under threat from 

actions by adjacent landowners.

Examples

This indicator would be answered “Yes” in the following circumstances:

• None of the adverse effects in the following list are observed.
GDE: Level I 101 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• A large pumping well is located adjacent to the site, off of NFS 

lands, and is dewatering the site.

• Other activities off of NFS lands are adversely affecting the site.

Land management plan: The land and resource management 

plan provides for effective site protection.

Forest or grassland plans define desired conditions or standards 

and guidelines for management of forest resources. 

Examples

This indicator would be answered “Yes” in the following circumstances:

• The forest or grassland plan states that springs and wetlands 

are managed to promote long-term viability of ecological 

function.

This indicator would be answered “No” in the following circumstances:

• The forest plan does not recognize that springs and wetlands 

are managed to promote long-term viability of ecological 

function.

Environmental compliance: Authorized and administrative uses 

are in compliance and are not adversely affecting the site.

Water developments are authorized under special-use authorization regulations. This indicator is used to alert the land manager 

of unauthorized activities that need to be addressed.

Examples

This indicator would be answered “Yes” in the following circumstances:

• None of the adverse effects in the following list are observed.
GDE: Level I 102 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• A water development was not constructed as specified in the 

permit.

• Grazing within the site is not in compliance with allotment 

management plan requirements.

Water Uses: There are no substantial water uses in 

the watershed or in the aquifer supplying groundwater 

to the site that could directly or cumulatively adversely 

affect the GDE. 

The purpose of this indicator is to assess the scope and extent of 

water use (including that from water rights) within the watershed 

and/or aquifer to assess the potential for direct or cumulative 

adverse affects to the GDE. 

Water use from surface or groundwater sources should be accounted for under either State or Federal authority. All water use, 

whether exempt from State application procedures or not, needs 

to be properly documented and tracked relative to the amount 

of water used and location of withdrawal and use. Information 

from the Water Rights and Uses (WRU) database/site visit field 

form, which can be included in the GDE inventory process, is 

used to assess if there is substantial water use, individually or 

cumulatively, from water uses. 

Examples

This indicator would be answered “Yes” in the following circumstances:

• The density of water uses and rights is small relative to 

streamflow availability or aquifer capacity.

• Water uses and water rights that affect the site have been 

inventoried and accounted for and are being used as intended 

and within the limits of the right or exemption.

• Infrastructure adjacent to the site or within the watershed has 

evidence of maintenance and is functioning well.
GDE: Level I 103 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• The density of water uses and rights is moderate to high relative to streamflow availability or aquifer capacity.

• Water uses and water rights have not been inventoried; many 

uses are unidentified or unknown, with little to no information 

on amount or frequency of use. 

• Infrastructure adjacent to site or within the watershed is 

extensive, with no inventory information to assess the extent 

of infrastructure and water use.

Water Rights: Water rights have been filed for the site 

under State law or water uses exempted under State 

law are documented. Forest Service Federal reserved 

rights are documented as appropriate. Third-party 

water use is in accordance with all elements of the 

water right or conditions of the exemption and with 

the Forest Service authorization that allows the use. 

The purpose of this indicator is to assess the water rights and 

uses disposition of the site (see description under the previous 

“water uses” section). Information from the WRU database and 

site visit field form, which can be included in the GDE inventory 

process, is used to assess if there is substantial water use, 

individually or cumulatively, from water uses.

Examples

This indicator would be answered “Yes” in the following circumstances:

• A reasonable amount of water is being consumed for the 

specific purpose. Amount and timing of water withdrawal is 

comparable to similar uses at sites/watersheds with similar 

conditions. 

• If metered, metering is accurate and measurements are used 

in assessments.

• The water right or use is valid and used in accordance to 

specifications of the right or use.

• Infrastructure and diversions are in good working condition.
GDE: Level I 104 Inventory Field Guide

This indicator would be answered “No” in the following circumstances:

• Water right or use is in violation of exemptions and is not 

authorized under State law or subject to forfeiture.

• Water is not metered and is required to be metered under 

State law or special-use permit.

• Infrastructure is not maintained and water use is not controlled.
GDE: Level I 105 Inventory Field Guide

Post-Field Survey Activities (in office)

After the field survey, additional activities need to be completed 

in the office or laboratory to supplement or enhance the field 

data. These activities are described in the following list (in the 

same manner they are listed in the “Using the Level I Field 

Guide” section in the beginning of this field guide).

Obtain or Verify Data 

Based upon the location data (UTM or latitude/longitude) 

acquired at the site, the following are examples of attributes that 

can be determined, verified, or updated in the office, primarily 

with GIS tools. 

• Watershed(s) hydrologic unit codes.

• Ecological system. 

• Local feature-type name.

• Site name (an existing site name that was not known at the 

field visit may exist).

• Primary lithology (groundwater source aquifer).

• Secondary lithology.

Laboratory Analyses

If samples or specimens were collected in the field, then they 

need to be transferred to a location where they can be analyzed. 

Plant specimens should be taken to a botanist or herbarium for 

identification. Macroinvertebrate specimens should be sent to 

a laboratory that follows general processing and identification 

guidelines for identification (described in the Lab Identification 

part of the Aquatic Macroinvertebrates section). Water samples 

and soil samples should be sent to a laboratory that follows 

standardized guidelines of quality assurance.
GDE: Level I 106 Inventory Field Guide

Implement Data Management and Interpretation 

Procedures

Field data recorded either on paper forms or field data recorders 

will need to be entered into the corporate database. A significant 

amount of time needs to be allotted for data entry from paper 

forms. The database can generate summaries for each attribute 

and those should be reviewed for obvious errors that might have 

been made in recording or entering the data. A site summary can 

be generated in the database as well, which includes all of the 

attributes and the basic site information.

Photos taken with a digital camera need to be downloaded, 

labeled, and stored in a location that is associated with the other 

site information. Handwritten materials such as drawings and 

notes should be scanned into electronic format and stored in a 

location that is associated with the other site information.

Validate and Confirm Management Indicator 

Tool Entries

The responses to the Management Indicator Tool should be 

compared to the summarized field data in the office. This will 

either confirm the field responses or provide information that can 

be used to edit the field responses. For example, it may have 

been noted that there were no invasive species at the site, but 

the summarized data in the office may indicate that there were 

indeed significant amounts of invasive plants or animals. The 

response to the statement on invasive species would then be 

updated based on the summarized field data.

Analyze and Evaluate Collected Information

Detailed techniques for analyzing and evaluating the data collected with this field guide are not described in this field guide.
GDE: Level I 107 Inventory Field Guide

Glossary

Some definitions are taken from Mitsch and Gosselink (2007). 

anoxia—Waters or soils with no dissolved oxygen.

aquifer—A saturated underground layer of water-bearing 

permeable rock or unconsolidated materials (gravel, sand, silt, or 

clay) from which groundwater can be extracted using a well. An 

aquifer can be confined, unconfined, or partially confined. The 

aquifer can be perched, local, or regional. Aquifers are connected 

to the hydrologic cycle through recharge, within and between 

unit flow, and through discharge.

artesian—Condition in which a confined aquifer is under 

pressure such that the static level within a cased borehole rises 

above an impermeable (confining) layer (e.g., peat layer) or in 

which water discharges to the surface from an unlined borehole.

base-flow stream—A perennial stream supported by groundwater discharge during periods of low or no precipitation or 

snowmelt.

bog—A peat-accumulating wetland that has no significant 

inflows or outflows and supports acidophilic mosses, particularly 

Sphagnum. In general, bogs are supported by precipitation.

bryophytes—Nonvascular land plants (mosses, liverworts, and 

hornworts) that have tissues and enclosed reproductive systems 

but lack vascular tissue that circulates liquids. They neither have 

flowers nor produce seeds because they reproduce via spores.

Carolina Bay—Elliptical depressions or shallow basins that 

occur throughout the Southeastern United States Coastal Plain. 

Their hydrology is dominated by precipitation inputs and evapotranspiration losses, and they range from nearly permanently 

inundated to frequently dry.

cave—A natural underground space formed by various geologic 

processes. Caves are common in karst terrain and areas of 

psuedokarst.

cienega—Usually a wet, marshy area at the foot of a mountain, 

in a canyon, or on the edge of a grassland where groundwater 

reaches the surface. Often, a cienega does not drain into a 

stream but instead evaporates. Also called helocrene.
GDE: Level I 108 Inventory Field Guide

crenobiontic—Organisms that live only in springs.

exposure spring (one of the spheres of discharge, as described 

by Springer and Stevens 2009)—Groundwater is exposed at 

the land surface but does not have surface inflow or outflow. 

Exposure springs occur in karst (sinkholes) and psuedokarst 

(lava flows) but could form in other types of vertical conduits into 

an aquifer.

fen—In general, wetlands that develop where a relatively constant supply of groundwater to the plant rooting zone maintains 

saturated conditions most of the time and the water chemistry 

reflects the mineralogy of the surrounding and underlying soils 

and geological materials. The U.S. Fish and Wildlife Service 

(1999) uses two criteria to classify a wetland as a fen: (1) the wetland is primarily supported by groundwater and (2) the wetland 

has organic soils meeting the U.S. Department of Agriculture, 

Natural Resources Conservation Service (2010) definition of 

a histosol or a histic epipedon in at least some part of the 

contiguous wetland.

fibric—Organic soil material that contains 3/4 or more recognizable fibers (after rubbing between fingers) of undecomposed 

plant remains. Bulk density is usually very low and water-holding 

capacity very high. Also referred to as peat.

flark—See string and flark microtopography. 

forb—Herbaceous flowering plant that is not a graminoid.

fountain spring (one of the spheres of discharge, as described 

by Springer and Stevens 2009)—Cool, artesian springs that are 

forced above the land surface by artesian or gas pressure.

geyser (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—Geothermal springs that emerge 

explosively and usually erratically. A geyser is a hot spring 

characterized by intermittent discharges of water that are ejected 

turbulently by a vapor phase.

graminoid—True grasses (Poaceae) or grass-like plants, such as 

sedges (Cyperaceae) or rushes (Juncaceae).

groundwater—All water below the ground surface, including 

water in the saturated and unsaturated zones.
GDE: Level I 109 Inventory Field Guide

groundwater-dependent ecosystems (GDEs)—Communities 

of plants, animals, and other organisms whose extent and life 

processes are dependent on access to or discharge of groundwater. 

gushet (one of the spheres of discharge, as described by Springer and Stevens 2009)—Discrete sources of flow pouring from 

cliff faces. Gushets typically emerge from perched, unconfined 

aquifers, often with dissolution enhancement along fractures, 

exhibit thin sheets of water flowing over rock faces.

hanging garden or wet wall (one of the spheres of discharge, as 

described by Springer and Stevens 2009)—Springs that emerge 

along geologic contacts or fractures and seep, drip, or pour onto 

underlying walls. Hanging gardens in the Southwestern United 

States typically emerge from perched, unconfined aquifers in 

Aeolian sandstone units. 

helocrene (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—Low-gradient springs and/or 

wetlands; often indistinct or multiple sources of groundwater. 

Also called wet meadows or cienegas.

hemic—Organic soil material at an intermediate degree of 

decomposition that contains 1/6 to 3/4 recognizable fibers (after 

rubbing between fingers) of undecomposed plant remains. Bulk 

density is usually very low and water-holding capacity very high. 

Also referred to as mucky peat.

herbaceous—A plant that has leaves and stems that die down 

to the ground at the end of the growing season. They have no 

persistent woody stems.

hillslope (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—Springs and/or wetlands on a 

hillslope (generally 20- to 60-degree slope), often with indistinct 

or multiple sources of groundwater.

histic epipedon—An 8- to 16-inch layer at or near the surface of 

a mineral hydric soil that is saturated with water for 30 consecutive days or more in most years and 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 inundated or saturated for 

sufficient periods to greatly retard aerobic decomposition of the 

organic surface and are considered to be hydric soils.
GDE: Level I 110 Inventory Field Guide

histosol—Histosols (organic soils) develop under conditions of 

nearly continuous saturation and/or inundation. All histosols are 

hydric soils except folists, which are freely drained soils occurring on dry slopes where excess litter accumulates over bedrock. 

Organic hydric soils are commonly known as peats and mucks.

hypocrene (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—A buried spring where flow does 

not reach the surface. This term is common to the Southwestern 

United States. Elsewhere, these features may be equivalent to 

shallow groundwater areas, including fens.

hyporheic zone—Area of a stream bed and bank where surface 

and ground waters mix. A similar area, the hypolentic zone, exists in lakes and ponds.

insurgence—The point of inflow for surface water into subsurface conduits in karst areas.

jurisdictional wetlands—Those areas that are inundated or 

saturated by surface or ground water (hydrology) at a frequency 

and duration sufficient to support and that, under normal circumstances, do support a prevalence of vegetation (hydrophytes) 

typically adapted for life in saturated soil conditions (hydric soils). 

Wetlands generally include swamps, marshes, bogs, and similar 

areas (40 Code of Federal Regulations 232.2(r)). 

karst—A terrain or type of topography generally underlain by 

soluble rocks, such as limestone, gypsum, and dolomite, in 

which the topography is chiefly formed by dissolving the rock; 

karst is characterized by sinkholes, depressions, caves, and 

underground drainage. Psuedokarst is an area of depressions, 

caves, and internal drainage that result from volcanic activity. 

limnocrene (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—Groundwater emerges in one or 

more pools.

marsh—A frequently or continually inundated wetland characterized by emergent herbaceous vegetation adapted to saturated 

soil conditions. 

mineralized mounds (one of the spheres of discharge, as 

described by Springer and Stevens 2009)—Springs that emerge 

from (usually carbonate) precipitate mounds. 
GDE: Level I 111 Inventory Field Guide

minerogenous—See minerotrophic peatlands.

minerotrophic peatlands—Peatlands that receive water that has 

passed through mineral soil. Also called minerogenous hydrological systems.

muck—Organic soil material in which the original plant parts are 

not recognizable. Contains more mineral matter and is usually 

darker in color than peat. Also referred to as sapric material.

mucky peat—Organic soil material in which a significant part of 

the original plant parts are recognizable and a significant part is 

not. Also referred to as hemic material.

National Resource Manager (NRM)-Automated Lands 

Program (ALP) database—The Forest Service national ALP is 

an information management system that contains all land status 

data for Forest Service managed land, including land survey, 

ownership, use restrictions, and boundaries.

NRM-Infrastructure (INFRA) database—NRM-INFRA is a Forest Service data management system that includes a collection 

of Web-based data entry forms, reporting tools, and Geographic 

Information System tools that enable forests to manage and 

report accurate information about their inventory of constructed 

features and land units as well as permits sold to the general 

public and to partners.

NRM-Natural Resource Information System (NRIS) Water 

Rights and Uses database—The NRIS is a set of Forest Service 

corporate databases and computer applications that contain basic natural resource data. The Water Rights and Uses database 

tracks core information about State and federally recognized 

water rights and uses. It also tracks related information about 

beneficiaries, purpose, quantity, and periods of water use. 

ombrogenous—Peatland with inflow from precipitation only. 

Also called ombrotrophic.

organic soil—Organic soils (histosols) develop under conditions 

of nearly continuous saturation and/or inundation. All organic 

soils are hydric soils except folists, which are freely drained soils 

occurring on dry slopes where excess litter accumulates over 

bedrock. Organic hydric soils are commonly known as peats and 

mucks.
GDE: Level I 112 Inventory Field Guide

peat—Organic soil material that is undecomposed or weakly 

decomposed. The plant remains are distinct and identifiable.

peatland—A generic term for any wetland that accumulates 

partially decayed plant matter (peat).

phreatophyte—Plant whose roots generally extend downwards 

to the water table and customarily feed on the capillary fringe. 

Phreatophytes are common in riparian habitats. Term literally 

means “well” plant or water-loving plant. 

piezometer—Small-diameter well open at a point or over a short 

length in the aquifer to allow measurement of hydraulic head at 

that location. 

pocosin—Peat-accumulating, nonriparian freshwater wetland, 

generally dominated by evergreen shrubs and trees and found 

on the Southeastern Coastal Plain of the United States. The term 

comes from the Algonquin word for “swamp on a hill.”

redoximorphic features—Features formed by the reduction, 

translocation, and/or oxidation of iron and manganese oxides; 

used to identify hydric soils.

rheocrene (one of the spheres of discharge, as described by 

Springer and Stevens 2009)—Flowing springs that emerge 

directly into one or more stream channels.

riparian—Pertaining to the bank of a body of flowing water; the 

land adjacent to a river or stream that is, at least periodically, 

influenced by flooding. Riparian sometimes is used to indicate 

the banks of lakes and ponds subject to period inundation by 

wave action or flooding.

sapric—Organic soil material that contains less than one out of 

six recognizable fibers (after rubbing between fingers) of undecomposed plant remains. Bulk density is usually very low, and 

water holding capacity very high. Also referred to as muck. 

seep—A discharge of water that oozes out of the soil or rock 

over a certain area without distinct trickles or rivulets.

specific conductance—A measure of an aqueous solution’s 

ability to carry an electrical current (also called electrical conductance or conductivity).
GDE: Level I 113 Inventory Field Guide

spring—A place where groundwater flows naturally from the 

earth into a body of surface water or onto the land surface.

spring brook—Runout channel from a spring, which may 

become a stream at some distance from the spring source.

spring source—The location where the spring emerges from 

the ground onto the land surface. Also referred to as the spring 

orifice.

string and flark microtopography—Slow groundwater movement through broad, gently sloped peatlands forms a series 

of linear hummock ridges called strings, separated by parallel 

hollows known as flarks. Strings and flarks are arranged perpendicularly to the flow of water through the peatland and can form 

a regular pattern of parallel ridges and hollows or an intricate, 

braided or branching (anastomosing) pattern.

swamp—Wetland dominated by trees or shrubs.

Terrestrial Ecological Unit Inventory (TEUI)—The national 

program of ecological classification within the Forest Service that 

was developed to classify ecological types and map ecological 

units to a consistent standard across National Forest System 

lands. TEUI establishes terrestrial mapping units derived from 

a combination of core datasets, which uniquely characterize a 

spatial region, including climate, geology, geomorphology, soil 

regime, and vegetation.

upland—Land that is not influenced by a consistent source of 

surface water or groundwater and, therefore, does not support 

wetland vegetation or hydric soil development as would a 

wetland or riparian area.

wet meadow—Area that is saturated with water for much of the 

year but does not have standing water, except for brief periods, 

during the growing season.

wetland—In general, wetlands are lands on which water covers 

the soil or is present either at or near the surface of the soil or 

within the root zone, all year or for varying periods of time during 

the year, including during the growing season. The U.S. Fish and 

Wildlife Service defines wetlands as “lands that are 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... (and) have one or more of the following attributes: (1) at 
GDE: Level I 114 Inventory Field Guide

least periodically, the land supports predominantly hydrophytes; 

(2) the substrate is predominantly undrained hydric soil; or (3) the 

substrate is nonsoil and is saturated with water or covered by 

shallow water at some time during the growing season of each 

year” (Cowardin et al. 1979). See also jurisdictional wetland.

wetland indicator status—A system of categorizing plant 

species in terms of their probability of occurring in wetlands. 

The system was developed by the U.S. Fish and Wildlife Service 

(1988). It has five general categories: obligate, facultative wetland, facultative, facultative upland, and upland. Obligate species 

almost always occur in wetlands, whereas upland species almost 

never occur in wetlands, as described in table 4.

Wetland indicator status Code Estimated probability 

a species occurs in wetlands

Obligate OBL Almost always (99%)

Obligate – OBL –

Facultative wetland + FACW +

Facultative wetland FACW Usually (67–99%)

Facultative wetland – FACW –

Facultative + FAC +

Facultative FAC Equally likely to occur in wetlands

or nonwetlands (34–66%)

Facultative – FAC –

Facultative upland + FACU +

Facultative upland FACU Not usually (1–33%)

Facultative upland – FACU –

Upland + UPL +

Upland UPL Almost never (1%)

Table 4.—Wetland indicator status codes and descriptions (USWFS 1988).
GDE: Level I 115 Inventory Field Guide

References

Baas-Becking, L.G.M.; Kaplan, I.R.; Moore, D. 1960. Limits of 

the natural environment in terms of pH and oxidation-reduction 

potentials. Journal of Geology 68: 243–284.

Brohman, R.J.; Bryant, L.D., eds. 2005. Existing vegetation classification and mapping technical guide. Version 1.0. Washington, 

DC: U.S. Department of Agriculture, Forest Service, Ecosystem 

Management Coordination Staff. 305 p.

Brown, J.; Wyers, A.; Aldous, A.; Bach, L. 2007. Groundwater 

and biodiversity conservation: a methods guide for integrating 

groundwater needs of ecosystems and species into conservation plans in the Pacific Northwest. Portland, OR: The Nature 

Conservancy. 184 p.

Cowardin, L.M.; Carter, V.; Golet, F.C.; LaRoe, E.T. 1979. 

Classification of wetlands and deepwater habitats of the United 

States. Washington, DC: U.S. Department of the Interior, Fish 

and Wildlife Service. 131 p.

Fleischner, T.L. 1994. Ecological costs of livestock grazing in 

Western North America. Conservation Biology. 8: 629–644.

Griffiths, R.E.; Springer, A.E.; Anderson, D.E. 2008. The 

morphology and hydrology of small spring-dominated channels. 

Geomorphology. 102: 511–521.

Gurrieri, J. 2007 (draft). Interim protocol, ground-water resource 

inventory and monitoring protocol, level I spring ecosystem 

inventory. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Region. 35 p.

Hall, F.C. 2001. Photo point monitoring handbook, part A—field 

procedures. PNW-GTR-526. Portland, OR: U.S. Department of 

Agriculture, Forest Service, Pacific Northwest Research Station. 

340 p.

Haskins, D.M.; Correll, C.S.; Foster, R.A.; et al. 1998. A geomorphic classification system. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 110 p.
GDE: Level I 116 Inventory Field Guide

Johnston, B.C.; Almy, J.; Stratton, B. 2009 (draft). Study plan: 

sampling of the polygons photointerpreted for possible fens on 

the Grand Mesa-Uncompahgre-Gunnison National Forest, Colorado. Delta, CO: U.S. Department of Agriculture, Forest Service, 

Grand Mesa-Uncompahgre-Gunnison National Forest. 23 p.

Kauffman, J.B.; Krueger, W.C. 1984. Livestock impacts on 

riparian ecosystems and streamside management implications: 

a review. Journal of Range Management. 37: 430–437.

Langmuir, D. 1996. Aqueous environmental geochemistry. Upper 

Saddle River, NJ: Prentice-Hall. 600 p. 

Magee, T.K.; Dwire, K.A.; Gwin, S.E.; et al. 1995. Field 

and laboratory operations report for the Oregon Wetlands 

Study. Corvallis, OR: U.S. Environmental Protection Agency, 

Environmental Research Laboratory. 206 p.

McCabe, D.J. 1998. Biological communities in springbrooks. 

In: Botosaneanu, L., ed. Studies in crenobiology: the biology of 

springs and springbrooks. Leiden, The Netherlands: Backhuys 

Publishers: 221–228.

Mitsch, W.J; Gosselink, J.G. 2007. Wetlands. 4th ed. New York: 

John Wiley and Sons. 582 p.

National Wetlands Working Group. 1997. The Canadian wetland 

classification system. Waterloo, Ontario: University of Waterloo, 

Wetlands Research Centre. 76 p.

NatureServe. 2011. International ecological classification 

standard: terrestrial ecological classifications. Arlington, VA: 

NatureServe Central Databases. http://www.natureserve.org/

getData/USecologyData.jsp. (12 May 2011).

Prichard, D. 2003. A user guide to assessing proper functioning 

condition and the supporting science for lentic areas. Rev. TR 

1737-16. Denver, CO: U.S. Department of the Interior, Bureau of 

Land Management. 110 p.

Richardson, C.J. 2003. Pocosins: hydrologically isolated or 

integrated wetlands on the landscape? Wetlands. 23: 563–576.

Sada, D.W. 2001. Demography and habitat use of the Badwater 

snail (Assiminea infima), with observations on its conservation 

status. Hydrobiologia. 466: 255–265.
GDE: Level I 117 Inventory Field Guide

Sada, D. W.; Pohlmann, K.F. 2006 (draft). U.S. National Park 

Service Mojave inventory and monitoring network spring survey 

protocols: level I and level II. Reno and Las Vegas, NV: Desert 

Research Institute. 95 p.

Schoeneberger, P.J.; Wysocki, D.A.; Benham, E.C.; Broderson, 

W.D. 2002. Field book for describing and sampling soils, version 2.0. Lincoln, NE: U.S. Department of Agriculture, Natural 

Resources Conservation Service, National Soil Survey Center. 

228 p. 

Sharitz, R.R. 2003. Carolina Bay wetlands: unique habitats of the 

Southeastern United States. Wetlands. 23: 550–562.

Springer, A.E.; Stevens, L.E. 2009. Spheres of discharge of 

springs. Hydrogeology Journal. 17(1): 83–94.

Stevens, L.; Kloeppel, H.; Springer, A.; Sada, D. 2006. Terrestrial 

springs ecosystems inventory protocols narrative. NPS Cooperative Agreement Number CA 1200-99-009, TASK# NAU-118. 

Flagstaff, AZ: National Park Service. 45 p.

Stevens, L.E.; Meretsky, V.J. 2008. Springs ecosystem ecology 

and conservation. In: Stevens, L.E.; Meretsky, V.J. eds. Aridland 

springs in North America: ecology and conservation. Tucson, AZ: 

University of Arizona Press: 3–10. 

Stevens, L.E.; Springer, A.E. In development. Springs ecosystem 

assessment protocol scoring criteria. Flagstaff, AZ: Springs 

Stewardship Institute. http://springstewardship.org/assessment.

html. (14 October 2011).

U.S. Army Corps of Engineers. 1987. Corps of Engineers 

wetlands delineation manual. Vicksburg, MS: U.S. Army Corps of 

Engineers, Waterways Experiment Station. 143 p.

U.S. Department of Agriculture (USDA), Forest Service. 2009. 

Site general: field guide. Washington, DC: U.S. Department of 

Agriculture, Forest Service, Rangeland Management Staff. 57 p.

USDA Natural Resources Conservation Service (NRCS). 2010. 

Keys to soil taxonomy. Washington, DC: U.S. Department of 

Agriculture, Natural Resources Conservation Service. 346 p.
GDE: Level I 118 Inventory Field Guide

USDA NRCS. 2006. Field indicators of hydric soils in the United 

States, Version 6.0. In: Hurt, G.W.; Vasilas, L.M., eds. U.S. Department of Agriculture, Natural Resources Conservation Service, 

in cooperation with the National Technical Committee for Hydric 

Soils. 47 p.

U.S. Environmental Protection Agency (EPA). 2008. Methods for 

evaluating wetland condition: biogeochemical indicators. EPA822-R-08-022. Washington, DC: U.S. Environmental Protection 

Agency, Office of Water. 44 p.

U.S. Fish and Wildlife Service (USFWS). 1988. National list of 

vascular plant species that occur in wetlands. U.S. Fish and 

Wildlife Service Biological Report 88(26.9). http://plants.usda.

gov/wetinfo.html. (16 June 2011).

USFWS. 1999. Peatland mitigation policy considerations. Lakewood, CO: U.S. Fish and Wildlife Service, Region 6: 35. 39 p. 

U.S. Geological Survey. (variously dated 1997 to 2011). National 

field manual for the collection of water-quality data: U.S. Geological Survey Techniques of water-resources investigations, book 9, 

chaps. A1–A9. http://water.usgs.gov/owq/FieldManual/. (15 

November 2011).

Voshell, J.R., 2002. A guide to common freshwater invertebrates 

of North America. Blacksburg, VA: McDonald and Woodward 

Publishing Co. 442 p.

Weixelman, D.A.; Cooper, D.J. 2009. Assessing proper functioning condition for fen areas in the Sierra Nevada and Southern 

Cascade Ranges in California: a user guide. Gen. Tech. Rep. 

R5-TP-028. Vallejo, CA: U.S. Department of Agriculture, Forest 

Service, Pacific Southwest Region. 52 p.

Winthers, E.; Fallon, D.; Haglund J.; et. al. 2005. Terrestrial 

ecological unit inventory technical guide. Washington, DC: U.S. 

Department of Agriculture, Forest Service, Washington Office, 

Ecosystem Management Coordination Staff. 245 p.
GDE: Level I 119 Inventory Field Guide

Appendix 1. Order of Data Collection

The methods are generally presented in the recommended order 

that they should be conducted on the site. The order presented 

here is partially intended to minimize the amount of walking on 

the Groundwater Dependent Ecosystems site and the number 

of trips into or across the site to avoid trampling the soil and 

vegetation. 

Recommended order of collecting field data

1. Wildlife (mammals, birds, etc.) observations upon arrival at 

site.

2. Water quality—surface water (if done).

3. Aquatic macroinvertebrates.

4. Location and geologic information (Universal Transverse 

Mercators, elevation, etc.).

5. Vegetation.

6. Soils: soil core and data collection.

7. Hydrology.

i. Water quality—subsurface water (use borehole from soil 

core or augered hole for water table).

ii. Water quantity.

a. Water table depth.

b. Flow. 

c. Spring brook measures (if applicable).

8. Aquatic and Terrestrial Fauna (macroinvertebrates are done 

earlier).

9. Photos.

10. Sketch map of site.

11. Natural and anthropogenic disturbances. 

12. Management indicator tool.
GDE: Level I 120 Inventory Field Guide
GDE: Level I 121 Inventory Field Guide

Appendix 2. Job Hazard Analysis

Appendix 2. Job Hazard Analysis

U.S. Dept. of Agriculture

Forest Service

JOB HAZARD ANALYSIS (JHA)

References-FSH 6709.11 and-12

(Instructions on reverse)

1. WORK PROJECT/ACTIVITYField Data Collection

2. LOCATION 3. UNIT

4. NAME OF ANALYST 5. JOB TITLE 6. DATE PREPARED

January 2010

7. TASK/PROCEDURES 8. HAZARDS 9. ABATEMENT ACTIONS

1. Driving from either official or 

temporary duty station to field location

a. Hazardous road conditions during 

some portions of the year

 Drive with extreme caution. All field personnel attend defensive driving class renewed at least every three 

portions of the year.

 See “Winter Travel” and “General Driving” JHA.

b. Driving in off-road situations with or 

without four-wheel drive

 All new personnel receive training on the use and operation of four-wheel drive 

vehicles.

 Drive with extreme caution.

c. Vehicle breakdown and unable to 

get to shelter

 Ensure that each vehicle is equipped with a seasonal survival kit that has been 

inspected and includes all items that are necessary.

d. Cell phones  Absolutely no using cell phones while driving a Government vehicle. This includes 

texting and talking.

e. Female traveling alone  Avoid hotel rooms on the ground floor. Do not accept a room with adjoining door 

entry. Keep cell phone handy and fully charged. Wear a wedding ring. Park in well lit areas.

2. Foot travel a. Slips, trips, and falls  Wear nonskid boots that are appropriate for conditions.

 Watch where walking. Stay on trails when able. Use a walking stick when necessary.

b. Allergic reaction to insect bites 

(e.g., bee stings)

 Ensure that all personnel with known allergic reactions to insect bites carry 

appropriate medication. In addition, the allergic individuals should make sure that their partner knows where the medication is kept and can administer it in an emergency situation.

 In case of a bite or sting, watch subject closely for any allergic reaction. Call 911 

or local emergency number and evacuate immediately if any reaction away from injury site is observed.
GDE: Level I 122 Inventory Field GuideGroundwater-Dependent Ecosystems Level II Inventory Field Guide 73

b. Allergic reaction to insect bites 

(e.g., bee stings)

 Ensure that all personnel with known allergic reactions to insect bites carry 

appropriate medication. In addition, the allergic individuals should make sure that their partner knows where the medication is kept and can administer it in an emergency situation.

 In case of a bite or sting, watch subject closely for any allergic reaction. Call 911 

or local emergency number and evacuate immediately if any reaction away from injury site is observed.

c. Branches striking eyes  Keep a safe distance from partner.

 Wear protective eyewear.

d. Crossing shallow streams  Always work with a partner when planning stream or river crossings with water 

depths over the knees. Choose crossing sites with shallow water, slow currents, and gradual slopes. Avoid crossing sites with water over mid-thigh depths or swift current.

 Use pole or walking stick to help maintain balance with three-point support. Move 

one foot or pole at a time.

 Watch for and avoid large, wet, rounded rocks because they may be slippery. Be especially alert to the possibility of one foot becoming entrapped in rocks or 

branches and current forcing individual off balance and under water. 

 Carry a rope or throw rope long enough to reach across the entire width of the 

crossing.

 Make the crossing one person at a time with one person on the bank at all times. 

Stretch the safety rope between the person on the bank and the person crossing.

 Logs should be used as last alternative and should be of sufficient size, dry, and 

algae free.

 Leave vest unbuttoned, remove workbelt from waist, disconnect waist and 

sternum straps on pack, and be prepared to ditch any equipment if you are unable to recover from a fall.

 Protect feet with proper footwear such as waders. Bring dry socks and footwear 

to wear during field work and hiking.

 Do not cross streams during unfavorable weather.
GDE: Level I 123 Inventory Field Guide

3. Use of snowmobile to travel to the 

field location

 See “Snowmobile Use” JHA.

4. Use of boat to travel to the field 

location

 See “Boat Travel” JHA.

5. Use of all-terrain vehicle to travel to 

the field location

 See “ATV Travel” JHA.

6. Driving FS/GSA vehicles  See “General Driving and 15 Passenger Vans” JHA.

7. Overnight travel  See “Overnight Travel” JHA.

8. Office work  See “Office Work” JHA.

9. Conducting field work a. Use of hand tools such as hand 

axe, pruning saw, and shovel

 When traversing slopes, carry hand tools on the downhill side. Hand axes should always be carried sheathed with leather flap snapped shut. Do not carry long handled tools over shoulder, or hatchets unsheathed in 

belt-loop.

b. Dehydration  Consume (in addition to regular meals) fruit and liquids that replace the loss 

of carbohydrates and maintain blood sugar levels at normal limits. Drink water regularly. Make sure you carry enough water. Take frequent breaks. Avoid open sunny areas if weather is extreme. Seek shaded areas.

c. Hypothermia  Prevent hypothermia by planning ahead and using your gear to stay warm and 

dry.

 On cool days be aware of overheating and then rapidly cooling down. Dress appropriately and in layers to account for temperature extremes. Stay hydrated and eat high-energy foods. See “Winter Travel” JHA for more detailed information.

d. Poisonous plants present 

(e.g., poison ivy)

 Make sure that crew members can identify poisonous plants in their work area. Wear gloves and long-sleeve shirts. Wash affected area with soap and water as soon as possible or use ivy-off 

products when water is not available. 

 Wash potentially contaminated clothing as soon as possible after returning from 

the field.

e. Falling branch or tree  Wear hardhat.
GDE: Level I 124 Inventory Field Guide

 Dress appropriately and in layers to account for temperature extremes. Stay hydrated and eat high-energy foods. See “Winter Travel” JHA for more detailed information.

d. Poisonous plants present 

(e.g., poison ivy)

 Make sure that crew members can identify poisonous plants in their work area. Wear gloves and long-sleeve shirts. Wash affected area with soap and water as soon as possible or use ivy-off 

products when water is not available. 

 Wash potentially contaminated clothing as soon as possible after returning from 

the field.

e. Falling branch or tree  Wear hardhat.

 Use extra caution during high-wind events.

f. Insect bites  Use appropriate insect repellent.

 Secure bottom of pant legs to reduce the ability for ticks to access your lower leg. Thoroughly examine your body for ticks when returning from field. If a tick is 

found, fully remove it using tweezers or fingernails. Do not use petroleum or try to burn the tick off. Save the tick for confirmation of Lyme disease. Monitor the area on body where tick was attached, watching for irritation or rash. If rash or flu-like symptoms develop, visit a doctor and inform him or her of tick bite.

g. Sun exposure  Use sun screen on exposed skin to prevent sunburn and skin damage. Know the 

signs and symptoms of heat exhaustion and heat stroke. Wear sunglasses and use sunscreen. Drink enough water to keep hydrated.

h. Altitude problems  Headache, shortness of breath, trouble sleeping, and dizziness. Drink more water 

than usual and reduce salty food intake.

i. Waders and wading boots  Only wear waders that are the correct size for your feet and body. Nylon breathable waders are adaptable to a wide variety of temperatures and conditions, and 

they are essential. Supportive wading boots are essential and give the traction and support necessary for stream work. Wading boots will be worn any time biological technicians are in streams.
GDE: Level I 125 Inventory Field Guide

10. Encountering hazardous situations a. Threatening individuals  Use positive communication and conflict management behaviors in early stages 

of conflict situations to prevent or diffuse low-level hostile behavior.

 If threatened in any way by members of the public, withdraw and report the 

incident to your supervisor.

 Always attain the landowner’s permission before entering private property.

b. Illegal activities  Leave the area immediately if you feel unsafe because of illegal activity.

 If an area appears to be used for illegal activities, such as a marijuana garden or 

methamphetamine lab, leave the area immediately by the same route taken to enter the area.

 Report suspicious activity to your supervisor. Always attain the landowner’s permission before entering private property.

c. Wild animals such as black bears, 

wolves, bison, elk, deer, moose, bobcats, poisionus snakes, feral swine, etc.

 Make noise by talking loudly or using a noisemaker such as a bell or whistle to 

reduce the chances of surprising an animal.

 Immediately leave the area by backtracking if you encounter any animal that 

appears injured or sick, or may be feeding, mating, or have young nearby. Report the incident to the proper authorities if the animal acted aggressively without provocation.

 Learn the appropriate actions to take if you are approached by any of the animals 

that may inhabit your work location. These actions differ depending on the type of animal.

 Learn to identify dangerous animals in your working area and never harrass or 

provoke wildlife.

 Avoid walking blindly through thick vegetation by using a stick or pole in front of 

you to part the brush or grass.

 In areas with poisonous snakes, tap the ground in front of you with a pole or stick 

as you walk to help you see snakes before you get too close.

 Wear snake-proof chaps when appropriate.

d. Domestic animals such as dogs, 

cattle, swine, etc.

 If an animal is acting aggressive or skittish, stay in the vehicle and wait for the 

landowner to come outside. Honk your horn if necessary to alert the landowner that you are there.

 Ask landowners over the phone about the location of potentially dangerous 

domestic animals and request that they be moved or tied up while you are visiting the location

or plan to 

isit 

hen the animal 

ill not be there
GDE: Level I 126 Inventory Field Guide

 In areas with poisonous snakes, tap the ground in front of you with a pole or stick 

as you walk to help you see snakes before you get too close.

 Wear snake-proof chaps when appropriate.

d. Domestic animals such as dogs, 

cattle, swine, etc.

 If an animal is acting aggressive or skittish, stay in the vehicle and wait for the 

landowner to come outside. Honk your horn if necessary to alert the landowner that you are there.

 Ask landowners over the phone about the location of potentially dangerous 

domestic animals and request that they be moved or tied up while you are visiting the location, or plan to visit when the animal will not be there.

 Make sure that landowners know when you are working in the area if you believe 

they may have an aggressive or protective animal.

e. Hazardous materials  Whenever encountering containers of unidentified liquids or powders, stay clear 

of the site. Do not walk into or touch spilled material. Avoid inhalation of fumes, smoke, and vapors, even if no hazardous materials are known to be involved. Do not assume that gases or vapors are harmless because they do not smell. Odorless gases or vapors may be harmful. Drums may contain toxic materials, leak, and contaminate their immediate surroundings.

 If it is possible to read any labels without risk of contaminating yourself, do so 

and write the information down. Note location, time of encounter, and any other pertinent information. Then report it to supervisor.

 Likely areas where hazardous materials are encountered include abandoned 

mine sites, old construction sites, and old homestead sites.

f. Encountering hunters  Plan field work appropriately given area hunting use and seasons.

 Wear blaze orange vest or clothing. Ensure landowners know where you will be and when you will be there. Inform hunters of where you will be and how long you expect to be there, and 

find out where they plan to hunt.

 If someone is hunting near your plot and is there first, return at a later date.

10. LINE OFFICER SIGNATURE 11. TITLE 12. DATE
GDE: Level I 127 Inventory Field Guide

JHA Instructions (References-FSH 6709.11 and .12) 

The JHA shall identify the location of the work project or activity, the name 

of employee(s) involved in the process, the date(s) of acknowledgment, 

and the name of the appropriate line officer approving the JHA. The line 

officer acknowledges that employees have read and understand the 

contents, have received the required training, and are qualified to perform 

the work project or activity. 

Blocks 1, 2, 3, 4, 5, and 6: Self-explanatory.

Block 7: Identify all tasks and procedures associated with the work 

project or activity that have potential to cause injury or illness 

to personnel and damage to property or material. Include 

emergency evacuation procedures (EEP).

Block 8: Identify all known or suspect hazards associated with each 

respective task/procedure listed in block 7. For example—

a. Research past accidents/incidents.

b. Research the Health and Safety Code, FSH 6709.11, or other 

appropriate literature.

c. Discuss the work project/activity with participants.

d. Observe the work project/activity.

e. A combination of the above.

Block 9: Identify appropriate actions to reduce or eliminate the hazards 

identified in block 8. Abatement measures listed below are in 

the order of the preferred abatement method:

a. Engineering controls (the most desirable method of abatement). For example, ergonomically designed tools, equipment, and furniture.

b. Substitution. For example, switching to high flashpoint, 

nontoxic solvents. 

c. Administrative controls. For example, limiting exposure by 

reducing the work schedule and establishing appropriate 

procedures and practices.

d. Personal protective equipment (PPE) (least desirable method 

of abatement). For example, using hearing protection when 

working with or close to portable machines (chain saws, rock 

drills, and portable water pumps).

e. A combination of the above.
GDE: Level I 128 Inventory Field Guide

Block 10: The JHA must be reviewed and approved by a line officer. Attach a copy of the JHA as justification for purchase orders when 

procuring PPE.

Blocks 11 and 12: Self-explanatory.

EEP Instructions (Reference FSH 6709.11)

Work supervisors and crew members are responsible for developing and 

discussing field EEP and alternatives in the event a person becomes seriously ill or injured at the worksite.

Be prepared to provide the following information:

a. Nature of the accident or injury (avoid using victim’s name).

b. Type of assistance needed, if any (ground, air, or water evacuation).

c. Location of accident or injury, best access route into the worksite (road 

name or number), identifiable ground and air landmarks. 

d. Radio frequencies.

e. Contact person. 

f. Local hazards to ground or aviation vehicles.

g. Weather conditions (wind speed and direction, visibility, and temperature).

h. Topography. 

i. Number of individuals to be transported.

j. Estimated weight of individuals for air or water evacuation. 

The items listed above serve only as guidelines for the development of EEPs. 

JHA and Emergency Evacuation Procedures Acknowledgment

We, the undersigned work leader and crew members, acknowledge 

participation in the development of this JHA (as applicable) and accompanying EEPs. We have thoroughly discussed and understand the provisions 

of each of these documents:

SIGNATURE DATE SIGNATURE DATE
GDE: Level I 129 Inventory Field Guide

Appendix 3. Field Forms

List of Acronyms

GDE = Groundwater-dependent ecosystems

FS = Forest Service

ID = Identification

LOV in FG = List of values in field guide

NRM-Infra = Natural Resource Manager-Infrastructure

HUC = hydrologic unit code

USGS = U.S. Geological Survey

LRR = Land Resource Region

MLRA = Major Land Resource Area

UTM = Universal Transverse Mercator

UOM = Unit of measure

F = Fahrenheit

C = Celsius

GPS = Global Positioning System

NAD = North American Datum

WGS = World Geodetic System

HCL = hydrochloric acid

mv = millivolts

mg/L = milligrams per liter

(mS/cm) = microsiemens/centimeter

ORP = Oxidation-reduction potential

DO = dissolved oxygen

ATV = All-terrain vehicle

SOI = Species of interest

TES = Threatened and endangered species

SOC = Species of concern
GDE: Level I 130 Inventory Field Guide

Forest Service GDE Level I Inventory 

Site Name ___________________ 

Recorder ____________________ 

Page _____ of _____ 

Pre-Field Survey (this site information is compiled prior to field visit and updated in the field as necessary) 

Site ID ________________________________________ Project Name __________________________________ 

Purpose(s) (LOV in FG) ___________________________________ State(s) ______________________________ 

County(s) __________________ Land Status(’s) _____________________ FS Region(s) _____________________ 

FS Forest/Grassland/Prairie(s) _________________________ FS District(s) _____________________________ 

Grazing Allotment Number _______________________ Grazing Allotment Name ________________________ 

NRM-Infra Reference Number _________________________________________________________________ 

Water Right Number _____________________________ Water Right Status ____________________________ 

HUC(s)(12-digits) ______________________________ Ecological Unit ________________________________ 

Ecological System (LOV in FG appendix) _________________________________________________________ 

Local Feature-Type Name _____________________________________________________________________ 

...................................................................................................................................... 

USGS Quad _______________________________________ Magnetic Declination _______________________ 

Geologic Map Name _____________________________ Geologic Map Unit ____________________________ 

Land Resource Region (LRR) and MLRA __________________________________________________________ 

Soil Map Name _________________________________ Soil Map Unit ________________________________ 

...................................................................................................................................... 

Information to help arrive at site, which will also be recorded in the field (on Field Survey Activities form) 

UTM coordinates: Zone __________________ Easting __________________ Northing __________________ 

Latitude Degrees ____________________ Minutes ____________________ Seconds ____________________ 

Longitude Degrees ____________________ Minutes ____________________ Seconds ___________________ 

Latitude Decimal Degree _______________________ Longitude Decimal Degree ________________________ 

Horizontal Datum ____________________________ Elevation __________________ UOM ______________ 

...................................................................................................................................... 

Location—Driving route _____________________________________________________________________ 

_________________________________________________________________________________________ 

_________________________________________________________________________________________ 

Location—Hiking route ______________________________________________________________________ 

_________________________________________________________________________________________ 

_________________________________________________________________________________________ 

Location—Other ___________________________________________________________________________ 

...................................................................................................................................... 

Preliminary GDE Type(s) ____________________________________________________________________ 

Determination Source _______________________________________________________________________ 

Archeological, Paleontological, Cultural, or Historic Sites or Use _______________________________________ 

_________________________________________________________________________________________ 

Available Data (other sources) _________________________________________________________________ 

Site and Geographic (p. 23) Mapping (p. 29) Route (p. 31) Other (p. 32) 

(Word and PDF files are available from the Forest Service Washington 

Office Groundwater Program.)
GDE: Level I 131 Inventory Field Guide

Forest Service GDE Level I Inventory 

Site Name ___________________ 

Recorder ____________________ 

Page _____ of _____ 

Weather (select 1) 

� Recent rain 

� Rain during survey 

� Snowfall, hail, sleet during survey 

� Snow on ground 

� No current/recent precipitation 

Relative Area of GDE 

____ % Spring emergence 

____ % Channel 

____ % Wetland/Riparian 

____ % Open water 

____ % Other or unknown 

Horizontal Datum (select 1) 

� NAD-27 

� NAD-83 (recommended) 

� WGS-72 

� WGS-84 

Geologic Structure Type 

(select 1) 

� Bedding 

� Contact 

� Fault 

� Fracture 

� Lineation 

� Conduit 

� Unknown 

Determined by 

� Observation 

� Geologic Map 

� Other: 

Field Survey Activities 

Site ID ___________________________________________________ 

Survey Date _________________ Time Start ________ End _________ 

Examiners ______________________________________________ 

Air Temp (UOM: F or C) _________________________________ 

Area of GDE (and UOM) _________________________________ 

Area Determined by (LOV in FG) ___________________________ 

Reference Point (briefly describe) ____________________________ 

_______________________________________________________ 

 Slope (%) _______________________ 

Aspect (degrees) __________________ 

...................................................................................................................................... 

GPS Make & Model ___________________ GPS Accuracy ______________ 

UTM Zone ______ Easting ________________ Northing _______________ 

Latitude Degrees ___________ Minutes ____________ Seconds __________ 

Longitude Degrees ___________ Minutes ___________ Seconds __________ 

Latitude Decimal Degree ________________________ Longitude Decimal Degree ________________________ 

Elevation _____________ UOM _________ Determined by (circle 1) GPS; Topo Map; Other _____________ 

..................................................................................................................................... 

Evidence of Groundwater (LOV in FG) __________________________________________________________ 

GDE Type, primary _________________________________________________ 

GDE Type, secondary(s) _____________________________________________ 

Surficial Material, primary (LOV in FG) _________________________________ 

Surficial Material, secondary(s) (LOV in FG) ______________________________ 

Lithology, primary (LOV in FG) _______________________________________ 

Is primary lithology also groundwater source aquifer (circle 1): Yes No Unknown 

Level of certainty (circle 1): Known Assumed Unknown 

Lithology, secondary (LOV in FG appendix) ______________________________ 

Landform, primary (LOV in FG appendix) _______________________________ 

Landform, secondary (LOV in FG appendix) _____________________________ 

Geology Notes _____________________________________________________________________________ 

Survey Information (p. 35) Geologic Setting (p. 43) Georeferencing (p. 40) 
GDE: Level I 132 Inventory Field Guide

Forest Service GDE Level I Inventory 

Site Name ___________________ 

Recorder ____________________ 

Page _____ of _____ 

Photos (p. 48) 

One photo can represent multiple things, as long as they are all noted in “Location” below.

Camera

Photo 

Number Location (from list above or other)

Notes (light, distance to camera, 

objects, etc.)

� Spring source (if applicable) 

For springs with outflow channels: 

o Looking downstream, standing at/near source 

o Looking upstream/uphill, standing at/near source 

� Overview, from a hill (if possible) 

Locations to take photos: 

� Reference point 

� Center of site 

� Water measurement locations 

� Soil hole locations 
GDE: Level I 133 Inventory Field Guide

Forest Service GDE Level I Inventory 

Site Name ___________________ 

Recorder ____________________ 

Page _____ of _____ 

Site Sketch Map (p. 50)

To include on map: 

� Reference point 

� Approximate locations/dimensions of major 

geomorphic surfaces 

� Springs: 

o Spring source 

o Channel locations 

o Structures including spring boxes, troughs, 

and pipelines 

o Pool location, if limnocrene 

� Areas of standing water (indicate deepest part) 

� Location of measurements: 

o Soil hole(s) 

o Water table measurement location(s) 

o Wells/piezometers 

o Water quality sample(s) 

� Structures or other human-made features 

� Indication of North (true recommended, or magnetic) 

� Indication of scale 

� Boundaries of GDE 
GDE: Level I 134 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Surrounding Vegetation (select 1)

� Tree dominated

� Shrub dominated

� Herbaceous dominated

� No dominant vegetation type

� Nonvegetated

Bryophyte Abundance

� None

� Minor component

� Common component

� Very abundant

Vegetation (p. 52) 

Lifeform

Lifeform 

Rank (1 is 

greatest, 5 is 

lowest; ok to 

list two of 

same rank) Dominant Species

Specimen 

Collected

Tree

Shrub & Sub-shrub

Graminoid

Forb/herb

Bryophyte

Aquatic plants 

(submerged or floating)

Unknown

Species of Interest (plants) (p. 53) 

In particular look for threatened or endangered species and invasive species.

Species Comment
GDE: Level I 135 Inventory Field Guide Forest Service GDE Level I Inventory Site Name ___________________ Recorder ____________________ Page _____ of _____ Soil (p. 55) Method of soil extraction _________________________________ Location Depth of Peat, Mucky Peat, and Muck (such as 8 cm to 17 cm) (and UOM) Depth to Mineral Layer (and UOM) Texture of Mineral Layer Color of Mineral Soil Redoximorphic Features and Depths (and UOM) Hydrogen Sulfide Odor Reaction to Dilute HCL Depth of Hole (and UOM) Comments Fen Characteristics (p. 60) Yes, fen characteristics observed or No, fen characteristics not observed Comments ______________________________ Yes, histosol or histic epipedon observed or No, histosol or histic epipedon not observed Comments ______________________________
GDE: Level I 136 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Water Table Type (select 1)

� Apparent

� Artesian

� Ponding

� Unknown

� Other:

Flow Patterns for Site 

 Inflow (select 1; LOV in FG):

________________________

Outflow (select 1; LOV in FG):

________________________

Surface Water (multiple ok)

� No standing or flowing water 

visible

� Patches of standing water

� Extensive standing water

� Flowing water in channels

Hydrology

Location

Source of Water Table 

Measurement

Hole Depth (and 

UOM)

Water Table Depth

(and UOM)

Dry

(yes or no)

 ..............................................................................................

.......................................

 

Site Flow Estimate: ______________________________ Comment: ____________________________________

Reason if no flow measurement (circle 1): Diffuse flow; No outflow; Not a spring; Spring is dry; Other _________ 

Hydroperiod (LOV in FG) ___________________ Length of Outflow Stream (LOV in FG) __________________ 

What Happens to Stream Outflow (LOV in FG) _____________________________________________________ 

.........................................................................................................................................

Location

Time of 

Day

Temperature

(UOM: F or 

C) Water pH

Specific 

Conductance 

(μS/cm) ORP (mV) DO (mg/L)

Location of Flow 

Measurement Flow Method 

Flow 

Instrument Flow (and UOM)

Percent 

Captured Comments

 

 

 

 

Flow and Spring Channel (p. 67) Water Quality (p. 71) Water Table (p. 64)
GDE: Level I 137 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Fauna (p. 76) 

Record the presence of animals observed at the site including aquatic vertebrates, terrestrial herpetofauna, terrestrial 

vertebrates, and aquatic macroinvertebrates. 

Species or Taxonomic Group Comment
GDE: Level I 138 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Hydrologic Alteration (multiple ok)

� Water diversion (permanently diverted) 

� Water diversion (water eventually returns to site)

� Upgradient extraction of surface water or 

groundwater (prespring emergence)

� Downgradient capture of surface water or 

groundwater (post-spring emergence)

� Extraction of water within a wetland

� Extraction of water at spring source

� Regulated water flow by impoundment/dam

� Pollution

� Flooding

� Wells

� None observed

� Other: _______________________________

Diverted Volume __________ UOM _______

Percent Diverted __________

Soil Alteration (multiple ok)

� Channel erosion

� Compaction

� Debris flow

� Deposition

� Displacement of soil 

� Erosion (general)

� Evaporate deposition

� Excavation 

� Ground disturbance (general)

� Gully erosion

� Mass wasting

� Mining

� Pedestals or hummocks (by people or animals)

� Pedestals (small-scale, rain-splash induced)

� Pipes

� Rill erosion

� Ruts (from vehicle tread)

� Sheet erosion

� Slump

� Splash erosion/ soil crust

� Wind erosion

� Soil mixing/churning

� Soil removal (peat mining)

� Trails (by people or animals)

� None observed

� Other: _______________________________

Structures (multiple ok)

� Buried utility corridors

� Enclosure (such as spring house, spring box or 

concrete enclosure)

� Erosion control structure

� Exclosure fence

� Oil and gas well

� Pipeline

� Point source pollution

� Power lines

� Road (includes construction and maintenance)

� None observed 

� Other: _______________________________

Recreational Effects (multiple ok)

� Camp sites

� Tracks or trails by vehicles (ATV, 4-wheel drive, 

etc.)

� None observed 

� Other: _______________________________

Animal Effects (multiple ok)

� Beaver activity

� Feral animals

� Grazing or browsing (by ungulates)

� Wild animals

� Livestock

� Trails by animals and people

� Trampling (by ungulates, native or nonnative)

� None observed

� Other: _______________________________

Miscellaneous (multiple ok)

� Fire

� Tree cutting (timber harvest or other)

� Refuse disposal

� None observed 

� Other: _______________________________

Disturbance (p. 77) 

Archeological, Paleontological, Cultural, Historic Sites/Use 

____________________________________________

____________________________________________

____________________________________________
GDE: Level I 139 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Management Indicator Tool (p. 82) 

Management Indicators

True 

(Yes)

False 

(No)

Does 

Not 

Apply

Unable 

To 

Assess Comment

Hydrology

1. Aquifer Functionality: No evidence suggests 

that the aquifer supplying groundwater to 

the site is being affected by groundwater 

withdrawal or loss of recharge.

 

2. Watershed Functionality: Within the 

watershed, no evidence suggests 

upstream/upgradient hydrologic alteration 

that could adversely affect the GDE site.

 

3. Water Quality: Changes in water quality 

(surface or subsurface) are not affecting the 

groundwater dependent ecosystem site.

 

Geomorphology and Soils 

4. Landform Stability: No evidence indicates 

human-caused mass movement or other 

surface disturbance affecting the GDE site 

stability.

 

5. Runout Channel: The channel, if present, is 

functioning naturally and is not entrenched, 

eroded, or otherwise substantially altered.

 

6. Soil Integrity: Soils are intact and functional. 

For example, saturation is sufficient to 

maintain hydric soils, if present; there is not 

excessive erosion or deposition.

 

Biology

7. Vegetation Composition: The site includes 

anticipated cover of plant species associated 

with the site environment, and no evidence 

suggests that upland species are replacing 

hydric species.

 

8. Vegetation Condition: Vegetation exhibits 

seasonally appropriate health and vigor.

 

9. TES, SOI/SOC, Focal Floral Species:

Anticipated floral species are present (will 

vary by ecological region and will require 

some baseline information).

10. Faunal Species: Anticipated aquatic and 

terrestrial faunal species associated with the 

site environment are present. 

11. TES, SOI/SOC, Focal Faunal Species:

Anticipated faunal species are present (will 

vary by ecological region and will require 

some baseline information).

 

12. Invasive Species: Invasive floral and faunal 

species are not established at the site. 

 
GDE: Level I 140 Inventory Field Guide

Forest Service GDE Level I Inventory

Site Name ___________________

Recorder ____________________

Page _____ of _____

Management Indicators

True 

(Yes)

False 

(No)

Does 

Not 

Apply

Unable 

To 

Assess Comment

Disturbances

13. Flow Regulation: Flow regulation is not 

adversely affecting the site.

 

14. Construction and Road Effects: 

Construction, reconstruction, or 

maintenance of physical improvements, 

including roads, is not adversely affecting 

the site.

 

15. Fencing Effects: Protection fencing and 

exclosures are appropriate and functional.

 

16. Herbivore Effects: Herbivory is not 

adversely affecting the site.

 

17. Recreational Effects: Recreational uses, 

including trails, are not adversely affecting 

the site.

 

18. Other Disturbance Effects: Wildland fire, 

insect, disease, wind throw, avalanches, or 

other disturbances are not adversely 

affecting the site.

 

Administrative Context

19. Cultural Values: Archaeological, historical, 

or tribal values will not affect inventory, 

restoration, use, or management of this site. 

 

20. Land Ownership: The entire site and 

immediate area is under the jurisdiction and 

management of the Forest Service.

 

21. Other Landowner Actions: Activities or 

management on lands outside Forest 

Service jurisdiction are not adversely 

affecting the site.

 

22. Land Management Plan: The land and 

resource management Plan provides for 

effective site protection.

 

23. Environmental Compliance: Authorized 

and administrative uses are in compliance 

and are not adversely affecting the site.

 

24. Water Uses: There are no substantial water 

uses in the watershed, or in the aquifer 

supplying groundwater to the site, that 

could directly or cumulatively adversely 

affect the GDE.

 

25. Water Rights: Water rights have been filed

for the site under State law or water uses 

exempted under State law are documented. 

Forest Service Federal reserved rights are 

documented as appropriate. Third-party 

water use is in accordance with all elements 

of the water right or conditions of the 

exemption, and with the Forest Service 

authorization that allows the use.

 
GDE: Level I 141 Inventory Field Guide

Appendix 4. Site Protection Guidelines

This section is provided to help minimize the disturbance from 

the data-collection process by researchers, managers, and data 

collectors. The potential disturbances that can result from the 

data-collection process include the following:

• Trailing, erosion, geomorphic alteration (from foot traffic, etc.). 

• Destruction or alteration of vegetation.

• Damage to peat.

• Soil compaction and altered soil-water storage.

• Hydrologic alteration from water measurement activities 

(wells, etc.).

• Spread of invasive species (by data collectors or managers).

To prevent damage to sites, please follow these guidelines:

Minimize

• Number of people who visit the site.

• Duration of visits.

• Frequency of visits.

• Walking on site.

• Digging holes.

• Destructive sampling.

• Collecting plant or animal specimens.

• Bringing heavy equipment to site.

• Placing heavy gear on wet areas.

• Using unsterilized equipment (nets, etc.).
GDE: Level I 142 Inventory Field Guide

Pre-Site Visit

• Decontaminate shoes/boots and equipment that will be 

brought to site to prevent importing invasive species or 

disease.

• Plan the visit to use the time wisely and to minimize the 

amount of walking on the site.

During the Site Visit

• Set equipment, especially heavy items, outside wet areas (in 

uplands).

• Consider taking pictures, or recording observations, instead of 

collecting specimens.

• Sit, eat lunch, etc., outside the wet area.

• Walk around the groundwater-dependent ecosystem site, 

rather than through it, as much as possible.

• Do multiple things on each trip through the site to minimize 

trampling.

• Place temporary wood planks on walking paths to avoid 

creating ruts that redirect and channelize water.

Post-Site Visit—Decontamination

At the end of each site visit, to prevent the spread of invasive 

species, decontaminate shoes/boots, waders, and all equipment 

used at the site. If you do not know if the decontamination was 

done after the last visit, then follow these procedures before a 

field visit. 

1. Use a scrub brush (tooth brush for small equipment) and water 

to remove all visible mud, vegetation, and other material. 

2. Dry the boots and equipment.

3. Soak boots in a Clorox solution or some other solution (such 

as Sparquat or 409) depending on the regional invasive species of concern. 

4. Rinse with water (distilled for equipment).

5. Allow boots and equipment to air dry (in the sun works best).
GDE: Level I 143 Inventory Field Guide

Appendix 5. Groundwater-Dependent 

Ecological Systems Described 

in NatureServe

The following table lists Ecological Systems from NatureServe 

(2011) that exhibit groundwater dependency and the States 

where they are known to occur or where they potentially could 

occur (indicated by "?").

Ecological system States

Fen systems

Boreal-Laurentian-Acadian Acidic 

Basin Fen

MA, ME, MI, MN, NH, NY, VT, WI

Ozark-Ouachita Fen AR, MO

North-Central Interior ShrubGraminoid Alkaline FenIA, IL, IN, MI, MN, ND, OH, PA, 

SD, WI

Interior Low Plateau Seepage Fen KY, OH?, TN

Southern and Central Appalachian 

Bog and Fen

GA, KY, NC, SC, TN, VA

Mediterranean California Serpentine 

Fen

CA, OR

North-Central Appalachian Seepage 

Fen

CT, MA, MD, NJ, NY, PA, VA, VT, 

WV

North Pacific Bog and Fen AK, OR, WA

Mediterranean California SubalpineMontane FenCA, NV, OR

Rocky Mountain Subalpine-Montane 

Fen

AZ, CO, ID, MT, NV, OR, UT, WA, 

WY

Laurentian-Acadian Alkaline Fen MA, ME, MI, MN, NH, NY, PA, 

VT, WI

West Gulf Coastal Plain Herbaceous 

Seepage Bog

AR?, LA, TX

Southern Coastal Plain Herbaceous 

Seep and Bog

AL, FL, LA, MS

East Gulf Coastal Plain Interior 

Shrub Bog

AL, GA, MS

North-Central Interior and 

Appalachian Acidic Peatland

CT, IL, IN, MA, ME, MI, MN, NH, 

NJ, NY, OH, PA, RI, VT, WI

Southern Ridge and Valley Seepage 

Fen

AL, GA
GDE: Level I 144 Inventory Field Guide

Ecological system States

Western North American Boreal 

Herbaceous Fen

AK

Alaskan Pacific Maritime Fen and 

Wet Meadow

AK

Western North American Boreal 

Black Spruce-Tamarack Fen

AK

Boreal-Laurentian Conifer Acidic 

Swamp and Treed Poor Fen

ME, MI, MN, NH, NY, VT, WI

Swamp systems

Atlantic Coastal Plain Streamhead 

Seepage Swamp, Pocosin, and 

Baygall

FL, GA, NC, SC, VA

East Gulf Coastal Plain Northern 

Seepage Swamp

AL, IL, KY, MS, TN

Laurentian-Acadian Alkaline ConiferHardwood SwampCT, ME, MI, MN, NY, VT, WI

North Pacific Hardwood-Conifer 

Swamp

AK, OR, WA

North Pacific Shrub Swamp AK, OR, WA

North-Central Appalachian Acidic 

Swamp

CT, MA, MD, NH, NJ, NY, OH, PA, 

RI, VA, VT

North-Central Interior Wet MeadowShrub Swamp

IA, IL, IN, MI, MN, MO, ND, OH, 

SD, WI

North-Central Interior and 

Appalachian Rich Swamp

CT, DE, IL, IN, MA, MD, MI, MN, 

NJ, NY, OH, PA, RI, VT, WI

Northern Appalachian-Acadian 

Conifer-Hardwood Acidic Swamp

CT, MA, ME, NH, NY, PA, VT

Northern Rocky Mountain Conifer 

Swamp

ID, MT, OR, WA, WY

Southern Coastal Plain Nonriverine 

Basin Swamp

AL, FL, GA, LA?, MS, SC

Southern Coastal Plain Seepage 

Swamp and Baygall

AL, FL, GA, LA, MS

West Gulf Coastal Plain Seepage 

Swamp and Baygall

AR, LA, OK, TX

Acadian-Appalachian Conifer 

Seepage Forest

ME, NH, NY, VT

Cumberland Seepage Forest AL, KY, TN, WV
GDE: Level I 145 Inventory Field Guide

Ecological system States

Central Atlantic Coastal Plain 

Nonriverine Swamp and Wet 

Hardwood Forest

GA, NC, SC, VA

Mediterranean California Serpentine 

Foothill and Lower Montane 

Riparian Woodland and Seep

CA, OR

Interior Highlands Forested Acidic 

Seep

AR, MO?, OK?

Central Florida Wet Prairie and 

Herbaceous Seep

FL

Atlantic Coastal Plain Sandhill Seep GA, NC, SC

Piedmont Seepage Wetland AL, GA, NC, SC, VA?

High Allegheny Wetland MD, PA, WV

Southern Appalachian Seepage 

Wetland

GA, KY, NC, SC, TN, VA

Marsh systems

North American Arid West Emergent 

Marsh

AZ, CA, CO, ID, MT, NM, NV, OR, 

TX, UT, WA, WY

Eastern Great Plains Wet Meadow, 

Prairie, and Marsh

IA, IL, KS, MN, MO, ND, NE, OK, 

SD, TX?

Northern Great Lakes Coastal Marsh MI, WI

Temperate Pacific Freshwater 

Emergent Marsh

AK, CA, OR, WA

Western Great Plains Open 

Freshwater Depression Wetland

KS, MT, ND, NE, OK, SD, TX, WY

Other systems

North Pacific Coastal Interdunal 

Wetland

AK, OR, WA

Mediterranean California Coastal 

Interdunal Wetland

CA, OR

Rocky Mountain Alpine-Montane 

Wet Meadow

AZ, CO, ID, MT, NM, NV, OR, SD, 

UT, WA, WY

Temperate Pacific SubalpineMontane Wet MeadowCA, NV, OR, WA

Colorado Plateau Hanging Garden AZ, CO, NV?, UT

Southern Coastal Plain Spring-Run 

Stream Aquatic Vegetation

FL, GA
GDE: Level I 146 Inventory Field Guide
GDE: Level I 147 Inventory Field Guide

Appendix 6. Equipment List

• Field forms (appendix 3).

• Clipboard.

• Electronic data recorder (personal digital assistant, etc.), if 

available.

• Pencils. 

• Notebook or paper (waterproof).

• Graph paper (for sketch map).

• Calculator.

• Topographic map of site. 

• Aerial photograph of site.

• GPS (global positioning system) unit.

• Compass. 

• Clinometer.

• Watch, stopwatch, or other timer.

• Photography.

§ Camera (digital is recommended, with extra memory and 

batteries). 

§ Photo scale.

§ Board or card for identifying photo location.

• Water quality. 

§ Temperature probe. 

§ pH probe. 

§ Oxidation-reduction potential (ORP) probe or dissolved 

oxygen (DO) probe. 

§ Water conductivity probe. 

§ Spare probes (temperature, pH, DO, ORP, and conductivity) and cable.
GDE: Level I 148 Inventory Field Guide

• Flow measurement (one or more of following).

§ Weir plate (and bubble level).

§ Current meter.

§ Flume (and bubble level).

§ Volumetric container(s).

§ Float (flagging, float device).

§ Current meter.

§ Wading rod. 

§ Short pipe (for concentrating and measuring low flows).

• Soil/subsurface.

§ Shovel, spade, auger, and/or push probe with clean-out 

tool. 

§ Soil knife/trowel.

§ Hand lens (10x or combination lenses).

§ pH kit.

§ Soil description sheets.

§ Water/spray bottle.

§ Soil color book (Munsell color chart with gley color plates).

§ Dilute hydrochloric acid (HCl) with dropper.

§ Local soil survey.

§ Bailing can—where groundwater can fill soil pits.

• Vegetation.

§ Plant press (with cardboard, newspaper, and felt).

§ Plant lists and identification resources for region.

§ Sample bags.

§ Digging tool (could be same as for soil sampling).
GDE: Level I 149 Inventory Field Guide

• Fauna.

§ Animal lists and identification resources for region.

§ Binoculars (for observing birds and other wildlife, or plants 

on cliff wall).

§ Aquatic macroinvertebrate and vertebrate sampling tools, 

as desired, such as hand net.

• Decontamination materials/supplies.
GDE: Level I 150 Inventory Field Guide
GDE: Level I 151 Inventory Field Guide

Appendix 7. Secondary Lithology

Secondary 

code Primary lithology Secondary lithology

ANBA Igneous extrusive Analcite basalt

ANDE Igneous extrusive Andesite

ANPO Igneous extrusive Andesite porphyry

BASA Igneous extrusive Basalt

BAPO Igneous extrusive Basalt porphyry

BAAN Igneous extrusive Basaltic andesite

BASN Igneous extrusive Basanite

DACI Igneous extrusive Dacite

DAPO Igneous extrusive Dacite porphyry

FELS Igneous extrusive Felsite

LATI Igneous extrusive Latite

LAPO Igneous extrusive Latite porphyry

LEBA Igneous extrusive Leucite dasanite

LEPH Igneous extrusive Leucite phonolite

LETE Igneous extrusive Leucite tephrite

LIMB Igneous extrusive Limburgite

LIPO Igneous extrusive Limburgite porphyry

MELI Igneous extrusive Melilitite

NELA Igneous extrusive Nepheline latite

NELAPO Igneous extrusive Nepheline latite porphyry

NEPH Igneous extrusive Nephelinite

OBSI Igneous extrusive Obsidian

OCEA Igneous extrusive Oceanite

OLBA Igneous extrusive Olivine basalt

OLNE Igneous extrusive Olivine nephelinite

PERL Igneous extrusive Perlite

PHON Igneous extrusive Phonolite

PHPO Igneous extrusive Phonolite porphyry

PITC Igneous extrusive Pitchstone

PUMI Igneous extrusive Pumice

QUBA Igneous extrusive Quartz basalt

QULA Igneous extrusive Quartz latite

QULAPO Igneous extrusive Quartz latite porphyry

RHYO Igneous extrusive Rhyolite

The secondary lithology list in the following table is based on 

USDA Forest Service (2009).
GDE: Level I 152 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

RHPO Igneous extrusive Rhyolite porphyry

SCOR Igneous extrusive Scoria

TEPR Igneous extrusive Tephrite

TEPO Igneous extrusive Tephrite porphyry

TING Igneous extrusive Tinguaite

TRAC Igneous extrusive Trachyte

TRPO Igneous extrusive Trachyte porphyry

TRAP Igneous extrusive Trap

VITR Igneous extrusive Vitrophyre

WYOM Igneous extrusive Wyomingite

ALSK Igneous intrusive Alaskite

ALGR Igneous intrusive Alkali granite

ALSY Igneous intrusive Alkali syenite

ANOR Igneous intrusive Anorthosite

APLI Igneous intrusive Aplite

CHAR Igneous intrusive Charnockite

DIAB Igneous intrusive Diabase

DIOR Igneous intrusive Diorite

DIPO Igneous intrusive Diorite porphyry

DITR Igneous intrusive Ditroite

DUNI Igneous intrusive Dunite

FERG Igneous intrusive Fergusite

FOYA Igneous intrusive Foyaite

GABB Igneous intrusive Gabbro

GAPO Igneous intrusive Gabbro porphyry

GADI Igneous intrusive Gabbro/diorite

GRAN Igneous intrusive Granite

GRPO Igneous intrusive Granite porphyry

GRAO Igneous intrusive Granodiorite

GDPO Igneous intrusive Granodiorite porphyry

GRGR Igneous intrusive Graphic granite

HARZ Igneous intrusive Harzburgite

LAMP Igneous intrusive Lamprophyre

LARV Igneous intrusive Larvikite

LESY Igneous intrusive Leucite syenite

LUXU Igneous intrusive Luxullianite

MALI Igneous intrusive Malignite

MISS Igneous intrusive Missourite
GDE: Level I 153 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

MONZ Igneous intrusive Monzonite

MOPO Igneous intrusive Monzonite porphyry

NEMO Igneous intrusive Nepheline monzonite

NEMOPO Igneous intrusive Nepheline monzonite porphyry

NESY Igneous intrusive Nepheline syenite

NESYPO Igneous intrusive Nepheline syenite porphyry

NORD Igneous intrusive Nordmarkite

NORI Igneous intrusive Norite

OLGA Igneous intrusive Olivine gabbro

PEGM Igneous intrusive Pegmattite

PERI Igneous intrusive Peridotite

PICR Igneous intrusive Picrite

PULA Igneous intrusive Pulaskite

PYRO Igneous intrusive Pyroxenite

QUDI Igneous intrusive Quartz diorite

QUDIPO Igneous intrusive Quartz diorite porphyry

QUGA Igneous intrusive Quartz gabbro

QUMO Igneous intrusive Quartz monzonite

QUMOPO Igneous intrusive Quartz monzonite porphyry

QUSY Igneous intrusive Quartz syenite

SHON Igneous intrusive Shonikite

SOSY Igneous intrusive Sodalite syenite

SYEN Igneous intrusive Syenite

SYPO Igneous intrusive Syenite porphyry

SYEO Igneous intrusive Syenodiorite

THER Igneous intrusive Theralite

THPO Igneous intrusive Theralite porphyry

TROC Igneous intrusive Troctolite

UNCO Igneous intrusive Uncompahgrite

UOLI Igneous intrusive Uolite

ACHO Metamorphic Actinolite hornfels

ACMA Metamorphic Actinolite marble

ACSC Metamorphic Actinolite schist

ACEPMA Metamorphic Actinolite-epidote marble

ALMISC Metamorphic Albite-mica schist

AMPH Metamorphic Amphibolite

AMGN Metamorphic Amphibolite gneiss

ANHO Metamorphic Andalusite hornfels
GDE: Level I 154 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

ANSC Metamorphic Andalusite schist

ANSPSL Metamorphic Andalusite spotted slate

ANBIHO Metamorphic Andalusite-biotite hornfels

ANGN Metamorphic Anorthosite gneiss

ATHO Metamorphic Anthophyllite hornfels

ARGN Metamorphic Arkose gneiss

AUGN Metamorphic Augen gneiss

BIGN Metamorphic Biotite gneiss

BISPSL Metamorphic Biotite spotted slate

BICLSC Metamorphic Biotite-chlorite schist

BLSL Metamorphic Black slate

BRMA Metamorphic Brucite marble

CAHO Metamorphic Calc-silicate hornfels

CLSL Metamorphic Calcareous slate

CASC Metamorphic Calcite schist

CASL Metamorphic Carbonaceous slate

CHSC Metamorphic Chiastolite schist

CHSPSL Metamorphic Chiastolite spotted sate

CLMA Metamorphic Chlorite marble

CLSC Metamorphic Chlorite schist

CDSC Metamorphic Chloritoid schist

CHMA Metamorphic Chondrodite marble

COGN Metamorphic Conglomerate gneiss

COHO Metamorphic Cordierite hornfels

COANHO Metamorphic Cordierite-anthophyllite hornfels

CRME Metamorphic Crystalline metamorphic

DBGN Metamorphic Diabase gneiss

DIMA Metamorphic Diopside marble

DIGN Metamorphic Diorite gneiss

ECLO Metamorphic Eclogite

EPAM Metamorphic Epidote amphibolite

EPGN Metamorphic Epidote gneiss

EPHO Metamorphic Epidote hornfels

EPCHSC Metamorphic Epidote-chlorite schist

FLCO Metamorphic Flaser conglomerate

FLDI Metamorphic Flaser diorite

FLGR Metamorphic Flaser granite

GBGN Metamorphic Gabbro gneiss

GABIGN Metamorphic Garnet biotite gneiss
GDE: Level I 155 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

GAGN Metamorphic Garnet gneiss

GAHO Metamorphic Garnet hornfels

GACLSC Metamorphic Garnet-chlorite schist

GAPYAM Metamorphic Garnet-pyroxene amphibolite

GLSC Metamorphic Glaucophane schist

GNEI Metamorphic Gneiss

GRGN Metamorphic Granite gneiss

GDGN Metamorphic Granodiorite gneiss

GRNO Metamorphic Granofels

GRNU Metamorphic Granulite

GRMA Metamorphic Graphite marble

GRSC Metamorphic Graphite schist

GWGN Metamorphic Graywacke gneiss

GRSL Metamorphic Green slate

GREN Metamorphic Greenschist

GREE Metamorphic Greenstone

HOBISC Metamorphic Hornblende-biotite schist

HORN Metamorphic Hornfels

KYHO Metamorphic Kyanite hornfels

KYSC Metamorphic Kyanite schist

MAGN Metamorphic Magnetite

MARB Metamorphic Marble

MEAR Metamorphic Meta-argillite

METC Metamorphic Metaconglomerate

METQ Metamorphic Metaquartzite

MEME Metamorphic Metasedimentary melange

METS Metamorphic Metasedimentary rocks

MSCA Metamorphic Metasedimentary alcareous

MSNC Metamorphic Metasedimentary noncalcareous

METV Metamorphic Metavolvanic rocks

MISC Metamorphic Mica schist

MIGM Metamorphic Migmatite

MOGN Metamorphic Monzonite gneiss

MYLO Metamorphic Mylonite

OLMA Metamorphic Olivine marble

PEGN Metamorphic Peridotite gneiss

PHYL Metamorphic Phyllite

PHLN Metamorphic Phyllonite

PLGN Metamorphic Plagioclase gneiss
GDE: Level I 156 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

PYSC Metamorphic Pyrophyllite schist

PRGN Metamorphic Pyroxene gneiss

PYHO Metamorphic Pyroxene hornfels

PRSC Metamorphic Pyroxene schist

QUDIGN Metamorphic Quartz diorite gneiss

QUPOGN Metamorphic Quartz porphyry gneiss

QUMISC Metamorphic Quartz-mica schist

QUSESC Metamorphic Quartz-sericite schist

QUAR Metamorphic Quartzite

QUGN Metamorphic Quartzite gneiss

RHGN Metamorphic Rhyolite gneiss

SAGN Metamorphic Sandstone gneiss

SCHI Metamorphic Schist

SCQU Metamorphic Schistose quartzite

SERP Metamorphic Serpentine

SEMA Metamorphic Serpentine marble

SEME Metamorphic Serpentine melange

SIGASC Metamorphic Sillimanite garnet schist

SIGN Metamorphic Sillimanite gneiss

SISC Metamorphic Sillimanite schist

SISL Metamorphic Silty slate

SKAR Metamorphic Skarn

SKGN Metamorphic Skarn gneiss

SLAT Metamorphic Slate

SOAP Metamorphic Soapstone

SPSL Metamorphic Spotted slate

STGN Metamorphic Staurolite gneiss

STSC Metamorphic Staurolite schist

SYGN Metamorphic Syenite gneiss

TASC Metamorphic Talc schist

TOHO Metamorphic Tourmaline hornfels

TOSC Metamorphic Tourmaline schist

TOMISC Metamorphic Tourmaline-mica schist

TRGN Metamorphic Trachyte gneiss

TRHO Metamorphic Tremolite hornfels

TRMA Metamorphic Tremolite marble

ULTR Metamorphic Ultramylonite

WOHO Metamorphic Wollastonite hornfels

WOMA Metamorphic Wollastonite marble
GDE: Level I 157 Inventory Field Guide

AGGL Sedimentary Agglomerate

ANHY Sedimentary Anhydrite

ARGI Sedimentary Argillite

ARKO Sedimentary Arkose

ARAR Sedimentary Arkose argillaceous

ARCA Sedimentary Arkose calcareous

ARSI Sedimentary Arkose siliceous

ASPH Sedimentary Asphalt

BENT Sedimentary Bentonite

BREC Sedimentary Breccia

CALI Sedimentary Caliche

CHAL Sedimentary Chalk

CHER Sedimentary Chert

CHOO Sedimentary Chert oolitic

CLAS Sedimentary Claystone

CLSI Sedimentary Claystone siliceous

COAN Sedimentary Coal, anthracite

COBI Sedimentary Coal, bituminous

CONG Sedimentary Conglomerate

COQU Sedimentary Coquina

DIAT Sedimentary Diatomite

DOLO Sedimentary Dolomite

GILS Sedimentary Gilsonite

GRAY Sedimentary Graywacke

GRCA Sedimentary Graywacke calcareous

GRSA Sedimentary Greensand

GYPS Sedimentary Gypsum

HALI Sedimentary Halite

HEMA Sedimentary Hematite

INLISA Sedimentary Interbedded limestone and 

sandstone

INLISH Sedimentary Interbedded limestone and shale

INLISI Sedimentary Interbedded limestone and 

siltstone

INSASH Sedimentary Interbedded sandstone and 

shale

INSASI Sedimentary Interbedded sandstone and 

siltstone

IRON Sedimentary Ironstone

Secondary 

code Primary lithology Secondary lithology
GDE: Level I 158 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

LIGN Sedimentary Lignite

LIME Sedimentary Limestone

LIAN Sedimentary Limestone arenaceous

LIAR Sedimentary Limestone argillaceous

LIBI Sedimentary Limestone bituminous

LICR Sedimentary Limestone carbonaceous

LICH Sedimentary Limestone cherty

LICL Sedimentary Limestone clastic

LIFE Sedimentary Limestone iron-rich

LIOO Sedimentary Limestone oolitic

LIOR Sedimentary Limestone organic

LIPH Sedimentary Limestone phosphatic

LISI Sedimentary Limestone siliceous

LISICL Sedimentary Limestone siliciclastic

LIMO Sedimentary Limonite

MARLST Sedimentary Marlstone

MUDS Sedimentary Mudstone

MUSI Sedimentary Mudstone siliceous

OOCA Sedimentary Oolite calcareous

OOFE Sedimentary Oolite iron-rich

OOPH Sedimentary Oolite phosphatic

OOSI Sedimentary Oolite siliceous

ORTH Sedimentary Orthoquartzite

ORFS Sedimentary Orthoquartzite feldspathic

ORLI Sedimentary Orthoquartzite lithic

PHOS Sedimentary Phosphorite

PORC Sedimentary Porcellanite

RADI Sedimentary Radiolarite

ROSA Sedimentary Rock Salt

SANS Sedimentary Sandstone

SAAR Sedimentary Sandstone argillaceous

SAARFS Sedimentary Sandstone argillaceous 

feldspathic

SAARLI Sedimentary Sandstone argillaceous lithic

SAARQU Sedimentary Sandstone argillaceous quartz

SACA Sedimentary Sandstone calcareous

SACAFS Sedimentary Sandstone calcareous 

feldspathic

SACALI Sedimentary Sandstone calcareous lithic
GDE: Level I 159 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

SACAQU Sedimentary Sandstone calcareous quartz

SACRQU Sedimentary Sandstone carbonaceous quartz

SAFS Sedimentary Sandstone feldspathic

SAFE Sedimentary Sandstone iron-rich

SAFEQU Sedimentary Sandstone iron-rich quartz

SALI Sedimentary Sandstone lithic

SAQU Sedimentary Sandstone quartz

SHAL Sedimentary Shale

SHBI Sedimentary Shale bituminous

SHCA Sedimentary Shale calcareous

SHCR Sedimentary Shale carbonaceous

SHFE Sedimentary Shale iron-rich

SHPH Sedimentary Shale phosphatic

SHSI Sedimentary Shale siliceous

SIDE Sedimentary Siderite

SILS Sedimentary Siltstone

SICA Sedimentary Siltstone calcareous

SICR Sedimentary Siltstone carbonaceous

SIFE Sedimentary Siltstone iron-rich

SUBG Sedimentary Subgraywacke

SUCA Sedimentary Subgraywacke calcareous

TRAV Sedimentary Travertine

TUFA Sedimentary Tufa

TUFF Sedimentary Tuff

VOBR Sedimentary Volcanic breccia

VOLC Sedimentary Volcaniclastic

MIEXME Undifferentiated Mixed extrusive and 

metamorphic

MIEXSE Undifferentiated Mixed extrusive and 

sedimentary

MIIG Undifferentiated Mixed igneous (extrusive & 

intrusive)

MIIGME Undifferentiated Mixed igneous and metamorphic

MIIGSE Undifferentiated Mixed igneous and sedimentary

MIINME Undifferentiated Mixed intrusive and 

metamorphic

MIINSE Undifferentiated Mixed intrusive and sedimentary

MIMESE Undifferentiated Mixed metamorphic and 

sedimentary
GDE: Level I 160 Inventory Field Guide

Secondary 

code Primary lithology Secondary lithology

ALLU Unconsolidated Alluvium

ASLO Unconsolidated Ash/loess mixture

CIND Unconsolidated Cinders

COLL Unconsolidated Colluvim

CRYO Unconsolidated Cryoturbate

DIAM Unconsolidated Diamicton

DIEA Unconsolidated Diatomaceous earth

EOLI Unconsolidated Eolian deposit

GLAC Unconsolidated Glacial deposit

GLMO Unconsolidated Glacial moraine deposit

GLTI Unconsolidated Glacial till deposit

GLFL Unconsolidated Glaciofluvial deposit

GLLA Unconsolidated Glaciolacustrine deposit

GLMA Unconsolidated Glaciomarine deposit

GRSA Unconsolidated Greensand

GYSA Unconsolidated Gypsum sand

HUCA Unconsolidated Human cause/constructed

LACU Unconsolidated Lacustrine sediments

LAHA Unconsolidated Lahar

LADE Unconsolidated Landslide deposit

MARI Unconsolidated Marine sediments

MARL Unconsolidated Marl

MIXE Unconsolidated Mixed

MUCK Unconsolidated Muck

ORGA Unconsolidated Organic deposits

PEAT Unconsolidated Peat

RESI Unconsolidated Residuum

TALU Unconsolidated Talus deposit

TEPH Unconsolidated Tephra (undifferentiated)

TRAN Unconsolidated Transitional marine/continental 

deposits

VOAS Unconsolidated Volcanic ash

Reference

U.S. Department of Agriculture (USDA), Forest Service. 2009. 

Site general: field guide. Washington, DC: U.S. Department of 

Agriculture, Forest Service, Rangeland Management Staff. 57 p.
GDE: Level I 161 Inventory Field Guide

Appendix 8. Landform

Geomorphic term Process/landform Code

aa flow Volcanic landform AAFL

air-fall tephra field Volcanic landform AFTF

alluvial fan Fluvial landform ALFA

anticline Tectonic landform ANTI

avalanche talus Mass wasting element landform AVTA

backshore terrace Coastal marine and lacustrine element 

landform

BATE

badlands Landscape term and fluvial landform BADL

bajada Landscape term and fluvial landform BAJA

bald Common landform BALD

bank Fluvial landform BANK

bar Fluvial landform and microfeature BAR

bay Common landform BAY

beach Coastal marine and lacustrine landform BEAC

beach ridge Coastal marine and lacustrine element BERI

beaver Lacustrine subprocess BEAV

bench Common landform BNCH

block field Periglacial landform BLFI

blowout Common landform BLOW

caldera Volcanic landform CALD

canyon Landscape term CANY

canyonlands Landscape term CALA

Carolina Bay Coastal marine landform CABA

channel Fluvial landform and microfeature CHAN

cinder cone Volcanic landform CICO

cirque Glacial element landform CIRQ

cliff Common landform CLIF

colluvial slope Mass wasting element landform COSL

crater Volcanic landform CRAT

cuesta Fluvial landform CUES

debris flow Mass wasting landform DEFL

deflation basin Eolian landform DEBA

delta Fluvial landform and landscape term DELT

The landform list in the following table is based on Haskins et al. 

(1998).
GDE: Level I 162 Inventory Field Guide

Geomorphic term Process/landform Code

depositional stream 

terrace

Fluvial landform DEST

depression Common landform DEPR

dike Landform DIKE

drainage channel 

(undifferentiated)

Glacial element landform DRCH

draw Common landform DRAW

drumlin Glacial landform DRUM

earth flow Mass wasting landform EAFL

erosional stream 

terrace

Fluvial landform ERST

escarpment Common landform ESCA

esker Glacial landform ESKE

fault scarp Tectonic landform FASC

fault trace Tectonic landform FATR

flood plain Fluvial landform FLPL

fold Tectonic landform FLDS

foredune Eolian landform FORE

frost action Periglacial subprocess FRAC

glaciated uplands Landscape term GLUP

gorge Common landform GORG

graben Landscape term and tectonic landform GRAB

ground moraine Glacial landform GRMO

gully Common landform GULL

hanging valley Glacial landform HAVA

hillslope bedrock 

outcrop

Mass wasting element landform HIBO

hogback Fluvial landform HOGB

interdune flat Eolian landform INFL

interfluve Common landform INTE

intermontane basin Landscape term INBA

kame Glacial landform KAME

karst Landscape term KRST

kettle Glacial element landform KETT

kettled outwash plain Glacial landform KEOP

lahar Volcanic landform LAHA

lake Lacustrine landform LAKE

lake bed Lacustrine landform LABE
GDE: Level I 163 Inventory Field Guide

Geomorphic term Process/landform Code

lateral moraine Glacial landform LAMO

lava flow 

(undifferentiated)

Volcanic landform LAFL

loess deposit 

(undifferentiated)

Eolian landform LODE

meander scar Fluvial element landform MESR

medial moraine Glacial landform MEMO

mesa Fluvial landform MESA

monocline Tectonic landform MONO

moraine 

(undifferentiated)

Glacial landform MORA

mud flat Coastal marine landform MUFL

outwash fan Glacial landform OUFA

outwash plain Glacial landform OUPL

outwash terrace Glacial landform OUTE

oxbow Fluvial element landform OXBO

pediment Fluvial landform PEDI

permafrost Periglacial subprocess PERM

point bar Fluvial element landform POBA

pyroclastic flow Volcanic element landform PYFL

recessional moraine Glacial landform REMO

ridgetop bedrock 

outcrop

Mass wasting element landform RIBO

rock glacier Mass wasting landform ROGL

rock slide-rock fall Mass wasting landform RSRF

rotational slide Mass wasting landform ROSL

saddle Common landform SADD

sand boil Microfeature SABO

sandhills Landscape term SAND

scarp Common landform SCAR

seep Common landform SEEP

shield volcano Volcanic landform SHVO

sinkhole 

(undifferentiated)

Solution landform SINK

slide Mass wasting subprocess SLID

slough Common landform SLOU

slump pond Lacustrine landform SLPO

solifluction lobe Mass wasting landform SOLO
GDE: Level I 164 Inventory Field Guide

Geomorphic term Process/landform Code

stream terrace 

(undifferentiated)

Fluvial landform STTE

syncline Tectonic landform SYNC

talus Common landform TALU

tarn Lacustrine landform TARN

terminal moraine Glacial landform TEMO

till plain Landscape term TIPL

valley floor Fluvial element landform VAFO

Reference

Haskins, D.M.; Correll, C.S.; Foster, R.A.; et al. 1998. A geomorphic classification system. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 110 p.
GDE: Level I 165 Inventory Field Guide

Appendix 9. Plant Labels 

(Cut Along Dashed Lines)
GDE: Level I 166 Inventory Field Guide
GDE: Level I 167 Inventory Field Guide

Appendix 10. 

Measurement of Discharge at 

Springs and Wetlands

1. Introduction

Measurement of discharge at springs and wetlands, although 

similar to such measurements in streams, presents additional 

challenges. Each site is unique, so that a measurement method 

that may be appropriate at one site may not be appropriate at 

another site. The field investigator must evaluate each site and 

choose the appropriate method to use, and, if necessary, modify 

the method to adjust to conditions at the site. For example, if 

discharge at a spring or wetland site is diffuse or coming from 

several points, a channel might be dug to incorporate such diffuse flow into a single channel that can then be measured.

These instructions are modified from: Rantz et al. (1982). Additional information may be obtained from sources listed in the 

References section.

2. Purpose

This is a description of techniques for measurement of discharge 

at springs and in wetlands that have flowing waters. The situations and methodologies discussed include the following: 

• Current meter.

• Timed observation of floats. 

• Volumetric measurement. 

• Use of a calibrated portable weir plate. 

• Use of a calibrated portable Parshall flume.

• Static head change procedure.

• Visual estimate.
GDE: Level I 168 Inventory Field Guide

3.Key Scientific Concepts, Considerations, and 

Assumptions

Measuring the discharge of some springs and wetlands can be 

challenging because the amount of discharge is small, waters 

are usually shallow and broadly and unevenly spread over a 

wide area, and areas with moving water are sometimes limited. 

Multiple observations are recommended to quantify precisely 

the hydrologic period or long-term discharge characteristics, 

because discharge changes diurnally, seasonally, and annually.

The way the flow (or discharge) is measured will vary depending 

on the site-specific factors, therefore, a variety of methods are 

presented. Table 10.1 lists the various instruments recommended 

for a range of discharge conditions. 

Table 10.1.—Recommended methods to measure discharge based on flow 

(Stevens et al. 2006).

Discharge (metric) Discharge (gpm) Instrument(s)

< 10 mL/s < 0.16 Volumetric

10 to 100 mL/s 0.16 to 1.6 Weir, volumetric

0.1 to 1 L/s 1.6 to 16 Weir, flume

1 to 10 L/s 16 to 158 Weir, flume

10 to 100 L/s 158 to 1,585 Flume

0.1 to 1 m3

/s 1,585 to 15,850 Current meter

1 to 10 m3

/s 15,850 to 158,500 Current meter

> 10 m3

/s > 158,500 Current meter

Note: Of all of the instruments listed, the flume is the largest and most difficult 

to carry. Therefore, it should not be carried into the back country unless it is 

essential to obtain an accurate measurement or if the spring has a discharge 

magnitude making a flume the optimal instrument.

Hanging gardens and limnocrenes, in particular, present a challenge for measuring flow. Flow measurements at a hanging garden could be taken at the base of the wall where flow coalesces 

into a channel. If this is not possible, photo documentation of 

the wetted area of rock face is an option. For limnocrenes that 

do not have outflow, the static head change method is used. For 

limnocrenes that have an outflow, one of the other measurement 

techniques described in the following paragraphs would be 

appropriate.
GDE: Level I 169 Inventory Field Guide

If a single channel exists, the discharge measurement should 

be taken as close as possible to the spring orifice. If multiple 

channels exist, and if they all converge to a single channel, the 

discharge can be measured in the single channel as close as 

possible to the confluence of all of the multiple channels. Alternatively, the flow at each orifice can be measured. 

3.1 Accuracy of Discharge Measurements

Accuracy of a discharge measurement is dependent on many 

factors, including the equipment used, the location and characteristic of the measuring section, the number and spacing of 

measurements, the rate of change in stage, the measurement 

depth and velocity, presence of ice and/or debris, wind, and (especially) the experience of the person conducting the measurement (Turnipseed and Sauer 2010, p. 79). The accuracy is often 

evaluated qualitatively, taking all of these factors into account.

See Rantz et al. (1982) and Turnipseed and Sauer (2010) for 

information on field equipment used for some of the methods 

described in the following section. 

4. Procedure

4.1 Current Meter

A current meter is an instrument used to measure the velocity 

of flowing water at a specific point in a channel. Several types 

of current meters are now available. Selecting which meter to 

use at a site will depend on purpose, site conditions, and cost. 

Historically, the U.S. Geological Survey (USGS) has used verticalaxis current meters (price current meter), which are mechanical 

devices that use spinning cups to measure the current velocity 

(Rantz et al. 1982 pp. 86–88). A smaller version (pygmy meter) is 

used at sites where water is shallow, such as a spring or wetland. 

Advancements in acoustic technology have led to important 

developments in the use of acoustic Doppler current profilers, 

acoustic Doppler velocimeters, and other emerging technologies 

for the measurement of discharge. These new instruments, based 

on acoustic Doppler theory, have the advantage of no moving 

parts, and in the case of the acoustic Doppler current profiler, 

quickly and easily provide three-dimensional stream-velocity 

profile data through much of the vertical water column. Additional 

information on current USGS stream-gaging procedures, including 
GDE: Level I 170 Inventory Field Guide

information on use of electronic field notebooks and personal 

digital assistants (PDAs), is available in Turnipseed and Sauer 

(2010).

Current meters are necessary in springs or in wide channels or 

high-discharge channels where flow cannot be routed into a 

weir or a flume. Measurement locations are selected in a straight 

reach where the streambed is free of large rocks, weeds, and 

protruding obstructions that create turbulence and where a flat 

streambed profile occurs to eliminate vertical components of 

velocity.

The cross-section of the channel is divided into partial sections, 

and the area and mean velocity of each section is measured separately. A partial section is a rectangular region in which depth is 

equal to the depth measured at that location, and for which width 

is equal to the sum of half the distances of adjacent verticals. At 

each vertical, the following observations are recorded on the data 

sheet: (1) the distance to a reference point on the bank along the 

tag line, (2) the depth of flow, and (3) the velocity as indicated by 

the current meter. The velocity should be measured at a depth 

that is 0.6 of the depth from the surface of water in the channel. 

The discharge of each partial section is calculated as the product 

of mean velocity times depth at the vertical times the sum of half 

the distances to adjacent verticals. The sum of the discharges of 

each partial section is the total discharge.

Measurements are made by wading in the stream with the 

current meter along the tag line. The person wading the channel should stand downstream of the velocity meter. Detailed 

procedures for use of current meters is documented in Rantz et 

al. (1982) and Turnipseed and Sauer (2010).

Accuracy of current-meter measurements can be evaluated using 

methods described by Sauer and Meyer (1992). Their study indicated that accuracy can range from 2-percent measurement error 

under ideal measurement conditions to 20-percent measurement 

error under poor conditions. Under generally normal conditions, 

standard errors of measurement range from 3 to 6 percent.

4.2 Float Method

Floats are useful for measuring discharges at springs and 

wetlands, where water is shallow and velocities may be too small 

to accurately use a current meter. Floats can be almost any 
GDE: Level I 171 Inventory Field Guide

distinguishable article that floats, such as wooden disks; bottles 

partly filled with water, soil, or stones; or oranges. Floating ice 

cakes or distinguishable pieces of drift may be used if they are 

present in the stream. Fluorescent dye can also be used.

Two cross-sections are selected along a reach of straight channel for a float measurement. The cross-sections should be far 

enough apart so that the time the float takes to pass from one 

cross-section to the other can be measured accurately. A travel 

time of at least 20 seconds is recommended, but a shorter time 

may be used for streams with such high velocities that it is not 

possible to find a straight reach of channel having adequate 

length. The distance between the two sections is measured with 

a measuring tape, and recorded. The width and depth of each 

channel cross-section is measured with a tape measure and recorded. In making a float measurement, the float is introduced a 

short distance upstream from the upstream cross-section so that 

it will be traveling at the speed of the current when it reaches the 

upstream section. A stopwatch is used to time its travel between 

the end cross-sections of the reach. This procedure is repeated 

3 to 5 times, as the float is placed at different locations across 

the channel at the upstream cross-section. The average velocity 

of the measurement is then calculated. An example field sheet for 

use with this method is shown in table 10.2. 

The velocity of the float is equal to the distance between the end 

cross-sections divided by the time of travel. The mean velocity in 

the vertical is equal to the float velocity multiplied by a coefficient 

whose value is dependent on the shape of the vertical-velocity 

profile of the stream, and on the depth of immersion of the float 

with respect to stream depth. Coefficients of 0.85 to 0.88 are 

commonly used to convert the velocity of a surface float to mean 

velocity in the vertical (Turnipseed and Sauer 2010, p. 85). 

The procedure for computing the discharge is similar to that used 

in computing the discharge for a conventional current-meter 

measurement. Discharge is computed by multiplying the area of 

the channel by the mean vertical velocity.

Float measurements of discharge that are carefully made under 

favorable conditions may be accurate to within +/- 10 percent. 

Wind may adversely affect the accuracy of the computed 

discharge due to its effect on the velocity of the floats. If a nonuniform reach is selected, measurement results may be in error 

by as much as 25 percent. 
GDE: Level I 172 Inventory Field Guide

4.3 Volumetric Measurement

The volumetric measurement of discharge is the most accurate 

method of measuring small flows (less than a few gallons per 

minute). The time required to fill a container of known capacity, 

or the time required to partly fill a calibrated container to a known 

volume, is recorded. The only equipment required, other than the 

calibrated container, is a stopwatch.

Volumetric measurements are usually made where the flow is 

concentrated in a narrow stream, or can be so concentrated, so 

that all the flow may be diverted into a container. Examples of 

sites presenting the opportunity for volumetric measurement of 

discharge are a V-notch weir, a natural or artificial control where 

all the flow is confined to a notch; or a cross section of natural 

channel where a temporary earth dam can be built over a pipe 

of small diameter, through which the entire flow is directed. 

Sometimes it is necessary to place a trough against the artificial 

control to carry the water from the control to the calibrated 

container. If a small temporary dam is built, the stage behind the 

dam should be allowed to stabilize before the measurement is 

begun. The measurement should be made three or four times to 

be certain no errors have been made and to be sure the results 

are consistent. Several calibrated containers of varying sizes 

should be taken to the field site.

4.4 Portable Weir Plate

A portable weir plate is useful for determining discharge when 

depths are too shallow and velocities too low for a reliable 

current-meter measurement of discharge. A 90-degree V-notch 

Table 10.2.—Example field sheet for use with the float method.

Float method

Reach length:

Trial Time elapsed Velocity

(reach length/time)

#1

#2

#3

Average velocity:

Average velocity x 0.85:
GDE: Level I 173 Inventory Field Guide

weir is particularly suitable because of its sensitivity at low flows. 

The USGS commonly uses three different sizes of weir plate; 

their recommended dimensions are given in figure 10.1. 

The weir plate is made of galvanized sheet iron, using 10- to 

16-gauge metal. The 90-degree V-notch that is cut in the plate 

is not beveled but is left with flat, even edges. A staff gage, 

attached to the upstream side of the weir plate with its zero at 

the elevation of the bottom of the notch, is used to read the head 

on the weir. The staff gage should be installed far enough from 

the notch to be outside the region of drawdown of water going 

through the notch. Drawdown becomes negligible at a distance 

from the vertex of the notch that is equal to twice the head on 

the notch. Consequently, if the weir plate has the dimensions 

recommended in figure 10.1, the staff gage should be installed 

near one end of the plate.

Figure 10.1.—Portable weir plate sizes.
GDE: Level I 174 Inventory Field Guide

To install the weir, the weir plate is pushed into the streambed. 

A pick or shovel may be necessary to remove stones or rocks 

that prevent even penetration of the plate. A carpenter’s level is 

used to ensure that the top of the plate is horizontal and that the 

face of the plate is vertical. Soil or streambed material is packed 

around the weir plate to prevent leakage under and around it. It 

ordinarily requires only one person to make the installation. 

A large weir plate of the dimensions shown in figure 10.1 can 

measure discharges in the range from 0.02 to 2.0 ft3

/s (0.00057 

to 0.057 m3

/s) with an accuracy of +/- 3 percent, if the weir is not 

submerged. A weir is not submerged when air circulates freely 

around all sides of the nappe. The general equation for flow over 

a sharp-edged 90-degree V-notch weir is 

Q = Ch5/2

where 

Q = discharge, in cubic feet per second or cubic meters per 

second, 

h = static head above the bottom of the notch, in feet or 

meters, 

C = coefficient of discharge.

Each weir should be rated to determine C by volumetrically measuring the discharge corresponding to various values of head. In 

the absence of such a rating, a value of 2.47 may be used for C 

when British units are used, or 1.36 when metric units are used. 

When the weir is installed, it will cause a pool to form on the 

upstream side of the plate. No readings of head on the notch 

should be recorded until the pool has risen to a stable elevation. 

The head should then be read at half-minute intervals for about 

3 minutes, and the mean value of those readings should be used 

as the value for head in the equation to compute discharge. After 

the completion of the measurement, the weir plate is removed. 

An online method for calculating discharge using a V-notch weir 

is available at http://www.lmnoeng.com/Weirs/vweir.htm.
GDE: Level I 175 Inventory Field Guide

4.3 Portable Parshall Flume

A portable Parshall flume is another device for determining 

discharge when depths are too shallow and velocities too low for 

a current-meter measurement of discharge. The portable flume 

used by the USGS is a modified form of the standard Parshall 

flume having a 3-inch (0.076 meter) throat. The modification 

consists, primarily, of the removal of the downstream diverging 

section of the standard flume. The purpose of the modification is 

to reduce the weight of the flume and to make it easier to install. 

Because the portable Parshall flume has no downstream diverging section, it cannot be used for measuring flows when the 

submergence ratio exceeds 0.6. The submergence ratio is the 

ratio of the downstream head on the throat to the upstream head 

on the throat. Although a submergence ratio of 0.6 can be tolerated without affecting the rating of the portable flume, in practice 

the flume is usually installed so that the flow freely passes the 

throat without being slowed by ponding below the flume. That 

installation is usually accomplished by building up the streambed 

a couple of inches under the level converging floor of the flume. 

Figure 10.2 shows the plan and elevation of the portable Parshall 

flume. The gage height or upstream head on the throat is read in 

the small stilling well that is hydraulically connected to the flow 

by a 3/8-inch hole. The rating for the flume is given in table 10.3. 

When the flume is installed in the channel, the floor of the converging section is set in a level position by using the level bubble 

that is attached to one of the braces (fig. 10.2). A carpenter’s 

level can be used for that purpose if the flume is not equipped 

with a level bubble. Soil or streambed material is then packed 

around the flume to prevent leakage under and around it. After 

the flume is installed, water will pool upstream from the structure. 

No gage-height readings should be recorded until the pool has 

risen to a stable level. As with the portable weir, after stabilization of the pool level, gage-height readings should be taken at 

30-second intervals for about 3 minutes. The mean value of 

those readings is the gage height used in table 10.3 to obtain the 

discharge. A carefully made measurement should have an accuracy of +/- 2 or 3 percent. After completion of the measurement, 

the portable flume is removed.
GDE: Level I 176 Inventory Field Guide

Figure 10.2.—Working drawing of modified 3-inch Parshall flume. 
GDE: Level I 177 Inventory Field Guide Gage height (ft) Discharge (ft3/s) Gage height (ft) Discharge (ft3/s) Gage height (ft) Discharge (ft3/s) 0.01 0.0008 0.21 0.097 0.41 0.280 0.02 0.0024 0.22 0.104 0.42 0.290 0.03 0.0045 0.23 0.111 0.43 0.301 0.04 0.0070 0.24 0.119 0.44 0.312 0.05 0.010 0.25 0.127 0.45 0.323 0.06 0.013 0.26 0.135 0.46 0.334 0.07 0.017 0.27 0.144 0.47 0.345 0.08 0.021 0.28 0.153 0.48 0.357 0.09 0.025 0.29 0.162 0.49 0.368 0.10 0.030 0.30 0.170 0.50 0.380 0.11 0.035 0.31 0.179 0.51 0.392 0.12 0.040 0.32 0.188 0.52 0.404 0.13 0.045 0.33 0.198 0.53 0.417 0.14 0.051 0.34 0.208 0.54 0.430 0.15 0.057 0.35 0.218 0.55 0.443 0.16 0.063 0.36 0.228 0.56 0.456 0.17 0.069 0.37 0.238 0.57 0.470 0.18 0.076 0.38 0.248 0.58 0.483 0.19 0.083 0.39 0.259 0.59 0.497 0.20 0.090 0.40 0.269 Table 10.3.—Rating table for 3-inch modified Parshall flume.
GDE: Level I 178 Inventory Field Guide

4.6 The Static Head Change Procedure

This method may be used for a relative comparison value for 

change in elevation of standing pools or limnocrenes with no 

outflow. A staff gage is placed in the standing pool and relative 

gage elevation recorded, or efforts are made to locate and 

record an existing fixed point in or near the standing pool and the 

vertical distance to the pool surface recorded. Periodic measurements of changes in the static head on the staff gage or fixed 

point are recorded.

4.7 Visual Estimate

Site conditions, such as dense vegetation cover, steep or flat 

slope, diffuse discharge into a marshy area, and limited or 

dangerous access sometimes do not allow for a direct measurement of discharge by the techniques listed previously. Typically, 

the visual estimate method is used along with a gross estimate 

of flow velocity with a float but is only recommended as a last 

resort. Discharge class is estimated based on those listed in 

table 10.1. Photographs should be taken to record the surface 

area wetted or covered by water and observations recorded on 

a datasheet. Also, it should be noted if another method could be 

recommended to measure discharge for future site visits.

5. Documentation and Data Management

The name, serial number (if available), accuracy of the instrument 

used to measure discharge, and any other important observations should be recorded. Important observations may include 

the markers of any recent high discharges, such as high water 

marks, oriented vegetation, or debris on or above the channel or 

floodplain.

All computation sheets for discharge calculations should be neat 

and legible. Errors or modifications should be indicated by a 

single line drawn through them (no erasures or blackouts). These 

computations should be checked by an independent reviewer. 

Copies of computation sheets should be kept in project files and 

archived according to required procedures. Electronic copies of 

computations should be archived in the appropriate database.
GDE: Level I 179 Inventory Field Guide

6. Additional Information

American Society for Testing and Materials. 2007. Standard 

test method for open-channel flow measurement of water with 

thin-plate weirs. ASTM D5242 - 92(2007). West Conshohocken, 

PA. http://www.astm.org/Standards/D5242.htm. (21 November 

2011).

Desert Managers Group. 2001. Protocol for hydrologic data to be 

collected at desert wetland sites by BLM and NPS personnel in 

support of the California DMG water study. 4 p. http://www.dmg.

gov/documents/PRT_Springs_Data_Collection_DMG_052401.

pdf. (21 November 2011).

International Organization of Standards. 1980. Water flow measurement in open channels using weirs and venturi flumes—Part 

1: thin plate weirs. ISO 1438/1-1980(E). http://global.ihs.com. (21 

November 2011).

Oberg, K.A.; Morlock, S.E.; and Caldwell, W.S. 2005. Qualityassurance plan for discharge measurements using acoustic 

Doppler current profilers. U.S. Geological Survey Scientific 

Investigations Report 2005-5183. 35 p. http://pubs.usgs.gov/

sir/2005/5183. (21 November 2011).

U.S. Department of the Interior, Bureau of Reclamation. 1997. 

Water measurement manual. 3rd ed. http://www.usbr.gov/pmts/

hydraulics_lab/pubs/wmm/index.htm. (21 November 2011).

7. References 

Rantz, S.E. et al. 1982. Measurement of stage and discharge. In: 

Measurement and computation of streamflow: volume 1. U.S. 

Geological Survey, water supply paper 2175. 313 p. http://pubs.

usgs.gov/wsp/wsp2175/. (21 November 2011).

Sauer, V.B.; Meyer, R.W. 1992. Determination of error in 

individual discharge measurements. U.S. Geological Survey 

Open-File Report 92-144. 21 p. http://water.usgs.gov/software/

MEASERR. (21 November 2011).

Stevens, L.; Kloeppel, H.; Springer, A.; Sada, D. 2006. Terrestrial 

springs ecosystems inventory protocols. Cooperative Agreement 

Number CA 1200-99-009, TASK# NAU-118. Flagstaff, AZ: 

National Park Service. 45 p.
GDE: Level I 180 Inventory Field Guide

Turnipseed. D.P.; Sauer, V.B. 2010. Discharge measurements at 

gaging stations. In: U.S. Geological Survey techniques and methods, book 3, chap. A8. 87 p. http://pubs.usgs.gov/tm/tm3-a8. (21 

November 2011).
GDE: Level I 181 Inventory Field Guide

Appendix 11. 

Identification of Freshwater 

Invertebrates

This appendix has representative drawings of groups of 

aquatic macroinvertebrates important in springs and other 

groundwater-dependent ecosystems. A substantial amount of 

training is needed to identify many macroinvertebrate species, 

but identifying most groups (such as order or family) and many 

nonnative species may be accomplished with minimal training. 

These descriptions and illustrations can facilitate identification of 

important taxa in the field. Useful references that provide more 

detail include A Guide to Common Freshwater Invertebrates 

of North America (Voshell 2002) and Aquatic Entomology: The 

Fisherman’s and Ecologist’s Illustrated Guide to Insects and 

Their Relatives (McCafferty 1981). At the end of this appendix is 

a “Key to Macroinvertebrate Life in the River,” developed by the 

University of Wisconsin, in an easy-to-use flowchart format.

The following illustrations, other than those in the “Key to Macroinvertebrate Life in the River,” were drawn by Luke Boehnke.

All three insect orders described in 11.1 to 11.6 leave the water 

to mate as winged adults. Large swarms of mating mayflies 

and caddisflies often occur when all the individuals of a single 

species emerge at the same time. The females of all three groups 

fly upstream and drop their eggs onto the water or dive into the 

stream to attach them to rocks or leaves.
GDE: Level I 182 Inventory Field Guide

11.1-11.2. Mayflies are insects that spend most of their lives in 

streams, emerging briefly as adults to mate and lay eggs. Many 

species have gills that are visible along the abdomen. Most 

mayflies have three tails, but some have only two tails. Mayfly 

diversity declines as aquatic conditions are degraded; mayflies 

are particularly sensitive to mine waste. (Size: 6 to 25 millimeters)

11.3-11.4. Stonefly nymphs are almost always found in flowing 

water. Some stoneflies feed on other invertebrates while other 

taxa eat dead organic matter and have a preference for coarse 

substrate. Stoneflies look similar to mayflies but are stockier, 

have two claws (rather than one) on each foot, and have two tails 

instead of the usual three in mayflies. There are no gills on the 

abdomen. Diversity of these animals declines rapidly at the first 

sign of human disturbance. (Size: 12 to 40 millimeters)
GDE: Level I 183 Inventory Field Guide

11.5-11.6. Caddisflies are insects that emerge to mate as winged 

adults. They use silk to build cases from gravel, twigs, needles, 

or sand. The larva is caterpillar-like with three pairs of legs, two 

claws at the posterior (rear) end of the abdomen, and a tendency 

to curl up slightly. They may be found in a stick, rock, or leaf 

case, with the head sticking out. Different species build distinct 

cases or chambers, often on or under rocks. Free-living caddisfly 

larvae do not build cases; many are predators and need to move 

quickly to capture other animals for food. Some caddisflies are 

very sensitive to human disturbance, but others are tolerant. 

(Size: 12 to 40 millimeters)

11.7-11.10. These four families of true bugs commonly occur in 

western North American springs. True bug larvae look similar to 

the adults. They can be distinguished from other aquatic insects 

by the following combination of characteristics: mouthparts are an 

elongated beak that folds back under the head when not feeding, 

wingpads are present on the thorax, three pairs of segmented 

legs with two claws on some of them, and no gills are present.
GDE: Level I 184 Inventory Field Guide

11.11-11.12. Riffle beetle larvae are specially adapted to cling 

to smooth rocks in fast-flowing water (riffles). After emergence, 

adults fly for a short time but return to water to feed in the same 

habitat as the larvae. Both larvae and adults are rather small 

and tend to drift to the bottom of a sample. Many beetle families 

occur in aquatic habitats, but comparatively few crenobiontic 

species exist. In the Western United States, most crenobiontic 

riffle beetles are in two genera, Stenelmis and Microcylloepus. 

Differentiating between these genera is difficult in the field 

because individuals are small (less than 3 millimeters long) and 

difficult to examine without magnification. They are easy to see 

in samples, however. Riffle beetles are black or dark brown with 

long, spindly legs. They move slowly by crawling, and they have 

weak swimming ability. (Size: less than 3 millimeters)

11.13. Long-toed water beetles are common in riffles and on 

woody debris or rocks. Adults use long, sharp claws to cling to 

debris and sometimes they crawl on the bottom or along the 

shore. The body is dull gray or brown and often covered with 

fine hairs, and the head is mostly withdrawn into the thorax. 

(Size: 4 to 8 millimeters)
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11.14. Many species of true flies exist, but in springs, there are 

three main groups or families. Midge larvae (or chironomids) are 

very small (up to 6 millimeters), often C-shaped, with a segmented 

body and a spastic squirming movement. They are often whitish 

to clear, but occasionally bright red. Midge larvae have distinct 

heads with two small prolegs in the front of the body and are often 

attached to debris by their tiny legs. Blackfly larvae (or simuliids) 

are dumb-bell shaped and soft (up to 6 millimeters). The body is 

larger at the rear end, similar to the shape of a bowling pin. The 

distinct head contains fan-like mouth brushes. Blackfly larvae 

often curl into a “u” shape when held in your hand. They attach 

themselves to the stable substrate such as rocks, large wood, 

or rooted vegetation. Crane fly larvae (or tipulids) are large (8 to 

60 millimeters) with a fleshy, worm-like, segmented body with 

finger-like projections (gills) at the back end. They occur in a 

variety of colors (clear, white, brown, and green) and bury themselves in soft sediment.
GDE: Level I 186 Inventory Field Guide

11.16. Amphipods (or scuds) occur in many springs and are 

usually very numerous. They are comparatively large (up to 10 

millimeters long), active, and easy to identify in a macroinvertebrate sample. Amphipods are very fast swimmers that look like 

shrimp. They have many appendages that give them a fuzzy 

appearance. Amphipods can be common in very degraded 

sites. Isopods (or sowbugs) are usually found creeping through 

leaf litter. They have a flat, segmented body (6 to 20 millimeters) 

with an “armored” appearance and seven pairs of legs. Unlike 

amphipods, isopods are flattened top to bottom.

11.15. Flatworms (e.g., Planaria), roundworms (nematodes), and 

freshwater segmented worms (oligochaetes, leeches, earthworms) are properly called worms, but should not be confused 

with the soft-bodied larvae of flies. Nematodes and oligochaetes 

are long, thin, and writhe like snakes, while planarians glide. 

These animals do not have legs.
GDE: Level I 187 Inventory Field Guide

11.17. Ostracods (seed shrimp) are the oldest known microfauna 

and have been extensively used in paleoclimate studies. They 

are small (usually less than 2 millimeters long), flattened animals 

with a calcitic shell and an external morphology that is similar to 

a plant seed. They are brown to pale olive green or gray, active, 

and are usually easy to see in a sample because they constantly 

move. Ostracods may occur in the water column or on the 

substrate, and they are usually abundant in springs.

11.18. Crayfish generally occur only in large springs that do not 

dry. In some places, nonnative crayfish have been introduced 

into springs, with often dramatic negative effects on native plants 

and animals.
GDE: Level I 188 Inventory Field Guide

11.19-11.20. Springsnails are small, black or brown crenobiontic 

species that have an operculum (lid) and a shell that opens on 

the right. Most species in southern U.S. deserts are in the genera 

Pyrgulopsis or Tryonia, which occur in two general body forms. 

Most Pyrgulopsis species are round and slightly inflated, while 

most Tryonia species are elongated. Pyrgulopsis species generally occur on gravel and cobble substrates and on watercress 

in areas with higher water velocity. Tryonia species are usually 

found in slow currents with fine substrates. (Size: less than 5 

millimeters)

11.21. Physid snails are found in springs and, although some are 

introduced, many are native and likely endemic. There is no operculum, and the shell opens on the left. (Size: 5 to 20 millimeters)
GDE: Level I 189 Inventory Field Guide

11.22. Fingernail clams are small and usually bury themselves in 

habitats with fine sediment and low current velocity. They may 

be tan colored, but they are usually white and often translucent. 

Magnification is needed to differentiate species, which precludes 

field identification of species. When present, they are usually common and comparatively easy to find. (Size: 2 to 5 millimeters wide)

11.23. Red-rimmed melania (Melanoides tuberculata) is a mollusk that was introduced into North America from Asia by the 

aquarium trade and has become widespread throughout the 

Western United States. It is parthenogenic (reproduces asexually) and can survive long periods out of water. It can be easily 

transplanted, is tolerant of harsh conditions, and prefers warm, 

slow water and fine substrates. Red-rimmed melania is easy to 

identify by its distinctive shape and color. It is long and conical, 

with body whorls terminating at a sharp point. Its shell is slightly 

sculptured and its coloration is an attractive and distinct mottled, 

reticulated mixture of tan and brown. Because these mollusks are 

easily transported, care should be taken to completely clean and 

inspect field gear to ensure they are not carried and introduced 

into other springs. (Size: up to 25 millimeters)
GDE: Level I 190 Inventory Field Guide

The following “Key to Macroinvertebrate Life in the River” was 

developed by the University of Wisconsin.
GDE: Level I 191 Inventory Field Guide

References

McCafferty, W.P. 1981. Aquatic entomology: the fisherman’s and 

ecologist’s illustrated guide to insects and their relatives. Boston, 

MA: Science Book International. 448 p.

Voshell, J.R., 2002. A guide to common freshwater invertebrates 

of North America. Blacksburg, VA: McDonald and Woodward 

Publishing Co. 442 p.