U.S. Department of the Interior

Bureau of Land Management

RIPARIAN AREA MANAGEMENT

TR 1737-16 1999, Revised 2003

A User Guide to Assessing Proper

Functioning Condition and

the Supporting Science for Lentic Areas

U.S. Department of Agriculture

Forest Service

U.S. Department of Agriculture

Natural Resources Conservation Service
Copies available from:

Bureau of Land Management

National Business Center

BC-650B

P.O. Box 25047

Denver, Colorado 80225-0047

BLM/RS/ST-99/001+1737+REV03
RIPARIAN AREA MANAGEMENT

A User Guide to Assessing Proper

Functioning Condition and

the Supporting Science for Lentic Areas

by

Don Prichard - Work Group Leader

Fishery Biologist/Riparian-Wetland Coordinator

Bureau of Land Management

National Applied Resource Sciences Center, Colorado

Work Group

Technical Reference 1737-16

1999, revised 2003

U.S. Department of the Interior

Bureau of Land Management

National Applied Resource Sciences Center

P.O. Box 25047

Denver, CO 80225-0047

Forrest Berg

Stream Mechanics Engineer

Natural Resources Conservation Service

Riparian/Wetland Technical Team

Bozeman, Montana

Warren Hagenbuck

Regional Wetland Coordinator (retired)

U.S. Fish and Wildlife Service

Albuquerque, New Mexico

Russ Krapf

Soil Scientist

Bureau of Land Management

National Training Center

Phoenix, Arizona

Robert Leinard

Plant Ecologist

Natural Resources Conservation Service

Riparian/Wetland Technical Team

Bozeman, Montana

Steve Leonard

Riparian Ecologist/Grazing Management Specialist

Bureau of Land Management

National Riparian Service Team

Prineville, Oregon

Mary Manning

Ecologist

Forest Service

Northern Region

Missoula, Montana

Chris Noble

Soil Scientist

Natural Resources Conservation Service 

Riparian/Wetland Technical Team

Bozeman, Montana

Janice Staats

Hydrologist

Forest Service

National Riparian Service Team

Prineville, Oregon

iii

Acknowledgments

The authors would like to thank the following individuals for the time they offered

in review, comment, and development of this document: Al Amen, Mark

Biddlecomb, Clay Bridges, Pam Clemmer, Mary D’Aversa, Jim Fogg, Karl

Gebhardt, Paula Ledford, Ramone McCoy, and Paul Summers from the Bureau of

Land Management; Lorena Corzatt and Susan Holtzman from the Forest Service;

and Terry Costner, Marcus Miller, and Sandy Wyman from the Natural Resources

Conservation Service.

The authors also extend a special thank you to Linda Hill and Jennifer Kapus of the

National Applied Resource Sciences Center, and to the National Business Center, for

doing a fine job in editing, layout, design, and production of the final document.

v

Contents

Page

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii

I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

II. Method Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

III. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

IV. PFC Assessment Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

A. Review Existing Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

B. Analyze the Definition of PFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

C. Assess Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1. Attributes and Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

2. Capability and Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3. Functioning Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

4. Functional Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

D. Institute the Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

1. Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

2. Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

3. Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

V. Quantification of Checklist Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

A. Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Item 1: Riparian-wetland area is saturated at or

near the surface or inundated in “relatively frequent” events . . . . . . .19

Item 2: Fluctuation of water levels is not excessive . . . . . . . . . . . . . . .23

Item 3: Riparian-wetland area is enlarging or has achieve

potential extent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Item 4: Upland watershed is not contributing to

riparian-wetland degradation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Item 5: Water quality is sufficient to support

riparian-wetland plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Item 6: Natural surface or subsurface flow patterns are not altered

by disturbance (i.e., hoof action, dams, dikes, trails, roads,

rills, gullies, drilling activities) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Item 7: Structure accommodates safe passage of flows

(e.g., no headcut affecting dam or spillway) . . . . . . . . . . . . . . . . . . .32

B. Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Item 8: There is diverse age-class distribution of riparian-wetland 

vegetation (recruitment for maintenance/recovery) . . . . . . . . . . . . . .34

Item 9: There is diverse composition of riparian-wetland vegetation 

(for maintenance/recovery) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
vi

Item 10: Species present indicate maintenance of

riparian-wetland soil moisture characteristics . . . . . . . . . . . . . . . . . .37

Item 11: Vegetation is comprised of those plants or

plant communities that have root masses capable of

withstanding wind events, wave flow events, or overland flows

(e.g., storm events, snowmelt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Item 12: Riparian-wetland plants exhibit high vigor . . . . . . . . . . . . . . .40

Item 13: Adequate riparian-wetland vegetative cover is

present to protect shoreline/soil surface and dissipate energy

during high wind and wave events or overland flows . . . . . . . . . . . .42

Item 14: Frost or abnormal hydrologic heaving is not present . . . . . . . .43

Item 15: Favorable microsite condition (i.e., woody material,

water temperature, etc.) is maintained by adjacent site

characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

C. Erosion/Deposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Item 16: Accumulation of chemicals affecting plant

productivity/composition is not apparent . . . . . . . . . . . . . . . . . . . . . .47

Item 17: Saturation of soils (i.e., ponding, flooding frequency,

and duration) is sufficient to compose and maintain hydric soils . . . .48

Item 18: Underlying geologic structure/soil material/permafrost

is capable of restricting water percolation . . . . . . . . . . . . . . . . . . . . .51

Item 19: Riparian-wetland is in balance with the water and

sediment being supplied by the watershed (i.e., no excessive

erosion or deposition) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Item 20: Islands and shoreline characteristics (i.e., rocks, coarse

and/or large woody material) are adequate to dissipate wind

and wave event energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

VI. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Appendix A: Riparian-Wetland Lentic Checklist . . . . . . . . . . . . . . . . . . . . . . . . .57

Appendix B: Potential and Capability Examples . . . . . . . . . . . . . . . . . . . . . . . . .63

Appendix C: Lentic Riparian-Wetland Examples . . . . . . . . . . . . . . . . . . . . . . . .77

Appendix D: PFC—What It Is and What It Isn’t . . . . . . . . . . . . . . . . . . . . . . . .89

Appendix E: Common Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Appendix F: Problem Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103

Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
1

A User Guide to Assessing Proper

Functioning Condition and

the Supporting Science for Lentic Areas

I. Introduction

Riparian-wetland areas are some of our most productive resources. They are highly

prized for their recreation, fish and wildlife, water supply, cultural, and historic

values, as well as for their economic values, which stem from their use for livestock

production, timber harvest, and mineral extraction.

This document provides guidance for assessing the condition of any riparian-wetland

area other than a lotic (riverine) area. These areas, which are called lentic areas, not

only include jurisdictional wetlands as defined by the U.S. Army Corps of Engineers

(1987), but also nonjurisdictional areas (e.g., deep water, freshwater, saline, marine,

and estuarine) that provide enough available water to the root zone to establish and

maintain riparian-wetland vegetation.

Proper functioning condition (PFC) is a qualitative method for assessing the condition of riparian wetland areas. The term PFC is used to describe both the assessment

process and a defined, on the-ground condition of a riparian-wetland area.

The PFC assessment refers to a consistent approach for considering hydrology,

vegetation, and erosion/deposition (soils) attributes and processes to assess the

condition of riparian wetland areas. A checklist is used for the PFC assessment

(Appendix A), which synthesizes information that is basic for determining a

riparian-wetland area’s health.

The on-the-ground condition termed PFC refers to how well the physical processes

are functioning. PFC is a state of resiliency that will allow a lentic riparian-wetland area to hold together during wind and wave action events or overland flow

events with a high degree of reliability. This resiliency allows an area to then produce desired values, such as waterfowl habitat, neotropical bird habitat, or forage

over time. Riparian-wetland areas that are not functioning properly cannot sustain

these values.

PFC is a qualitative assessment based on quantitative science. The PFC assessment

is intended to be performed by a trained and experienced interdisciplinary (ID) team.

Quantitative techniques support the PFC checklist and should be used in conjunction

with the PFC assessment for individual calibration, where answers are uncertain, or

where experience is limited. PFC is also an appropriate starting point for determining and prioritizing the type and location of quantitative inventory or monitoring

necessary. 
2

The PFC assessment has proven to be an excellent communication tool for bringing

diverse groups to consensus. This process provides a common vocabulary for identifying the building blocks for the development of desired condition (DC) and

resulting values.

Again, the method developed for assessing PFC is qualitative and is based on using

a checklist to make a relatively quick determination of condition. The purpose of

this technical reference is to explain how this methodology was developed for lentic

areas and to assist an ID team in answering checklist items by providing examples

of and references to methods of quantification where necessary.
3

II. Method Development

The Bureau of Land Management (BLM), the Fish and Wildlife Service (FWS), and

the Natural Resources Conservation Service (NRCS), formerly the Soil Conservation

Service, worked together to develop the PFC method. The methodology for

assessing the condition of running water (lotic) systems is presented in BLM

Technical Reference (TR) 1737-9, Process for Assessing Proper Functioning

Condition (Prichard et al. 1993), and the methodology for standing water (lentic)

systems is presented in TR 1737-11, Process for Assessing Proper Functioning

Condition for Lentic Riparian-Wetland Areas (Prichard et al. 1994). 

Technical Reference 1737-15, A User Guide to Assessing Proper Functioning

Condition and the Supporting Science for Lotic Areas (Prichard et al. 1998) provides

the background for how the PFC tool was developed. The PFC method has been

implemented by BLM and adopted by several other agencies. In 1996, the BLM

and the USDA Forest Service (FS) announced a cooperative riparian-wetland management strategy, which would include the NRCS as a principal partner. A National

Riparian Service Team was formed to act as a catalyst for implementing this

strategy.

This cooperative strategy recognized that if riparian-wetland areas are to be productive, they have to be managed on a watershed basis, which requires working together

across ownership boundaries. To be successful, the agencies would need to use

common terms and definitions and determine a minimum method for evaluating the

condition of riparian-wetland areas. The BLM and the FS identified the PFC

method as the starting point—as the minimum level of assessment for riparianwetland areas.

5

III. Definitions

To assess the condition of a riparian-wetland area, there must be a gauge to measure

against. The definition of PFC in TR 1737-9 and TR 1737-15 establishes the gauge

for assessing lotic systems. This definition has to be adjusted for lentic systems

because they are affected by wind and wave energies or overland flow energies

versus high flow events, and they typically have a restrictive layer (e.g., geologic

structure/soil material/permafrost/manmade restrictive layer) that limits water percolation and maintains the site:

Proper Functioning Condition - Lentic riparian-wetland areas are functioning properly when adequate vegetation, landform, or debris is present to:

dissipate energies associated with wind action, wave action, and overland

flow from adjacent sites, thereby reducing erosion and improving water

quality; filter sediment and aid floodplain development; improve flood-water

retention and ground-water recharge; develop root masses that stabilize

islands and shoreline features against cutting action; restrict water percolation; develop diverse ponding characteristics to provide the habitat and the

water depth, duration, and temperature necessary for fish production, waterbird breeding, and other uses; and support greater biodiversity.

The components of this definition are in order relative to how processes work on the

ground.

When adequate vegetation, landform, or debris is present to dissipate energy associated with wind and wave action or overland flow, then a number of physical changes

begin to occur, such as reduced erosion, floodplain development, and improved

flood-water retention. As physical aspects of an area begin to function, they start the

process of developing wetland characteristics. These physical aspects have to be

functioning properly to sustain characteristics that provide habitat for resource

values.

For areas that are not functioning properly, changes have to be made to allow them

to recover (e.g., acquire adequate vegetation). A change such as increasing vegetation cover results in changes that improve function. Recovery starts with having the

right elements present to dissipate energy, which puts the physical process into

working order and provides the foundation to sustain the desired condition.

Each riparian-wetland area has to be judged against its capability and potential. The

capability and potential of natural riparian-wetland areas are characterized by the

interaction of three components: 1) hydrology, 2) vegetation, and 3) erosion/

deposition (soils).

Potential is defined as the highest ecological status a riparian-wetland area

can attain given no political, social, or economical constraints; it is often

referred to as the “potential natural community” (PNC).
6

Capability is defined as the highest ecological status a riparian-wetland area

can attain given political, social, or economical constraints. These constraints are often referred to as limiting factors.

Examples of how both potential and capability apply to the checklist and rating can

be found in Appendix B. A more detailed discussion on potential and capability is

found in Appendix B of TR 1737-15.

If a riparian-wetland area is not in PFC, it is placed into one of three other categories: 

Functional—At Risk - Riparian-wetland areas that are in functional condition, but that have an existing soil, water, or vegetation attribute that makes

them susceptible to degradation.

Nonfunctional - Riparian-wetland areas that clearly are not providing adequate vegetation, landform, or woody debris to dissipate energies associated

with flow events, and thus are not reducing erosion, improving water quality,

etc.

Unknown - Riparian-wetland areas for which there is a lack of sufficient

information to make any form of determination.
7

IV. PFC Assessment Procedure

The process for assessing lentic areas involves reviewing existing documents, analyzing the PFC definition, and assessing functionality using an ID team. Each step

is important because it provides a foundation and a certain level of understanding

necessary to complete the next step.

A. Review Existing Documents

An ID team should review TR 1737-9, TR 1737-11, and TR 1737-15 before

assessing functioning condition of lentic riparian-wetland areas. The ID team should

also review the other technical references identified in TR 1737-9 and TR 1737-15,

which provide a basis for assessing PFC, as well as thought processes that will be

useful in assessing the functional status of any riparian wetland area. Reviewing

these documents helps an ID team develop an understanding of the concepts of the

riparian-wetland area they are assessing.

Other documents to review may include Classification of Wetland and Deepwater

Habitats of the United States (Cowardin et al. 1979), local riparian-wetland vegetation

classifications, soil survey reports, and riparian-wetland ecological site descriptions.

The level of information necessary to assess PFC for lentic riparian-wetland areas

will vary. Some will require the magnitude of effort provided by an ecological site

inventory (ESI) to assess functionality, while others can be assessed by using the

lentic checklist in Appendix A. Information pertaining to ESI applications can be

found in BLM’s TR 1737-7, Procedures for Ecological Site Inventory—with Special

Reference to Riparian-Wetland Sites (Leonard et al. 1992a).

When using the PFC method to assess functioning condition, existing files should be

reviewed for pertinent information. For some riparian-wetland areas, enough information may exist to assess functionality without having to go to the field. However,

field verification is desirable, if not necessary, in most cases. For other areas, the

existing information will be useful in establishing capability and potential or trend.

B. Analyze the Definition of PFC

When assessing PFC for lentic riparian-wetland areas, the definition of PFC must be

analyzed. One way to do this is by breaking the definition down as follows:

Lentic riparian-wetland areas are functioning properly when adequate vegetation,

landform, or debris is present to:

• dissipate energies associated with wind action, wave action, and overland

flow from adjacent sites, thereby reducing erosion and improving

water quality; 

• filter sediment and aid floodplain development;
8

• improve flood-water retention and ground-water recharge; 

• develop root masses that stabilize islands and shoreline features against

cutting action;

• restrict water percolation;

• develop diverse ponding characteristics to provide the habitat and the

water depth, duration, and temperature necessary for fish production,

waterbird breeding, and other uses; 

• and support greater biodiversity. 

Lentic riparian-wetland areas are functioning properly when there is adequate stability present to provide the listed benefits applicable to a particular area. The

analysis must be based on the riparian-wetland area's capability and potential. If, for

example, the system does not have the potential to support woody vegetation, that

criteria would not be used in the assessment.

C. Assess Functionality

Assessing the condition of a lentic riparian-wetland area requires an ID team to look

at the entire area. Attributes and processes do not always occur in equal balance

throughout a lentic riparian wetland area. For example, overland flow might enter a

given riparian-wetland area at one end and exit at the opposite end. In order to

answer specific items on the lentic checklist, an ID team is going to have to go to

the location where water and sediment are being supplied from the watershed to

assess balance, to the location of the outlet to assess safe passage of flows, and look

at the entire area to determine if flow patterns are altered by disturbance.

Stratified sampling may be appropriate for lentic areas when you assess and extrapolate from one riparian-wetland area to another area of the same type as long as environmental, management, and other factors relating to the assessment are constant.

Even when these factors are constant, current aerial photos need to be checked to

ensure conditions are the same. The procedure to do this is explained in BLM’s TR

1737-12, Using Aerial Photographs to Assess Proper Functioning Condition of

Riparian-Wetland Areas (Prichard et al. 1996).

1. Attributes and Processes

Assessing PFC involves understanding the attributes and processes occurring in a

lentic riparian wetland area. An ID team must determine the attributes and processes

important to the riparian wetland area that is being assessed. If they do not spend

the time to develop an understanding of the processes affecting an area, their judgement about PFC will be incomplete and may be incorrect. The attributes and

processes for the area being evaluated need to be identified. Table 1 provides a list of

attributes and processes that may occur in any given lentic riparian-wetland area. 

To understand these processes, an example of an Alaskan palustrine wetland area in

both a functional and nonfunctional condition is provided in Figure 1. Applying the
9

Hydrogeomorphic

Ground-Water

Discharge

Recharge

Permafrost

Continuous

Discontinuous

Flood Modification

Inundation

Depth

Duration

Frequency

Semipermanently Flooded

Shoreline Shape

Vegetation

Community Types

Community Type Distribution

Density

Cover

Community Dynamics and Succession

Recruitment/Reproduction 

Root Characteristics

Survival

Erosion/Deposition

Shoreline Stability

Depositional Features

Soils

Soil Type

Distribution of Aerobic/ Anaerobic Soils

Annual Pattern of Soil Water States

Ponding Frequency and Duration

Restrictive Material

Water Quality

Temperature

pH

Dissolved Solids

Dissolved Oxygen

Biotic Community

Aquatic Plants

Recruitment/Reproduction

Nutrient Enrichment

Table 1. Attributes/Processes List.*

* This list provides examples of various attributes/processes that may be present in a riparian- wetland area. By no means is it complete. 

Wet Meadow/Marsh Mesic Meadow

^ Water Table

Water Table >

Mesic Meadow

Stratified

Soil Material

Fragmental

Substrate

Basalt

Bedrock Permafrost

State

B

State

A

Figure 1. Proper functioning condition (State A) and nonfunctional condition (State B) for

a lentic palustrine wetland area.
10

PFC definition, State A would be classified as PFC. Important attributes and

processes present for State A are:

Hydrogeomorphic - Continuous permafrost; shoreline shape; 

and depth, duration, and frequency of inundation.

Vegetation - Community types and distribution, recruitment and 

reproduction, root density, community dynamics, and survival.

Erosion/Deposition - Shoreline stability.

Soils - Distribution of anaerobic soil and ponding frequency and duration.

Water Quality - No change.

Biotic Community - Aquatic plant recruitment and reproduction.

Land activities and natural processes that disrupt the permafrost layer would result

in State A progressing to State B. State B would be classified as nonfunctional.

The following changes in attributes and processes are likely in State B:

Hydrogeomorphic - Continuous permafrost (lost); shoreline shape (changed);

and depth, duration, and frequency of inundation (decreased).

Erosion/Deposition - Shoreline stability (decreased).

Soils - Distribution of anaerobic soil and ponding frequency and duration 

(decreased).

Water Quality - Temperature (increased), pH (changed).

Biotic Community - Aquatic plant recruitment and reproduction (decreased).

The previous example is found in Alaska and represents only one of many types of

lentic riparian wetlands. However, it is important to remember that there are other

types and that:

Riparian-wetland areas do have fundamental commonalities in how they

function, but they also have their own unique attributes. Riparian-wetland

areas can and do function quite differently. As a result, most areas need to

be evaluated against their own capability and potential. Even for similar

areas, human influence may have introduced component(s) that have

changed the area's capability and potential. Assessments, to be correct, must

consider these factors and the uniqueness of each area. 

2. Capability and Potential

Determining functionality of lentic riparian-wetland areas involves determining an

area's capability and potential. The approach is:

• Look for reference areas (relic areas, exclosures, preserves, etc.).

• Seek out historic photos, survey notes, and/or documents that indicate 

historic condition.
11

• Search out species lists (animals and plants - historic and present).

• Determine species habitat needs (animals and plants) related to species that 

are/were present.

• Examine the soils and determine if they were saturated at one time and 

are now well-drained.

• Examine the hydrology; establish the frequency and duration of 

flooding/ponding.

• Identify vegetation that currently exists and determine if the same species 

occurred historically. 

• Determine the entire watershed's general condition and identify its major 

landform(s).

• Look for limiting factors, both human-caused and natural, and determine if 

they can be corrected.

This approach forms the basis for initiating an inventory effort like ESI. For some

areas, conducting an ESI effort will be the only way to assess an area's capability

and potential.

3. Functioning Condition

The steps in Figure 3 of TR 1737-15 provide examples of the relationship between

PFC and vegetation community succession for a lotic riparian-wetland area. This

relationship can be applied to lentic riparian-wetland areas as well. If vegetation

succession continues uninterrupted (Step 1 to Step 2), the riparian-wetland site will

progress through some predictable changes from early seral to potential natural community (although not necessarily as linearly as depicted). As the vegetation community progresses, the riparian-wetland area will advance through phases of not

functioning, functioning at-risk, and functioning properly.

At various stages within this successional process, the riparian-wetland area will

provide a variety of values for different uses (Step 4). Optimal conditions for

grazing occur when forage is abundant and the area is stable and sustainable.

Wildlife goals depend upon the species for which the area is being managed. If the

riparian-wetland area is to provide nesting habitat for songbirds, the optimum conditions might be late seral. If the area is to provide feeding habitat for shorebirds, the

optimum condition might be mid-seral. Lentic riparian-wetland areas can function

properly before they achieve their potential. The PFC definition does not mean

potential or optimal conditions for a particular species have to be achieved for an

area to be rated as functioning properly. The threshold for any goal is at least PFC

because any rating below this would not be sustainable. For riparian-wetland

areas, PFC may occur from early seral to late seral. Desired plant community

(DPC) is then determined based on management objectives through an interdisciplinary approach (Step 5 in Figure 3, TR 1737-15), eventually achieving the desired

condition (Figure 2). Plant communities and future condition need to be balanced

within a watershed(s) and within an ecoregion(s).
12

Figure 2. A riparian-wetland area in PFC may contain several different plant communities. A

desired management condition may include several of these communities in some proportion.

When determining whether a lentic riparian-wetland area is functioning properly, it

is important to determine the condition of the entire watershed. The entire watershed can influence the quality, size, and stability of a riparian-wetland area by

affecting production of sediment, water, and nutrients, influencing inundation/

saturation frequency and duration, and modifying the distribution of chemicals.

When rating functionality, it will be easy to categorize many lentic riparian-wetland

areas as being in PFC or nonfunctional. For others it will not be easy. Difficulty in

rating PFC usually arises in identifying the thresholds that allow a riparian-wetland

area to move from one category to another. Using the lentic checklist (Appendix A)

helps to ensure consistency in assessing functionality.

This checklist may not answer the question of functionality for all lentic riparianwetland areas. On occasion, ID teams will find that blending the lentic checklist

with the lotic checklist is necessary to assess functionality for some riparian-wetland

areas. Some areas may require a more intensive inventory, like ESI. ID teams can

add elements to the lentic checklist to address unique riparian wetland attributes and

processes. If an item is added, an ID team needs to make sure this addition can be

quantified. Appendix C provides examples of lentic riparian-wetland areas that

depict the categories of PFC, functional—at risk, and nonfunctional to further assist

in assessing functionality. 

As with any tool, PFC has its limits. Appendix D describes what PFC is and isn’t,

and what it can and can’t do.

Riparian-Wetland Area

Desired Condition

Proper Functioning Condition

Minimum threshold

Vegetative community succession

Each desired plant community (DPC) is based

on management objectives and values that are

determined through an interdisciplinary approach

D

P

C

D

P

C

12 3 4 5

D

P

C

D

P

C

D

P

C
13

4. Functional Rating

Following completion of the checklist, a “functional rating” is determined based on

an ID team’s discussion. When determining the functional rating, it is important for

the ID team to understand the type of riparian-wetland being assessed. Appendix E

provides examples of some of the more common riparian-wetland types while

Appendix F provides examples of some of the more complex riparian-wetland types.

The ID team must review the “yes” and “no” answers on the checklist and their

respective comments about the severity of the situation, then collectively agree on a

rating of proper functioning condition, functional—at risk, or nonfunctional. If an

ID team agrees on a functional—at risk rating, a determination of trend is then made

whenever possible.

There is no set number of “no” answers that dictate whether an area is at-risk or

nonfunctional. This is due to the variability in kinds of lentic riparian-wetland areas

(based on differences in climatic setting, geology, landform, and substrate) and the

variability in the severity of individual factors relative to an area’s ability to withstand wind action, wave action, and overland flow. A properly functioning

riparian-wetland area will provide the elements contained in the definition:

• dissipate energies associated with wind action, wave action, and overland

flow from adjacent sites, thereby reducing erosion and improving water

quality

• filter sediment and aid floodplain development

• improve flood-water retention and ground-water recharge

• develop root masses that stabilize islands and shoreline features against 

cutting action

• restrict water percolation

in accordance with its capability and potential.

If a riparian-wetland area possesses these elements, then it has a high probability to

withstand wind action, wave action, and overland flow events. If all the answers

on the checklist are “yes,” this area is in proper functioning condition. However, if

some answers on the checklist are “no,” this area may still meet the definition of

PFC. The ID team reviews the “no” answers and determines if any of these answers

make this riparian-wetland area susceptible to degradation from wind action, wave

action, and overland flow events. If they do, the ID team would rate the area and

explain why it is something less than PFC.

A functional—at risk riparian-wetland area will possess some or even most of the

elements in the definition, but have at least one attribute/process (Table 1) that gives

it a high probability of degradation with wind action, wave action, and overland

flow event(s). Most of the time, several “no” answers will be evident because of the

interrelationships between items. If the ID team thinks that these “no” answers collectively provide the probability for degradation from the events mentioned above,

then the rating is functional—at risk. If there is disagreement among team members

after all comments have been discussed, it is probably advisable to be conservative

in the rating (i.e., if the discussion is between PFC and functional—at risk, then the
14

rating should be functional—at risk). One situation where only one “no” answer

indicates a lentic riparian wetland area is at risk is when a structure is not accommodating safe passage of flows because a headcut is starting to affect the dam or

spillway. The riparian-wetland above the structure is then rated as functional—at

risk regardless of other factors. The prairie pothole wetland example in Appendix C

provides an example of this.

Trend must be determined, if possible, when a rating of functional—at risk is given.

Preferably, trend is determined by comparing the present situation with previous

photos, trend studies, inventories, and any other documentation or personal knowledge attained in a review of existing documents or interviews prior to the PFC

assessment. In the absence of information prior to the assessment, indicators of

“apparent trend” may be deduced during the assessment process. Recruitment and

establishment of riparian-wetland species (or the absence thereof) that indicate an

increase (or decline) in soil moisture characteristics can be especially useful.

However, care must be taken to relate these indicators to recent climatic conditions

as well as to management. If there is insufficient evidence to make a determination

that there is a trend toward PFC (upward) or away from PFC (downward), then the

trend is not apparent.

Nonfunctional riparian-wetland areas clearly lack the elements listed in the PFC

definition. Usually nonfunctional riparian-wetland areas translate to a preponderance of “no” answers on the checklist, but not necessarily all “no” answers. A

riparian-wetland area may still be saturated at or near the surface or inundated in

“relatively frequent” events, but be clearly nonfunctional because it lacks vegetation

to protect the area from erosion and deposition. The lack of vegetation and inability

to buffer the sediment being supplied greatly reduce the extent of this wetland and

prevent it from recovering.

It is imperative for management interpretation of the checklist to document factors contributing to unacceptable conditions outside management’s control for 

functional—at risk and nonfunctional ratings where achievement of PFC may be

impaired. It is desirable to document any of the factors listed if they occur, even if they

don’t appear to be affecting the achievement of PFC. Their presence may still affect

achievement of desired condition for other values when compared to a natural system.

D. Institute the Process

1. Planning

The process established in TR 1737-15 for incorporating information into a management plan would apply to lentic riparian-wetland areas also:

Step 1 Existing Condition - Determine the existing riparian-wetland and 

watershed condition using the standard checklist.

Step 2 Potential - Each area is assessed relative to its potential. Determine 

potential by using reference areas, historic photos, etc. (ESI process).
15

Step 3 PFC - Determine the minimum conditions required for the area to 

function properly.

Step 4 Resource Values - Determine existing and potential resource values and 

the plant communities necessary to support these values. 

Step 5 Management Goals - Identify specific objectives to reach management 

goals for the watershed, PFC, DPC, or DC.

Step 6 Planned Actions - Design management actions to achieve PFC and 

then DC.

Step 7 Monitoring - Design appropriate monitoring strategies to assess 

progress towards meeting management goals.

Step 8 Flexibility - Maintain management flexibility to accommodate 

change based upon monitoring results.

2. Management 

Successful management of lentic riparian-wetland areas requires implementation of

a well-conceived plan. Appropriate strategies and practices that consider the entire

watershed should be used. Upland and lentic riparian-wetland areas are interrelated

and cannot be managed separately.

Inferences about habitat condition can be made from the PFC assessment.

Generally, a lentic riparian-wetland area in nonfunctional condition will not provide

quality habitat conditions. One that is in PFC can be expected to provide at least

some quality habitat. Additionally, an area in PFC can be managed for improved

habitat, if that is an objective.

The PFC assessment can be used as a tool for prioritizing either additional inventory

needs or restoration activities. PFC provides a sorting that allows the establishment

of priorities. Functional—at risk areas with a downward trend should receive priority for treatment. These areas may be near the threshold of rapidly degrading into

a nonfunctional condition. Planned actions to begin recovery can usually be implemented at a much lower cost in these areas. Once an area is nonfunctional, the

effort, cost, and time required for recovery may dramatically increase.

Restoration of nonfunctional systems should be reserved for those situations when: 

• recovery is possible,

• efforts are not at the expense of at-risk systems,

• or unique opportunities exist.

At the same time, areas that are functioning properly are usually not the highest priorities for restoration because they are more resilient than the at-risk areas. It is crit-
16

ical to manage PFC areas to retain their resilience and further recovery toward

desired condition. Identifying systems in PFC also allows local managers to assess

why these systems have fared well in the past and to possibly use them as models

for recovery of similar systems.

The PFC assessment can also help determine the appropriate timing and design of

riparian-wetland restoration projects (including structural and management changes). It

can identify situations where structures are either entirely inappropriate or premature.

The results of the PFC assessment can be used in watershed analysis. While the

methodology and resultant data are site-specific, the ratings can be aggregated and

analyzed at the watershed scale. The PFC method is most useful when condition is

determined based on local information, experience, and knowledge of functions and

processes at the watershed scale. Information from the PFC assessment, along with

other watershed and habitat condition information, helps provide a good picture of

watershed health and the possible causal factors affecting watershed health. Using

the PFC method will help to identify watershed-scale problems and suggest management remedies and priorities. These management decisions are derived by concentrating on the “no” answers on the checklist. Additional uses for this information

can be found in TR 1737-15, Appendix E.

There are other documents that can be helpful in assisting with this process: BLM’s

TR 1737-14, Grazing Management for Riparian-Wetland Areas (Leonard et al.

1997), provides grazing management principles, concepts, and practices that have

been effective in improving and maintaining desired conditions on riparian-wetland

areas, and Prescribed Grazing (USDA NRCS Field Office Technical Guide, Section

IV, Practice No. 528) provides guidance for establishing grazing management plans.

For other forms of management, such as recreation development, mining opportunities, timber practices, and watershed treatments, BLM’s TR 1737-6, Management

Techniques in Riparian Areas (Smith and Prichard 1992), provides suggested practices. With a change in management, most riparian-wetland areas can achieve PFC

in a few years, but some will take many years to achieve the identified DPC or

advanced ecological status.

3. Monitoring 

Management effectiveness and progress can be assessed and documented with monitoring. A good monitoring plan, including a schedule for field visits and the protocol

to be used, must be developed as a part of the management plan. For monitoring to

be effective, field sites must be revisited on a scheduled basis. Monitoring reflects

trends and will show whether the planned objectives are being achieved.

A number of references are available to help when developing monitoring plans.

Inventory and Monitoring of Riparian Areas, BLM TR 1737-3 (Myers 1989), provides

guidance. The Integrated Riparian Evaluation Guide (USDA FS 1992) provides some

specific protocols that can be used for monitoring riparian-wetland areas. The National

Range and Pasture Handbook (USDA NRCS 1998c) provides general guidance for

rangeland monitoring, which can also be used for riparian-wetland area monitoring.
17

V. Quantification of Checklist Items

As long as the procedure is followed and the definitions are understood, the PFC

assessment will work for most sites because it was developed from rigorous science

(ESI) and is performed by a trained and experienced ID team. However, there will

be times when items from the checklist need to be quantified.

There is a considerable body of literature addressing relationships between soils,

vegetation, hydrology, and other riparian-wetland functions, as well as a growing

number of “success stories” from which empirical comparisons can (and have) been

made. The references presented here are selected as examples of supporting documentation for the PFC assessment. By no means are these references allencompassing, as there are many other ways to quantify these items.

The checklist items are designed to address the common attributes and processes

that have to be in working order for a lentic riparian-wetland area to function properly. Each item on the checklist is answered with a “yes,” meaning that the attribute

or process is working, a “no,” meaning that it is not working, or an “N/A,” meaning

the item is not applicable to that particular area. For any item marked “no,” the

severity of the condition must be explained in the “Remarks” section and must be

discussed by the ID team in determining riparian-wetland functionality. Using the

“Remarks” section to also explain items marked “yes” is encouraged but not

required.

The intent of each checklist item, examples of how each item might be answered,

and ways to quantify each item are outlined below. These examples should not be

misconstrued as a cookbook, as there are many riparian-wetland types. Before

assessing condition of any riparian wetland area, its attributes and processes have to

be defined to answer the checklist items correctly.

It is important to note that many of the checklist items are closely related. This provides a system of checks and balances for how any one item is answered. For

example, if item 6 (natural surface or subsurface flow patterns are not altered by disturbance) is answered “yes” for a recovering system, item 1 should be answered

“yes” because the riparian-wetland area is being saturated or inundated in relatively

frequent events. It is also important to note the items are numbered for the purpose

of cataloging comments and that the numbers do not declare importance. The

importance of any one item will vary relative to a riparian-wetland area’s attributes

and processes. However, there is an order to when some of the items are answered

“yes.” Any time item 13 is answered “yes,” more than likely items 8, 9, 10, and 11

will be answered “yes.” For a riparian-wetland area to recover or be maintained, the

right plants have to establish themselves and then produce the adequate amount of

cover. The supporting science for some of the items is the same or overlapping.

Explanations are with the most appropriate items, but some cross-referencing may

be required. 
18

A. Hydrology

Hydrologic attributes and processes are addressed in this section relative to presence

and function. The term “wetland hydrology” encompasses all hydrologic characteristics of lentic areas that are periodically inundated or have soils saturated to the surface at some time during the growing season. Areas with evident characteristics of

wetland hydrology are those where the presence of water has an overriding influence

on characteristics of vegetation and soils due to anaerobic and reducing conditions,

respectively. Such characteristics are usually present in areas that are inundated or

saturated to the surface for sufficient duration to develop hydric soils and support

vegetation typically adapted for life in periodically anaerobic soil conditions.

Hydrology is often the least exact of the parameters, and indicators of wetland

hydrology are sometimes difficult to identify in the field. However, it is essential to

establish that a wetland area is periodically inundated or has saturated soils during

the growing season (Prichard et al. 1994).

The Federal Government’s standard for classifying wetlands is described in Cowardin

et al. (1979), which is available on the Internet at http://www.nwi.fws.gov. This

system provides ecological and hydrological information for the identification, classification, and mapping of wetlands and deepwater habitats in the United States and its

territories. The standard was selected by the Federal Geographic Data Committee in

1996. Systems are the highest level of the classification hierarchy; five are defined—

marine, estuarine, riverine, lacustrine, and palustrine. Systems are further divided by

subsystems and classes. Water regime, water chemistry, and soil modifiers are used

at the class level to further describe wetlands. For riverine systems, the process for

assessing PFC for lotic systems should be used (TR 1737-15). Palustrine wetlands

that are periodically inundated from overbank flows may occur adjacent to riverine

systems, but are not included as part of the riverine system. In those cases, and in

others where a mixture of lotic and lentic systems occur, both the lotic and lentic PFC

definitions and checklist questions should be examined in order to understand the

important attributes and processes of those systems.

BLM’s TR 1737-7 (Leonard et al. 1992a) details field procedures for describing and

documenting site information (ESI) as it applies to the interaction of soils,

hydrology, and vegetation for riparian-wetland resources and uplands. This method

is a rigorous science base for classifying riparian-wetland sites and the quantitative

measures used in ESI can be used for items 1-7 in the hydrology section of the

checklist.

References associated with the hydrogeomorphic model (HGM) (Brinson 1993;

Smith et al. 1995; Brinson et al. 1995; and Walton et al. 1995) describe another

approach for assessing wetland functions that could also be used for items 1-7 in the

hydrology section. The HGM approach includes a development and application

phase. In the development phase, wetlands are classified into regional subclasses

based on hydrogeomorphic factors. A functional profile is developed to describe the

characteristics of the regional subclass, identify the functions that are most likely to

be performed, and discuss the characteristics that influence how those functions are
19

performed. Reference wetlands are selected to represent the range of variability

exhibited by the regional subclass in a reference domain, and assessment models are

constructed and calibrated by an ID team based on reference standards and data

from reference wetlands. Reference standards are the conditions exhibited by the

undisturbed, or least disturbed, wetlands and landscapes in the reference domain.

The functional indices resulting from the assessment models provide a measure of

the capacity of a wetland to perform functions relative to other wetlands in the

regional subclass. The application phase of the approach or assessment procedure

includes characterizing the wetland, assessing its functions, analyzing the results of

the assessment, and applying them to a specific project (Smith et al. 1995).

Item 1: Riparian-wetland area is saturated at or near the 

surface or inundated in “relatively frequent” events

Purpose

Water creates and maintains all wetlands. Cowardin et al. (1979) state, “In general

terms, wetlands are lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface.” The purpose of item 1 is to document that

inundation or saturation is long enough in duration and occurs frequently enough to

maintain wetland characteristics.

Examples

Item 1 would be answered “yes” if evidence of inundation or saturation, such as

hydric soils, standing water, or recent deposits of sediment and/or debris on the

floodplain from overbank flows, is apparent. Another indicator for a “yes” answer

would be if obligate wetland (OBL) species and/or facultative wetland (FACW)

species dominate a site. Additional information on how vegetation is used as a wetland indicator is provided in the vegetation section. 

Item 1 would be answered “no” if the evidence of saturation or inundation is less

than in the past. One indicator of this may be where obligate upland (UPL) and facultative upland (FACU) species are encroaching on OBL and FACW species, indicating a loss of hydrology. Another indicator is a soil with hydric properties, which

presently lacks periods of inundation or saturation.

There is a strong relationship between item 1 and items 3, 6, 10, and 17. If item 1 is

answered “no,” then these items will usually be answered “no” also.

Supporting Science/Quantitative Methodologies

Even though the factors influencing the wetness of an area are numerous (e.g., precipitation, topography, soil characteristics, plant cover, ground water), all lentic sites

have a source of water consistent enough to cause anaerobic (no oxygen) and

reducing (i.e., loss of electrons from metal or metallic element) conditions. The
20

source of water for riparian-wetland areas may be precipitation, runoff, flooding,

tidal influence, ground water, or some combination of sources.

Inundation or saturation must occur often enough (frequency) and long enough

(duration) to develop and maintain the anaerobic and reducing conditions. Both

“measurements” and “field observations” are helpful to document that saturation or

inundation is occurring in the “relatively frequent” events within the potential or

capability of the site. Local knowledge and historical records should be used as

much as possible, especially where problem wetlands are concerned. If a jurisdictional wetland determination is made, the U.S. Army Corps of Engineers (COE)

1987 Wetlands Delineation Manual should be consulted for information on the criteria, primary indicators, and secondary indicators necessary to meet the wetland

hydrology, soils, and vegetation requirements. However, within the context of PFC,

riparian-wetland areas are broadly defined to include nonjurisdictional types that do

not meet the hydric soils or wetland hydrology definition in U.S. Army COE (1987)

or the Clean Water Act.

Where available, hydrology data from local soil surveys should be used in conjunction with recorded data. Gage data, such as lake, tidal, ground water, and stream

stage, along with precipitation data, are available from different sources, depending

on the location. These sources include the U.S. Geological Survey (USGS); COE

District Offices; Bureau of Reclamation (BOR); NRCS; Tennessee Valley Authority

(TVA); National Oceanic and Atmospheric Administration (NOAA); Highway

Departments; and other State, County, and local agencies.

USDA NRCS (1997) describes a nine-step process for using stream and lake gages

to document the timing, duration, and frequency of inundation adjacent to streams

and lakes. At least 10 years of gage data during the growing season are needed.

The highest stage of each year that is exceeded for a predetermined duration is determined. If the inundation criterion is 7 days, the lowest stage occurring during those

7 days of high flow is recorded. The median recorded stage readings are tabulated

in descending order, and the median value computed. Any land in the immediate

vicinity of the gage below this median elevation would be inundated for the inundation criterion by out-of bank flooding during the growing season in 50 percent of the

years, thus meeting the wetland criterion.

Few riparian-wetland areas have sufficient existing information on ground-water conditions or wells for mapping the water table, so it may be necessary to install well

points. Well points are small-diameter (1-1/4- to 3-inch) metal or PVC well casings

with short screened intervals to allow water to flow into the casings. The COE has

installation procedures for placing monitoring wells in wetlands (Sprecher 1993).

The NRCS state geologist or hydraulic engineer can also provide information on

specifications for installing, casing, and sealing wells; taking and recording measurements; and local regulations concerning well development (USDA NRCS 1997). 

Existing wells were likely drilled into the regional aquifer for water supply, and the

water level might not be representative of the shallow ground-water conditions that
21

support the riparian wetland area of interest. Using information from both nearby

existing wells and installed well points helps an ID team to determine whether the

riparian-wetland area is the result of a perched aquifer or is hydraulically connected

to a regional system. This information is crucial for determination of regional

versus local effects. Details on well depth, screened interval, and date of drilling for

many wells are available from the USGS Water Resources Division. Well information for many wells drilled on public land and assistance in designing/planning

ground-water monitoring projects can be obtained from BLM’s National Applied

Resource Sciences Center.

Aerial photographs are useful for documenting evidence and extent of wetland

inundation or soil saturation (Clemmer 1994; Prichard et al. 1996). Comparing several years of photos will help in interpreting the effect of very dry or very wet

periods. Acquiring photos taken during similar seasons or months will provide a

more accurate comparison. Photography can also assist in preliminary identification

of lentic sites for further field investigation based on the spectral response of localized vegetation around the site. 

USDA NRCS (1997) describes a method using annual rainfall data and aerial photographs to document wetland hydrology. The annual rainfall total for each year is

compared to the annual boundaries for wet and dry from the WETS table (see

www.wcc.nrcs.usda.gov and click on climate for WETS table and associated documentation). The WETS table identifies the boundary where 3 in 10 of the precipitation amounts are wetter than normal value and the boundary where 3 in 10 values

are drier than normal. Normal is considered to be values that fall between these two

boundaries. Aerial photographs from years of average precipitation are compared

with aerial photographs from wet years and dry years. If a wet signature appears for

a site only in wet years, a good probability exists that wetland hydrology is not present under normal circumstances. If a wet signature is seen in both dry and wet

years, the site may well meet wetland hydrology criteria. Where the wet signatures

appear in wet and normal years, further study is needed to determine whether wetland hydrology exists on the site.

While recorded data can provide valuable information, field observations are also

important. There are a number of hydrologic indicators that can be observed in the

field: 

• Inundation. Seasonal conditions and recent weather conditions should be 

considered. Surveyed cross sections can be used to document the elevation 

of high water. Harrelson et al. (1994) is a good reference for surveying 

basics and surveying cross sections. 

• Soil saturation. Digging a soil pit to a depth of 16 inches and observing the 

water level in the hole after sufficient time has been allowed for water to 

drain into the hole will indicate soil saturation. The time required varies 

depending on the soil texture. In some cases, the depth to the water table (or 

upper level at which water is flowing into the pit) can be observed by 
22

examining the wall of the hole. Because of the capillary fringe, saturated 

soils will be nearer the surface (U.S. Army COE 1987). 

Using an auger hole to confirm saturation may be inaccurate or misleading in

clayey soils when only macropores are filled with water. Macropores may

have filled during a recent rain while the soil matrix remained unsaturated.

Tightly sealed piezometers or tensiometers are recommended to confirm saturation. These instruments should be sealed with clay (e.g., bentonite) to

prevent surface water from running down the sides of the instruments

(Vepraskas 1994).

There are hydric soils indicators that will show that wetland hydrology is

present or has been present at some time. Histosols, Histic Epipedon, Black

Histic, Hydrogen Sulfide Odor are usually saturated or inundated for much of

most years for soil of all textures. Sandy Gleyed Matrix, Polyvalue Below

Surface, Thin Dark Surface are the wetter hydric soil indicators for soil with

sand or loamy sand soil textures. Loamy Gleyed Matrix, Thick Dark Surface

are the hydric soil indicators for wetter soils of soil textures of sandy loam,

sandy clay loam, clay loam, loam, silt loam, silty clay loam, sandy clay, and

clay. While soils with all other hydric indicators will require a shorter duration of saturation or inundation, they will still have or have had wetland

hydrology. See item 17 for more information on hydric soils.

Steel rods (rebar) can also be used to measure the depth to the water table in

a wetland (Brigdham et al. 1991). Rebar is pounded into the wetland soil.

The oxidation/reduction process that occurs during saturation will change the

color of the steel rod and can be measured to indicate the depth to water

table.

• Watermarks. Watermarks can be observed on fixed objects, such as woody 

vegetation, bridge pillars, fences, bedrock, or boulders. 

• Drift lines. Evidence consists of linear deposition of debris or debris 

entangled in fixed objects such as vegetation. Debris is usually deposited 

parallel to the direction of water flow and provides an indication of the 

minimum portion of the area inundated during a flooding event.

• Sediment deposits (mineral or organic). Sediment deposition on vegetation 

and other objects provides an indication of the minimum inundation level.

• Drainage patterns (surface evidence of drainage flow into or through an 

area). Evidence consists of drainage patterns eroded into the soil, debris 

oriented perpendicular to the direction of water flow, or the absence of leaf 

litter. Scouring is often evident around roots of persistent vegetation. 

Because drainage patterns also occur on upland areas (i.e., ephemeral 

channels), topographic position must also be considered. 
23

• Oxidized rhizospheres (zone of soil where living plant root and 

microorganisms occur). These are associated with living plant roots in the 

upper 12 inches of the soil.

• Water-stained leaves (works better in the eastern United States than in the 

western United States). Water stains on leaf litter indicate areas that have 

been inundated with water.

• Vegetation. Vegetation can be a useful indicator that an area is being 

saturated near the surface or inundated often enough. Existing vegetation 

needs to be compared against the potential for the site using an ecological 

site description, vegetation classification, or similar reference. When 

riparian-wetland species are not clearly dominant on a site, the FAC-neutral 

test (U.S. Army COE 1987) can be used and compared to the potential.

• Soil Survey Data. This data provides climatic information, soil 

classifications, and wetness characteristics of soils, such as frequency, 

duration, and timing of inundation.

Indicators above are mostly from the U.S. Army COE 1987 Wetland Delineation

Manual. For nonjurisdictional riparian-wetland areas, the water table and wetland

soil criteria may occur at a greater depth.

Item 2: Fluctuation of water levels is not excessive

Purpose

Riparian-wetland vegetation plays an important role in the stability of most lentic

riparian-wetland areas. Periodic flooding or saturation of these areas is necessary to

promote and sustain this vegetation, but to do so, these water level changes must be

within the range of plant tolerance. The purpose of item 2 is to determine if these water

level changes are within the limits that will sustain the riparian-wetland vegetation.

Examples

Most lentic riparian-wetland areas require vegetation to function properly. The vegetation on these sites for the most part should be OBL and/or FACW species. If a

riparian-wetland area is dominated by OBL and/or FACW species, the answer to

item 2 would be “yes.” However, some lentic riparian-wetland areas only have the

potential to produce facultative (FAC) species (see Appendix F). The answer to item

2 would be “yes” if these sites are dominated by FAC species. There are some sites

that only produce OBL, FACW, FAC species during wet years and are dominated by

UPL species during dry years (see Appendix F). The answer to item 2 would be

“yes” if these sites are producing OBL, FACW, or FAC species during wet years

even though they are dominated by UPL species during dry years, as this is the norm

(see playa wetland example from New Mexico in Appendix B). Understanding the

potential of the site is critical in order to answer the question correctly.
24

Item 2 would be answered “no” if bare soil or annual UPL species are present in

place of OBL and FACW species as a result of changes in the water level. An

example of this is a reservoir with constantly fluctuating water levels resulting in a

zone of no vegetation. Other wetlands can also experience this if water is removed

or added on an irregular basis. Natural systems will occasionally experience this as

a result of irregular water fluctuation. Again, understanding site potential is crucial

in these situations.

“N/A” would apply for those wetland types that do not require riparian-wetland 

vegetation to function properly.

There is a strong relationship between item 3 and items 1, 10, 12, and 17. If item 3

is answered “no,” then these items will often be answered “no” as well.

Supporting Science/Quantitative Methodologies

Riparian-wetland plants living along the edges of standing water bodies have

adapted so that during drying periods, as long as water levels do not drop drastically,

the plants will expand and occupy the newly exposed sites. During wetter periods,

as the water body fills up again, some plants may be drowned out around the edges.

If the elevation of the water level changes faster than the plants can respond, a

“bathtub ring” effect occurs where riparian-wetland plants cannot survive, leaving

bare ground. Excessive ground-water fluctuations or the combination of excessive

ground-water and surface-water changes can cause similar vegetation effects. The

“bathtub ring” effect is very obvious on aerial photos.

The recorded data discussed in item 1 can be used to document water level changes

for this item (i.e., lake gage data). Comparing the rate of fill and the rate of withdrawal with similar systems in the region will help determine whether the water

fluctuation is appropriate because of site potential or is a problem accelerated by

some human-caused disturbance.

Item 3: Riparian-wetland area is enlarging or has achieved

potential extent

Purpose

Depending on a lentic area’s site characteristics, degradation can lead either to accelerated sedimentation (filling in faster) or to loss or lowering of the water table.

Either process has a detrimental effect on the riparian-wetland vegetation. Some

riparian-wetland areas initially appear to be enlarging as they fill in. Deposition

around shorelines provides more shallow water area for emergent vegetation.

However, over the long-term, there is a decrease in extent as the circumference

shrinks with declining catchment capacity. A loss or lowering of the water table can

result in water stress (loss of vigor), lowered production, and eventually a complete

loss of riparian-wetland vegetation. Recovery is expressed by an increase in

riparian-wetland vegetation. The purpose of item 3 is to determine if a riparianwetland area is recovering or has recovered.
25

Item 3 addresses two situations, enlarging or achieving potential extent, in order that

a “yes” answer is always applied for a positive attribute or process.

Examples

Evidence that a riparian-wetland area is widening/enlarging may include an increase

in the amount of appropriate vegetation (i.e., sedges, rushes, willows) that is

replacing upland species, a rising water table, and the establishment of riparianwetland vegetation in soils deposited along a shoreline/soil surface. Any of this

evidence would result in a “yes” answer for item 3.

Potential extent can be largely determined by the adjacent topography (e.g., valley

bottom width). If a riparian-wetland area has achieved potential extent, the answer

to item 3 would be “yes.”

Evidence that a riparian-wetland area is shrinking in extent may include an increase

in upland vegetation (e.g., sagebrush, rabbitbrush, cheatgrass) and replacement of

riparian-wetland species, such as sedges and rushes, with more drought-tolerant

species, such as Kentucky bluegrass, western wheatgrass, and cheatgrass (especially

on small raised areas). Any of this evidence would result in a “no” answer for item

3. The age of these nonwetland plants should be noted to determine the apparent

trend. If they are old and the wetland species present are young and vigorous, the

area may be enlarging rather than shrinking.

For areas where there is no potential for vegetation, an “N/A” answer would be

given, as landform dictates functionality.

There is a strong relationship between item 3 and items 1, 10, 12, and 17. If item 3

is answered “no,” then these items will often be answered “no” as well.

Supporting Science/Quantitative Methodologies

The presence of hydric soil and riparian-wetland vegetation are indicators of soil

moisture conditions and water table. Soils and vegetation are key in delineating the

extent of riparian wetland areas. Some hydric soil indicators, such as redoximorphic

features, can persist in the soil even after a water table drops, indicating that the

extent of a riparian-wetland area has been reduced. Change in composition from

upland species like sagebrush to riparian-wetland species like Nebraska sedge is a

good indicator that the riparian-wetland area is widening. 

Where available, original survey notes should be obtained. Often the original surveyors made notes about the riparian-wetland areas they saw, and their observations

can be very helpful in comparing a site with current riparian-wetland extent.

Aerial photos are a great tool for documenting change over time in riparian-wetland

area acreages (Clemmer 1994; Prichard et al. 1996). The National Aerial

Photography Program (NAPP) provides coverage of the lower 48 states every 5 to 7

years. Some shrinking and expansion of riparian-wetland areas can be associated
26

with climate fluctuation. However, there may be a time lag for areas that are dependent on ground-water recharge.

To measure riparian-wetland extent in the field, several transects for soils and vegetation information should be established perpendicular to the down valley axis of the

riparian complex. For soils, standard identification and delineation procedures

(USDA NRCS 1998b and other NRCS soils manuals and handbooks; U.S. Army

COE 1987) should be used. Vegetation community complex composition can be

assessed using a line intercept transect (USDA FS 1992). Additional detail is

included in the supporting science for the vegetation section (the questions are interrelated).

Monitoring wells discussed in item 1 can also be used to measure the expansion or

contraction of a riparian-wetland.

Item 4: Upland watershed is not contributing to 

riparian-wetland degradation

Purpose

The condition of the surrounding uplands can greatly affect the condition of a

riparian-wetland area. Changes in upland condition can influence the magnitude,

timing, or duration of overland flow events, which in turn can affect a riparianwetland area. The purpose of item 4 is to determine if there has been a change in

the water or sediment being supplied to a riparian-wetland area, and whether it is

resulting in degradation. Although a correlation can exist, the focus here is on

whether uplands are or are not contributing to degradation, and not on the condition

of the uplands.

Examples

It is possible to have disturbances in the uplands and still not see major changes in

magnitude, timing, or duration of overland flows having a negative impact on

riparian-wetland areas. If there is no evidence of erosion deposits from the uplands

that are degrading a riparian-wetland area, the answer to item 4 is “yes,” even if the

uplands are not in good condition.

Evidence that a riparian-wetland area is being degraded could include the formation

of a large delta or sediment plumph where the overland flow enters a riparianwetland, indicating that the water and sediment are not in balance with the watershed

(see item 19). If this characteristic is present, the answer to item 4 would be “no.”

Item 4 will never be answered “N/A;” it will always have a “yes” or “no” answer. 

There is a strong relationship between item 4 and item 19. If item 4 is answered

“no,” then item 19 will usually be answered “no” also.
27

Supporting Science/Quantitative Methodologies 

The watershed surrounding a riparian-wetland area can influence the hydrologic

regime, water quality, sediment supply, and plant community composition. Water

quality is discussed in item 5, and plant community composition is discussed in the

vegetation section.

The hydrologic functions of riparian-wetland areas are governed by a water budget and

a sediment budget. Depending on the type of riparian-wetland area, water enters a

wetland as precipitation, incoming channel flow, overbank flow, overland flow from

adjacent slopes, ground-water discharge, or some combination of these. Water is

stored in a wetland as surface and subsurface storage, and is lost as runoff, evaporation/transpiration, and/or ground-water recharge. Sediments are deposited in a wetland

from bedload, filtered from surface runoff, or precipitated from dissolved minerals in

runoff and ground-water flows, and are lost through erosion (Zeedyk 1996). When a

natural system is in dynamic equilibrium, it maintains a level of stability that permits

internal adjustments of variables without producing rapid changes to the system.

Detrimental changes in water supply come from constraining or diverting surface

and/or subsurface flows. An example would be upslope road ditches and cross

drainage structures installed in a manner that concentrates overland flows away from

the riparian-wetland area, causing desiccation of meadow soils (Zeedyk 1996). If

human disturbance in a watershed increases the sediment delivery to a riparianwetland area, the progression of states can be accelerated (Figure 3).

Aerial photos that cover several years or decades can be used to identify riparianwetland adjustments through time for a particular riparian-wetland complex.

Information on the use of aerial photos is provided in Clemmer (1994) and Prichard

et al. (1996). Most of the photo interpretive techniques and procedures described in

Prichard et al. (1996) for lotic sites can be applied to lentic sites.

A simplified method for analyzing a wetlands water budget and determining the relative importance of hydrologic and hydraulic processes is described in Walton et al.

(1995). The processes can be based on the following balance equation:

Qi + R + G = Qo + ET + I

where

Qi = surface water flow into the system

R = direct rainfall on the wetland

G = ground-water discharge to the wetland

Qo = surface water flow out of the system

ET = evapotranspiration from the wetland

I = infiltration to the ground water.
28

Figure 3. Filling and aging of a pond. State A: The pond is recently formed and deep,

with steep, rocky walls. The water is very clear and productivity is low, with sparse

plankton, no shore vegetation, and no bottom algae. Sediments, primarily silt brought in by

streams, are beginning to accumulate on the bottom. State B: The pond has accumulated

substantial sediments and is partly filled and the rock walls have eroded and are less steep.

There is some shore vegetation and bottom algae, and productivity and the nutrient content

of the water are higher. State C: The pond is largely filled by silt and organic sediments.

The shores are on gradually sloping sediment; there are extensive marshes and shore vegetation, and algae occur over most of the bottom area. Productivity of the much-reduced

volume of water is still high. State D: Filling of the pond and its occupation by terrestrial

vegetation are completed. A small central marsh is the only remnant of the pond in an area

of forest.

Bedrock

Pond

Progression of States

Sediments

State A

State B

State C

State D
29

For many wetlands, these variables can be estimated using empirical methods or

known data or both. For more information on water budgets, see USDA NRCS

(1997) and Chapter 8 of Dunne and Leopold (1978).

Wetlands Research Program Technical Note SD-CP-4.1 describes four methods to

measure sedimentation rates in wetland systems. The advantages and disadvantages

of each are discussed, and their application to wetland evaluation considered (WRP

1993). The four methods are: 

• Modified sediment trap method. A sediment trap in limnological and 

oceanographic research consists of a cylindrical column, which is 

approximately five times as tall as it is wide, that is submerged into the water 

body. These 5:1 aspect ratio columns are designed to prevent any

resuspension of the trapped material. In situations where the cylinders 

would not stay submerged for the sampling period and resuspension of 

materials is a significant aspect of the sedimentation patterns of the wetland 

type, a method of using “sediment plates” has been developed. These plates 

are 15-cm-diameter Plexiglas circles. Each disk is anchored a known 

distance and direction from a known point to aid in relocating the disks later. 

Sampling frequency is determined by the hydrology of the system. The 

accumulated material is measured.

• Feldspar clay marker horizon method. Feldspar clay is spread out on the 

wetland surface, at a rate of 2 liters (L) per 0.25 square meter (m2

), at a 

known distance and direction from a known point. Sampling consists of 

locating the clay pad and taking a small core of the sediments deposited 

above the clay and the clay itself. The amount of material deposited above 

the bright white marker horizon can be easily measured. Sampling frequency 

depends on the hydrology of the wetland system. This method can be used 

in shallow standing water, as the feldspar clay will sink to the bottom and 

create a good marker horizon.

• 137 Cesium atmospheric fallout method. 137 Cesium is a product of nuclear 

fission reaction and does not occur naturally in the environment. Widespread 

global dispersal of 137 cesium began with thermonuclear weapons testing in 

late 1952 and measurable amounts began to appear in the soil in 1954. Peak 

quantities occurred in 1963-64. 137 Cesium is rapidly absorbed by suspended 

particles and the clay components of sediments and soil. Once deposited, it 

establishes a fairly stable marker. To measure 137 cesium, sediment cores are 

taken in wetland and are sliced in increments appropriate to the anticipated 

rate of sedimentation. The sections are dried and 137 cesium activity is 

counted with a lithium drifted germanium detector and multichannel 

analyzer. The procedure is expensive.

• Dendrogeomorphic method. Cores or cross sections of specific trees are 

taken to obtain the age relative to geomorphic processes.

Models such as the Pacific Southwest Interagency Committee Sediment Yield

Procedure (PSIAC) can be used to estimate sedimentation rates. PSIAC is a sedi-
30

ment prediction model that includes overland production from uplands and channel

erodibility.

Discussions on watershed health and riparian-wetland condition and quantitative

methodologies for riverine wetlands can be found in Brinson et al. (1995), DeBano

and Schmidt (1989), and Prichard et al. (1998) .

Item 5: Water quality is sufficient to support

riparian-wetland plants

Purpose

The maintenance of water quality is important for these sites to function properly.

The purpose of item 5 is to determine if water quality is being maintained,

thus allowing these sites to produce the kind of vegetation necessary for proper

functioning.

Examples

Item 5 would be answered “yes” if multiple riparian-wetland species, such as black

grass, salt grass, and salt meadow cord grass, are present in an estuarine intertidal

wetland type. Presence of water smartweed, bladderwort, and pondweed in a palustrine emergent wetland would yield a “yes” answer to item 5 (examples of these

wetlands can be found in Cowardin et al. 1979).

Item 5 would be answered “no” when a site is dominated by species that indicate

poor water quality. An example of this would be when an algae bloom early in the

growing season dominates a site. Another example for a “no” answer would be

when only one species is present where there should be multiple species. A foul

smell or discolored water should be further investigated to determine whether a

water quality problem exists, or whether the foul smell is from anaerobic conditions

and the discoloration is from a natural accumulation of organics.

If water quality is limiting (a “no” answer) and there are still plants present, they

will almost always exhibit low vigor as described in item 12. However, the reverse

is not always true; low vigor does not necessarily indicate a water quality problem.

“N/A” would apply for those wetland types that do not require riparian-wetland vegetation to function properly.

There is a strong relationship between items 5 and items 8 through 13. If water

quality is so poor that it will not support riparian-wetland vegetation, then items 8

through 13 will usually be answered “no.”

Supporting Science/Quantitative Methodologies

Lentic areas are “sinks” where water, nutrients, sediments, and other components

accumulate as part of the natural processes. But, the presence of pollutants in any
31

water body, including ground water, can cause problems with the health and vigor of

plant life. A few examples are:

• Freshwater aquatic plants are negatively affected by cadmium (a heavy 

metal) at concentrations ranging from 2 to 7400 micrograms per liter (μg/l) 

and cyanide from 30 to 26000 μg/l. 

• Abnormal accumulations of salts can stress some plants or change the 

composition to plants that can tolerate elevated amounts of salts.

• Inorganic suspended materials reduce light penetration into the water body, 

and can lead to the formation of films on plant leaves, which blocks sunlight 

and impedes photosynthesis (EPA 1986). 

The geology of some watersheds naturally yield salts, calcium carbonates (from

limestone), or other components that can inhibit plant growth. Understanding the

geology, soils, and water source is important to assess whether the cause is appropriate because of site potential or is a problem accelerated by some human-caused

disturbance in the watershed. 

Water samples need to be collected and analyzed following each state’s protocols

(check with the State Department of Water Quality or equivalent), and the results

compared against known quality criteria.

Item 6: Natural surface or subsurface flow patterns are not 

altered by disturbance (i.e., hoof action, dams, dikes, trails, 

roads, rills, gullies, drilling activities)

Purpose

Alteration of surface or subsurface flow patterns may affect the functionality of a

site. For areas where riparian-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 dissipate energies and function properly. For others, it may

mean a change in extent of wetland or complete loss. The purpose of item 6 is to

determine if surface or subsurface flow patterns are being maintained.

Examples

A “yes” answer would be given for item 6 for the PFC prairie pothole example from

Montana in Appendix C. No disturbances, such as trailing, roads, or dams, are present that would affect surface flow patterns to the wetland. Disturbance within a

watershed does not necessarily mean flow patterns are automatically altered. Roads,

trails, dikes, and dams can be built and not affect the amount, time, or frequency of

surface or subsurface flows. A key concept for a “yes” answer is whether a riparianwetland area is receiving a normal range of surface and subsurface flows, even if

there is disturbance within its watershed.

Item 6 would be answered “no” for the New Mexico lacustrine wetland example

provided in Appendix C. The development of trails has intercepted, diverted, and
32

concentrated overland flows away from the wetland site. This diversion and concentration of flows have initiated a headcut that is draining the site, thus reducing the

wetland’s ability to dissipate energies and function properly. Another example of a

“no” answer would be where a highly variable seasonal wetland was excavated in

the center, resulting in a reduction of the extent or the loss of wetland.

Item 6 can never be answered “N/A;” it is always answered “yes” or “no.”

There is a strong relationship between item 6 and items 1, 3, 10, 14, and 17. If item

6 is answered “no,” then one or more of these items may be answered “no.”

Supporting Science/Quantitative Methodologies

If the natural surface or subsurface flow patterns of lentic areas are altered, the

timing, frequency, magnitude, and duration of inundation or saturation can be

affected, with corresponding changes to the soils and vegetation. Some examples

are when a riparian-wetland is not inundated because a dike keeps flood waters out;

a lentic area is drained by diverting surface or subsurface flow away from the site; or

an area has compacted soils, which reduces the infiltration rate and increases runoff. 

Surface flow pattern changes can be tracked using aerial photography (Clemmer

1994; Prichard et al. 1996). Also refer to the discussions under item 3 regarding

changes in the extent of riparian wetland areas and under item 4 regarding changes

in water flow.

Item 7: Structure accommodates safe passage of flows (e.g., no 

headcut affecting dam or spillway)

Purpose

Some lentic riparian-wetland areas have been altered through the addition of 

structures designed to capture more runoff, thus creating a more permanent or larger

wetland. The prairie pothole region in eastern Montana and North Dakota provides

many examples. However, when structures are placed to alter a riparian-wetland

area, it is very important that the structure is designed and maintained to accommodate safe passage of flows. The purpose of item 7 is to determine if these structures

are accommodating safe passage of flows.

Examples

If the ID team determines the structure is stable and accommodating flows, the

answer to item 7 would be “yes.” If there is erosion, leakage, or a headcut affecting

the integrity of the dam or spillway, the answer to item 7 would be “no.” An

example is provided in Appendix C. For the functional—at risk prairie pothole

example in Montana (Appendix C), item 7 would be answered “no” because a

headcut has developed in the spillway and is threatening the integrity of the dam.

If no structures are present, item 7 is answered “N/A.”
33

Supporting Science/Quantitative Methodologies

Gully erosion occurs when headcuts form and an area downcuts. As the gully

bottom downcuts, it deepens and then widens, thereby endangering the structure.

Headcuts extend upstream or upslope into ungullied headwater areas, increasing the

number of drainage channels (i.e., by developing additional tributaries) (Heede

1976). If there is a headcut or nickpoint present downstream of a dam or other

structure, there is the possibility that the headcut will advance upstream, removing

part of the structure and causing the wetland area to be eroded and drained. If left

unchecked, a headcut will proceed upstream until some hard point, such as a

bedrock outcrop, is encountered or a smooth transition between upstream and downstream gradient is attained (Heede 1980).

When assessing item 7, the presence or absence of any headcuts below a structure

should be noted.

B. Vegetation

Items 8-15 address vegetation attributes and processes that should be in working

order for a lentic riparian-wetland system to function properly. Landform can play a

major role in defining the riparian-wetland setting. Wide, flat valley bottoms result

in mosaics of vegetation, or complexes. The riparian-wetland complex as described

in the Intermountain Region Integrated Riparian Evaluation Guide (USDA FS 1992)

is influenced by the valley bottom setting. The complex is comprised of patches of

community types, in various amounts and locations. In assessing functionality, the

whole complex should be considered in order to understand such items as age class

distribution and species diversity.

The site potential should be evaluated when determining vegetation types that can be

found in lentic riparian-wetland areas. Many lentic riparian-wetland areas do not

have the soil and hydrology conditions needed to support tree or shrub species.

Many of these wetland types do not need tree or shrub species for physical stability.

These species may be a component for desired condition, but are not required to designate a lentic riparian-wetland area as functioning properly.

Factors such as the kind, proportion, and amount (cover or density) of vegetation in

the riparian wetland community contribute to the assessment of shorelineforming/soil surface vegetation and the encroachment of upland vegetation. The

linear distribution of vegetation is the primary factor affecting the extent of eroded

shorelines/soil surfaces, assuming that the right kinds and proportions of species are

in the community (or simply the inverse relationship—the amount of shorelines or

soil surfaces lacking the right kind and amount of vegetation). Lateral distribution

of vegetation determines the riparian-wetland area’s ability to accommodate periods

of wind action, wave action, and overland flows and drought. In order to persist or

improve, the plant species or communities of interest must be both healthy (vigorous) and replacing or increasing their numbers or extent through recruitment into

the community.
34

The level III riparian area evaluation from the USDA FS (1992) provides measurement techniques for cross-section composition of the riparian-wetland complex, vegetation composition within a complex and along the greenline, and woody species

regeneration. Each item, except for items 12, 14, and 15, can be quantified or interpreted from quantified information using these techniques.

Riparian-wetland plants are classified into five types based on the likelihood of their

occurrence in wetlands or nonwetlands (Reed 1988). These classes are: obligate

wetland (OBL), facultative wetland (FACW), facultative (FAC), facultative upland

(FACU), and obligate upland (UPL). OBL species are likely to occur in wetlands

>99 percent of the time, whereas FACW species occur in wetlands between >67-99

percent of the time. The FAC species are likely to occur in wetlands 33-67 percent

of the time; FACU species are likely to occur 1-<33 percent of the time. UPL

species almost never (<1 percent) occur in wetlands. The FACW, FAC and FACU

categories are subdivided by “+” and “-” modifiers. An FACW- would be closer to

an FAC, or would reflect slightly drier conditions based on probability of occurrence

(U.S. Army COE 1987). 

Plant lists have been compiled by the FWS for each region in the United States.

Some species may be listed as a different wetland indicator type, depending on the

state and region in which it occurs. Some states have developed localized plant lists

as a subset of the national list.

Item 8: There is diverse age-class distribution of riparianwetland vegetation (recruitment for maintenance/recovery) 

Purpose

In most cases, a riparian-wetland area should have more than one age class of wetland plants present for maintenance and/or recovery. This item is not asking

whether all possible age classes are present. It is only asking whether a sufficient

number of age classes are present to provide recruitment to maintain an area or to

allow an area to recover. Most riparian-wetland areas can do this with two age

classes, as long as one is young (for recruitment). Mature woody species (e.g.,

willow, birch, alder) usually survive due to deep roots. Herbaceous plants can

respond to changing site conditions more quickly because they are shallow-rooted.

Most herbaceous riparian wetland plants spread vegetatively. A lack of spreading by

these plants may indicate a lack of age class diversity, possibly due to a change in

site conditions. Many lentic riparian-wetland sites need only the right kind of herbaceous vegetation for stability and proper function.

Examples

For riparian-wetland areas that require woody vegetation to achieve functionality,

this item would be answered “yes” if there are seedlings and saplings present. It

would be answered “no” if these age classes aren’t present. However, it is important

to determine the mode and timing of regeneration. In some systems, the site condi-
35

tions may not be favorable (either too wet or too dry) for germination, even though

there are many seeds on-site (a long-lived seed bank). Only one young age class

may be present when germination occurs infrequently. Willow and cottonwoods

have many seeds that are viable for about 2 weeks. If the mineral soil is too dry, the

seeds will desiccate. A dense layer of sedges also limits establishment, since the

seeds cannot come in contact with wet mineral soils. The seed source is always present, but the site conditions are not always favorable for seedling establishment. 

Herbaceous riparian-wetland communities are typically dominated by grasslike

(graminoid) plants that regenerate vegetatively by tillering, rhizomes, or stolons. It

can be more difficult to distinguish between age classes. However, if you know the

habit of these species, i.e., if they are dense mat-forming sedges such as Nebraska

sedge, you expect to see continuous, robust cover composed of many stems and

blades. In this case, the answer to this item would be “yes.” However, if the cover

is clumped or there are only scattered individuals, the answer would be “no.” 

Many riparian-wetland areas have potential for both woody and herbaceous vegetation. For example, wide valley bottoms can be occupied by a complex of geyer and

booth willow with continuous cover of beaked sedge in the undergrowth. The

answer would be “yes” if young willows and robust cover of the sod-forming sedge

are present. 

This item is evaluating riparian-wetland vegetation, not upland vegetation. If the

area has basin big sagebrush, with all age classes represented, but only has old,

decadent willows, then the answer to this item would be “no.” The same is true for

items 9-13. One exception is “problem wetlands” (see Appendix F), such as highly

variable seasonal wetlands, that may be dominated by upland plants during the drier

part of the growing season or sometime after drought. 

An “N/A” answer would apply for those riparian-wetland areas that occur in

bedrock, such as some high mountain lakes. 

This item is very closely linked to items 3 and 12. 

Supporting Science/Quantitative Methodologies

Age-class distribution may vary by the type of life form (tree versus grass) and

species, but in general, healthy, expanding populations have many young-age-class

individuals, decreasing to fewer individuals of progressively older age classes, due

to natural thinning processes. If there are more older age classes, and little or no

young age classes represented, then the population is decreasing. Long-lived

species, such as woody plants, usually reproduce by seed. The site conditions have

to be appropriate during the time that the seeds are viable. If this happens infrequently, the age class distribution will reflect this. Episodic events, such as flooding

or drying may create favorable conditions for establishment, resulting in patchy distributions of individuals of the same age. 

Age of multistemmed woody species (particularly shrubs such as willows) is difficult to determine, since coring the stems is practically impossible. Single stemmed
36

willows, such as peachleaf and Gooding’s willow, could be cored. Most shrubs,

however, are “aged” based on the number of stems and proportion of live to dead

stems (USDA FS 1992). Myers (1989) recommends using “stem age” for age-class

analysis of woody plants. A high correlation between basal stem diameter and age

for several riparian-wetlands species is also presented.

Herbaceous species that reproduce vegetatively through tillering, rhizomes, or

stolons usually have a less patchy appearance, since the “young” individuals are

attached to the “parent” plant. Site conditions likely matter less in this mode of

regeneration, since the plant has already established and is simply expanding.

Bunch grasses, such as tufted hairgrass, may not be as common in riparian-wetland

systems. However, if present, they will regenerate by seed, or by tillering, which

enlarges the tuft. Again, age-class distribution is often associated with vigor.

Item 9: There is diverse composition of riparian-wetland 

vegetation (for maintenance/recovery)

Purpose

In addition to diverse age-class distribution, diverse species composition is generally

also important for maintenance and recovery. This item is not asking if all plants are

present that an area can potentially support. Rather, the intent is to document that

the existing species composition is sufficient for maintenance or recovery. This generally means that two or more riparian-wetland species are present, but varies by the

potential of the site to support a given number of species. Some sites are dominated

by one species of sedge, such as beaked sedge. This may be due to both site characteristics and the competitive advantage of the species over other species. However,

these monospecific sites may be more vulnerable to disease or extreme climate

changes, depending on the ecological amplitude of the dominant species. If it can

only survive within a narrow range of conditions, any change may lead to loss of

that species and degradation of the area. Capability of the site must also be considered. If the hydrology has been altered by some activity in the upper watershed,

altered flows into the wetland may limit the types of species that can survive.

Typically, sites are occupied by more than one species, unless there is a unique soil

property or water regime, or the species is aggressive and outcompetes other species. 

Examples

If an ID team determines an area can function with either woody or herbaceous vegetation and the area has planeleaf willow and Wolf’s willow, the answer to item 9

would be “yes” even though other species may be potentially present on the site. If

this same area contained only Wolf’s willow, the answer would be “no.” If the same

area contained Nebraska sedge and Baltic rush and no woody vegetation, the answer

would also be “yes.” 

If however, the ID team determines that an area requires both woody and herbaceous

vegetation, and only Nebraska sedge and Baltic rush are present, the answer to item
37

9 would be “no.” Even though two herbaceous species are present to maintain or

recover the area, the team determined that both woody and herbaceous components

were necessary. At least one woody species and one herbaceous species are required

in the species mix for that area.

Some riparian areas have the potential for only one species. If that species is present, then the answer is “yes.” Understanding the site potential will help in this

determination.

Many riparian-wetland areas function without woody vegetation. Marshes and wet

meadows may be completely dominated by sedges, rushes, other graminoids, and

mosses. These may form a mosaic where the patches are dominated by a single

species. In some cases, woody vegetation may be desired, but the site has limited

potential to produce woody species. This system still functions properly. If an upland

species or a drier site species, such as silver sagebrush or shrubby cinquefoil, were present, this would likely indicate that the site is drying. The presence of these types of

species should not be considered as part of the number of wetland species present

when addressing this question. They instead reflect a shift in composition away from

riparian wetland species. However, it is important to know the potential of the area

before determining whether the species present should or should not be there. 

“N/A” would apply to those types of areas that do not require vegetation to function

properly.

Supporting Science/Quantitative Methodologies

In order to know the potential (i.e., the types of species and associated community

types) for a given lentic area, it is critical to consult the local classification or ecological site descriptions (USDA NRCS 1998c) if they exist. Regional riparianwetland classifications, even those from adjacent states or regions, are a good

resource. They provide descriptions of types that may also occur across the Western

States, due to the presence of water, regardless of their location. That makes it

easier to refer to classifications from adjacent states if you don’t have one in your

local area. For example, many classifications have a Geyer willow/becked sedge

type that are very similar for major species and site characteristics from Montana

(Hansen et al. 1995) to Nevada (Manning and Padgett 1995). These classifications

have been helpful in evaluating sites in adjoining states where no current classification existed. The type descriptions, along with the constancy/average cover tables

help describe the range of characteristics in terms of site, location, hydrology, and

species composition and structure. Without these classifications it is difficult to

assess potential and determine the number of species that should be present. 

Item 10: Species present indicate maintenance of riparianwetland soil moisture characteristics

Purpose

The intent of this item is to look for those species that indicate the presence of a

shallow water table, which maintains riparian-wetland species over time. A persis-
38

tent water table typically is essential to the maintenance or recovery of a riparianwetland area. This item is not asking the amount or stabilizing ability of the species,

but rather if the presence of these species indicate maintenance of riparian-wetland

moisture conditions. Even annuals, such as ovate spikerush (OBL) and rabbit-foot

grass (FACW), may indicate maintenance of the water table in the absence of deeprooted perennials. This depends on how degraded the area appears and the types of

species present.

Examples

When OBL or FACW plants (e.g., bog birch, baltic rush) are present, this item

would be answered “yes” since these plants usually occur under natural conditions

in riparian-wetland areas. If FACU or UPL plants (e.g., rabbitbrush, Sandbergs

bluegrass) dominated the area, this item would be answered “no” since these species

typically occur in upland settings. 

Some intermittent/seasonal systems, depending on timing/frequency of precipitation

or inundation, could be somewhat different; their potential may be FAC plants, such

as chokecherry. In these situations, this item would be answered “yes.” However, if

these systems are dominated by FACU and/or UPL plants, then this item would be

answered “no.” 

It is important to look at the age of the wetland indicator plants. If there are mature

Geyer and Drummond willows (OBL species), but no young willows and no OBL

herbaceous undergrowth, then the site may be drying out. The mature woody

species can access the deep water table, but the herbaceous species are more sensitive to changes in soil moisture. They reflect the depth and duration of the water

table and will respond more rapidly. It also helps to know what species one would

expect to find in these communities; local classifications help in determining if the

undergrowth is appropriate for that riparian-wetland community.

An “N/A” answer would apply for those riparian-wetland areas that are confined in

bedrock, such as some high mountain lakes.

There is a strong relationship between item 10 and items 1, 3, 6, and 17. If item 10

is answered “no,” then items 1, 3, 6, and 17 will often be answered “no” as well.

Supporting Science/Quantitative Methodologies

Most riparian-wetland classifications address those types that reflect drier states

(Leonard et al. 1992b). For example, willow types with Kentucky bluegrass undergrowth (Manning and Padgett 1995) usually indicate a shift in undergrowth away

from wet site species, such as sedges, due to either disturbance and/or site drying.

Myers (1989) also cites an increase in upland plants as indicators of a declining

water table. These could initially be undergrowth species, such as Douglas sedge, or

woody species, such as rabbitbrush. 

In order to address this item, it is recommended that species composition and ageclass distribution be assessed. This assessment may show an apparent trend from
39

which an inference can be made about whether the system is maintaining soil moisture characteristics. For example, if young willow and sedges are present and only

old sagebrush remain, then the wetland species would appear to be reoccupying a

site that at one time was drier. In particular, expansion of residual clones of rhizomatous sedges will indicate that the water table is probably nearer the surface, and

at a longer duration than when the sagebrush dominated the site.

The FAC-neutral test (U.S. Army COE 1987) can be used to calculate whether

species indicate maintenance of riparian-wetland soil moisture characteristics.

Item 11: Vegetation is comprised of those plants or plant 

communities that have root masses capable of withstanding 

wind events, wave flow events, or overland flows (e.g., storm 

events, snowmelt)

Purpose

Lentic riparian-wetland areas such as marshes can have open water or they can be

wet meadows that may have standing water some part of the year. In both situations, the root masses anchor the soil and protect either the shoreline or the soil surface from wind and wave action or overland flow. The intent of this item is to

document that the shorelines/soil surfaces have the right plants or community types

to protect the riparian-wetland area from erosion. It is asking if those species have

root systems capable of withstanding such events. It is only asking if those species

are present, it is not asking for an amount. However, there must be enough (i.e.,

more than a few scattered individuals) to stabilize exposed soil and shorelines with

proper management.

Most perennial plants that are OBL and FACW have root masses capable of withstanding these events, while most FACU and UPL plants do not. Typically, herbaceous species with rhizomes or stolons, which form a continuous mat of roots (rather

than isolated individual bunch grasses), are most effective. 

Examples

Woody riparian-wetland species, such as willow, alder, dogwood, and birch, have a

dense root wad that is very effective in armoring shorelines against wave action, ice

damage, undercutting, and bank collapse. Coyote willow has a colonizing habit—it

expands vegetatively by underground shoots that stabilize bare soil surfaces such as

those along pond and marsh margins. Herbaceous wetland species, particularly rhizomatous graminoids, such as cattails, bulrush, sedges, rushes, and some wetland

grasses, have dense fibrous root systems that create a stable soil, bound together by

an extensive network of fine roots. These roots and rhizomes have such a strong stabilizing effect on the soils that they can armor the soil surfaces and shoreline against

extreme events. They are particularly effective in protecting against ice damage,

which removes unvegetated soil away from the shoreline and exposes more shoreline

to further damage. The ice crystals cannot break apart the root network. If these

plants are dominant, then the answer would be “yes.” If, however, a weakly rhizomatous grass such as Kentucky bluegrass, or a tap-rooted shrub such as basin big sage-
40

brush, were dominant, then the answer would be “no.” These species do not have a

sufficient root system to stabilize the soil surface/shoreline against these events. 

Intermittent/seasonal areas would be an exception. For many of these areas, dominance of FAC plants may be all that is required for a “yes” answer. For example,

dry meadows that are dominated by Douglas sedge and mat mulhy, with minor

amounts of baltic rush, have the potential for only these species to dominate, since

they dry out early in the growing season. 

There are situations, such as with high mountain lakes surrounded by boulder fields,

where vegetation has no influence on shoreline stability. For these, the answer

would be “N/A.”

Supporting Science/Quantitative Methodologies

A good indicator is the presence of OBL and FACW species, because they typically

have high erosion control potential, which is determined from the species’ rooting

habits (Lewis 1958; Manning et al. 1989), or preferably from ratings or discussions

of both species and community types, such as in Weixelman et al. (1996), Hansen et

al. (1995), Manning and Padgett (1995), USDA FS (1992), and Kovalchik (1987).

In general, graminoids with rhizomes or stolons are the best soil binders since they

form a continuous, interwoven mat of rhizomes and large, medium, and fine roots.

It is the high proportion (both in mass and density) of fine roots (over 90 percent in

Nebraska sedge) within this mat, however, that aids in aggregate formation, root

turnover, and inputs of organic matter into the soil. These properties aid in soil

development, which in turn creates a more favorable environment for wetland plant

establishment.

Even though the above publications are for local areas, the species and similar community types occur broadly throughout the Western States. Certain species, such as

Nebraska sedge, beaked sedge, and baltic rush, are common throughout the 11

Western States. 

Again, there are exceptions (e.g., bedrock-controlled lake) where vegetation contributes little, if any, to shoreline stability. It may provide habitat to many wildlife

and invertebrate species, but it doesn’t provide stability. 

Item 12: Riparian-wetland plants exhibit high vigor

Purpose

The intent of this item is to determine if riparian-wetland plants are healthy and

robust or weakened and stressed and being lost from the plant community. The

aboveground expression is a reflection of the condition of the root system and the

ability of riparian-wetland species to hold an area together. As riparian-wetland

plants weaken, they can become decadent and eventually die, making the area subject to degradation.
41

Examples

This item is very important, but is sometimes difficult to answer. For most riparianwetland areas, plant size, shape, and leaf color during the growing season can be

used to determine vigor. However, variability between site characteristics and climate between years can produce differences as great as those differences between

stressed and unstressed plants on similar sites. Knowledge of reference areas is necessary to distinguish effects of site differences from induced stress.

It is useful to separate woody plants and herbaceous plants when assessing vigor.

For example, shape and percent of dead stems may be the important indicators for

willows, whereas plant height and leaf width may be the important indicators for

Nebraska sedge. If willows for a given area are well rounded and robust, and associated (ungrazed) Nebraska sedge plants averaged 80 cm high with leaves 10 mm

wide at the base, the answer to item 12 would be “yes.” If these same willows were

highlined/mushroom-shaped, contained a lot of dead stems, and the (ungrazed)

Nebraska sedge plants only averaged 20 cm high with leaf widths of only 5 mm on a

similar site, the answer is “no.” It is common to have a mixed answer indicated on

the form as a “liner” with comments that the willows, for instance, had low vigor

but the herbaceous components appeared healthy. Exclosures on similar sites can

help in assessing vigor.

Another example of when this item would be answered “no” would be if plant

leaves are turning yellow (chlorosis) during the growing season. This may happen

as a result of water being removed or added to a system, which stresses the plants.

For plants adapted to prolonged saturation, the stress is usually greatest when water

is removed, but plants requiring periodic aeration may suffer stress either way.

Change in leaf color can also indicate a disease problem, water chemistry (toxicity)

problem, or climatic factors such as temperature stress.

Abundance of herbaceous plants can also be used to assess vigor, but must be used

with caution. If Nebraska sedge forms a dense, continuous sod, the answer to item

12 would be “yes.” If Nebraska sedge occurs as isolated plants or broken clumps

that are not forming communities, the answer is probably “no.” However, a recent

change in management can result in healthy, vigorous clumps that simply haven’t

had time to develop into dense swards. Leaf width, plant height, and degree of new

tillers can help make that determination.

“N/A” would be used for riparian-wetland areas that have no potential to produce

vegetation.

Supporting Science/Quantitative Methodologies

Vigor is difficult to quantify, possibly because the relative health of plants within a

community can be expressed in many morphological and physiological forms. The

reproductive indicators for herbaceous species discussed in item 8 (unhealthy plants

don’t reproduce as well), along with plant size or volume; leaf area, number, size,

and color; and root growth are all associated with relative plant health or vigor. A
42

review of plant physiological responses to various stresses (Sosebee 1977) indicates

that reduced productivity is associated with most, if not all, responses. There is

abundant information on the use of production as a measure and its associated

advantages and disadvantages (Elzinga 1998). Production can be especially problematic to measure on trees and shrubs. Growth form (morphology), leader length,

and the proportion of dead or dying stems in comparison with young leaders (Cole

1958) are longstanding indicators of vigor on shrubs.

Chlorosis (yellowing), necrosis (tissue degeneration), and wilting are also good indicators of loss of vigor from moisture, chemical, temperature, or disease stress.

Although there are direct measurements associated with these indicators, the most

common field measurements would still be relative productivity, size, or reproduction of plants.

Weixelman et al. (1996) have established procedures for documenting mean rooting

depth and expected ranges of rooting depth associated with various ecological conditions of specific riparian community types. Shallower rooting depths associated

with the declining status of an ecological type can, in part, be a quantitative measure

of the vigor of the community.

Item 13: Adequate riparian-wetland vegetative cover is present 

to protect shoreline/soil surface and dissipate energy during 

high wind and wave events or overland flows

Purpose

Vegetation filters sediment, aids floodplain development, protects shorelines, etc., all

of which dissipate energies associated with wind action, wave action, and overland

flow events. The purpose of this item is to determine if there is an adequate amount

of vegetation present to dissipate energies from these events.

This item is crucial for areas where vegetation is required for proper functioning.

For a riparian wetland area to recover, composition of the right plants, recruitment,

etc., are necessary. However, until the right amount is present, the riparian-wetland

area will not cross the threshold that would allow it to function properly.

Examples

For a wetland that receives periodic wind and wave action, the shoreline opposite

the direction of the prevailing winds may require 90 percent cover. If an area has

adequate cover of riparian wetland plants, the answer to item 13 would be “yes.”

For other wetland types with different site potential, the shoreline may only need 70

percent cover for the answer to be “yes.”

If a shoreline being assessed is dominated by upland plants, the answer to item 13

would be “no.” If this same shoreline is 50 percent riparian-wetland plants and 50

percent upland plants, the answer to item 13 would still be “no.”
43

Item 13 would be answered “N/A” for riparian-wetland areas that do not need vegetation to achieve PFC.

It is important to understand that item 13 deals with amount, while items 8-12 deal

with composition, age class, etc., not amount. Generally item 13 will be answered

“no” if one or more of the other vegetation items are answered “no.”

Supporting Science/Quantitative Methodologies

The best protection against excessive erosion is the preservation of adequate vegetative cover to dissipate the erosive forces acting upon a shoreline/soil surface during

periods of wind action, wave action, and overland flows. Forces resisting erosion

include physical properties of the shoreline/soil surface and vegetative protection

from erosive shear. Physical properties of the shoreline/soil surface are primarily

related to cohesive strength of shoreline/soil surface materials and other factors

increasing tensile strength. Cohesive strength of shorelines/soil surfaces materials is

largely a function of soil texture (especially particle size), soil chemistry, and soil

structure. However, vegetation root mass and length also increase the tensile

strength of the shoreline/soil surface.

Vegetation has the potential to influence the balance of energy during wind action,

wave action, and overland flows in at least two ways. First, living or dead vegetation (or any other cover) that extends into the wind action, wave action, and overland flow has the potential to reduce energies, thus reducing erosive shear forces

acting upon the shoreline/soil surface.

Vegetation also influences the balance of energy during flow events by increasing

resisting forces in the shoreline/soil surface. Particularly in noncohesive soils and

sediments, vegetation greatly increases the resistive forces in shoreline/soil surface

materials. Tensile strength provided by root masses of riparian-wetland vegetation

may be the primary source of resistance in the soil of many western riparian-wetland

areas. Tensile strength will be dependent upon both the kind of vegetation present

and the extent and density of root masses in the soil. Determination of root mass

adequacy will be site-specific, as less cohesive sediments will require greater root

mass to achieve the same level of stability as more cohesive soils elsewhere.

A preferred method of quantification is to calculate a greenline stability rating

(USDA FS 1992 and similar documents). A stability rating of 7-10 would generally

be considered adequate. However, there may be instances in low-energy systems

where a rating of 5-6 might suffice, but these are expected to be rare situations.

Item 14: Frost or abnormal hydrologic heaving is not present

Purpose

Frost or hydrologic heaving occurs when soil pores contain free water conducive to

the development of segregated ice lenses or crystals and when temperatures drop

below freezing. Expansion when water changes from a liquid to a solid state and
44

continued growth of ice crystals or lenses over time can expand the soil surface

upward. This is a natural process that can be aggravated by impacts that either seal

parts of the surface, which restricts water infiltration between plants, or reduces pore

space by compaction between plants. Excessive removal of vegetation acting as

thermal cover can also exaggerate the effects of freezing. Over time, vegetated

hummocks of increasing elevation develop between the sealed or compacted interspaces. Riparian wetland vegetation on the hummocks may be diminished or

replaced by upland vegetation as the surface becomes elevated above the water

table. Root shearing becomes a problem and interspace areas are exposed to

increased erosional forces. Slope wetlands may experience a higher ground water

discharge from the site as hummocks increase. The intent of this item is to determine whether frost or hydrologic heaving is occurring, and if so, whether it is occurring at a normal or aggravated rate.

Examples

Before answering item 14, the ID team has to determine that frost or hydrologic

heaving can occur on the site. Many riparian areas will not experience this

attribute/process. For frost or hydrologic heaving to occur, the right amount of

moisture, soil conditions, and freezing temperatures must be present to allow water

droplets in the soil to form ice crystals. For areas that do not meet these requirements, including most of the riparian-wetlands that occur in the desert Southwest,

the answer to item 14 would be “N/A.”

When this process does occur, the ID team judges if the rate of frost heaving is normal

or aggravated. If the configuration of frost heaves is normal relative to height and

density of mounds, the answer to item 14 is “yes.” If the mounds are significantly

higher than normal or more frequent, then the answer is “no.” Appendix C provides

an example of a lacustrine wetland in Colorado that shows both. The frost heaving on

the left is more column like, with more frequent and often narrower hummocks. Most

hummocks on the left are also slightly higher. Also note the higher proportion of nonvegetated interspace. The answer to item 14 would be “no” for the area on the left and

“yes” for the area on the right, which is considered to be “natural.”

The example provides an easy comparison because of the fenceline contrast across

the same valley bottom with presumably the same soil and hydrology. Comparisons

of different locations should be assessed on sites with similar soil, moisture, and

ambient temperature.

Appendix C provides another example of excessive hydrologic heaving on a wet

meadow wetland in Idaho. 

Supporting Science/Quantitative Methodologies

Frost heaving doesn’t typically occur in clean sands and gravels, but does occur as

the silt and nonplastic clay content in the soil increases. The proper moisture content and freezing temperatures are also necessary for frost heaving to occur (Hough

1957).
45

The National Soils Handbook (USDA 1983) describes the basic processes and engineering significance of frost heaving. Empirical evidence indicates that severity of

the frost action can be aggravated through management practices such as improper

livestock grazing. However, there is little additional literature on the precise mechanisms leading to that result or quantification of ecological consequences in different

settings. The hummock topography in wet meadows is different than other frost

heave situations. Raised portions of natural frost boils are higher on the barren portion of the heave than vegetated surroundings (Fahey 1974), whereas the raised portion of meadow hummocks are vegetated. The compacted area in vehicle tracks

seems to have greater frost heave and subsequent subsidence (Gatto 1997), whereas

the probable compacted area between the hummocks appears to have less severe

heaving. Differential frost heave (Fowler and Noon 1997) may have some bearing

on the differences observed, but the relationship has not been described for the situation here (to our knowledge). The National Range and Pasture Handbook (USDA

NRCS 1998c) also describes frost heaving of forage plants, but it does not describe

the hummock topography. It is possible that downward and outward expansion in

the interspace is squeezing the soil and plant tussocks up like squeezing toothpaste

out of a tube, but that is speculation by the authors. Our suggestion is that this

process is sufficiently common to warrant additional research on management

impacts in natural settings subject to frost heave.

Measurement of the hummock topography for comparison purposes can be accomplished using a one-dimensional soil roughness analysis described by Grossman and

Pringle (1987). One dimensional soil roughness is the variation in ground surface

height along a line. In the procedure used, the distance is measured at regular intervals to the ground surface from a leveled rod. Heights are then corrected for the

ground surface slope and the standard deviation of the corrected height is calculated.

The procedure can be adjusted to obtain roughness at different scales.

Item 15: Favorable microsite condition (i.e., woody material, 

water temperature, etc.) is maintained by adjacent site 

characteristics

Purpose

Some riparian-wetland areas require very specific conditions to sustain temporal

water budgets. If seasonal inflows, outflows, and/or evapotranspiration characteristics are significantly altered, the type and extent of the riparian-wetland area can also

be altered. Adjacent site characteristics can directly influence both inflow and outflow by buffering surface runoff. Changes in the type of vegetation can also change

evaporation versus transpiration rates. Increases or decreases in one may not be proportional to changes in the other, thus affecting annual patterns of soil water states.

In some riparian-wetland areas, adjacent site characteristics can affect vegetation

recruitment potential on-site by shading, temperature modification, available seed

germination sites, etc. If functionality is dependent on these particular species, then

the adjacent site characteristics must also be maintained. The intent of this item is to
46

determine whether microsite conditions are necessary for proper functioning, and if

so, whether adjacent site characteristics are maintaining those conditions.

Examples

Forested depressional wetland areas in the Pacific Northwest require the presence of

nursery logs that provide sites for some plants such as western red cedar to establish.

The decaying logs must also maintain adequate moisture and temperature for germination. Trees on adjacent sites can buffer inflows to these sites to prevent excessive

inundation. Probably more importantly, a certain density of tall trees provides shade

that prevents surface drying during germination. The mature trees surrounding the

site are also a greater source of nursery logs than the trees on-site.

In this situation, the absence of large trees for shade and nursery logs within falling

distance of the riparian-wetland area would result in a “no” answer for item 15. If

there is a mixed age class of trees on adjacent sites with sufficient canopy to provide

solar insulation to the site, item 15 would be answered “yes.” If they are not present

or being maintained, then the answer to item 15 would be “no.”

Maintaining favorable microsite conditions may also be necessary for retention of

permafrost for some areas such as black spruce wetlands in Alaska (Post 1996).

In many cases, the effects associated with adjacent site characteristics will have

already been considered in item 4 (upland watershed) or item 6 (surface or subsurface flow patterns). Before answering item 15, it is important to determine if

microsite conditions have to be present to function properly and then identify what

these conditions are. Most riparian-wetland areas do not require these special conditions. In sites that do not require these conditions to be present to function properly,

the answer to item 15 would be “N/A.”

Supporting Science/Quantitative Methodologies

Brinson (1993) and Walton et al. (1995) describe wetland hydraulic and hydrological

processes including those that may be influenced by adjacent sites. Daily water

stage can be measured as a direct indicator. However, effects of overall watershed

conditions versus adjacent site and evapotranspiration characteristics is difficult to

determine. Surface-level solar radiation and daily maximum and minimum temperatures can also be measured as direct indicators for sites such as the forested wetland

described above. There may be other microsite conditions that affect different types

of wetlands and their function.

The publication An Approach for Assessing Wetland Functions Using

Hydrogeomorphic Classification, Reference Wetlands, and Functional Indices

(Smith et al. 1995) describes a procedure for characterization, assessment, and

analysis that should help identify and model relationships of adjacent sites to

microsite conditions where they exist.
47

C. Erosion/Deposition

Items 16-20 deal with erosion/deposition attributes and processes that have to be in

working order for an area to function properly. Some of the documents referenced in

the introductions to the sections on hydrology and vegetation are also appropriate here.

Item 16: Accumulation of chemicals affecting plant 

productivity/composition is not apparent

Purpose

Maintaining a chemical balance in a lentic riparian-wetland area is necessary for

functionality. The accumulation of harmful chemicals can potentially affect plant

composition and/or productivity. The intent of this item is to determine if the vegetation is being affected by chemicals in the system.

Examples

If a riparian-wetland area shows no accumulation of harmful chemicals and requires

vegetation to function properly, the answer to item 16 would be “yes.” If there is

accumulation of chemicals, the ID team must then determine if the accumulation is

affecting productivity/composition of riparian-wetland plants. If this accumulation

of chemicals is not affecting plant productivity or composition, the answer to item

16 would still be “yes.” But if this accumulation is affecting plant productivity

and/or composition, item 16 would be answered “no.” 

An ID team has the option of taking samples for further evaluation should they be

unable to adequately answer this question. Many chemicals that would typically be

found in a lentic riparian wetland area, such as phosphates and nitrates, may actually

enhance vegetative production. But they may also cause algae blooms, reduction of

oxygen in open water systems, and rapid eutrophication that is not necessarily good.

There are situations where the accumulation of chemicals is obviously harmful to

vegetation, even to the point of being toxic (in some situations, potentially a health

hazard to people). An excellent example would be the established Superfund site

near Butte, Montana. The heavy metal content in the water of this area has essentially created such harsh conditions in the riparian-wetland area that no vegetation

except a few scattered plants can survive. Flocculated metal salts contained in the

water may be deposited on the soil surface. The answer in this situation would be

“no.”

“N/A” would apply for those riparian-wetland areas that do not require vegetation to

function properly.

Item 16 is closely associated to items 8, 9, and 18. When item 16 is answered “no,”

either item 8 or 9 must also be answered “no.” When item 16 is answered “no,”

item 18 should be viewed as a possible cause.
48

Supporting Science/Quantitative Methodologies

The amount of accumulation of chemicals that affects plant growth depends on soil

texture, distribution and type of salts in the soil, and plant species (USDA NRCS

1998a). Singer and Magnus (1987) found that drainage and high evaporation also

promote the accumulation of salts. Salts of sodium, calcium, and magnesium with

chloride, sulfate, and bicarbonate are the most common. 

Chemicals (salts and heavy metals) are delivered to the soil surface by capillary

action, ponded water, ground water, and overland flow. Salts are transported to the

soil surface by capillary action and are precipitated out during evaporation of the

soil water. The amount of salt that accumulates depends on the soil texture, depth of

the water table, and depth of restricting layers. The height of capillary rise in the

unsaturated soil above the water table depends on the soil grain size. The predicted

height of capillary rise in sediments varies from 750 cm for fine silts to 1.5 cm for

fine gravel (Fetter 1994). Evaporation from the pond surface causes salts to precipitate along the shoreline as the surface area of the pond decreases. In these evaporation zones, salts accumulate and salts and other solutes in the soil water lower the

osmotic component of the soil moisture. For plants to grow in an environment of

increased salts, the plant must change the concentration of the solute in the cells.

This process of osmotic regulation costs the plant energy and decreases its growth

(Singer and Magnus 1987). Plant growth also decreases in response to toxicity of

one or more ions of salt. 

Because different plant species have different tolerance levels to salts, the plant community composition changes with the changing concentrations of salt. In addition to

changing the osmotic component, high levels of salt alter the pH of soils, thus

changing the availability of such micronutrients as Fe, Mn, Cu, and Zn. 

Chemical- (salt-) affected areas may be detected by observing: 1) salt crystals or

crusts on the surface, 2) zones of accumulation in the soil profile, and 3) reduced

plant vigor. The degree of chemical accumulation may be determined from saturated soil paste extracts (USDA U.S. Salinity Laboratory 1954; USDA NRCS 1996).

Salinity can be determined in the field by a portable salinity tester.

Item 17: Saturation of soils (i.e., ponding, flooding frequency, 

and duration) is sufficient to compose and maintain hydric soils

Purpose

Hydric soils are developed and maintained through frequent flooding, ponding, or

saturation for a long enough time for anaerobic conditions to develop. The intent of

item 17 is to determine whether hydric soils are being created or maintained in those

areas that should have hydric soils. 

Examples

Soils that are regularly flooded usually produce indicators that they are being

flooded and are hydric. These indicators are accumulations of iron and manganese
49

oxides (redox concentrations) and/or organic matter, iron and clay depletions (redox

depletions), and matrices that have low chroma color in situ (reduced matrices).

When soils display these characteristics, the answer to item 17 would be “yes.”

When soils display these characteristic and lack saturation or inundation, the answer

to item 17 would be “no.” 

“N/A” would apply to those riparian-wetland areas where hydric soil conditions do

not form, for example, a rocky shore or gravel beach.

Because hydric soils are developed and maintained by inundation or saturation,

items 17 and 1 are closely associated. When answering item 17, the ID team should

refer to how they answered item 1. A “no” answer to item 1 may result in a “no”

answer to item 17.

There is a strong relationship between item 17 and items 3, 6, and 10. If item 17 is

answered “no,” then one or more of these related items will also be answered “no.”

Supporting Science/Quantitative Methodologies

A soil is considered hydric if it forms under conditions of saturation, flooding, or

ponding long enough during the growing season to form anaerobic conditions in its

upper part. Hydric soils are formed by biogeochemical processes that promote the

accumulation of organic matter and the reduction, translocation, and accumulation of

iron, manganese, sulfur, and carbon compounds. In the wettest soils, a rotten egg

odor (hydrogen sulfide) is a strong indicator of hydric soils. Other indicators are

either the depletion or concentration of Fe/Mn. Hydric soils with parent materials

low in Fe/Mn may have low chroma colors that are not related to the moisture content. In these situations, as well as in the absence of hydrogen sulfide, the accumulation of carbon should be used as an indicator. These indicators include presence of

Histosols or Histic Epipedon (Vepraskas 1994).

The presence of a hydric soil indicator is the easiest way to demonstrate that soil saturation is sufficient to develop and maintain hydric soils. In cases where hydric soil

indicators are not present, other more complicated measures can be taken to determine soil saturation. Certainly if long-term hydrologic data is available, saturation

can be determined. Also, weather data, measurement of redox potential, and dyes,

such as alpha alpha dipyridyl, can be used (Vepraskas 1994).

Hydric soils may be difficult to identify in the field if: 1) they are derived from

grayish or reddish parent materials, 2) they have a high pH or low organic matter

content, 3) they are Mollisols or Vertisols, 4) they have relict redoximorphic features, or 5) they have been disturbed, as in cultivated and filled areas. Artificially

drained or protected soils are considered hydric if they have at least one of the indicators.

The hydric soils criteria (1995) can be found in USDA NRCS (1998b): 

1. All Histosols except Folists, or

2. Soil in Aquic suborders, great groups, or subgroups, Albolls suborder,

Aquisalids, Pachic subgroups, or Cumulic subgroups that are:
50

a. somewhat poorly drained with a water table equal to 0.0 foot (ft)

from the surface during the growing season, or 

b. poorly drained or very poorly drained and have either:

(1) water table equal to 0.0 ft during the growing season if textures

are coarse sand, sand, or fine sand in all layers within 20 inches

(in), or for other soils,

(2) water table of less than or equal to 0.5 ft from the surface during

the growing season if permeability is equal to or greater than 

6.0 in/hour (h) in all layers within 20 in, or

(3) water table at less than or equal to 1.0 ft from the surface during

the growing season if permeability is less than 6.0 in/h in any

layer within 20 in, or

3. Soils that are frequently ponded for long or very long duration during the

growing season, or

4. Soils that are frequently flooded for long or very long duration during the

growing season.

The main purpose for the criteria is to create hydric soil lists. According to the

National Technical Committee for Hydric Soils, criteria 1, 3, and 4 can be used to

document the presence of a hydric soil; however, proof that anaerobic conditions

exist also must be obtained. Either data or best professional judgement may be used

to document anaerobic conditions. Criteria 2 cannot be used to document the presence of a hydric soil; hydric soil indicators are used to document the presence of a

hydric soil for these saturated soils (Hurt and Carlisle 1997).

Field indicators for hydric soils vary from one land resource region to another

(USDA NRCS 1998b). These indicators include color, presence of redoximorphic

features, thickness, and depth.

The following steps should be included in any method for identifying hydric soils

(USDA NRCS 1998b):

a) All organic materials (leaves, needles, bark, etc.) should be removed to

expose the surface.

b) Several holes should be dug to a depth or 50 cm (20 in.) or as deep as needed

to make an accurate description. Multiple holes will ensure that the soil profile description is representative of the site and will remove variations caused

by small changes in elevation. 

c) From the description, field indicators that have been met should be specified.

d) Measurements should be made from muck or mineral soil surface unless

instructed otherwise.

e) All colors refer to moist Munsell colors. Soil chroma should not be rounded

to meet an indicator. A soil matrix with a chroma between 2 and 3 should be

listed as having a chroma of 2+. (If the indicator has a chroma of 2 or less, a

chroma of 2+ would not meet the requirements.) Values should be rounded

to the nearest color chip. Methods of characterizing redoximorphic features,

such as quantity, class, size, contrast, color, and moisture state, are based on

established field techniques (USDA NRCS 1998b).
51

Item 18: Underlying geologic structure/soil material/per

mafrost is capable of restricting water percolation

Purpose

Lentic or standing water riparian-wetland areas often have an underlying material

that causes a site to persist. This underlying material restricts water percolation, 

producing permanent or seasonal ponding, saturation, or inundation. This material

may be a geologic structure such as bedrock, a soil type like clay, or permafrost.

This underlying material has to be maintained for an area to function properly.

The best way to describe the importance of maintaining this underlying material is to

compare a riparian-wetland area to a bathtub with a plug. As long as the plug stays

in place, the tub can retain water, but as soon as the plug is pulled, it can no longer

retain water. When this happens, an area can no longer maintain existing hydrology

and associated vegetation because it is being drained and will eventually be lost.

The intent of item 18 is to identify whether this underlying material is being maintained.

Examples

If a riparian-wetland area shows no signs that its underlying material has been disturbed and is restricting water percolation, the answer to item 18 would be “yes.” If

an ID team observes activities such as dredging or the formation of a headcut that is

draining an area, the answer to item 18 would be “no.” The functional—at risk

lacustrine wetland in New Mexico (Appendix C) provides an example of when item

18 would be answered “no.” Surface disturbance has initiated a headcut that has

disrupted the underlying material and is draining the wetland area.

“N/A” would be used for a riparian-wetland area that does not have a restricting

layer, such as one that is sustained by the upward movement of ground water.

Supporting Science/Quantitative Methodologies

An underlying restrictive layer is a prerequisite for most standing water systems.

Natural restrictive layers may be caused by geologic materials or activities, compacted soil material such as clay or hardpans, and in some areas, permafrost. In artificial standing water systems, synthetic fabrics, clay layers, or chemical applications

may form restrictive layers. 

If saturation or inundation hydrology is observed, then the obvious answer to item

18 is “yes.” However, if hydrology is not observable at the time of the assessment,

then recent aerial photography can be used to observe if an underlying material is

being maintained. If direct observation of hydrology or aerial photography at the

wet time of year are not available, then local geology or soils information should be

used to indicate if a layer restrictive to water movement occurs in the area. Layers
52

that are restrictive to water movement are often too deep for direct observation with

hand tools.

Where disturbance is suspected to have altered a restrictive layer, tests should be

made by comparing disturbed area attributes to the undisturbed area attributes.

Many restrictive layers are not perfectly sealed and disturbance can accelerate the

rate of loss, thereby reducing the riparian wetland area extent.

Item 19: Riparian-wetland is in balance with the water and 

sediment being supplied by the watershed (i.e., no excessive 

erosion or deposition)

Purpose

Over geologic time, lentic riparian-wetland areas typically fill with sediment and

may even convert to an upland area type, which is natural. However, this conversion rate can be accelerated by activities within a watershed, such as road building,

logging, water diversions, farming, or grazing, if not done properly. Too many roads

or roads in the wrong location may accelerate erosion within a watershed. This erosion may result in excessive amounts of sediment being supplied to a riparianwetland area, filling it faster. When this happens, an area will no longer function

properly. The intent of item 19 is to identify that water and sediment are being supplied at a natural rate and can function properly.

Also, if flows increase into a riparian-wetland area, increased energy may form

headcuts, endangering the area. Increased flows may also change the type of

riparian-wetland (i.e., marsh to lake).

Examples

If a lentic riparian-wetland area shows no evidence of excessive deposition and is

not filling any faster than its normal rate as a result of excess sediment from the

watershed, the answer to item 19 would be “yes.” If flow has been added from a

diversion, and excessive erosion or deposition is taking place as a result of this

increased flow, the answer to item 19 would be “no.” Indicators of excessive erosion or deposition can include unstable shorelines, deltas extending into a wetland,

and loss of open water. The Nevada seep wetland in Appendix C provides an

example of a wetland for which the answer to item 19 would be “no.”

Item 19 will never be answered “N/A;” it will always have a “yes” or “no” answer.

Since water and sediment are supplied from the watershed, this item is closely tied

to item 4.

Supporting Science/Quantitative Methodologies

Riparian-wetland areas are constantly adjusting to the water and sediment being supplied by the watershed. Changes in riparian-wetland areas correspond to changes in
53

overland flow and sediment being supplied. Understanding riparian-wetland areas

requires an understanding of changes in overland flows and sediment production

upslope from the areas. The riparian-wetland balance can be quantified by some of

the methods described under item 4.

Adjustment should be evaluated for both time and spatial considerations.

Item 20: Islands and shoreline characteristics (i.e., rocks, 

coarse and/or large woody material) are adequate to dissipate 

wind and wave event energies

Purpose

Riparian-wetland areas with islands and shorelines have to be able to dissipate energy

during wind action and wave action events to function properly. These islands and

shorelines need characteristics that create forces resistant to wind action and wave

action. While most lentic riparian-wetland areas require riparian-wetland vegetation

along islands and shorelines to do this, some do not. The presence of rocks and/or

woody material can dissipate energies associated with wind action and wave action,

thereby providing the elements necessary for a system to function properly. The

intent of item 20 is to address those systems that do not require vegetation. 

Examples

If a palustrine wetland has adequate rock or coarse and/or large woody material

along its shoreline to dissipate energies from wind action and wave action, the

answer to item 20 would be “yes.” If a riparian-wetland area does not have adequate rock material, etc., the answer to item 20 would be “no.”

If a palustrine wetland requires riparian-wetland vegetation versus rock material,

etc., along its shoreline to dissipate energy from wind and wave action, then item 20

is answered “N/A.” The Nevada palustrine wetland (Appendix C) provides an

example of when item 20 would be answered “N/A.” 

Riparian-wetland areas that require vegetation on islands and shorelines to dissipate

energy are addressed in item 13. However, there will be systems that have both,

such as a high mountain lake where one side is a talus slope and the other side is an

extensive wet meadow. If this is the case, both items 13 and 20 have to be

addressed. It is important to remember that each riparian wetland area is rated

according to its capability and potential.

Supporting Science/Quantitative Methodologies

Rocks on or near the surface of shorelines reduce the impact of waves. The amount

of rock along islands and shorelines needed to dissipate wind and wave event energies depends on: 1) amount, kind, and size of rock on-site; 2) size and depth of

water sources; 3) frequency, timing, direction, and duration of event energies; 
54

4) slope of the shoreline; 5) use of the area; 6) adjacent topography; and 7) length of

fetch. On shorelines lacking wave action, unprotected soil could be stable (Wingate

1999). 

Loss of shorelines affect lentic areas by: 1) lowering water quality, 2) reducing the

capacity to hold water, and 3) altering the plant community.

The impact of wind and wave event energies can be determined by: 1) comparing

changes in the riparian-wetland areas over several years using aerial photos

(Prichard et al. 1996), 2) establishing photo points, 3) surveying distances from a

reference point to the edge of water, 4) measuring the sedimentation rates of the

lentic system, and 5) setting markers at the edge of water and comparing changes

over time.
55

VI. Summary

The BLM and the FS, working with the NRCS, have initiated an effort to restore and

manage riparian-wetland areas in 11 Western States. To be effective, these agencies

have established common terms and definitions, as well as a method for evaluating

the condition of these areas, which has been extensively reviewed and tested. This

method is the proper functioning condition assessment (see TR 1737-9, TR 1737-11,

and TR 1737-15). 

The method for assessing PFC is a qualitative, yet science-based process that considers both abiotic and biotic factors as they relate to physical function. It facilitates

communication about the condition of a riparian-wetland area and focuses attention

on the physical process before considering values. A standard checklist ensures consistency in evaluating the condition of lentic riparian-wetland areas.

The PFC method is straightforward: review existing documents, analyze the PFC

definition, and assess functionality using the checklist. The assessment requires the

use of an ID team. To assess the condition of a riparian-wetland area, an ID team

has to understand its capability and potential and identify its attributes and

processes. If an ID team does not spend the time to develop this understanding,

their judgement about PFC will be incomplete and may be incorrect.

Riparian-wetland areas are rated in four categories: proper functioning condition,

functional—at risk, nonfunctional, and unknown. The condition of some riparianwetland areas will be relatively easy to discern, while the condition of others will be

less evident. Occasionally, items on the checklist will have to be quantified to determine how they should be answered. There are numerous ways these items can be

quantified, including those summarized in this document. 

For areas that are functional—at risk, trend should be identified, as it is a key consideration in interpreting data. At-risk areas with a downward trend are often the

highest management priority because a decline in resource values is apparent. Yet

these areas often retain much of the resiliency associated with a functioning area.

There is usually an opportunity to reverse this trend through changes in management. At-risk areas with an upward trend are often a priority for monitoring efforts.

These areas should be monitored to ensure that they continue to improve. 

Conversely, trend is not determined for areas that are nonfunctional. While these

areas could theoretically still be in decline, most of the riparian values have already

been lost. The presence of sufficient riparian-wetland attributes and processes to

warrant a determination of trend usually results in a rating of functional—at risk.

Once proper functioning condition is reached, trend relates to specific objectives. It

is common for an area in PFC to continue to have an upward trend toward other

desired conditions. Many sites that are properly functioning must continue to

improve to meet site-specific objectives. However, a downward trend may put the

area at-risk.
56

The lack of specific information will place some riparian-wetland areas into the category of unknown. It is imperative that areas for which no data exists be evaluated

and added to the database. As information is acquired and resource values are identified, best management practices need to be implemented. Successful management

strategies have to address the entire watershed, as upland and riparian-wetland areas

are interrelated and cannot be considered separately. 

To manage riparian-wetland areas successfully requires a state of resiliency that

allows an area to hold together during frequent wind action, wave action, and overland flow events. When a riparian-wetland area’s physical aspects are in working

order, then characteristics are maintained that sustain the area’s ability to produce

resource values. Function comes first, then values (desired condition). 

Managing riparian-wetland areas does not cease once PFC is achieved—it has just

started. Existing and potential resource values and the plant communities necessary

to support these values have to be identified. Once these values have been identified, specific objectives can be derived to ascertain desired condition. Management

actions to achieve desired condition can then be designed and implemented. 
57

Appendix A:

Riparian-Wetland Lentic Checklist

59

General Instructions

1) This checklist constitutes the Minimum National Standards required to

determine proper functioning condition of lentic riparian-wetland areas.

2) As a minimum, an ID team will use this checklist to determine the degree of

function of a riparian-wetland area. 

3) An ID team must review existing documents, particularly those referenced

in this document, so that the team has an understanding of the concepts of

the riparian-wetland area they are assessing.

4) An ID team must determine the attributes and processes important to the

riparian wetland area that is being assessed.

5) Mark one box for each element. Elements are numbered for the purpose of

cataloging comments. The numbers do not declare importance.

6) For any item marked “No,” the severity of the condition must be explained in

the “Remarks” section and must be a subject for discussion with the ID

team in determining riparian-wetland functionality. Using the “Remarks”

section to also explain items marked “Yes” is encouraged but not required.

7) Based on the ID team's discussion, “functional rating” will be resolved and

the checklist's summary section will be completed.

8) Establish photo points where possible to document the area being assessed.

Lentic Standard Checklist

Name of Riparian-Wetland Area:__________________________________________

Date:___________ Area/Segment ID: _________________ Acres:___________

ID Team Observers: ____________________________________________________

Yes No N/A HYDROLOGY

1) Riparian-wetland area is saturated at or near the surface or inundated in 

“relatively frequent” events

2) Fluctuation of water levels is not excessive 

3) Riparian-wetland area is enlarging or has achieved potential extent

4) Upland watershed is not contributing to riparian-wetland degradation

5) Water quality is sufficient to support riparian-wetland plants

6) Natural surface or subsurface flow patterns are not altered by disturbance 

(i.e., hoof action, dams, dikes, trails, roads, rills, gullies, drilling activities)

7) Structure accommodates safe passage of flows (e.g., no headcut affecting 

dam or spillway)

Yes No N/A VEGETATION

8) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

9) There is diverse composition of riparian-wetland vegetation

(for maintenance/recovery)

10) Species present indicate maintenance of riparian-wetland soil 

moisture characteristics

11) Vegetation is comprised of those plants or plant communities that have 

root masses capable of withstanding wind events, wave flow events, or 

overland flows (e.g., storm events, snowmelt)

12) Riparian-wetland plants exhibit high vigor

13) Adequate riparian-wetland vegetative cover is present to protect 

shoreline/soil surface and dissipate energy during high wind and wave 

events or overland flows

14) Frost or abnormal hydrologic heaving is not present

15) Favorable microsite condition (i.e., woody material, water temperature, 

etc.) is maintained by adjacent site characteristics

Yes No N/A EROSION/DEPOSITION

16) Accumulation of chemicals affecting plant productivity/composition is 

not apparent 

17) Saturation of soils (i.e., ponding, flooding frequency, and duration) is 

sufficient to compose and maintain hydric soils

18) Underlying geologic structure/soil material/permafrost is capable of

restricting water percolation

19) Riparian-wetland is in balance with the water and sediment being supplied

by the watershed (i.e., no excessive erosion or deposition)

20) Islands and shoreline characteristics (i.e., rocks, coarse and/or large

woody material) are adequate to dissipate wind and wave event energies

(Revised 1999)

61
62

Remarks

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

Summary Determination

Functional Rating:

Proper Functioning Condition ________

Functional—At Risk ________

Nonfunctional ________

Unknown ________

Trend for Functional—At Risk:

Upward _____

Downward _____

Not Apparent _____

Are factors contributing to unacceptable conditions outside the control

of the manager?

Yes ___

No ___

If yes, what are those factors?

___ Dewatering ___ Mining activities ___ Watershed condition

___ Dredging activities ___ Road encroachment ___ Land ownership

___ Other (specify)____________________________________
63

Appendix B:

Potential and Capability Examples

65

The following examples show how to fill out the checklist and determine functioning condition for a variety of scenarios, and explain how to consider and apply

potential and capability:

Example 1: Assessing functionality of a problem wetland.

Example 2: Assessing functionality of a natural lake that is limited by the 

presence of a pumping station.

Example 3: Assessing functionality of a system that is not at potential.

67

Example 1. Assessing functionality of a problem wetland: This area is a playa wetland, a

depressional area that has wetland indicators (i.e., hydrology, soil, vegetation) during wetter

portions of its growing season, but normally lacks these indicators during the drier portion

of the growing season. In addition, some playa wetlands lack field indicators of hydric soil.

OBL and FACW plants are present during the wet season while FACU and UPL plants are

present during the dry season. The soils underlying this playa are intact and are capable of

restricting water percolation. The watershed for this playa wetland is intact.

Figure B1. Cocklebur Lakes, New Mexico.

Clay Bridges
68

Yes No N/A HYDROLOGY

X 1) Riparian-wetland area is saturated at or near the surface or inundated in 

"relatively frequent" events

This wetland is inundated at its normal rate.

X 2) Fluctuation of water levels is not excessive

The rate of fluctuation of this wetland is normal.

X 3) Riparian-wetland area is enlarging or has achieved potential extent

It has achieved potential extent.

X 4) Upland watershed is not contributing to riparian-wetland degradation

The watershed is intact and in good shape.

X 5) Water quality is sufficient to support riparian-wetland plants

X 6) Natural surface or subsurface flow patterns are not altered by disturbance 

(i.e., hoof action, dams, dikes, trails, roads, rills, gullies, drilling activities)

Flow patterns have not been altered.

X 7) Structure accommodates safe passage of flows (e.g., no headcut affecting 

dam or spillway)

No artificial structures are involved.

Yes No N/A VEGETATION

X 8) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

During the wet growing season, OBL and FACW plants dominate the site; they are of diverse age 

classes that can maintain this site and they are vigorous.

X 9) There is diverse composition of riparian-wetland vegetation (for 

maintenance/recovery)

During the wet growing season, OBL and FACW plants dominate the site and

are maintaining the site.

X 10) Species present indicate maintenance of riparian-wetland 

soil moisture characteristics

See items 8 & 9.

X 11) Vegetation is comprised of those plants or plant communities that have

root masses capable of withstanding wind events, wave flow events, or 

overland flows (e.g., storm events, snowmelt)

See items 8 & 9.

X 12) Riparian-wetland plants exhibit high vigor

See items 8 & 9.
69

X 13) Adequate riparian-wetland vegetative cover is present to protect 

shoreline/soil surface and dissipate energy during high wind and wave 

events or overland flows

See items 8 & 9.

X 14) Frost or abnormal hydrologic heaving is not present

This process does not occur in the deserts of the Southwest.

X 15) Favorable microsite condition (i.e., woody material, water temperature, 

etc.) is maintained by adjacent site characteristics

Microsite conditions are not necessary for this site to persist.

Yes No N/A EROSION/DEPOSITION

X 16) Accumulation of chemicals affecting plant productivity/composition is not 

apparent

There is no accumulation of chemicals.

X 17) Saturation of soils (i.e., ponding, flooding frequency, and duration) is

sufficient to compose and maintain hydric soils

This site does not express hydric soils.

X 18) Underlying geologic structure/soil material/permafrost is capable of 

restricting water percolation

X 19) Riparian-wetland is in balance with the water and sediment being supplied 

by the watershed (i.e., no excessive erosion or deposition)

There is no evidence of erosion or deposition.

X 20) Islands and shoreline characteristics (i.e., rocks, coarse and/or large

woody material) are adequate to dissipate wind and wave event energies

Shorelines are protected by vegetation.

Summary Determination

Functional Rating:

Proper Functioning Condition ________

Functional—At Risk ________

Nonfunctional ________

Unknown ________

Trend for Functional—At Risk:

Upward ________

Downward ________

Not Apparent ________

Rationale For Rating: This system is in proper functioning condition because the checklist

items have been answered “yes” or “NA.” This area is functioning “as best it can” within its

attributes and processes defined by the current geoclimatic setting.

Are factors contributing to unacceptable conditions outside the control

of the manager?

Yes ___

No ___

If yes, what are those factors?

___ Dewatering ___ Mining activities ___ Watershed condition

___ Dredging activities ___ Road encroachment ___ Land ownership

___ Other (specify)____________________________________

X

X
70

Example 2. Assessing functionality of a natural lake that is limited by the presence of

a pumping station: This lake, located in a mountain range in Nevada, is classified as a

palustrine wetland. The water rights for this lake are privately owned. A pumping station

has been located on this lake to pump water into an irrigation system for agriculture lands in

the valley. The pumping activity has limited this lake’s ability to maintain riparian-wetland

plants along parts of its shoreline.

The presence of the pumping station is a limiting factor that makes it necessary to consider

the capability of this riparian-wetland area when completing the checklist. This constraint

to the area’s potential cannot be changed by the land manager. The checklist items are

answered according to the area’s potential or its capability. The question “Are factors contributing to unacceptable conditions outside the control of the manager?” is answered “yes,”

and the factor involved is checked to show that the new capability is beyond the ability of

the land manager to change.

Figure B2. Sonoma Lake, Nevada.

Clay Bridges
71

Yes No N/A HYDROLOGY

X 1) Riparian-wetland area is saturated at or near the surface or inundated in

"relatively frequent" events

This lake fills each year from snowmelt and rainfall. 

X 2) Fluctuation of water levels is not excessive

Pumping activities result in excessive fluctuation of water levels. This has affected the ability of 

riparian-wetland plants to maintain themselves.

X 3) Riparian-wetland area is enlarging or has achieved potential extent

Pumping activities have reduced the extent of the riparian-wetland area.

X 4) Upland watershed is not contributing to riparian-wetland degradation

There is no evidence of degradation to the riparian-wetland area from the watershed.

X 5) Water quality is sufficient to support riparian-wetland plants

There is no evidence of water quality affecting riparian-wetland plants.

X 6) Natural surface or subsurface flow patterns are not altered by disturbance 

(i.e., hoof action, dams, dikes, trails, roads, rills, gullies, drilling activities)

There is no evidence of flow patterns being altered.

X 7) Structure accommodates safe passage of flows (e.g., no headcut affecting 

dam or spillway)

Yes No N/A VEGETATION

X 8) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

A young age class of riparian-wetland plants is lacking due to fluctuating water levels.

X 9) There is diverse composition of riparian-wetland vegetation (for 

maintenance/recovery)

Several species of riparian-wetland plants exist.

X 10) Species present indicate maintenance of riparian-wetland 

soil moisture characteristics

X 11) Vegetation is comprised of those plants or plant communities that have

root masses capable of withstanding wind events, wave flow events, or 

overland flows (e.g., storm events, snowmelt)

Riparian-wetland plants present have root masses that can withstand wind events

and wave flow events.

X 12) Riparian-wetland plants exhibit high vigor

Riparian-wetland vegetation vigor is affected by fluctuating water levels.
72

X 13) Adequate riparian-wetland vegetative cover is present to protect 

shoreline/soil surface and dissipate energy during high wind and wave 

events or overland flows

A good proportion of the shoreline is bare soil, which is a result of the fluctuating water levels.

X 14) Frost or abnormal hydrologic heaving is not present

X 15) Favorable microsite condition (i.e., woody material, water temperature, 

etc.) is maintained by adjacent site characteristics

Yes No N/A EROSION/DEPOSITION

X 16) Accumulation of chemicals affecting plant productivity/composition is not 

apparent

There is no evidence of accumulation of chemicals.

X 17) Saturation of soils (i.e., ponding, flooding frequency, and duration) is

sufficient to compose and maintain hydric soils

Evidence does not exist that hydric soils are being maintained.

X 18) Underlying geologic structure/soil material/permafrost is capable of 

restricting water percolation

X 19) Riparian-wetland is in balance with the water and sediment being supplied 

by the watershed (i.e., no excessive erosion or deposition)

There is no evidence of a delta forming in the inlet to indicate excessive depositions.

X 20) Islands and shoreline characteristics (i.e., rocks, coarse and/or large

woody material) are adequate to dissipate wind and wave event energies

Course and large rocks are present on portions of the shoreline and are adequate to dissipate 

energies. The remaining shoreline requires vegetative cover to dissipate energies, which is 

addressed in item 13.

Summary Determination

Functional Rating:

Proper Functioning Condition ________

Functional—At Risk ________

Nonfunctional ________

Unknown ________

Trend for Functional—At Risk:

Upward ________

Downward ________

Not Apparent ________

Rationale For Rating: This system is rated functional—at risk with no apparent trend. The 

limiting factor (dewatering) has altered this system and is outside of management control. 

There are no options available to management to improve this system.

Are factors contributing to unacceptable conditions outside the control

of the manager?

Yes ___

No ___

If yes, what are those factors?

___ Dewatering ___ Mining activities ___ Watershed condition

___ Dredging activities ___ Road encroachment ___ Land ownership

___ Other (specify)____________________________________

X

X

X

X
73

Example 3. Assessing functionality of a system that is not at potential: The hydrology

of this riparian-wetland area is intact but there is no riparian-wetland development. Current

management is preventing riparian-wetland vegetation from developing. There is no protection to the area from erosion and deposition. As a result, the riparian-wetland area’s extent

has been greatly reduced.

Figure B3. Coyote Hole, Nevada.

Clay Bridges
74

Yes No N/A HYDROLOGY

X 1) Riparian-wetland area is saturated at or near the surface or inundated in

"relatively frequent" events

The hydrology of this system is intact.

X 2) Fluctuation of water levels is not excessive

See item 1.

X 3) Riparian-wetland area is enlarging or has achieved potential extent

The extent of this riparian-wetland area is greatly reduced.

X 4) Upland watershed is not contributing to riparian-wetland degradation

There is evidence of sediment deposits from the uplands that are degrading the 

riparian-wetland area.

X 5) Water quality is sufficient to support riparian-wetland plants

There is no evidence of water quality affecting riparian-wetland plants.

X 6) Natural surface or subsurface flow patterns are not altered by disturbance 

(i.e., hoof action, dams, dikes, trails, roads, rills, gullies, drilling activities)

Flow patterns have been altered by hoof action.

X 7) Structure accommodates safe passage of flows (e.g., no headcut affecting 

dam or spillway)

Yes No N/A VEGETATION

X 8) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

Most of the riparian-wetland vegetation has been lost from this system as a result of past 

management practices. This loss of vegetation has resulted in excessive erosion. The remaining 

vegetation is dominated by upland species.

X 9) There is diverse composition of riparian-wetland vegetation (for 

maintenance/recovery)

See item 8.

X 10) Species present indicate maintenance of riparian-wetland 

soil moisture characteristics

See item 8.

X 11) Vegetation is comprised of those plants or plant communities that have

root masses capable of withstanding wind events, wave flow events, or 

overland flows (e.g., storm events, snowmelt)

See item 8.

X 12) Riparian-wetland plants exhibit high vigor

See item 8.
75

X 13) Adequate riparian-wetland vegetative cover is present to protect 

shoreline/soil surface and dissipate energy during high wind and wave 

events or overland flows

See item 8.

X 14) Frost or abnormal hydrologic heaving is not present

X 15) Favorable microsite condition (i.e., woody material, water temperature, 

etc.) is maintained by adjacent site characteristics

Yes No N/A EROSION/DEPOSITION

X 16) Accumulation of chemicals affecting plant productivity/composition is not 

apparent

There is no evidence of accumulation of chemicals that might affect plant productivity.

X 17) Saturation of soils (i.e., ponding, flooding frequency, and duration) is

sufficient to compose and maintain hydric soils

X 18) Underlying geologic structure/soil material/permafrost is capable of 

restricting water percolation

X 19) Riparian-wetland is in balance with the water and sediment being supplied 

by the watershed (i.e., no excessive erosion or deposition)

There is evidence of excessive erosion.

X 20) Islands and shoreline characteristics (i.e., rocks, coarse and/or large

woody material) are adequate to dissipate wind and wave event energies

Summary Determination

Functional Rating:

Proper Functioning Condition ________

Functional—At Risk ________

Nonfunctional ________

Unknown ________

Trend for Functional—At Risk:

Upward ________

Downward ________

Not Apparent ________

Rationale For Rating: This riparian-wetland area is rated nonfunctional because it clearly is 

not providing adequate vegetation to dissipate energies associated with flows and thus is not

allowing any wetland development.

Are factors contributing to unacceptable conditions outside the control

of the manager?

Yes ___

No ___

If yes, what are those factors?

___ Dewatering ___ Mining activities ___ Watershed condition

___ Dredging activities ___ Road encroachment ___ Land ownership

___ Other (specify)____________________________________

X

X

77

Appendix C:

Lentic Riparian-Wetland Examples

79

Forested Wetland - Oregon

Proper Functioning Condition

This photo shows an example of a landslide sag pond found in the Coastal Range,

Oregon. According to the definition, this lentic form of wetland would be rated

PFC. The wetland contains adequate vegetation, landform, and large woody debris

to provide root masses that stabilize shoreline features against cutting actions; filter

sediment and aid floodplain development; maintain hydric soils; restrict water percolation; and provide favorable microsite conditions that support greater biodiversity. 

Clay Bridges
80

Forested Wetland - Oregon

Functional—At Risk

This photo shows an example of a lentic wetland in Oregon that would be rated

functional—at risk. Most of the physical attributes/processes (i.e., diverse composition of vegetation for maintenance/recovery, underlying materials that restrict water

percolation, etc.) are in place to allow this system to function properly. However,

this wetland is rated functional—at risk because it lacks adjacent site characteristics

to control water temperatures and to prevent inundation of the site from excessive

erosion.

Clay Bridges
81

Lacustrine Wetland - New Mexico

Functional—At Risk

This photo shows an example of a lacustrine wetland in New Mexico that would be

rated functional—at risk because natural overland flow patterns have been altered

by surface disturbance. Surface disturbance, like the trails in this photo, intercept,

divert, and concentrate overland flows away from the wetland site. The diversion

and concentration of overland flows increases energies, which form headcuts that

drain the site, thus reducing the wetland’s ability to maintain hydric soils and associated vegetation. If allowed to continue, the wetland eventually will be lost.

Clay Bridges
82

Playa Wetland - New Mexico

Proper Functioning Condition

In New Mexico, depressional areas (playas) such as those in this photo have wetland

indicators during the wetter portion of the growing season, but normally lack indicators during the drier portion of the growing season (see Appendix F). Assessing

functionality of a playa requires understanding that system's attributes/processes

(i.e., ponding frequency and duration, vegetation community dynamics and succession, recruitment and reproduction, etc.). The playa wetland in this photo would

normally be rated PFC.

This wetland would be rated functional—at risk if underlying materials that

restricted percolation have been disturbed or if overland flows to the playa have

been restricted. Alteration of the natural topography that drains the wetland would

result in a rating of nonfunctional.

Clay Bridges
83

Lacustrine Wetland - Colorado

Functional—At Risk/Proper Functioning Condition

The lacustrine wetland in this photo would be rated functional—at risk on the left

side and PFC on the right side. Most of the attributes/processes on the left side

indicate a functioning system (i.e., diverse composition of vegetation, saturation of

soils sufficient to compose and maintain hydric soils, no excessive erosion or deposition, etc.). The reason the left side is rated functional—at risk is due to the presence of abnormal hydrologic heaving. Over time, hydrologic heaving will change

the composition of vegetation and may drain the site.

All the attributes/processes on the right side of the above photo indicate a functioning system.

BLM Kremmling Resource Area
84

Seep Wetland - Nevada

Nonfunctional

This photo shows an example of a seep located in Nevada that would be rated as

nonfunctional relative to the definition of proper functioning condition. This wetland clearly does not provide adequate vegetation to filter sediment and aid wetland

development, lacks adequate cover to protect the area from erosion or deposition as

a result of overland flows, lacks diverse age-class distribution and composition of

vegetation to allow recovery, and does not provide wetland characteristics necessary

to support aquatic or other species. This lack of vegetation and the area’s lack of

balance with the sediment being supplied has permitted three things to occur: 1) the

extent of the wetland has been greatly reduced, 2) the wetland’s water quality has

been altered, and 3) the wetland’s diversity of aquatic vegetation has been greatly

reduced. The area provides little biodiversity.

Mark Biddlecomb
85

Palustrine Wetland - Nevada

Proper Functioning Condition

Wetlands that have achieved late seral state or PNC, as Locke's Pond has in this

photo, can easily be placed into the appropriate category. Using the definition of

proper functioning condition, Locke's Pond would have a rating of PFC.

Completing a lentic checklist on this area would result in a “yes” or “N/A” answer

for all items. The physical processes are functioning and the wetland is supporting

diverse ponding characteristics that provide the habitat and the water depth, duration, and temperature necessary for fish production, waterbird breeding, and other

uses. Locke's Pond is providing biodiversity.

Clay Bridges
86

Wet Meadow Wetland - Idaho

Functional—At Risk

The wet meadow in this photo would be rated functional—at risk relative to the

definition of proper functioning condition, even though most of the

attributes/processes indicate a functioning system. Currently, most of the wetland is

saturated at or near the surface with “relatively frequent events” that maintain its

hydric soils, it contains a diverse composition of vegetation that can maintain the

wetland, it is comprised of those plants or plant communities that have root masses

capable of withstanding overland flow events, and it is in balance with the water and

sediment being supplied by the watershed (i.e., no excessive erosion or deposition),

etc.

The reason this wetland is rated functional—at risk is that abnormal frost heaving is

present. Hydrologic or frost heaving, allowed to continue over time, will change the

vegetation composition. This change in vegetation will reduce the extent of the wetland and may eventually drain the wetland.

Steve Leonard
87

Prairie Pothole Wetland - Montana

Proper Functioning Condition

Prairie potholes are classified as highly variable seasonal wetlands. During drier climatic cycles or the drier portion of a growing season, these wetlands may lack

hydrology and/or hydrophytic vegetation indicators that would identify them as wetlands. During wet years, they provide a diverse composition of wetland vegetation,

but during dry years, the wetland species may be replaced with upland species,

which is necessary information for assessing their functionality. Potholes in

Montana, on average, are inundated only 1 in 5 years.

This photo shows an example of a Montana prairie pothole wetland that would be

rated PFC. This pothole contains adequate vegetation to dissipate energies associated with wind action, wave action, and overland flow from adjacent sites; restricts

water percolation; and provides ponding characteristics that provide habitat for

waterbird breeding, etc., relative to its capability and potential.

Ramone McCoy
Prairie Pothole Wetland - Montana

Functional—At Risk

These photos show an example of an artificially enhanced prairie pothole. An

earthen dam has been constructed that collects and stores additional overland flow,

creating a more permanent site. Previously this pothole would have been classified

as a highly variable seasonal wetland, but now it would be classified as a palustrine

wetland.

At first glance, this wetland would be rated PFC. The wetland is saturated at or

near the surface in relatively frequently events, provides water quality that supports

wetland plants, provides a diverse age-class and composition of vegetation, has adequate vegetative cover to protect shorelines during high wind and wave events, and

provides greater biodiversity, etc. However, this wetland is not rated PFC because

the structure is no longer accommodating the safe passage of flows. A headcut has

developed in the spillway that threatens the integrity of the dam (see insert). The

spillway is located to the left of the rock in the main photo. The correct rating

would be functional—at risk.

88

Photos by: Ramone McCoy
89

Appendix D:

PFC—What It Is and What It Isn’t

91

PFC is: A methodology for assessing the physical functioning of riparian-wetland areas. 

The term PFC is used to describe both the assessment process, and a defined, 

on-the-ground condition of a riparian-wetland area. In either case, PFC defines 

a minimum level or starting point for assessing riparian-wetland areas.

The PFC assessment provides a consistent approach for assessing the physical 

functioning of riparian-wetland areas through consideration of hydrology, 

vegetation, and soil/landform attributes. The PFC assessment synthesizes 

information that is foundational to determining the overall health of a 

riparian-wetland area.

The on-the-ground condition termed PFC refers to how well the physical 

processes are functioning. PFC is a state of resiliency that will allow a 

riparian-wetland area to hold together during a wind action, wave action, or 

overland flow event, sustaining that system’s ability to produce values related to 

both physical and biological attributes.

PFC isn’t: The sole methodology for assessing the health of the aquatic or 

terrestrial components of a riparian-wetland area.

PFC isn’t: A replacement for inventory or monitoring protocols designed to 

yield information on the “biology” of the plants and animals 

dependent on the riparian-wetland area.

PFC can: Provide information on whether a riparian-wetland area is physically 

functioning in a manner that will allow the maintenance or recovery of desired 

values (e.g., fish habitat, neotropical birds, or forage) over time.

PFC isn’t: Desired condition. It is a prerequisite to achieving 

desired condition.

PFC can’t: Provide more than strong clues as to the actual condition of habitat 

for plants and animals. Generally a riparian-wetland area in a 

physically nonfunctioning condition will not provide quality habitat 

conditions. A riparian-wetland area that has recovered to proper 

functioning condition would either be providing quality habitat 

conditions, or would be moving in that direction if recovery is 

allowed to continue. A riparian-wetland area that is functioning 

at-risk would likely lose any habitat that exists during a wind 

action, wave action, or overland flow event.

Therefore: To obtain a complete picture of riparian-wetland area health, including the 

biological side, one must have information on both physical status, provided 

through the PFC assessment, and biological habitat quality. Neither will 

provide a complete picture when analyzed in isolation. In most cases, proper 

functioning condition will be a prerequisite to achieving and maintaining 

habitat quality.

PFC is: A useful tool for prioritizing restoration activities. By concentrating on the 

“at-risk” systems, restoration activities can save many riparian-wetland areas 

from degrading to a nonfunctioning condition. Once a system is nonfunctional, 

the effort, cost, and time required for recovery is dramatically increased. 

Restoration of nonfunctional systems should be reserved for those situations 

where the riparian-wetland has reached a point where recovery is possible, when 

efforts are not at the expense of “at-risk” systems, or when unique opportunities 

exist. At the same time, systems that are properly functioning are not the 

highest priorities for restoration. Management of these systems should be 
92

continued to maintain PFC and further recovery towards desired condition. 

PFC is: A useful tool for determining appropriate timing and design of riparian-wetland 

restoration projects (including structural and management changes). It can 

identify situations where structures are either entirely inappropriate 

or premature.

PFC is: A useful tool that can be used in watershed analysis. While the methodology and 

resultant data is “area based,” the ratings can be aggregated and analyzed at the 

watershed scale. PFC, along with other watershed and habitat condition information 

helps provide a good picture of watershed health and the possible causal factors 

affecting watershed health. Use of PFC will help to identify watershed-scale problems 

and suggest management remedies and priorities.

PFC isn’t: Watershed analysis in and of itself, or a replacement for 

watershed analysis.

PFC is: A useful tool for designing monitoring plans. By concentrating implementation 

monitoring efforts on the “no” answers, greater efficiency of resources (people, dollars, 

time) can be achieved. The limited resources of the local manager in monitoring 

riparian-wetland parameters can be prioritized to those factors that are currently “out of 

range” or at risk of going out of range. The role of research may extend to validation 

monitoring of many of the parameters.

PFC isn’t: Designed to be a long-term monitoring tool, but it may be an 

appropriate part of a well-designed monitoring program.

PFC isn’t: Designed to provide monitoring answers about attaining desired 

conditions. However, it can be used to provide a thought process 

on whether a management strategy is likely to allow attainment of 

desired conditions.

PFC can: Reduce the frequency and sometimes the extent of more data- and laborintensive inventories. PFC can reduce time and cost by concentrating efforts on 

the most significant problem areas first, thereby increasing efficiency.

PFC can’t: Eliminate the need for more intensive inventory and monitoring 

protocols. These will often be needed to validate that riparianwetland area recovery is indeed moving toward or has achieved 

desired conditions (e.g., good quality habitat) or simply to establish 

what the existing habitat quality is.

PFC is: A qualitative assessment based on quantitative science. The PFC assessment is intended 

for individuals with local, on-the-ground experience in the kind of quantitative sampling 

techniques that support the checklist. These quantitative techniques are encouraged in 

conjunction with the PFC assessment for individual calibration where answers are 

uncertain or where experience is limited. PFC is also an appropriate starting point for 

determining and prioritizing the type and location of the quantitative inventory or 

monitoring that is necessary. 

PFC isn’t: A replacement for quantitative inventory or monitoring protocols. 

PFC is meant to complement more detailed methods by providing a 

way to synthesize data and communicate results.

Appendix E:
93

Common Wetlands

Riparian-wetland systems can be either nonjurisdictional or jurisdictional. The

latter refers to those types that meet the legal requirements of a wetland as defined

95

by the Wetland Delineation Manual (U.S. Army COE 1987). Activities, such as

dredge and fill, in those regulated wetlands are subject to section 404 of the Clean

Water Act. These activities are regulated by the COE and NRCS on agricultural

lands. The three parameters, vegetation, soils, and hydrology, are used to make the

determination. The wetland indicator plant list (Reed 1988) is used to determine

wetland species status. 

However, not all lentic types of riparian-wetlands are jurisdictional, and the PFC

assessment is not intended to be used to make this determination. Several classifications describe various wetland types. The system described by Cowardin et al.

(1979) defines wetland types using hydrologic and geomorphic factors, along with

chemical and biological factors. The hydrogeomorphic (HGM) system uses geomorphic setting, water sources, and hydrodynamics to classify wetlands. In addition,

numerous vegetative classifications have been developed. Windell et al. (1986)

describe systems such as marshes, fens, bogs, wet meadows, playas, potholes,

willow carrs, and forested wetlands. A comparison of HGM and Cowardin types, as

well as some examples, follow:

HGM Class Examples Cowardin System

Slope Fen Palustrine

Seep Springs

Riverine Riparian Riverine

Oxbow Palustrine

Depressions Potholes Lacustrine

Playas Palustrine

Vernal Pools

Tidal Fringe Estuaries Estuarine

Tidal Ponds

Lacustrine Fringe Lake Edges Lacustrine

Marshes Palustrine

Mineral Soil Flats Broad Interfluves Palustrine

Large Relict Lakes

Organic Soil Flats Extensive Peatlands Palustrine

Windell et al. (1986) define the following broad vegetative riparian-wetland types,

which are common in the Western States:
96

Marsh - Open water system, herbaceous (e.g., cattails, bulrush) species dominate.

Peatland - Standing water early in season, organic soils, dominated by herbaceous

vascular plants, but also nonvascular (e.g., mosses), and woody species (e.g., bog

birch, willows, blueberry)

Fens - Surface- and ground-water fed, mainly herbaceous

Rich (high pH nutrients) and poor (low pH nutrients) 

Bog - Receive moisture only from precipitation; they typically occur

in Alaska.

Willow Carr - Dominated by willows or other woody OBL species

Wet Meadow - Standing water early in season. Greater variability in water table

depth, persistence, and fluctuation. Typically mineral soils, although there are Histic

integrades (i.e., they have organic surface horizons). They are not true peatlands.

Sedges dominate, along with various forbs, grasses, and mosses. 

Depressional Wetland - HGM class. Intermountain and prairie (glacial) potholes.

Zones of herbaceous species based on water level. Typically form a complex of potholes within an upland matrix. Some are hydrologically connected; some aren’t. 

Forested Wetland - Usually in subalpine wet meadows and peatlands, they are dominated by spruce, subalpine fir, silver fir, red fir, and lodgepole pine, with sedge and

shrub undergrowths. Cycles of drying and inundation thin out the conifer overstory. 

Playa Wetlands - Standing water early in the season, drying rather rapidly. Fine textured clayey soils high in salt and/or sodium content. They typically hold water

longer due to fine texture. Salt adapted species, such as greasewood, saltbush, pickleweed, and saltgrass, dominate. 

Appendix F:
97

Problem Wetlands

Certain wetlands may be difficult to identify because field indicators of the three

wetland identification criteria may be absent, at least at certain times of the year.

99

These wetlands are considered problem wetlands because the difficulty in identification is generally due to normal environmental conditions and is not the result of

human activities or catastrophic natural events, with the exception of newly created

wetlands. Because of the difficulty in identifying these areas as wetlands, there will

be a degree of difficulty in assessing their functionality. ID teams may need to add

elements to the lentic checklist to assess these problem wetlands.

Examples of these problem wetlands are discussed below. Learning how to recognize these wetlands and to understand their attributes/processes is important for

assessing functionality.

1. Wetlands Dominated by Facultative Upland (FACU) Plant Species

Since wetlands often exist along a natural wetness gradient between permanently

flooded substrates and better-drained soils, the wetland plant communities sometimes may be dominated by FACU species. Although FACU-dominated plant communities are usually uplands, they sometimes become established in wetlands. In

order to determine whether a FACU-dominated plant community constitutes

hydrophytic vegetation, the soil and hydrology must be examined. If the area meets

the hydric soil and wetland hydrology criteria, then the vegetation is hydrophytic.

2. Evergreen Forested Wetlands

Wetlands dominated by evergreen trees occur in many parts of the country. In some

cases, the trees are obligate wetland (OBL) species, facultative wetland (FACW)

species, and facultative (FAC) species, e.g., Atlantic white cedar (Chamaecyparis

thyoides), black spruce (Picea mariana), balsam fir (Abies balsamae), slash pine

(Pinus elliottii), and loblolly pine (P. taeda). In other cases, however, the dominant

evergreen trees are FACU species, including red spruce (Picea rubens), Engelmann

spruce (P. engelmannii), white spruce (P. glauce), Sitka spruce (P. sitchensis),

eastern white pine (Pinus strobus), pitch pine (P. rigida), lodgepole pine (P.

contorta), longleaf pine (P. palustris), ponderosa pine (P. banksiana), eastern hemlock (Tsuga canadensis), western hemlock (T. heterophylla), Pacific silver fir (Abies

amabilis), white fir (A. concolor), and subalpine fir (A. lasiocarpa). In dense stands,

these evergreen trees may preclude the establishment of understory vegetation or, in

some cases, the understory vegetation may also be FACU species. Since these plant

communities are usually found on nonwetlands, the ones established in wetland

areas may be difficult to recognize at first glance. The landscape position of the

evergreen forested areas, such as a depression, drainageway, bottomland, flat in

sloping terrain, and seepage slope, should be considered because it often provides

clues to the likelihood of wetlands. Soils also should be examined in these situations. The wetlands can be identified by following the procedures for FACU-dominated wetlands described above.

3. Glacial Till Wetlands
100

Sloping wetlands occur in glaciated areas where thin soil covers relatively impermeable glacial till or where layers of glacial till have different hydraulic conditions that

permit ground-water seepage. Such areas are seldom, if ever, flooded, but downslope ground-water movement keeps the soils saturated for a sufficient portion of the

growing season to produce anaerobic and reducing soil conditions. This promotes

development of hydric soils and hydrophytic vegetation. Indicators of wetland

hydrology may be lacking during the drier portion of the growing season. Hydric

soil indicators also may be lacking because certain areas are so rocky that it is difficult to examine soil characteristics within 18 inches.

4. Highly Variable Seasonal Wetlands

In many regions (especially in arid and semiarid regions), depressional areas occur

that may have indicators of all three wetland criteria during the wetter portion of the

growing season, but normally lack indicators of wetland hydrology and/or

hydrophytic vegetation during the drier portion of the growing season. In addition,

some of these areas lack field indicators of hydric soil. OBL and FACW plant

species normally are dominant during the wetter portion of the growing season,

while FACU and obligate upland (UPL) species (usually annuals) may be dominant

during the drier portion of the growing season and during and for some time after

droughts. Examples of highly variable seasonal wetlands are pothole wetlands in the

upper Midwest, playa wetlands in the Southwest, and vernal pools along the coast of

California. It is important to become familiar with the ecology of these and similar

types of wetlands, and to be particularly aware of drought conditions that permit

invasion of UPL species (even perennials).

5. Interdunal Swale Wetlands

Along the U.S. coastline, seasonally wet swales supporting hydrophytic vegetation

are located within sand dune complexes on barrier islands and beaches. Some of

these swales are inundated or saturated to the surface for considerable periods during

the growing season, while others are wet for only the early part of the season. In

some cases, swales may be flooded irregularly by the tides. These wetlands have

sandy soils that generally lack field indicators of hydric soil. In addition, indicators

of wetland hydrology may be absent during the drier part of the growing season.

Consequently, these wetlands may be difficult to identify.

6. Vegetated River Bars and Adjacent Flats Wetlands

Along western streams in arid and semiarid parts of the country, some river bars and

flats may be vegetated by FACU species while others may be colonized by wetter

species. If these areas are frequently inundated for 1 or more weeks during the

growing season, they are wetlands. The soils often do not reflect the characteristic

field indicators of hydric soils, however, and thereby pose delineation problems.

7. Vegetated Flats Wetlands
101

Vegetated flats are characterized by a marked seasonal periodicity in plant growth.

They are dominated by annual OBL species, such as wild rice (Zizania aquatica),

and/or perennial OBL species, such as spatterdock (Nuphar luteum), that have nonpersistent vegetative parts (i.e., leaves and stems break down rapidly during the

winter, providing no evidence of the plant on the wetland surface at the beginning of

the next growing season). During winter and early spring, these areas lack vegetative cover and resemble mud flats; therefore, they do not appear to qualify as wetlands. But during the growing season, the vegetation becomes increasingly evident,

qualifying the area as a wetland. In evaluating these areas, which occur both in

coastal and interior parts of the country, the time of year of the field observation and

the seasonality of the vegetation must be considered. Again, it is important to

become familiar with the ecology of these wetland types.

8. Newly Created Wetlands

These wetlands include manmade (artificial) wetlands, beaver-created wetlands, and

other natural wetlands. Artificial wetlands may be purposely or accidentally created

by human activities (e.g., road impoundments, undersized culverts, irrigation, and

seepage from earth-dammed impoundments). Many of these areas will have indicators of wetland hydrology and hydrophytic vegetation. But the area may lack typical

field characteristics of hydric soils since the soils have just recently been inundated

and/or saturated. Since all of these wetlands are newly established, field indicators

of one or more of the wetland identification criteria may not be present.

9. Entisols (Floodplain and Sandy Soils) Wetlands

Entisols are usually young or recently formed soils that have little or no evidence of

pedogenically developed horizons. These soils are typical of floodplains throughout

the U.S., but are also found in glacial outwash plains, along tidal waters, and in

other areas. They include sandy soils of riverine islands, bars, and banks and finer

textured soils of floodplain terraces. Some entisols are easily recognized as hydric

soils such as the sulfaquents of tidal salt marshes, whereas others pose problems

because they do not possess typical hydric soil field indicators. Wet sandy entisols

(with loamy fine sand and coarser textures in horizons within 20 inches of the surface) may lack sufficient organic matter and clay to develop hydric soil colors.

When these soils have a hue between 10YR and 10Y and distinct or prominent mottles present, a chroma of 3 or less is permitted to identify the soil as hydric.

10. Mollisols (Prairie and Steppe Soils) Wetlands

Mollisols are dark-colored, base-rich soils. They are common in the central part of

the conterminous U.S. from eastern Illinois to Montana and south to Texas. Natural

vegetation is mainly tall grass prairies and short grass steppes. These soils typically

have deep, dark topsoil layers (mollic epipedons) and low chroma matrix colors to

considerable depths. They are rich in organic matter due largely to the vegetation

(deep roots) and reworking of the soil and organic matter by earthworms, ants,
102

moles, and rodents. The low chroma colors of mollisols are not necessarily due to

prolonged saturation, so be particularly careful in making wetland determinations in

these soils must be made carefully. It is important to become familiar with the characteristics of mollisols with aquic moisture regimes.

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Glossary of Terms

Advanced Ecological Status - A community with a high coefficient of similarity to
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a defined or perceived PNC for an ecological site, usually late seral or PNC ecological status.

Aerobic - A condition in which molecular oxygen is a part of the environment.

Anaerobic - A condition in which molecular oxygen is absent (or effectively so)

from the environment.

Duration - A general descriptive term for the average amount of time that inundation lasts per flood occurrence for a geographic area. Categories include: very brief

(less than 2 days); brief (2 to 7 days); long (7 days to 1 month); very long (more

than 1 month); and flash flooding (less than 2 hours).

Facultative (FAC) Species - Plant species that are equally likely to occur in wetlands or nonwetlands (estimated probability 34-66 percent).

Facultative Upland (FACU) Species - Plant species that usually occur in nonwetlands (estimated probability 67-99 percent), but that are occasionally found in wetlands (estimated probability 1-33 percent).

Facultative Wetland (FACW) Species - Plant species that usually occur in wetlands (estimated probability 67-99 percent), but that are occasionally found in nonwetlands.

Flooding - When the soil surface is temporarily covered with flowing water from

any source, such as overflowing streams or rivers, runoff from adjacent slopes, and

inflow from high tides.

Frequency - A general descriptive term for the relative chance of reoccurrence of a

flooding event for a geographic area. Categories include: none (0 percent chance);

rare (0 to 5 percent chance); occasional (5 to 50 percent chance); and frequent

(greater than 50 percent chance).

Frost (or Abnormal Hydrologic) Heaving - The lifting of a surface by the internal

action of frost or hydrostatic pressure. It generally occurs after a thaw, when the soil

is filled with water droplets and when a sudden drop in temperature below freezing

changes the droplets into ice crystals, which involves expansion and consequently

causes an upward movement of the soil. The process is exacerbated when there is

compaction between plant tussocks (e.g., from hoof action) and/or excessive

removal of thermal vegetation cover. The result is the hummocked appearance of

plants being elevated above the normal ground surface, root shearing between

plants, and exposure of interspaces to increased erosional forces.

Gleyed Matrix - (USDA NRCS 1998b) Soils with a gleyed matrix have the following combination of hue, value, and chroma, and the soils are not glauconitic:

10Y, 5GY, 10GY, 10G, 5BG, 10BG, 5B, 10B, or 5PB with value 4 or more and

chroma is 1; or 5G with value 4 or more and chroma is 1 or 2; or N with value 4 or
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more; or (for testing only) 5Y, value 4 , and chroma 1. In some places the gleyed

matrix may change color upon exposure to air (reduced matrix). This phenomenon

is included in the concept of gleyed matrix.

Histic Epipedon - A thick (20- to 60-cm) organic soil horizon that is saturated with

water at some period of the year unless artificially drained and that is at or near the

surface of a mineral soil.

Histosols - Organic soils that have organic materials in more than half of the upper

80 cm (32 in), or that are of any thickness if they overlay rock or fragmental materials that have interstices filled with organic soil materials.

Hydric Soil (1994) - A soil that formed under conditions of saturation, flooding, or

ponding long enough during the growing season to develop anaerobic conditions in

the upper part.

Hydrogen Sulfide Odor - An odor similar to rotten eggs associated with H2S.

Hydrogeomorphic - Features pertaining to the hydrology and/or geomorphology of

a riparian wetland area.

Inundation - A condition in which water from any source temporarily or permanently covers a land surface.

Obligate Upland (UPL) Species - Plant species that occur in wetlands in another

region, but almost always occur (estimated probability >99 percent) under natural

conditions in nonwetlands in the region specified.

Obligate Wetland (OBL) Species - Plant species that occur almost always (estimated probability >99%) under natural conditions in wetlands.

Ponding - A condition in which water stands in a closed depression. The water is

removed only by percolation, evaporation, or transpiration.

Potential Natural Community - Represents the seral stage the botanical community would achieve if all successional sequences were completed without human

interference under the present environmental conditions.

Redox Concentration - Bodies of apparent accumulation of Fe-Mn oxides

(Vepraskas 1994).

Redox Depletions - Bodies of low chroma (<2) having values of 4 or more where

Fe-Mn oxides alone have been stripped out or where both Fe-Mn oxides and clay

have been stripped out (Vepraskas 1994).

Redoximorphic Features - Features formed by the reduction, translocation, and

oxidation of Fe and Mn oxides. Both iron and manganese are used because the two

are virtually inseparable in soils.
109

Reduced Matrices - Soil matrices that have a low chroma color in situ because of

the presence of Fe(II), but whose color changes in hue or chroma when exposed to

air as the Fe(II) is oxidized to Fe(III) (Vepraskas 1994).

Reduction - The gaining of electrons by an atom or ion, thereby reducing its variance. For the purpose of hydric soil indicators, it is when the redox potential (Eh) is

below the ferric/ferrous iron threshold as adjusted for pH. In hydric soils, this is the

point when transformation of ferric iron (Fe+++) to ferrous iron (Fe++) occurs.

Riparian-Wetland Area - An area that is saturated or inundated at a frequency and

duration sufficient to produce vegetation typically adapted for life in saturated soil

conditions. It is also the transitional area between permanently saturated wetlands

and upland areas often referred to as a riparian area. This transition area has vegetation or physical characteristics reflective of permanent surface or subsurface water

influence. Wetlands and wetland transitions are usually managed as a unit. These

systems can be either nonjurisdictional or jurisdictional.

Riparian-Wetland Ecological Site - An area of land with a specific potential plant

community and specific physical site characteristics, differing from other areas of

land in its ability to produce vegetation and to respond to management. Ecological

site is synonymous with range site.

Saturation - When the soil water pressure is zero or positive. Most all the soil

pores are filled with water.

Vegetation Community Dynamics - Response of plant communities to changes in

their environment, to their use, and to stresses to which they are subjected. Climatic

cycles, fire, insects, grazing, and physical disturbances are some of the many causes

of changes in plant communities. Some changes are temporary while others are

long-lasting.

Vegetation Community Succession - A sequence of plant community changes from

the initial colonization of a bare soil toward a PNC (primary succession). It may

involve sequences of plant community changes from PNC due to perturbations, or a

sequence toward PNC again following a perturbation (secondary succession).

Vegetation community succession may be accompanied by subtle but significant

changes in temporal soil characteristics, such as bulk density, nutrient cycling, and

microclimatic changes, but it is differentiated from major physical state changes,

such as landform modification or long-term elevation or lowering of a water table,

that would change the PNC of an ecological site.

Woody Debris - Woody vegetation that enters a riparian-wetland area and is large

enough to stay for a period of time and operate as a hydrologic modifier. Often

referred to as woody material.
110