Federal Energy 

Regulatory 

Commission

Office of 

Energy Projects

March 2004

Research of Wetland Construction and

Mitigation Activities for Certificated

Section 7(c) Pipeline Projects

Washington, D.C. 20426
RESEARCH OF WETLAND CONSTRUCTION AND 

MITIGATION ACTIVITIES FOR CERTIFICATED 

SECTION 7(c) PIPELINE PROJECTS

Federal Energy Regulatory Commission

Office of Energy Projects

March 2004
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

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EXECUTIVE SUMMARY

The Federal Energy Regulatory Commission (FERC) undertook this study, Research of 

Wetland Construction and Mitigation Activities for Certificated Section 7(c) Pipeline 

Projects, to evaluate the effectiveness of the wetland provisions in the 1994 Wetland and 

Waterbody Construction and Mitigation Procedures (1994 Procedures) and to determine 

if natural gas pipeline companies were successful in restoring wetlands following pipeline 

construction, according to the FERC's criteria for success. These criteria require that the 

post-construction wetlands have at least 80 percent vegetative cover by native species, that 

the plant diversity of the restored wetland be at least 50 percent that of the pre-construction 

condition, and that the wetland satisfies the requirements of the current Federal

methodology for identifying and delineating wetlands. 

A fundamental objective of this study was to evaluate the success of wetland restoration 

for pipeline projects from diverse geographic regions throughout the United States to

determine if there was a regional difference. The study design was based on Robert G. 

Bailey’s Ecoregions of the United States, and six separate ecoregion divisions were 

sampled throughout the United States. Field data were collected at 80 on-right-of-way 

(ROW) and 80 off-ROW sites within each of the six ecoregions, resulting in a total of 

960 wetlands sampled. These wetlands were located along 13 different pipeline projects 

within 15 different states. Field data collection started in August 2002 and was

completed in June of 2003. 

Collected data were then entered into a Microsoft© Access Database specifically

designed for the project. Queries were written to test each wetland against the success 

criteria established by FERC staff in the 1994 Procedures (Appendix A). Query results 

were then reviewed to identify trends that could be attributed to wetland restoration

success or failure. These trends were then tested to determine statistical significance

(Appendix B). 

Results

Wetlands designated as “passing” the FERC criteria were required to meet all three of the 
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Restoration criteria. Wetlands identified as “failing” failed one or more of the three

criteria. Wetland restoration success rates ranged from 89% in the humid eastern

ecoregions, to 32% in the arid western ecoregions. The overall nationwide wetland 

restoration success rate based on the 1994 Procedures was 65% (313 wetlands) and the 

failure rate was 35% (167 wetlands). A total of 86% (411) of the wetlands surveyed met

the definition for a federal wetland following construction. The most common single

factor contributing to restoration failure was wetlands having less than 80% percent

vegetative cover by native species.

Statistical tests, including nine independent factors, revealed three factors as having a 

significant influence on whether or not a wetland was successfully restored. These three 

factors were, ecoregion, evidence of human disturbance (post-construction), and whether 

or not the wetland was restored to preconstruction grades (construction). Based on

statistical testing, wetlands located in the Midwestern and eastern ecoregions had a

statistically greater success rate than those in the western ecoregions. Wetlands

exhibiting evidence of human disturbance were less likely to be successfully restored. 

Wetlands not restored to preconstruction grades were also less likely to be successfully 

restored. 

Conclusions

A variety of factors that could potentially influence success were examined and are

presented in Section 4 of this report. The following is a summary of conclusions and 

notable trends: 

ß Existing wetland monitoring reports were largely unavailable from pipeline

companies contacted. Based on post-construction wetland monitoring reports that 

were received, it is evident that the pipeline industry does not have a consistent 

approach to performing post-construction wetland monitoring. The FERC's

revised 2003 Procedures (VI.D.3.) now requires that a report be filed with the 

Secretary identifying the status of the wetland revegetation efforts at the end of

three years following construction. This requirement is anticipated to improve the 

status of post-construction wetland monitoring for pipeline projects.
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ß Based on detailed quantitative field studies, approximately two thirds of all

wetlands studied nationwide achieved all three wetland restoration success criteria 

identified in the 1994 Procedures. Most wetlands that failed the FERC success 

criteria failed due to insufficient vegetative cover.

ß The study revealed strong differences in overall success by ecoregion. Eastern

and Midwestern wetlands have significantly higher success rates than Western

ecoregions. Regional climates and weather conditions reveal noticeable trends in 

relative wetland restoration success and failure. 

ß The presence of human disturbance in wetlands was associated with higher failure 

rates, likely due to its influences on the percent vegetative cover criterion. The 

most common human disturbance category was farming, which includes cattle

grazing, and could be a contributing factor to the lower success rate for wetlands 

occurring in the western ecoregions.

ß Wetlands that achieved pre-construction grades (i.e., grading of the wetland was 

reestablished to pre-construction conditions) were significantly more successful 

than wetlands that did not meet pre-construction grades.

ß Soil conditions appear to have some influence on wetland revegetation success, 

with wetlands underlain by clay-dominated soils having a greater failure rate than 

wetlands dominated by other soil types. Although this was a noticeable trend, soil 

texture was not a significant factor based on the statistical analysis. 

ß The data showed a strong trend of conversion of forested and scrub-shrub 

wetlands to emergent wetlands. This observation may be the result of the short 

period of time since implementation of the 1994 Procedures relative to the

expected time frame for the re-establishment of arboreal vegetation. Therefore, 

this trend is considered inconclusive. In addition, we expect this trend to persist 

over portions of the ROW because ROW vegetation maintenance (removal of

woody vegetation over the pipeline) is commonly used to facilitate monitoring

required by the U.S. Department of Transportation to ensure pipeline integrity. 
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Recommendations

The following is a summary of recommendations resulting from this study:

ß Methods used to monitor wetland restoration success should be standardized to 

ensure that wetland restoration can be evaluated consistently between Projects and 

geographic regions over time. The wetland monitoring dataform used for this

study (Appendix D) should be used as a template for future wetlands monitoring.

ß Wetlands in the arid western ecoregions have a much higher rate of failure than 

wetlands in more humid regions of the country. This stark contrast warrants

consideration of a modified version of the Procedures for the western regions that 

takes into consideration climate differences and local successional processes. 

Duration of monitoring and success criteria may need to be modified for these 

regions (i.e., longer monitoring periods, lower cover and diversity requirements, 

etc.).

ß Evidence of human disturbance was associated with lower success rates

regardless of ecoregion, and, evidence of human disturbance was more prevalent 

for the western ecoregions than the eastern ecoregions. Post-construction 

monitoring to evaluate the effects of human disturbance on wetland restoration

should be encouraged so that remedial measures can be suggested. 

ß Although only 23 of the 480 wetlands were not restored to pre-construction 

grades, this factor had a substantive effect in determining success. Therefore, 

current procedures that enforce the restoration of pre-construction grades should 

continue to be developed.

ß FERC may want to consider modifying the criteria, as follows:

ÿ Wetlands with standing water commonly have areas of vegetation

interspersed with open water, and therefore are characterized as having

less than 80% cover of vegetation (due to greater than 20% open water). 

The open water/vegetation mix is generally considered to be a positive 

habitat feature and thus should not be discouraged except in instances
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where standing water indicates that post-construction grades were

established lower than pre-construction conditions. 

ÿ Pipeline companies should be encouraged to identify "problem wetlands" 

(i.e., wetlands with greater than 20% surface rock or open water, shallow 

to bedrock soils, or wetlands dominated by annual plant species) to the 

FERC staff prior to construction and provide ample pre-construction 

photographic documentation for these wetlands. These wetlands should

be considered “successfully restored” following construction, if preconstruction conditions are reestablished and this can be documented to 

the satisfaction of FERC staff.

ÿ Farmed wetlands – Once a ROW is cleared, farmers often take advantage 

of the additional area and moist soils of seasonally saturated wetlands to 

plant additional crops or graze cattle. The presence of agricultural activity 

greatly reduces the chances that a wetland will meet the criteria for

restored wetland. This issue was addressed in the revised 2003 Procedures 

(Section I.B.2.) where wetlands that are actively cultivated, or are

considered rotated cropland, are excluded from the definition of a

"wetland".

ÿ Post-construction human disturbance is observed on two-thirds of all

failed wetlands and is likely a contributing factor in failure. These

extenuating circumstances should be considered when evaluating wetland 

restoration success.
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TABLE OF CONTENTS

Section Page

EXECUTIVE SUMMARY............................................................................................ES-1

Results................................................................................................................ES-1

Conclusions........................................................................................................ES-2

Recommendations..............................................................................................ES-4

TABLE OF CONTENTS..................................................................................................... i

LIST OF TABLES .............................................................................................................iii

LIST OF FIGURES ........................................................................................................... iv

1.0 INTRODUCTION .................................................................................................. 1

2.0 STUDY OBJECTIVES........................................................................................... 2

3.0 METHODS ............................................................................................................. 4

3.1 DATA SOURCES........................................................................................................ 4

3.2 STUDY DESIGN AND SITE SELECTION....................................................................... 6

3.3 VEGETATION SAMPLING AND RIGHT-OF-WAY CHARACTERIZATION ....................... 9

3.3.1 Qualitative Assessment ................................................................................... 9

3.3.2 Quantitative Assessment ............................................................................... 10

3.4 COLLECTION PROTOCOL........................................................................................ 11

3.5 DATA ANALYSIS .................................................................................................... 12

3.5.1 Analyses Relative to FERC Success............................................................. 12

3.5.2 Trends Analysis............................................................................................. 14

3.5.3 Statistical Analysis........................................................................................ 14

4.0 RESULTS AND DISCUSSION........................................................................... 22

4.1 GENERAL RESULTS AND TRENDS IN POST-CONSTRUCTION PLANT COMMUNITIES . 22

4.1.1 Project Wetland Restoration Summary......................................................... 22

4.1.2 Wetland Restoration Success by Ecoregion.................................................. 24

4.1.3 Wetland Cover Classes................................................................................. 30

4.1.4 Conversions of Wetland Cowardin Classes Following Construction........... 32

4.2 INFLUENCE OF PHYSICAL FACTORS ON RESTORATION SUCCESS............................ 34

4.2.1 Wetland Landscape Position......................................................................... 34

4.2.2 Soil Type....................................................................................................... 35

4.2.3 Wetland Hydrology....................................................................................... 37

4.3 INFLUENCE OF HUMAN DISTURBANCE ON RESTORATION SUCCESS ....................... 38

4.3.1 Wetlands Affected by Human Disturbance .................................................. 38

4.3.2 Waterbar Placement...................................................................................... 41
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4.3.3 Pipeline Construction Dates.......................................................................... 42

4.3.4 Post-construction Grading............................................................................. 43

4.4 STATISTICAL ANALYSIS ......................................................................................... 43

5.0 CONCLUSIONS AND RECOMENDATIONS................................................... 46

5.1 RECOMMENDATIONS.............................................................................................. 47

6.0 PREPARERS ........................................................................................................ 50

7.0 REFERENCES ..................................................................................................... 52

APPENDICES

APPENDIX A Database Results Summary Reports

APPENDIX B Statistical Analysis Summary Report

APPENDIX C Vegetation and Diversity Summary Reports

APPENDIX D Wetlands Monitoring Dataform

APPENDIX E Wetlands Monitoring Database and Technical Documentation
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LIST OF TABLES

Section Page

Table 3-1. Results of Phase I – Existing Wetlands Monitoring Data Collection. ........... 5

Table 3-2. Cover Classes of Braun-Blanquet. ............................................................... 11

Table 4-1. Overall Wetland Restoration Summary. ...................................................... 23

Table 4-2. Distribution of Wetland Restoration Success and Failure by Ecoregion..... 25

Table 4-3. U.S. Drought Monitor Drought Severity Classifications............................. 29

Table 4-4. Wetland Cowardin Classification Distribution by Ecoregion and Restoration 

Results.......................................................................................................... 31

Table 4-5. Comparison of Pre-Construction and Post Construction Wetland Cowardin 

Classifications.............................................................................................. 31

Table 4-6 Summary of Wetland Restoration Relative to Position of Wetland in 

Landscape. ................................................................................................... 34

Table 4-7. Wetland Restoration Success Related to Soil Type. .................................... 36

Table 4-8. Wetland Restoration Related to Depth of Surface Water. ........................... 37

Table 4-9. Wetlands Affected by Human Disturbance. ................................................ 39

Table 4-10. Wetland Restoration Relative to Existence or Placement of Waterbars...... 41

Table 4-11. Wetland Restoration Summary for Pipeline Construction Years. .............. 42

Table 4-12. Multiple Factor Analysis of Variance Effects Test on Success.................. 44

Table 4-13. Significant Factors in Determining Successful Restoration. ....................... 45

Table 4-14. Significant Explanatory Factors Between Eastern and Western Grouped 

Ecoregions. .................................................................................................. 45
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LIST OF FIGURES

Section Page

Figure 3-1. Ecoregions of the United States Robert G. Bailey U.S. Forest Service......... 7

Figure 3-2. Eco-Divisions Used to Select Wetlands to be Monitored.............................. 8

Figure 3-3. Wetlands Monitored in Warm Continental Division................................... 16

Figure 3-4. Wetlands Monitored in Hot Continental Division....................................... 17

Figure 3-5. Wetlands Monitored in Subtropical Division .............................................. 18

Figure 3-6. Wetlands Monitored in Prairie Division...................................................... 19

Figure 3-7. Wetlands Monitored in Temperate Steppe Division.................................... 20

Figure 3-8. Wetlands Monitored in Mediterranean Division ......................................... 21

Figure 4-1. Distribution of Wetland Failures by FERC Criterion. ................................. 24

Figure 4-2. Wetland Success and Failure by Ecoregion. ................................................ 25

Figure 4-3. Climate Diagrams for Study Ecoregions ..................................................... 27

Figure 4-4. U.S. Drought Monitor Map for Week Ending September 10, 2002. ........... 29

Figure 4-5. U.S. Drought Monitor Map for Week Ending June 10, 2003...................... 30

Figure 4-6. Changes in Cowardin Classification from Pre- to Post-construction 

Conditions.................................................................................................... 33

Figure 4-7. USDA Soils Textural Classes...................................................................... 36

Figure 4-8. Breakdown of Types of Human Disturbance Observed in Wetlands. ......... 40

Figure 4-9. Wetland Failing Cover Criterion Due to Impacts from ATV’s. .................. 40
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1.0 INTRODUCTION

In 1994, the staff of the Federal Energy Regulatory Commission (FERC) established its 

minimum guidelines for minimizing wetland impacts during construction of natural gas

pipelines by issuing the “Wetland and Waterbody Construction and Mitigation

Procedures” (1994 Procedures). These 1994 Procedures were developed based on a 

compilation of FERC staff (Staff) project experience and many years of project feedback 

relating to pipeline construction and wetland impact minimization from local, state, and 

Federal regulators across the United States. Adherence to the measures prescribed in the 

1994 Procedures is generally considered by the FERC staff to be the baseline (minimal) 

mitigation appropriate for construction of natural gas projects.

Since issuance of the 1994 Procedures, the FERC has generally required all jurisdictional 

pipeline construction projects to adopt the 1994 Procedures, or similar approved, companyidentified procedures, that offer a comparable or greater level of environmental protection. 

The FERC staff has gained valuable insight into the effectiveness of the 1994 Procedures 

through their ongoing construction inspection program. However, attempts to quantify the 

effectiveness of the 1994 Procedures in relation to wetland restoration had not previously 

been examined. The FERC initiated this study to evaluate the long-term effectiveness of the 

1994 Procedures and to determine if changes to the Procedures are warranted.

The 1994 Procedures identified three success criteria that must all be met for the wetland to 

be considered successfully restored:

1. The area must satisfy the requirements of the current Federal methodology for 

identifying and delineating wetlands (Section I.C.2.)

2. The wetland must have at least 80 percent vegetative cover by native species 

(Section VI.E.3.)

3. The diversity of native species must be at least 50 percent of the diversity

originally found in the wetland (Section VI.E.3.)
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2.0 STUDY OBJECTIVES

A number of objectives were established to meet the goal of determining if the 1994 

Procedures were facilitating successful restoration of wetlands. These objectives were a 

direct outcome of a project scoping meeting held during October 2001 at the FERC office 

in Washington, D.C. At this meeting, FERC biologists, regulatory staff, and FERC’s

environmental consultants, Northern Ecological Associates, Inc. (NEA) and Tetra Tech, 

(the Team) worked together to refine study objectives, and to identify the most

appropriate means for achieving both the overall goal and the objectives. 

The following objectives were identified:

1. Compile information from pipelines and wetlands in diverse regions of the United 

States;

2. Examine wetlands of various cover types in approximate proportion to their

abundance in that region of the country;

3. Examine the influence of physical factors on the success of wetland restoration, 

including hydrology, landscape position, soil textural class, subsoil/topsoil

mixing, etc.;

4. Examine the significance of human-caused factors on success of wetland

restoration, including improper construction of waterbars, inadequate removal of 

construction debris, and post-construction disturbances such as ATV traffic,

farming, logging, or residential/commercial development; 

5. Document trends in post-construction vegetation communities; and,

6. Evaluate a subset of the most frequently requested exceptions (variances) to the 

1994 Procedures. 

A number of other items related to the scope, objectives, and methods of the study were 

discussed at the October 2001, and subsequent June 2002, Team meetings. 

An initial aspect of the study was to establish the quality and quantity of existing postconstruction monitoring data previously compiled by pipeline companies. Section 3.1 of 

this report (Data Sources) addresses this in detail. Depending on these data, a set of
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regionally diverse pipeline projects, certificated after the issuance of the 1994 Procedures 

(December 1994), were selected for inclusion in the study. 

The project also included design and application of a specially designed Microsoft© 

Access Database (hereafter “the Database”) for organizing and analyzing all data

collected for the study. A unique data form was created to facilitate the timely collection 

of the data. The data form was designed to operate on a handheld field computer (PDA 

device) and to allow for easy transfer to the Database. Data were then analyzed to

identify trends associated with successful and unsuccessful wetland restoration. These 

trends were analyzed to allow a critical review of the 1994 Procedures and their

implementation by the natural gas industry, and to identify whether modifications to the 

1994 Procedures may be warranted to improve wetland restoration success
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3.0 METHODS

3.1 DATA SOURCES

An original directive of the project was to use existing monitoring data previously

compiled by individual pipeline companies to the greatest extent possible. Section

VI.E.3, Post Construction Maintenance, of the 1994 Procedures requires certificate

holders1 to monitor the success of wetland revegetation annually for the first 3 to 5 years 

after construction. However, because the FERC did not require formal filing of wetland 

monitoring reports during the study period, it was necessary to obtain this information

from the pipeline companies directly. Because both the availability and quality of the 

existing data was uncertain, the following phased approach was used for this assessment 

of data sources:

ß Phase I - Existing monitoring data would be collected from pipeline companies 

for pipeline projects constructed between 1994 and 1999. (The 1999 end date was 

established to allow for a minimum of three growing seasons following

construction; 1994 is the effective date of the Procedures.)

ß Phase II - Field verification would be conducted to supplement existing

monitoring data. The original proposal assumed that existing data would be

supplemented with newly collected data from 250 wetlands. This phase would 

include on-site wetland monitoring of selected pipeline projects based on an

ecologically significant division of the United States.

ß Phase III – Post-construction wetland monitoring data derived from Phases I and 

II would then be transferred into a project-specific Database, analyzed, trends 

identified, and presented in draft and final reports to the FERC.

Following the initial scoping meeting, the FERC compiled a list of 117 pipeline

construction projects constructed between 1994 and 1999. These projects were

constructed by 24 different pipeline companies. For each pipeline company, the Team 

identified a single point of contact for acquisition of the required data. A letter formally 

 

1 A certificate holder is an individual or company that has received a Certificate of Public Convenience and 

Necessity pursuant to Section 7(c) of the Natural Gas Act.
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requesting copies of existing wetlands monitoring data was sent to each of these

companies in January of 2002. Follow up telephone calls were made to ensure the letter 

was received, and to answer questions regarding the request. Table 3-1 provides a 

summary of the Phase I Existing Monitoring Data Collection Task. 

Table 3-1. Results of Phase I – Existing Wetlands Monitoring Data Collection.

Result Companies Projects

Information Received and of Good Quality1 9 14

Information Not Available 7 72

Information Available, but Not Submitted 3 8

No Response or Wetlands Not Crossed 5 23

Totals 24 117

1 Wetland monitoring reports were considered “good quality” if they included data for percent cover and diversity and identified 

the methods used to obtain the data.

Wetland monitoring reports of relatively good quality were received from 9 pipeline

companies representing 14 pipeline projects. However, further review revealed that the 

data collected varied widely in sampling methods, types of information collected, and the 

format of monitoring results. 

Following this phase of the project, another status meeting was held at the FERC’s 

Washington, D.C. offices in June of 2002. During this meeting the Team presented the 

results of the Phase I data collection. The Team agreed that insufficient existing

monitoring data were available and that additional field data collection would be

necessary. After thorough review, a revised study approach was approved by the FERC 

in August of 2002. 

The new approach proposed collection of all new field data to ensure a standardized data 

set for all wetlands surveyed. Additionally, to account for the preconstruction condition 

of the on-ROW wetland, a reference wetland would also be sampled. The reference 

wetland would be an undisturbed wetland, ideally a portion of the same wetland located 

adjacent to the construction ROW, but not impacted by construction. Best professional 
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judgment would be used to select a reference wetland that would best represent the onROW wetland’s preconstruction conditions.

This approach ensured that consistent qualitative and quantitative survey methods,

criteria, and methods of analysis were applied to the study. New data would be collected 

from pipeline projects sampled from major ecoregions throughout the United States. 

For maximum efficiency, pipeline projects to be sampled would be based on location

within ecoregions, length of ROW, number of total wetlands along ROW, and access

considerations.

3.2 STUDY DESIGN AND SITE SELECTION

A fundamental component of the study design was to evaluate projects from different

regions throughout the United States and to evaluate differences in restoration results

throughout the country. The Team determined that Robert G. Bailey’s Ecoregions of the 

United States, (Figure 3-1) best represents the different climate zones within the

conterminous United States and would yield the most meaningful results from an

ecological perspective. In this system, ecoregions (regions of ecological significance) are 

mapped based on climate and vegetation. The result is a hierarchy containing three

levels, domains, divisions, and provinces. Domains and divisions, the two broadest

levels, are based on large ecological and climatic zones. The third level, provinces, is 

based on vegetational micro features. There are 4 domains, 13 divisions, and 52

provinces within the United States. 

The division ecoregion level (Figure 3-2) was selected as the most appropriate for

meeting study objectives. This was due largely to the logistics of collecting data sets 

large enough to allow meaningful analyses in 52 provinces and the limitations associated 

with evaluating only four domains, two of which (Polar and Humid Tropical) were likely 

to have very few, if any, pipeline projects to survey.
Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-1. Ecoregions of the

United States

Robert G. Bailey

U.S. Forest Service

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200 100 0 200

Scale in Miles

BASIS OF MAP UNITS

ECO-REGIONS

Intermountain Semi-Desert Province

Intermountain Semi-Desert and Desert Province

Laurentian Mixed Forest Province

Lower Mississippi Riverine Forest Province

Outer Coastal Plain Mixed Forest Province

Ozark Broadleaf Forest - Meadow Province

Pacific Lowland Mixed Forest Province

Prairie Parkland (Subtropical) Province

Prairie Parkland (Temperate) Province

Southeastern Mixed Forest Province

Southwest Plateau and Plains Dry Steppe and Shrub Province

Arizona-New Mexico Mountains Semi-Desert-Open

Woodland-Coniferous Forest-Alpine Meadow Province

Adirondack-New England Mixed Forest-Coniferous Forest-Alpine Meadow Province

American Semi-Desert and Desert Province

Black Hills Coniferous Forest Province

California Coastal Chapparral Forest and Shrub Province

California Coastal Range Open Woodland-Shrub-Coniferous Forest-Meadow Province

California Dry Steppe Province

Cascade Mixed Forest-Coniferous Forest-Alpine Meadow Province

Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow Province

Chihuahuan Semi-Desert Province

Colorado Plateau Semi-Desert Province

Eastern Broadleaf Forest (Continental) Province

Eastern Broadleaf Forest (Oceanic) Province

Everglades Province

Great Plains Steppe Province

Great Plains Steppe and Shrub Province

Southern Rocky Mountain Steppe-Open

Woodland-Coniferous Forest-Alpine Meadow Province

Middle Rocky Mountain Steppe-Coniferous

Forest-Alpine Meadow Province

Nevada-Utah Mountains-Semi-Desert-Coniferous

Forest-Alpine Meadow Province

Northern Rocky Mountain Forest-Steppe-Coniferous

Forest-Alpine Meadow Province

Sierran Steppe-Mixed Forest-Coniferous

Forest-Alpine Meadow Province

State Boundaries

Great Plains-Palouse Dry Steppe Province

Ouachita Mixed Forest - Meadow Province

This map depicts ecosystems of regional extent. A hierarchial order is

obtained by defining successively smaller ecosystems within larger

ecosystems. At each successive level a different ecosystem component

is assigned prime importance in the placing of map boundaries. Domains

and divisions are based largely on the large ecological climate zones.

Each division is further subdivided into provinces on the basis of

macro-features of the vegetation. Mountains exhibiting altitudinal

zonation and having the climatic regime of the adjacent lowlands

are distinguished according to the character of the zonation.
TEMPERATE STEPPE

DIVISION

MARINE

DIVISION

MEDITERRANEAN

DIVISION

TROPICAL/SUBTROPICAL

DIVISION

TROPICAL/SUBTROPICAL

DESERT DIVISION

WARM CONTINENTAL

DIVISION

HOT CONTINENTAL

DIVISION

PRAIRIE

DIVISION

SUBTROPICAL

DIVISION

SAVANNA

DIVISION

TEMPERATE STEPPE

DIVISION

MARINE

DIVISION

MEDITERRANEAN

DIVISION

TROPICAL/SUBTROPICAL

DIVISION

TROPICAL/SUBTROPICAL

DESERT DIVISION

WARM CONTINENTAL

DIVISION

HOT CONTINENTAL

DIVISION

PRAIRIE

DIVISION

SUBTROPICAL

DIVISION

SAVANNA

DIVISION

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-2. Eco-Divisions Used

to Select Wetlands

to be Monitored

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Scale in Miles

BASIS OF MAP UNITS

This map depicts ecosystems of regional extent. A hierarchial order is

obtained by defining successively smaller ecosystems within larger

ecosystems. At each successive level a different ecosystem component

is assigned prime importance in the placing of map boundaries. Domains

and divisions are based largely on the large ecological climate zones.

Each division is further subdivided into provinces on the basis of

macro-features of the vegetation. Mountains exhibiting altitudinal

zonation and having the climatic regime of the adjacent lowlands

are distinguished according to the character of the zonation.
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The "Ecoregions of the United States" map (revised 1994) was obtained in ARC/ INFO 

(GIS format) at a scale of 1:7,500,000 (1 inch=118 miles) from the U.S. Forest Service. 

Overlaying the 117 pipeline projects identified by the FERC on the ecoregion map, the 

Project Team determined that 6 of the 11 division-level ecoregions were well

represented: Warm Continental, Hot Continental, Subtropical, Prairie, Temperate Steppe, 

and Mediterranean. Further, it was concluded that a minimum of 80 wetlands per

division would be required for a valid sample size, such that, a total of 480 wetlands on 

ROW, and 480 reference wetlands (total of 960 wetlands) were proposed for monitoring 

in the six major ecoregions across the United States.

Projects were selected based on those with the maximum number of impacted wetlands 

and those within reasonable geographic proximity to other pipeline projects; so that the 

necessary 80-study area and 80 control wetlands per ecoregion could be efficiently

surveyed. Pipeline projects surveyed within each ecoregion are presented in Figures 3-3 

through 3-8 at the end of Section 3. 

3.3 VEGETATION SAMPLING AND RIGHT-OF-WAY CHARACTERIZATION

A number of biological and physical parameters were identified that were critical for 

determining success of wetland restoration and for providing insight into the other study 

objectives. These parameters were measured using both qualitative and quantitative

sampling methods, as described below.

3.3.1 Qualitative Assessment

Qualitative assessments included a general site reconnaissance of the wetland and visual 

assessment of the overall condition of the site. Visual observations were made and

recorded on a variety of variables, including: surface grade, hydrology (surface water and 

drainage patterns), soil type, dominant plant species, vegetative cover, vegetation vigor, 

community composition, presence of stump resprouting, evidence of nuisance weed

invasion, residual construction impacts (waterbars, construction debris, rock fragments, 

and topsoil and subsoil mixing), and land use impacts (off-road vehicle damage, erosion, 

farming, and residential or roadway construction). Additionally, an assessment based on 
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best professional judgment was made in the field as to whether the wetland was, or was 

not, successfully restored. 

Similar data were also collected for a "matching" reference wetland. The selected

reference wetland was ideally an undisturbed portion of the same wetland located

adjacent to the construction ROW, but not affected by construction. If an undisturbed 

portion of the same wetland was not available, best professional judgment was used to 

select an off-ROW reference wetland in close proximity that best represented the onROW wetland’s preconstruction conditions. 

For both the on-ROW and reference wetlands, observations were documented on the data 

form, sketches were recorded, digital photographs were taken, and GPS location data

recorded. 

3.3.2 Quantitative Assessment

The Braun-Blanquet Relevé Method (Barbour et. al. 1987), an established plant sampling 

technique, was utilized by field teams to collect data on species richness and vegetative 

cover. The Relevé Method involves an overall assessment of the wetland to determine 

the location that best represents the wetland plant community as a whole. This location 

then becomes the center of the sample plot. Minimum plot sample size is established 

based on an assessment of nested quadrats. For this study the initial quadrat consisted of 

a 1-meter radius, circular plot. The sample size is then increased until the sample plot 

contains 90 - 95% of the dominant species present in the plant community, identified

during the initial qualitative assessment phase. 

Several parameters are recorded within each quadrat. The parameters include percent cover of 

each species present and the number of plant species within each quadrat. Percent cover 

estimates were visually estimated within cover classes defined by the Braun-Blanquet cover 

scale (Table 3-2 [Barbour et al. 1987]).
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Table 3-2. Cover Classes of Braun-Blanquet. 

Class Range of % Cover Mean

 5 75-100 87.5

 4 50-75 62.5

 3 25-50 37.5

 2 5-25 15.0

 1 1-5 2.5

 T1 <1 0.1

1

 Individuals occurring seldom or only once: cover contribution assumed to be insignificant.

3.4 COLLECTION PROTOCOL

10 wetland biologists working in two-person field teams implemented the field data

collection process. The teams sampled 13 pipeline projects in 15 states across six

ecoregions, starting in August 2002 and ending in June of 2003. The study design 

targeted peak growing season for data collection within each of the ecoregions. 

To ensure consistency in the field data collection, a two-day training session was

conducted for all biologists participating in field surveys. The first half of the training 

consisted of an in-office review of the data form specifically designed for this study, and 

the format and objectives of the data to be collected. Data management protocols were 

also established for both paper and electronic data. Electronic data would be downloaded 

each night to avoid the possibility of losing data due to equipment failure or damage. 

Training was also provided on how to select reference wetlands as the best representation 

of what was likely the pre-construction condition of the on ROW wetland.

The second half of the training was in the field to ensure consistent interpretations of the 

field data collection protocol and to provide an opportunity for on-site discussions

pertaining to any topic that might be unclear. Field teams were also instructed to prepare 

field sketches of wetland systems, take additional photographs where appropriate, and 

record observations relating to wetland field conditions.

Following field surveys, field teams immediately photocopied field survey notes and

secured originals in appropriately designated binders to ensure that no data was lost or 

misfiled. Copies of the field notes were then used to perform quality assurance\quality 

control (QA\QC) on photo logs and for data entry into the specifically designed Database. 
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Preliminary queries were run on the Database following data entry to ensure accurate 

data entry and that no null values were observed in query results. Preliminary Vegetation 

and Diversity Summary Reports were also printed and reviewed for accuracy following 

each field survey event.

3.5 DATA ANALYSIS

After information on field data forms was entered into the Database, queries were written 

to test each wetland against the success criteria set by the FERC in the 1994 Procedures. 

Additionally, results from each of the queries were reviewed to identify trends that could 

be attributed to wetland restoration success or failure. Fields that were reviewed included 

pipeline construction year, current land use practices, climatic conditions, human

disturbance, landscape position, soil type, and ecoregion. Reports for these analyses were 

designed into the Database and are included in Appendix A.

3.5.1 Analyses Relative to FERC Success

Total Vegetative Cover Criterion

Eighty percent (80%) vegetative cover was determined based on visual estimation of total 

vegetative cover for the portion of the wetland located on ROW. If the subject wetland 

had a vegetative cover of 80% or greater, the vegetative cover criterion was met. If the 

total vegetative cover was less than 80%, then the wetland failed to meet this success 

criterion.

Wetland Vegetation Criterion

Hydrophytes are species of plants adapted for life in wet conditions and that are typically 

found in wetland habitats. The National List of Plant Species that Occur in Wetlands

(Reed 1988) (hereafter “National list”) was used to determine which species are

considered hydrophytes. A digital version of each regional list was obtained from the 

United States Fish and Wildlife Service (USFWS) and was inserted in the Database as the 

best representation of the National list. Regional lists were used to ensure that species 

occurring in more than one region were assigned the appropriate indicator status for the 

geographic region in which it was found. 
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Using the Database, the cover class midpoints (Table 3-2) for all hydrophytes were

summed and the relative cover of hydrophytes was calculated by expressing the sum of 

the hydrophytes as a percentage of the sum of the midpoints for all the species recorded 

in the sample plot. To exclude the contribution of non-native species from the

calculation, all nonindigenous species, as identified by the United States Geological

Survey Nonindigenous Aquatic Species database (USGS 2003), were assigned a hydric 

class of “NA”, excluding their midpoints from the calculation for relative cover of

hydrophytes. If the relative cover of hydrophytes was 50 percent or greater, then this 

success criterion was met. If the relative cover of hydrophytes was less than 50 percent, 

then the wetland failed to meet the hydrophytic vegetation criterion for jurisdictional

wetlands as defined in the United States Army Corps of Engineers (USACE) Wetland 

Delineation Manual, Technical Report Y-87-1 (USACE 1987).

Diversity Criterion

Diversity is a measurement of the number of species within a unit area (species richness) 

and the relative abundance or distribution (evenness) of those species. The FERC

success criterion for diversity requires that the post-construction wetland have at least

50% of the diversity of the original wetland. For this study, the Shannon-Weiner Index, 

one of the simplest and most extensively used diversity indices in plant ecology, was 

used. 

The formula for the Shannon-Weiner function is:

H’ = (3.3219) [log10N –

1

/N 3(pilog10pi)]

Where:

H’= Diversity index

N = Sum of the cover class mean for all species

pi = Proportion of all individuals in the sample which belong to species i

log10pi = the log to the base 10 of that proportion

The Database calculates and compares the diversity index of the wetland located on

ROW to that of the reference wetland. If the diversity of the on-ROW wetland is 50 
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percent or greater than the reference wetland, then the success criterion is met. If the 

diversity of the subject wetland was less than 50 percent of the diversity of the reference 

wetland, then the wetland failed to meet the diversity success criterion. Copies of both 

Vegetation and Diversity Summary Reports for each of the wetlands surveyed, organized 

by ecoregion, are presented in Appendix C.

3.5.2 Trends Analysis

Data collected during the field effort were reviewed for completeness and then entered 

into the Database. Reports were then generated and analyzed to identify trends in the 

data (Appendix B). Study objectives were to observe trends in the results and to identify 

relationships between those results and the 1994 Procedures. Queries were run in the 

Database to tally total number of passing and failing wetlands based on the 1994

Procedures. Summary reports were generated to display all fields of passing and failing 

wetlands. A committee of experienced wetland biologists, FERC staff, pipeline

environmental inspectors, and regulatory experts were then assembled to review the

preliminary results and to identify the formulation of additional queries to run with the 

Database. Study results were then subjected to statistical analyses, presented in Section 

3.5.3. 

3.5.3 Statistical Analysis

Statistical methods were used to examine the influence of several factors on the success 

of wetland restoration. For these analyses the dependent variable was identified as

“success” (1 = success, 0 = unsuccessful) and nine field variables were chosen to be 

independent factors. These nine independent factors were: ecoregion, evidence of

construction debris, evidence of erosion, meets preconstruction grade, waterbar within

100 feet, evidence of human disturbance, wetland position in the landscape, soil texture, 

and evidence of top soil mixing. 

A factorial design analysis of variance (ANOVA) (F Statistic) with a randomized

complete block design was used to test for significant independent variables. A Tukey 

HSD (Honestly Significantly Different) all-pairwise comparisons test was used to

examine differences between groups where ANOVA models indicated a difference was 
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present. Contingency tables and the Chi-square test (X2 Statistic) were used to test for 

homogeneity of the proportions between groups (e.g., ecoregions) for each of the

variables. The results of this statistical analysis are presented in Section 4.4. The 

Statistical Analysis Summary Report for this study is provided in Appendix B.
Maritimes & Northeast

Great Lakes Gas Transmission

Maritimes & Northeast

Great Lakes Gas Transmission

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-3. Wetlands Monitored in

Warm Continental Division

Division Location

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Date:

01/04

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150 75 0 150

Scale in Miles

WARM CONTINENTAL

DIVISION
CNG Dominion

Columbia Natural Gas

Maritimes & Northeast

CNG Dominion

Columbia Natural Gas

Maritimes & Northeast

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-4. Wetlands Monitored in

Hot Continental Division

Division Location

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Date:

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150 75 0 150

Scale in Miles

HOT CONTINENTAL

DIVISION
South Georgia Expansion Project

Florida Gas Transmission

Destin Pipeline

South Georgia Expansion Project

Florida Gas Transmission

Destin Pipeline

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-5. Wetlands Monitored in

Subtropical Division

Division Location

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Date:

01/04

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100 50 0 100

Scale in Miles

SUBTROPICAL

DIVISION
Northern Border

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-6. Wetlands Monitored in

Prairie Division

Division Location

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Date:

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200 100 0 200

Scale in Miles

PRAIRIE

DIVISION
Alliance Pipeline

Wyoming Interstate

TransColorado

Alliance Pipeline

Wyoming Interstate

TransColorado

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-7. Wetlands Monitored in

Temperate Steppe Division

Division Location

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Date:

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150 75 0 150

Scale in Miles

TEMPERATE STEPPE

DIVISION
Tuscarora

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 3-8. Wetlands Monitored in

Mediterranean Division

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Date:

01/04

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100 50 0 100

Scale in Miles

MEDITERRANEAN

DIVISION

Division Location
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4.0 RESULTS AND DISCUSSION

This section provides a summary of results and a discussion of major trends observed 

through analysis of the data. Section 4.1 provides an overall summary of the relative 

success or failure of the wetlands studied and general trends in the plant community

composition and condition. Section 4.2 provides a summary of trends observed in

physical factors that may have an effect on relative success or failure. Section 4.3

summarizes trends related to post-construction human disturbance and their suggested

effects on restoration success.

Summary reports for major variables analyzed are included in Appendix A. Each

summary report includes a tally of total wetlands successfully restored and a breakdown 

of wetland failures by ecoregion. The following sections provide results and discussion 

for these analyses.

4.1 GENERAL RESULTS AND TRENDS IN POST-CONSTRUCTION PLANT COMMUNITIES

4.1.1 Project Wetland Restoration Summary

Of the total 480 wetlands surveyed, 313 (65%) wetlands passed the 1994 Procedures 

restoration success criteria and 167 (35%) failed. Table 4-1 provides a breakdown of 

total wetlands passing and failing the wetland restoration criteria and a breakdown of

wetland failures by criterion. Wetlands designated “passing” were required to meet all 

three of the restoration criteria. Wetlands identified as “failing” only needed to fail one 

of the three criteria (but may have failed more than one criterion). The most common

single factor for failure was less than 80% vegetative cover by native species. 
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Table 4-1. Overall Wetland Restoration Summary. 

Factor Evaluated Number Percent of Total

TOTAL WETLANDS MONITORED 480 100

WETLANDS PASSING PROCEDURES CRITERIA1 313 65

WETLANDS FAILING PRODECURES CRITERIA2 167 35

Wetlands Failing More Than One Criterion 44 9

Wetlands Failing Cover and Diversity

Wetlands Failing Cover and Wetland Vegetative Cover

Wetlands Failing Diversity and Wetland Vegetative Cover

Wetlands Failing All Three Criteria

5

35

0

4

1

7

0

<1

Wetlands Failing Only One Criterion 123 26

Wetlands Failing 80% Cover Only

Wetlands Failing Diversity Only

Wetlands Failing Wetland Vegetation Criterion Only

73

20

30

15

4

6

SUMMARY OF WETLAND FAILURES BY CRITERION3- -

Total Wetlands Failing 80% Cover Criterion 117 24

Total Wetlands Failing Diversity Criterion 29 6

Total Wetlands Failing l Wetland Vegetation Criterion 69 14

1 Wetlands must pass all three criteria identified in the 1994 Procedures to be considered a passing wetland.

2 Wetlands only needed to fail one criterion to be considered a failed wetland.

3 The sum of "wetland failures by criterion" exceeds the total number of wetland failures because some wetlands failed two or 

more of the success criteria.

Figure 4-1 illustrates the distribution of wetland failures by FERC criterion, total number 

of wetland failures per criterion, and the overlap of wetlands failing for more than one 

criterion. As indicated in both Table 4-1 and Figure 4-1, failure to meet the 80% cover 

by native species criterion was the most common reason for wetland failure. One

hundred and seventeen (117) wetlands failed to achieve 80% cover by native vegetation, 

this is 24%, or almost one fourth of the total wetlands surveyed.
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Figure 4-1. Distribution of Wetland Failures by FERC Criterion.

4.1.2 Wetland Restoration Success by Ecoregion

The distribution of wetland success and failure for each ecoregion was assessed for all 

parameters evaluated in subsequent sections and are included in Appendix A. As

discussed in Section 3.2 Study Design, pipeline projects were selected for survey based 

on their location within division-level ecoregions across the United States. Table 4-2 

presents a summary of wetland restoration success and failure by ecoregion.

The objective of collecting field data across several ecoregions was to determine if

regional climatic conditions affect wetland restoration. Results of the study by ecoregion 

indicate differences in the relative success rate across the country. The average failure 

rate was 35% (range 11–68%). As illustrated in Figure 4-2, failure rates were highest in 

the Temperate Steppe (68%) and Mediterranean (66%) ecoregions, and wetland failure 

rates were lowest in the Warm Continental (14%) and Hot Continental (11%) ecoregions. 

4

5

20

4

35

30

4

5

35

73

Cover Wetland Vegetation Diversity

Failed Cover Only

Failed Diversity Only

Failed Wetland Vegetation Only

Failed Cover & Wetland Vegetation

Failed Cover & Diversity

Failed All Three Criteria
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Because the 1994 Procedures are applied consistently on projects regardless of

geographic region, other variables, likely climatic and edaphic, are suspected of having a 

determining effect. 

Table 4-2. Distribution of Wetland Restoration Success and Failure by Ecoregion

Passing Wetlands Failing Wetlands

Ecoregion Number Percent Number Percent

Warm Continental 69 86% 11 14%

Hot Continental 69 86% 11 14%

Subtropical 64 80% 16 20%

Prairie 56 70% 24 30%

Temperate Steppe 26 32% 54 68%

Mediterranean 27 34% 53 66%

Climate diagrams of representative climate stations within each of the ecoregions

surveyed are presented in Figure 4-3. These provide a long-term average comparison of 

mean monthly precipitation and temperature for 12 months of the year for each ecoregion 

Figure 4-2. Wetland Success and Failure by Ecoregion.

86%

14%

89%

11%

80%

20%

70%

30%

32%

68%

34%

66%

Warm

Continental

Hot

ContinentalSubtropical

Prairie

Temperate

Steppe

Mediterranean

Failing

Wetlands

Passing

Wetlands
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surveyed (Bailey 1995). As depicted in Figure 4-3, three of the six ecoregions studied 

have wetland restoration success rates that were substantially higher than the average of 

65% (86% Warm Continental, 89% Hot Continental, and 80% Subtropical). In each of 

these three ecoregions mean monthly precipitation exceeded mean monthly temperature. 

The wetland restoration success rate for the Prairie ecoregion was 70%. There is a

corresponding difference in the climate diagram for the Prairie ecoregion (compared to 

the Warm and Hot Continental and Subtropical) i.e., the mean monthly precipitation line 

is substantially closer to the mean monthly temperature line.

In both the Temperate Steppe and Mediterranean ecoregions, the mean monthly

temperature is depicted as exceeding mean monthly precipitation lines for certain months 

during the year (Figure 4-3). These areas are shown in brown on the Temperate Steppe 

and Mediterranean climate diagrams and are identified as relative periods of drought. 

These diagrams indicate that climatic conditions support periods of drought during parts 

of August, September, and October in the Temperate Steppe ecoregion, and during late 

May through September in the Mediterranean ecoregion. The establishment and

persistence of hydrophytic vegetation is tied to the presence of moist hydrologic

conditions. These data may provide an indication as to why both the Temperate Steppe 

and Mediterranean restoration failure rates (68% and 66% respectively) were

substantially higher than the study average of 35%. Reference wetlands within these 

ecoregions exhibited identical wetland failure rates as those located on ROW, supporting 

the hypothesis that wetland failures were not construction related but more likely

attributed to climatic conditions. In addition, wetland scientists noted evidence of

drought conditions during field surveys for the Temperate Steppe ecoregions. 
Mediterranean

Temperate

Prairie Division

Warm

Continental

Hot

Continental

Subtropical

Source: Ecoregions of North America, Revised-1997. U.S.

Department of Agiriculture, Forest Service Washington D.C.

Figure 4-3. Climate Diagrams

for Study Ecoregions

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CLIMATE DIAGRAM KEY

Mean Annual Temperature

Mean Annual Precipitation
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Because the climate diagrams provided in Figure 4-3 represent “average” climatic

conditions over a period of many years, additional research was performed in an effort to 

document “drought conditions” in these regions. Maps from the U.S. Drought Monitor 

were used for this study because they are based on a synthesis of multiple drought indices 

and represent a consensus of Federal and academic scientists

(http://www.drought.unl.edu/dm/monitor). The U.S. Drought Monitor is a partnership

consisting of the U.S. Department of Agriculture (Joint Agricultural Weather Facility and 

National Water and Climate Center), the National Weather Service's Climate Prediction 

Center, National Climatic Data Center, and the National Drought Mitigation Center at the 

University of Nebraska.

Figure 4-4 is the U.S. Drought Monitor Map for the week ending September 10, 2002, 

the same time period field surveys were performed in the Temperate Steppe ecoregion. 

This map shows severe, extreme, and exceptional drought conditions within the

Temperate Steppe ecoregion at the time of survey. Table 4-3 defines the categories used 

in the classification system employed by the U.S. Drought Monitor.

Figure 4-5 shows the U.S. Drought Monitor Map for the time period corresponding with 

field surveys in the Mediterranean ecoregion. This map indicates abnormally dry and 

moderate drought conditions at the time of survey. A review of the historic maps from

the U.S. Drought Monitor archives revealed abnormally dry conditions in the Temperate 

Steppe ecoregions in 1999; however, actual drought conditions were not depicted on the 

maps until February of 2000. Drought conditions ranging from moderate to exceptional 

have consistently been reported in the Temperate Steppe ecoregion since that time. 

Abnormally dry conditions were also observed within some portions of the

Mediterranean ecoregion in 1999, and moderate and minor areas of severe drought

conditions were reported from 2000 to 2003. 
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Figure 4-4. U.S. Drought Monitor Map for Week Ending September 10, 2002.

Other potential explanations for the high rate of failure of the wetlands in the Temperate 

and Mediterranean ecoregions, are a high incidence of wetlands with clay soils and

human- related wetland disturbances. These results are discussed in Sections 4.2 and 4.3 

respectively.

Table 4-3. U.S. Drought Monitor Drought Severity Classifications.

Category Description Possible Impacts

D0 Abnormally Dry Going into drought: short-term dryness slowing planting, growth of crops or pastures, fire 

risk above average. Coming out of drought: some lingering water deficits; pastures or 

crops not fully recovered.

D1 Moderate Drought Some damage to crops, pastures; fire risk high; streams, reservoirs, or wells low, some 

water shortages developing or imminent, voluntary water use restrictions requested

D2 Severe Drought Crop or pasture losses likely; fire risk very high; water shortages common; water 

restrictions imposed

D3 Extreme Drought Major crop/pasture losses; extreme fire danger; widespread water shortages or 

restrictions

D4 Exceptional Drought Exceptional and widespread crop/pasture losses; exceptional fire risk; shortages of water 

in reservoirs, streams, and wells, creating water emergencies
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Figure 4-5. U.S. Drought Monitor Map for Week Ending June 10, 2003

4.1.3 Wetland Cover Classes

A total of 480 wetlands, comprising nine Cowardin wetland classes (Cowardin et al. 

1979), were surveyed from among the six ecoregions studied (80 wetlands/ecoregion). 

Table 4-4 identifies the wetland Cowardin classes (preconstruction) for the wetlands

surveyed and provides a summary of their success or failure for each of the ecoregions. 

The most common wetland class surveyed was palustrine emergent (PEM), with 279

wetlands (55.5%). The other commonly surveyed wetland types were palustrine forested 

(PFO) (91 wetlands; 18.1%) and palustrine scrub-shrub (PSS) (49 wetlands; 9.7%). 

Although the distribution of wetland classes was not in exact proportion to their

abundance within each ecoregion, in general a fairly good representation of the wetland 

classes found commonly in each ecoregion was surveyed.
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Table 4-4. Wetland Cowardin Classification Distribution by Ecoregion and Restoration 

Results.

Warm 

Continental Hot Continental Subtropical Prairie

Temperate 

Steppe Mediterranean

Pre-construction 

Cowardin 

Classification

Total

Pass

Fail

Total

Pass

Fail

Total

Pass

Fail

Total

Pass

Fail

Total

Pass

Fail

Total

Pass

Fail

Total 

PEM 39 32 7 35 30 5 5 3 2 65 45 20 57 20 37 78 27 51 279

PSS 17 15 2 2 1 1 11 10 1 3 3 - 15 4 11 1 - 1 49

PFO 18 16 2 23 22 1 37 28 9 5 3 2 8 2 6 0 - - 91

POW 0 - - 0 - - 0 - - 0 - - 0 - - 1 - 1 1

PEM/POW 0 - - 0 - - 0 - - 0 - - 0 - - 0 - - 0

PEM/PSS 4 4 - 8 7 1 8 6 2 4 3 1 0 - - 0 - - 24

PEM/PFO 0 - - 11 10 1 2 1 1 2 1 1 0 - - 0 - - 15

PSS/POW 0 - - 0 - - 0 - - 0 - - 0 - - 0 - - 0

PSS/PFO 2 2 - 1 1 - 17 16 1 1 1 - 0 - - 0 - - 21

Total 80 69 11 80 71 9 80 64 16 80 56 24 80 26 54 80 27 53 480

1 PEM Palustrine Emergent; PSS Palustrine Scrub-Shrub; POW Palustrine Open Water; PFO Palustrine Forested.

Construction of a pipeline ROW requires that vegetation be cleared. Furthermore, the

conversion of the vegetation in ROW wetlands to early successional stages following

construction is well documented (Santillo 2000). Consistent with this, a comparison of 

the post-construction cover classes to their preconstruction types (Table 4-5) revealed a 

relatively large shift to early successional cover classes; over 78% of the ROW wetlands 

(394) were classified as PEM following construction while only 58% (279) were

classified as PEM prior to construction. Comparing ROW wetlands to the

preconstruction wetland classes, the number of wetlands in all wetland classes dominated 

by woody vegetation was reduced. 

Table 4-5. Comparison of Pre-Construction and Post Construction Wetland 

Cowardin Classifications.

Cowardin Class1 Pre-Construction On-ROW Post Construction Difference

1. PEM 279 394 + 115

2. PEM/PSS 24 31 + 7

3. PEM/POW 0 21 + 21

4. PSS 49 20 + 29

5. PFO 91 9 - 82

6. PSS/POW 0 2 + 2

7. PSS/PFO 21 2 - 19

8. POW 1 1 0

9. PEM/PFO 15 0 - 15

TOTAL 480 480 -

1 PEM Palustrine Emergent; PSS Palustrine Scrub-Shrub; POW Palustrine Open Water; PFO Palustrine Forested.

Cowardin wetland classifications are made based on the plants that constitute the uppermost layer of vegetation and that possess an areal coverage of at least 30%. For example, 
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a wetland with 50% areal coverage by trees over a shrub layer with a 60% areal coverage, 

would be classified as forested wetland (PFO); an area with 20% areal coverage of trees 

over the same 60% shrub layer would be classified as scrub-shrub (PSS). When trees or 

shrubs cover less than 30% of the wetland, but the total cover of vegetation (except

pioneer species) is 30% or greater, the wetland is assigned the appropriate class based on 

the predominant life form below the shrub layer.

In addition, tree species need to reach a certain size (greater than six meters in height) to 

be classified as a tree and not a shrub/sapling. Therefore, in order for a wetland to be 

classified as forested, tree species would have to have grown larger than 6 meters (19.2 

feet) and comprise at least 30% areal coverage of the wetland. Considering that pipeline 

projects surveyed were constructed beginning in 1994, it is reasonable to conclude that 

forested wetlands may not have had enough time to develop following construction to 

meet the classification criteria.

4.1.4 Conversions of Wetland Cowardin Classes Following Construction

Consistently throughout the ecoregions, PEM wetlands were restored as PEM, with

exceptions in the Prairie where one (out of 65) PEM is now PSS and Subtropical where 

one (out of 5) is now PEM/PSS.

All PFO’s were converted to PEM in Warm Continental and Hot Continental ecoregions. 

Whereas in the Prairie and Temperate Steppe ecoregions roughly 60% (3 out of 5 and 5 

out of 8, respectively) of the PFO’s were converted to PEM with the remaining wetlands 

restored as PFO’s. In the Subtropical ecoregion 20 out of 37 of the PFO’s were

converted to PEM, 10 were converted to PEM/PSS, 5 were converted to PSS, 1 was 

converted to PSS/PFO, and 1 wetland was restored to PFO.

Similar to the PFO’s, all PSS/PFO’s were converted to PEM in Warm Continental, Hot 

Continental, and Prairie ecoregions. In the Subtropical ecoregion 3 out of 17 of the

PSS/PFO’s were converted to PEM, 9 were converted to PEM/PSS, 1 was converted to 

PSS, 3 were converted to PFO, and only 1 wetland was restored to PSS/PFO. Figure 4-6 

shows a comparison of each Cowardin cover class pre- and post-construction. 
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0 50 100 150 200 250 300 350 400

PEM

PEM/PSS

PEM/OW

PSS

PFO

PSS/OW

PSS/PFO

POW

PEM/PFO

Post Construction Pre-construction

Study results showed an overall increase in PEM wetlands and decrease in PFO and PSS 

wetlands following construction. These trends may be the result of the short period of 

time since implementation of the 1994 Procedures relative to the expected time frame for

the re-establishment of arboreal vegetation. However, we expect this trend to persist over 

portions of the ROW because vegetation maintenance is commonly used to facilitate

monitoring required by the U.S. Department of Transportation to ensure pipeline

integrity. The 1994 Procedures (Section VI.E.1) allows for vegetation maintenace within 

the ROW to facilitate aerial corrosion and leak surveys. More specifically, the

Procedures allow for maintenance of vegetation in an herbaceous state within a 10 foot 

wide corridor (centered over the pipeline) and the removal or selective cutting of trees 

greater than fifteen feet in height from within 15 feet of the pipeline, or a 30 foot corridor 

centered over the pipeline. 

This trend is considered inconclusive due to the relatively short timeframe since

construction for many of the pipelines surveyed and, therefore, insufficient time for plant 

succession to occur. Overall, conversions of Cowardin classes were consistent with what 

Figure 4-6. Changes in Cowardin Classification from Pre- to 

Post-construction Conditions.
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would be expected following construction based on climatic conditions within

ecoregions, and time since construction. 

4.2 INFLUENCE OF PHYSICAL FACTORS ON RESTORATION SUCCESS

A number of key physical factors were identified by the Team for testing relative to their 

effect on wetland revegetation success or failure. Although data on numerous physical 

parameters were collected, the factors analyzed in this section were those considered by 

the Team to have the greatest likelihood of having an effect on wetland revegetation

success.

4.2.1 Wetland Landscape Position

Five wetland landscape positions were evaluated to determine if restoration success

varied among these types following pipeline construction. Table 4-6 presents results for 

wetland landscape position and lists the percent passing and failing wetlands in each

landscape position. Sixty percent (228) of all wetlands surveyed were located in the 

bottom landscape position. Sixty-eight percent (197 wetlands) of wetlands located in the 

bottom landscape position passed the FERC criteria. 

Table 4-6 Summary of Wetland Restoration Relative to Position of Wetland in 

Landscape.

Overall Distribution Passing Wetlands Failing Wetlands Landscape 

Position Number Percent Number Percent Number Percent

Percent of All 

Failures

Bottom 228 60% 197 68% 91 32% 54%

Vegetated Swale 100 21% 64 64% 36 36% 22%

Sidehill 14 3% 10 71% 4 29% 2%

Riparian 66 14% 39 59% 27 41% 16%

Other 12 3% 3 25% 9 75% 5%

Total 480 100% 313 65% 167 35% 100%

Vegetated swales are typically relatively narrow and shallow vegetated wetlands. 

Sidehill wetlands are found mid-slope or along a grade and are often supported by side 

hill seeps or surface hydrology. Riparian wetlands are those found along moving water 
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bodies (river, streams, brooks) and are usually hydrologically connected to the adjacent 

water body. The wetlands in the “other” category were identified as vernal pools. 

The average failure rate for wetlands, regardless of landscape position was 35%, and the 

range for landscape position was 29–75%. However, if the relatively small number of 

vernal pools (12) are omitted, then the percent of wetlands failing among the various

landscape positions fell within a relatively narrow range of 29 to 41%. Accordingly, 

there were no major patterns in the success of wetland restoration relative to landscape 

location. Although the low success rates for vernal pools may warrant consideration on 

future projects.

4.2.2 Soil Type

Soils were sampled within on-ROW and reference wetlands using the United States

Department of Agriculture's (USDA's) soil textural classification system. This system

includes the 12 soil textural classes shown in Figure 4-7. For this study, these 12 USDA 

soil textural classes were used to record soil textural classes in the field. These soil types 

were then grouped into six smaller classes based on dominant soil textural class. The six 

classes used in the soils analyses were rock, organic, sand, silt, clay, and loam. These 

groupings resulted in larger sample sizes for each soil type.

Table 4-7 presents the relative distribution of soil types found in the wetlands surveyed, 

along with the number and percent of passing and failing wetlands for each category of 

soils. Wetlands with clay dominated soils were the most common (38%) wetland type 

surveyed; sand dominated soils were the second most common (31%); and wetlands with 

loam-dominated soils were the third most common (18%).
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Figure 4-7. USDA Soils Textural Classes

Table 4-7. Wetland Restoration Success Related to Soil Type. 

Soil Texture Overall Passing Wetlands Failing Wetlands

Class Number Percent Number Percent Number Percent

Percent of All 

Failures

Rock 2 0% 1 50% 1 50% 1%

Organic 26 5% 20 77% 6 23% 4%

Sands 151 31% 113 75% 38 25% 23%

Silts 21 4% 15 71% 6 29% 4%

Clays 183 38% 95 52% 88 48% 53%

Loams 86 18% 64 74% 22 26% 13%

Inundated 11 2% 5 45% 6 55% 4%

Total 480 100% 313 65% 167 35% 100%

As indicated in Table 4-7, the percent of wetlands that failed was greatest in clay soils 

from among the five non-rock soil types; 48% of wetlands with clay soils were not

successfully restored. Eighty-four (84%) of these wetland failures were found in

wetlands located in the Temperate Steppe ecoregion, which was experiencing drought
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conditions at the time of survey (see Section 4.1.2). Clay soils can be especially

challenging during construction because of their capacity to hold water. Fine colloidal 

clays have approximately 10,000 times as much surface area as the same weight of

medium-sized sand (Brady 1984). Clay soil particles are also platy in shape causing

them to be plastic when wet and extremely hard to cemented when dry, a condition that 

might be expected under drought conditions. These soil characteristics can also pose

significant challenges for wetland restoration. In addition, fine-grained soils, such as 

clays, support relatively low rates of germination, establishment, and survival of seeds 

(Leck et al. 1989). Further evidence of this was observed by Santillo (2000) who found 

that vegetation recovery was lower on portions of pipeline ROWs where topsoil-subsoil 

mixing resulted in clay subsoil at the surface. The failure rates for the other four nonrock soil types (organic, sand, silt, and loam) fell within a narrow range of 23 to 29%.

4.2.3 Wetland Hydrology

Wetland hydrology was recorded to determine if there was any relationship between

saturation and depth of surface water and wetland restoration success and failure. In

general, reestablishment of natural surface hydrologic conditions is regarded as a major 

key to wetland restoration (Mitsch and Gosselink 1993), and the amount of water present 

has been documented to be a driving factor that determines what plant species become 

established (Van der Valk 1981). For this study, surface water depth was separated into 

four categories <1 inch, 1 to 6 inches, 6 to 12 inches, and >12 inches. Table 4-8 presents 

the depths of surface water observed in wetlands surveyed.

Table 4-8. Wetland Restoration Related to Depth of Surface Water.

Overall Distribution Passing Wetlands Failing Wetlands Surface Water 

Depth Number Percent Number Percent Number Percent

Percent of All 

Failures

< 1" 287 60% 172 60% 115 40% 69%

1" - 6" 157 33% 124 79% 33 21% 20%

6" - 12" 24 5% 15 63% 9 38% 5%

>12" 12 3% 2 17% 10 83% 6%

Total 480 100% 313 65% 167 35% 100%
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Sixty (60%) of wetlands surveyed were observed with <1 inch of surface water at the 

time of survey; this hydrologic class encompassed wetlands that had no standing water at 

the time of the survey. In addition, 33% had between 1 and 6 inches, 5% had between 6 

and 12 inches, and 3% had >12 inches of standing water at the time of survey. For 

wetlands with between 0 and 12 inches of water depth, the success rate was between 60 

and 79%. In general, this is consistent with other studies that have documented relatively 

rapid recovery of flooded emergent wetlands following disturbance (Farnsworth 1979, 

Odegard 1978). 

The hydrologic class with the highest rate of failure was > 12 inches of water; 83% of 

wetlands with >12 inches of water failed to meet the FERC criteria. The relatively high 

failure rate for wetlands in >12 inches of water was primarily related to not meeting the 

80% vegetative cover criterion. Before categorizing these wetlands as failures, however, 

these wetlands should be compared to preconstruction conditions, to establish if an area 

of open water (and lacking vegetative cover) was the normal condition that existed prior 

to construction. Such wetlands may not in fact be “failures” if they had areas of open

water prior to construction and did not have 80% cover in their preconstruction state. 

4.3 INFLUENCE OF HUMAN DISTURBANCE ON RESTORATION SUCCESS

4.3.1 Wetlands Affected by Human Disturbance

Six categories of human disturbance were identified as potentially having an effect on

wetland restoration success, including: all terrain vehicle (ATV) use, paving or fill

activities, farming, residential development or lawns, and other. Other types of wetland 

disturbance reported included: pond construction for recreational use, trampling by cattle, 

and various drainage-related construction. Table 4-9 presents study results for wetlands 

affected by human disturbance. No failures were reported for logging, therefore, logging 

results were not included in Table 4-9.
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Table 4-9. Wetlands Affected by Human Disturbance.

Type of Passing Wetlands Failing Wetlands

Human 

Disturbance

Total 

Wetlands 

Affected

Percent of 

Wetlands 

Surveyed Number Percent Number Percent

Percent 

of All 

Failures

Farming 130 27% 40 31% 90 69% 54%

ATV 78 16% 65 83% 13 17% 8%

Other 18 4% 10 56% 8 44% 5%

Lawn 3 1% 2 67% 1 33% 1%

Paved/Fill 1 0% 1 100% 0 0% 0%

Total 225 47% 115 51% 110 49% 66%

Forty-seven percent (47%) of all wetlands surveyed contained some evidence of human 

disturbance. Of the wetlands affected by human disturbance, 51% were successfully

restored and 49% failed to meet the FERC wetland restoration criteria. However, 66% of 

all failed wetlands overall had evidence of human disturbance, thus suggesting this to be 

a contributing factor to failure.

Of the wetlands with evidence of human disturbance and not successfully restored, 75% 

failed the cover criterion, 49% failed the wetland vegetation criterion, and 9% failed the 

diversity criterion. Figure 4-8 shows the distribution of types of human disturbance

observed within wetlands during field surveys. A breakdown of wetlands affected by

human disturbance by ecoregion is provided in Appendix A. Seventy-two percent (72%) 

of failed wetlands with human disturbance were located in the Temperate Steppe

Ecoregion, and 97% of these wetlands were reported to have farming-related human

disturbance.

A relatively high percentage (47%) of all wetlands surveyed were disturbed by human

activity. The obvious explanation is that most natural gas pipelines are constructed

within easements that allow property owners continued use of their land, and a cleared 

ROW invites various uses by landowners and the general public.
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The large proportion (58% or 130 wetlands) of farmed wetlands can be explained

because farmed land and subsurface pipelines are generally considered compatible land 

uses. The existence of the subsurface pipeline does not inhibit continued cultivation of 

the land and the existence of crops does not affect pipeline operations. 

The study revealed that 35% (78 of 225) of wetlands affected by human disturbance,

were disturbed by ATVs (Figure 

4-9); 83% of these wetlands 

damaged by ATVs passed, and

only 17% failed, the restoration

criteria. Smaller wetlands had a 

higher failure rate than larger

wetlands, potentially because the 

ATV trail covers a larger

percentage of the area of the

whole wetland. The portions of

wetlands that are affected (the

ATV trail) often are devoid of vegetation and have compacted soils, or are deeply rutted. 

ATV trails that run parallel to the direction of slope (straight down hill) and that damage 

permanent slope breakers making them ineffective generally cause the greatest damage. 

Figure 4-8. Breakdown of Types of Human Disturbance Observed in Wetlands.

Figure 4-9. Wetland Failing Cover Criterion 

Due to Impacts from ATV’s.

No Human 

Disturbance

52%

ATV

16% Paved/Fill

<1% Other

4%

Lawn

1%

Farming 

27%
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These ATV trails can become problematic sources of sedimentation in down-gradient and 

adjacent water resources, and can modify normal drainage patterns. 

There was ample evidence observed in the field that pipeline companies have gone to 

great lengths to deter ATV use on the ROWs, including: gates and fencing; signs with

warnings of severe penalties; and, placement of large boulders, logs, or trees across the 

trails. However, signs are often vandalized, boulders and logs are moved, and new trails 

are created in other locations to allow access by the ATVs. 

4.3.2 Waterbar Placement

The 1994 Procedures (Section VI.D.2.) require the placement of permanent slope

breakers or waterbars at the base of slopes near the boundary between wetlands and 

adjacent uplands. Waterbars are permanent slope breakers, usually earthen berms,

constructed perpendicular to the direction of slope. The purpose of waterbars is to slow 

the accumulation and velocity of surface water runoff (with sediments) and to divert

water off the ROW before it causes soil erosion. Table 4-10 presents wetland restoration 

results for wetlands observed with associated waterbars.

Table 4-10. Wetland Restoration Relative to Existence or Placement of Waterbars.

Overall Distribution Passing Wetlands Failing Wetlands Waterbar 

Position Number Percent Number Percent Number Percent

Percent of All 

Failures

No Waterbar 311 65% 187 60% 124 40% 74%

Upgradient 146 30% 108 74% 38 26% 23%

Downgradient 1 0% 0 0% 1 100% 1%

Both 22 5% 18 82% 4 18% 2%

Total 480 100% 313 65% 167 35% 100%

For the purpose of this study, it was assumed that wetlands surveyed that did not have 

waterbars did not require waterbars due to flat topographic conditions. Waterbar

placement was evaluated in this study because of the potential for waterbars to affect the 

amount of surface water entering a wetland, and because the absence of waterbars can

lead to the accumulation of sediment within wetlands. Where wetlands are dependent on 

upgradient surface water hydrology, a waterbar placed at the base of a slope could
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conceivably divert enough surface water away from the wetland, that it begins to

transition into an upland community. However, the results did not support this concept.

Waterbars were observed adjacent to 35% of all wetlands surveyed. Of the wetlands 

observed with upgradient waterbars, 74% (126) were successfully restored and passed the 

1994 Procedures. 

4.3.3 Pipeline Construction Dates

Pipeline construction dates were evaluated to determine if there is a relationship between 

wetland restoration success and the amount of time the wetlands have had to recover

following construction.

Table 4-11 shows the distribution of pipeline construction dates for the pipeline projects 

included in the study, along with the percent of passing and failing wetlands. The highest 

wetland restoration success rate (88%) was observed in the oldest pipeline construction 

year (1995). The lowest wetland success rate (39%) was observed in the second oldest 

pipeline construction year (1996). The second highest success rate (80%) was observed 

in the youngest (2001).

Table 4-11. Wetland Restoration Summary for Pipeline Construction Years. 

Pipeline Overall Distribution Passing Failing

Construction 

Year

Years Since 

Wetland 

Disturbance Number Percent Number Percent Number Percent

Percent 

of all 

Failures

1995 7 25 5% 22 88% 3 12% 2%

1996 6 90 19% 35 39% 55 61% 33%

1998 4 174 36% 132 76% 42 24% 25%

1999 3 151 31% 96 64% 55 36% 33%

2000 2 10 2% 4 40% 6 60% 4%

2001 1 30 6% 24 80% 6 20% 4%

Total - 480 100% 313 65% 167 35% 100%

The results of this study do not present a clear correlation between relative success rate 

and time since construction. Although the best success rate (88%) was achieved in the 

oldest projects surveyed (1995), the lowest rate (39%) was achieved only one year later 
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(1996). The remaining results show similar variability from year to year, thus indicating 

that other factors aside from time since construction are having an overriding effect on 

wetland restoration success and failure.

4.3.4 Post-construction Grading

Post-construction grading was evaluated to determine if there is a correlation between

wetland restoration success and the re-establishment of pre-construction grades within

wetlands. Qualitative judgments were made by field crews to determine if grading within 

the wetland was reestablished to preconstruction conditions. This observation was then 

recorded as a "yes" or "no" on the dataform. Typical field observations that indicate 

grades were not reestablished to pre-construction conditions include: obvious deviations 

from off-ROW topographic conditions (i.e., excess fill material higher than surrounding 

topography or large depressions atypical of surrounding conditions.) Of the wetlands 

that were restored to preconstruction grades 67% were successful, whereas in wetlands 

where preconstruction grades were not restored, only 35% of the wetlands were

successful. 

4.4 STATISTICAL ANALYSIS

Statistical methods were used to examine the influence of nine independent variables on 

the success of wetland restoration (Section 3.5.3). Each of the statistical models and test 

values are provided in Appendix B. Three factors were found as having a significant

influence on whether or not a wetland would be successfully restored (Table 4-12). 

These three factors are discussed as follows. 

The ecoregion from which the wetland was sampled had a significant influence on the 

success of the restored wetlands (Table 4-12). Further testing indicated that the success 

rate of the wetlands in the Hot Continental, Warm Continental, Subtropical, and Prairie 

ecoregions were not statistically different from each other, but the rates were significantly 

different than those of the Temperate Steppe and Mediterranean ecoregions. The success

rate of the Temperate Steppe and Mediterranean ecoregions were found to be similar. 
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Table 4-12. Multiple Factor Analysis of Variance Effects Test on Success.

Source Df SS MS F p

*Ecoregion 5 12.0580 2.4116

Construction Debris 1 0.0425 0.0425 0.25 0.6159

Evidence of Erosion 1 0.0006 0.0006 0.00 0.9518

*Meets Preconstruction Grade 1 1.0100 1.0100 5.99 0.0148

Water Bar within 100 Feet 1 0.0766 0.0766 0.45 0.5007

*Evidence of Human 

Disturbance

1 1.6755 1.6754 9.93 0.0017

Wetland Position in Landscape 4 0.6179 0.1544 0.92 0.4545

Soil Texture 13 3.0706 0.2362 1.40 0.1551

Top Soil Mix 1 0.0007 0.0007 0.00 0.9505

Error 451 46.0699 0.1686

Total 479 Grand Mean 1.47 CV 27.88

Notes: The whole model was significant (F = 6.95, P < 0.0001).

* Indicates significant factor.

Similar results were obtained using grouped soil texture categories (e.g., 

sands, clays).

The “eastern” (i.e., Hot Continental, Warm Continental, Subtropical, and Prairie)

ecoregions had an 82% success rate whereas those in the extreme west (i.e., Temperate 

Steppe and Mediterranean) had a 33% success rate (Table 4-13). 

Whether or not a wetland exhibited evidence of human disturbance was also found to be 

a significant factor in determining the success of a restored wetland. Wetlands with

evidence of human disturbance were associated with higher failure rates. Of the wetlands 

that exhibited evidence of human disturbance only 37% were successful, whereas if this 

evidence was absent 67% of the wetlands were successful (Table 4-12). In addition, in 

the more successful eastern ecoregions only 34% of the wetlands exhibited evidence of 

human disturbance when compared to the 72% for the western ecoregions (Table 4-13). 

Whether or not a wetland was restored to preconstruction grade was the third factor found 

to be a significant in determining the success of a restored wetland. Wetlands not

restored to preconstruction grade were associated with failure. Of the wetlands that were 

restored to preconstruction grade 67% were successful, whereas if preconstruction grade 

was not restored 35% of the wetlands were successful (Table 4-12). 
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Table 4-13. Significant Factors in Determining Successful Restoration.

% Successful

Hot 

Continental

Warm 

Continental

Subtropical Prairie Mediterranean Temperate 

Steppe

Ecoregion 86 86 80 70 34 32

Yes No

Evidence of 

Human 

Disturbance

37 63

Meets PreConstruction 

Grade

67 35

Table 4-14. Significant Explanatory Factors Between Eastern and Western 

Grouped Ecoregions.

Ecoregion Group 

(wetland restoration 

success rate)

% Wetlands w/Evidence of 

Human Disturbance

% of Wetlands Restored 

to Pre-Construction 

Grade

East (83) 34 97

West (17) 72 92

 Note: East group is comprised of the Hot Continental, Warm Continental, Subtropical, 

and Prairie ecoregions and the west group is comprised of the Temperate Steppe 

and Mediterranean ecoregions.
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5.0 CONCLUSIONS AND RECOMENDATIONS

The FERC’s 1994 Procedures were designed for the purpose of minimizing impacts to 

wetlands crossed by construction of natural gas pipelines and have been applied during 

pipeline construction since 1994. This study was designed to evaluate the effectiveness 

of the 1994 Procedures by analyzing the success and failure of wetland restoration

following pipeline construction. A variety of factors that could potentially influence

success were examined and presented in previous sections of this report. The following 

is a summary of substantive conclusions and notable trends: 

ß Existing wetland monitoring reports were largely unavailable from pipeline

companies contacted. Based on post-construction wetland monitoring reports that 

were received, it is evident that the pipeline industry does not have a consistent 

approach to performing post-construction wetland monitoring. The FERC's

revised 2003 Procedures (VI.D.3.) now requires that a report be filed with the 

Secretary identifying the status of the wetland revegetation efforts at the end of

three years following construction. This requirement is anticipated to improve the 

status of post-construction wetlands monitoring for pipeline projects.

ß Based on detailed quantitative field studies, approximately two thirds of all

wetlands studied nationwide achieved all three wetland restoration success criteria 

identified in the 1994 Procedures. Most wetlands that failed the FERC success 

criteria failed due to insufficient vegetative cover.

ß The study revealed strong differences in overall success by ecoregion. Eastern

and Midwestern wetlands have significantly higher success rates than western

ecoregions. Regional climates and weather conditions reveal noticeable trends in 

relative wetland restoration success and failure. 

ß The presence of human disturbance in wetlands was associated with higher failure 

rates, likely due to its influences on the percent vegetative cover criterion. The 

most common human disturbance category was farming, which includes cattle

grazing, and could be a contributing factor to the lower success rate for wetlands 

occurring in the western ecoregions.
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ß Wetlands that achieved pre-construction grades (i.e., grading of the wetland was 

reestablished to pre-construction conditions) were significantly more successful 

than wetlands that did not meet pre-construction grades.

ß Soil conditions appear to have some influence on wetland revegetation success, 

with wetlands underlain by clay-dominated soils having a greater failure rate than 

wetlands dominated by other soil types. Although this was a noticeable trend, soil 

texture was not a significant factor based on the statistical analysis. 

ß The data showed a strong trend of conversion of forested and scrub-shrub 

wetlands to emergent wetlands. This observation may be the result of the short 

period of time since implementation of the 1994 Procedures relative to the

expected time frame for the re-establishment of arboreal vegetation. Therefore, 

this trend is considered inconclusive. In addition, we expect this trend to persist 

over portions of the ROW because ROW vegetation maintenance (removal of

woody vegetation over the pipeline) is commonly used to facilitate monitoring

required by the U.S. Department of Transportation to ensure pipeline integrity. 

5.1 RECOMMENDATIONS

The following is a summary of recommendations resulting from this study:

ß Methods used to monitor wetland restoration success should be standardized to 

ensure that wetland restoration can be evaluated consistently between projects and 

geographic regions over time. The wetland monitoring data form used for this 

study (Appendix D) should be used as a template for future wetlands monitoring.

ß Wetlands in the arid western ecoregions have a much higher rate of failure than 

wetlands in more humid regions of the country. This stark contrast warrants

consideration of a modified version of the Procedures for the western regions that 

takes into consideration climate differences and local successional processes. 

Duration of monitoring and success criteria may need to be modified for these 

regions (i.e., longer monitoring periods, lower cover and diversity requirements,

etc.).
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ß Evidence of human disturbance was associated with lower success rates

regardless of ecoregion, and, evidence of human disturbance was more prevalent 

for the western ecoregions than the eastern ecoregions. Post-construction 

monitoring to evaluate the effects of human disturbance on wetland restoration

should be encouraged so that remedial measures can be suggested. 

ß Although only 23 of the 480 wetlands were not restored to pre-construction 

grades, this factor had a substantive effect in determining success. Therefore, 

current procedures that enforce the restoration of pre-construction grades should 

continue to be developed.

ß FERC may want to consider modifying the criteria, as follows:

ÿ Wetlands with standing water commonly have areas of vegetation

interspersed with open water, and therefore are characterized as having

less than 80% cover of vegetation (due to greater than 20% open water). 

The open water/vegetation mix is generally considered to be a positive 

habitat feature and thus should not be discouraged except in instances

where standing water indicates that post-construction grades were

established lower than pre-construction conditions. 

ÿ Pipeline companies should be encouraged to identify "problem wetlands" 

(i.e., wetlands with greater than 20% surface rock or open water, shallow 

to bedrock soils, or wetlands dominated by annual plant species) to the 

FERC staff prior to construction and provide ample pre-construction 

photographic documentation for these wetlands. These wetlands should

be considered “successfully restored” following construction, if preconstruction conditions are reestablished and this can be documented to 

the satisfaction of FERC staff.

ÿ Farmed wetlands – Once a ROW is cleared, farmers often take advantage 

of the additional area and moist soils of seasonally saturated wetlands to 

plant additional crops or graze cattle. The presence of agricultural activity 

greatly reduces the chances that a wetland will meet the criteria for
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

- 49 -

restored wetland. This issue was addressed in the revised 2003 Procedures 

(Section I.B.2.) where wetlands that are actively cultivated, or are

considered rotated cropland, are excluded from the definition of a

"wetland".

ÿ Post-construction human disturbance is observed on two-thirds of all

failed wetlands and is likely a contributing factor in failure. These

extenuating circumstances should be considered when evaluating wetland 

restoration success.
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

- 50 -

6.0 PREPARERS

Federal Energy Regulatory Commission (FERC)

Martin, James - Project Manager

M.S., Environmental Science, 1990, Indiana University

Masters of Public Affairs, 1990, Indiana University

B.S., Biology, 1987, Indiana University

Jones, Shannon

B.S., Natural Resources Management, 1998, University of Maryland-College Park

Kochhar, Medha

Ph.D., Plant Ecology, 1974, North Carolina State University

M.S., Botany, 1968, B.I.T.S., Pilani, India

B.S., Biology and Chemistry, 1966, University of Delhi, India

Lykens, Alisa

B.S., Biological Sciences, 1986, Old Dominion University

Swearingen, David

M.S., Marine Biology, 1996, University of North Carolina, Wilmington

B.S., Zoology, 1992, Louisiana State University

Turner, Laura

B.S., Geology, 1974, Indiana University

Wachholder, Joanne

M.S., Crop and Soil Sciences/Environmental Toxicology, 1997, Michigan State 

University

B.S., Environmental Biology, 1994, University of Wisconsin, Stevens Point

Northern Ecological Associates, Inc. (NEA)

Trettel, J. Roger – NEA Project Director

M.S., Wetland Ecology, 1989, Duke University

B.S., Forest Science, 1983, Pennsylvania State University

Miller, Kathleen R. – NEA Project Manager

B.S., Natural Resource Management, 1985, University of Maine, Orono

McCartney, Deborah J. – NEA Plant Ecology

M.S., Botany/Plant Ecology, 1988, University of Massachusetts/Amherst

B.S., Natural Resource Studies, 1983, University of Massachusetts/Amherst

B.S., Botany/Coastal & Marine Ecology, 1983, University of 

Massachusetts/Amherst
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

- 51 -

Hopperstead, Anders N. – NEA Database Manager

M.S. Public Policy, 1998, Harvard University

B.A., Political Science, 1996, Drew University

Swiezynski, Stephenie – NEA Field Team Leader

B.A., Environmental Science and Policy, 1998, University of Southern Maine

Wu, Jack – NEA Database Technician

B.S., Natural Resources/Marine Concentration, 1996, University of Maine/Orono

Santillo, David J. – NEA Quality Assurance/Quality Control

Ph.D., Environmental and Forest Biology, 2001, SUNY College of Environmental 

Science and Forestry/Syracuse 

M.S., Wildlife Management, 1987, University of Maine/Orono 

B.S., Forest Biology, 1984, SUNY College of Environmental Science and 

Forestry/Syracuse

Schaeffer, Brad A. – Statistical Analysis Task Manager

M.S., Wildlife Biology, 2002, University of Arkansas/Fayetteville

B.S., Forest Biology and Management, 1993, SUNY College of Environmental 

Science and Forestry/Syracuse

Shaw, Rose – Statistician

Ph.D., Applied Statistics, 1994, University of Northern Colorado/Greeley

M.S., Mathematics, 1966, Kansas State University/Manhattan

B.S., Mathematics & Composite Science, 1964, Dickinson State University/ 

Dickinson, North Dakota

Tetra Tech

Itani, Maher – Tetra Tech Program Manager

M.E.A., Engineering Administration, 1987, The George Washington University

B.S., Civil Engineering, 1985, The George Washington University
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

- 52 -

7.0 REFERENCES

Bailey, Robert G. 1995. Description of the Ecoregions of the United States. 2nd ed. Rev. 

and expanded (1st ed. 1980). Misc. Publ. No. 1391 (rev.), Washington. D.C.: 

USDA Forest Service. 108pp. with separate map at 1:7,500,000.

Brady, N.C., 1984. The Nature and Properties of Soils. Macmillian Publishing

Company. New York, New York. 

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

Wetlands and Deepwater Habitats of the United States. U.S. Fish & Wildlife 

Service. FWS/OBS-79/31. 103pp.

Farnworth, E.G. 1979. Natural revegetation of tidal freshwater marsh disturbed by

natural gas pipeline construction in Savannah, Georgia. Pages 42-1 to 42-29 in

R.E. Tillman ed. Proc. 2nd Symp. On the Environmental Concerns in Rightsof-way Management. Univ. of Michigan, Ann Arbor.

Leck, M.A., V.T. Parker, and R.L. Simpson. 1989. Ecology of soil seed banks. 

Academic Press, Inc. San Diego, CA. 462pp.

Mitch, W.J. and J.G. Gosslink. 1993. Wetlands. Van Nostrand Reinholt Company, Inc. 

New York, New York. 539pp.

Odegard, G.J. 1978. Revegetation of two wetlands following pipeline construction in

southern Maryland. 144th Annual Meeting of the American Association for the 

Advancement of Science. Wash. D.C.

Reed, Jr., Porter B. 1988. National List of Plant Species That Occur in Wetlands:

National Summary. U.S. Fish & Wildlife Service. Biol. Rep. 88 (24). 244 pp.

Santillo, D.J. 2000. The effects of construction of a new pipeline right-of-way on

wetland birds and vegetation in northern New York State. Ph.D. Thesis. 

SUNY College of Environmental Science and Forestry. Syracuse, NY.

Soil Survey Staff. 1990. Keys to Soil Taxonomy, fourth edition. SMSS technical

monograph no.6. Blacksburg, Virginia. 
Research of Wetland Construction Federal Energy Regulatory Commission

& Mitigation Activities for Certificated Final Report

Section 7(c) Pipeline Projects

- 53 -

U.S. Army Corps of Engineers. 1987. US Army Corps of Engineers Wetland

Delineation Manual, Technical Report Y-87-1. Environmental Laboratory

Department of the Army Waterways Experiment Station, Vicksburg,

Mississippi. 100 pp.

U.S. Department of Agriculture, Natural Resources Conservation Service. 1996. Field

Indicators of Hydric Soils in the United States. G.W. Hurt, Whited, P.M., and 

Pringle, R.F. (eds.). USDA, NRCS, Fort. Worth, TX.

U.S. Geological Survey. 2003. Nonindigenous Aquatic Species. Website:

http://nas.er.usgs.gov (Accessed July 30, 2003).

Van der Valk, A.G. 1981. Succession in wetlands: a Gleasonian approach. Ecology 

62(3):688-696.

Walter, H., Harnickell, E., Mueller-Dombois, D. 1975. Climate Diagram Maps of the 

Individual Continents and the Ecological Climate Regions of the Earth. Berlin: 

Springer-Verlag. 36 pp. with 9 maps.
Appendix A

Database Results Summary Reports
WETLANDS AFFECTED BY HUMAN DISTURBANCE

Restoration Summary

Total 

Wetlands 

Affected

Type of Human Passing Wetlands

Disturbance

Number Percent

Failing Wetlands

Number Percent

Percent of All 

Failures

Percent of All 

Wetlands

Percent of 

Wetlands 

Affected

ATV 78 16% 65 83% 13 17% 8% 3%

Paved/Fill 1 0% 1 100% 0 0% 0% 0%

Logging 0 0% 0 0% 0 0% 0% 0%

Farming 130 27% 40 31% 90 69% 54% 19%

Lawn 3 1% 2 67% 1 33% 1% 0%

Other 18 4% 10 56% 8 44% 5% 2%

Total 225 47% 115 51% 110 49% 66% 23%

Note: The Total does not equal the sum of the column because a wetland may exhibit multiple forms of human disturbance.

Summary of Wetland Failures by Criterion

Type of Human 80% Cover

Disturbance

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

ATV 7 6% 2 2% 5 5%

Paved/Fill 0 0% 0 0% 0 0%

Logging 0 0% 0 0% 0 0%

Farming 72 65% 7 6% 48 44%

Lawn 0 0% 0 0% 1 1%

Other 6 5% 1 1% 1 1%

Total 83 75% 10 9% 54 49%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.
WETLANDS AFFECTED BY HUMAN DISTURBANCE

Summary of Wetland Failures By Ecoregion

Type of Warm Continental

Human 

Disturbance Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

ATV 15 2 13% 23 7 30% 33 3 9% 5 0 0% 2 1 50% 0 0 0%

Paved/Fill 0 0 0% 1 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0%

Logging 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0%

Farming 7 2 29% 1 0 0% 2 1 50% 9 7 78% 59 44 75% 52 36 69%

Lawn 0 0 0% 0 0 0% 2 1 50% 1 0 0% 0 0 0% 0 0 0%

Other 0 0 0% 0 0 0% 5 3 60% 10 4 40% 1 0 0% 2 1 50%

Total 22 4 18% 25 7 28% 39 7 18% 24 11 46% 61 44 72% 54 37 69%

Note: The Total row represents the total number of wetlands affected by human disturbance in each ecoregion.
WETLAND LANDSCAPE POSITION

Restoration Summary

Landscape Passing Wetlands

Position

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

Bottom 288 60% 197 68% 91 32% 54%

Veg. Swale 100 21% 64 64% 36 36% 22%

Sidehill 14 3% 10 71% 4 29% 2%

Riparian 66 14% 39 59% 27 41% 16%

Other 12 3% 3 25% 9 75% 5%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Landscape 80% Cover

Position

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

Bottom 64 38% 16 10% 31 19%

Veg. Swale 25 15% 8 5% 19 11%

Sidehill 1 1% 1 1% 4 2%

Riparian 20 12% 4 2% 11 7%

Other 7 4% 0 0% 4 2%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.

Summary of Wetland Failures By Ecoregion

Landscape 

Position

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

Bottom 60 9 15% 48 4 8% 68 13 19% 22 10 45% 51 29 57% 39 26 67%

Veg. Swale 2 0 0% 16 4 25% 5 1 20% 42 9 21% 7 5 71% 28 17 61%

Sidehill 5 1 20% 3 0 0% 2 1 50% 2 1 50% 2 1 50% 0 0 0%

Riparian 13 1 8% 13 1 8% 5 1 20% 14 4 29% 18 17 94% 3 3 100%

Other 0 0 0% 0 0 0% 0 0 0% 0 0 0% 2 2 100% 10 7 70%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
SOIL TEXTURAL CLASS

Restoration Summary

Soil Texture Passing Wetlands

Class

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

Rock 2 0% 1 50% 1 50% 1%

Organic 26 5% 20 77% 6 23% 4%

Sands 151 31% 113 75% 38 25% 23%

Silts 21 4% 15 71% 6 29% 4%

Clays 183 38% 95 52% 88 48% 53%

Loams 86 18% 64 74% 22 26% 13%

Inundated 11 2% 5 45% 6 55% 4%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Soil Texture 80% Cover

Class

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

Rock 1 1% 0 0% 0 0%

Organic 4 2% 3 2% 0 0%

Sands 31 19% 4 2% 9 5%

Silts 4 2% 1 1% 4 2%

Clays 63 38% 13 8% 49 29%

Loams 9 5% 8 5% 6 4%

Inundated 5 3% 0 0% 1 1%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.
SOIL TEXTURAL CLASS

Summary of Wetland Failures By Ecoregion

Soil Texture 

Class

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

Rock 1 0 0% 0 0 0% 0 0 0% 1 1 100% 0 0 0% 0 0 0%

Organic 18 2 11% 1 1 100% 0 0 0% 1 0 0% 6 3 50% 0 0 0%

Sands 31 6 19% 36 5 14% 43 4 9% 5 0 0% 32 20 63% 4 3 75%

Silts 4 2 50% 5 0 0% 0 0 0% 3 0 0% 9 4 44% 0 0 0%

Clays 23 1 4% 27 2 7% 2 1 50% 25 9 36% 31 26 84% 75 49 65%

Loams 3 0 0% 10 1 10% 27 7 26% 45 14 31% 1 0 0% 0 0 0%

Inundated 0 0 0% 1 0 0% 8 4 50% 0 0 0% 1 1 100% 1 1 100%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
WETLAND HYDROLOGY

Restoration Summary

Surface Water Passing Wetlands

Depth

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

< 1" 287 60% 172 60% 115 40% 69%

1"- 6" 157 33% 124 79% 33 21% 20%

6"- 12" 24 5% 15 63% 9 38% 5%

> 12" 12 3% 2 17% 10 83% 6%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Surface Water 80% Cover

Depth

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

< 1" 79 47% 21 13% 54 32%

1"- 6" 20 12% 6 4% 14 8%

6"- 12" 8 5% 2 1% 0 0%

> 12" 10 6% 0 0% 1 1%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.

Summary of Wetland Failures By Ecoregion

Surface 

Water Depth

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

< 1" 50 5 10% 41 4 10% 18 2 11% 65 18 28% 53 40 75% 60 46 77%

1"- 6" 20 1 5% 38 5 13% 45 6 13% 12 4 33% 25 13 52% 17 4 24%

6"- 12" 5 2 40% 1 0 0% 13 4 31% 1 0 0% 2 1 50% 2 2 100%

> 12" 5 3 60% 0 0 0% 4 4 100% 2 2 100% 0 0 0% 1 1 100%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
WATERBAR PLACEMENT

Restoration Summary

Waterbar Passing Wetlands

Position

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

No Waterbar 311 65% 187 60% 124 40% 74%

Up gradient 146 30% 108 74% 38 26% 23%

Down gradient 1 0% 0 0% 1 100% 1%

Both 22 5% 18 82% 4 18% 2%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Waterbar 80% Cover

Position

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

No Waterbar 82 49% 25 15% 52 31%

Up gradient 30 18% 3 2% 13 8%

Down gradient 1 1% 0 0% 1 1%

Both 4 2% 1 1% 3 2%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.

Summary of Wetland Failures By Ecoregion

Waterbar 

Position

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

No Waterbar 33 5 15% 53 8 15% 26 7 27% 78 23 29% 48 32 67% 73 49 67%

Up gradient 44 6 14% 27 1 4% 37 7 19% 2 1 50% 29 19 66% 7 4 57%

Down gradien 0 0 0% 0 0 0% 0 0 0% 0 0 0% 1 1 100% 0 0 0%

Both 3 0 0% 0 0 0% 17 2 12% 0 0 0% 2 2 100% 0 0 0%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
WATERBAR PLACEMENT

Summary of Wetland Failures By Landscape Position

Waterbar Vegetated Swale

Position

Number Percent

Sidehill

Number Percent

Bottom

Number Percent

Riparian

Number Percent

Other

Number Percent

No Waterbar 32 7% 1 0% 69 14% 13 3% 9 2%

Up gradient 3 1% 2 0% 20 4% 13 3% 0 0%

Down gradient 0 0% 0 0% 0 0% 1 0% 0 0%

Both 1 0% 1 0% 2 0% 0 0% 0 0%

Total 36 8% 4 1% 91 19% 27 6% 9 2%
COWARDIN CLASSIFICATION

Restoration Summary

ROW Total Passing

Cowardin 

Class Number Percent

Total Failing

Number Percent

Percent 

of All 

Failures

Percent 

of Total 

Failures

Percent 

of Total 

Wetlands

On-ROW 

Cowardin 

Class

Overall

Number Percent

PSS/PFO 2 0% 2 100% 0 0% 0% PSS/PFO 0% 0%

PSS/OW 2 0% 0 0% 2 100% 1% PSS/OW 1% 0%

PEM/PSS 31 6% 26 84% 5 16% 3% PEM/PSS 3% 1%

PEM/PFO 0 0% 0 0% 0 0% 0% PEM/PFO 0% 0%

PEM/OW 21 4% 1 5% 20 95% 12% PEM/OW 12% 4%

PEM 394 82% 267 68% 127 32% 76% PEM 76% 26%

PSS 20 4% 11 55% 9 45% 5% PSS 5% 2%

PFO 9 2% 6 67% 3 33% 2% PFO 2% 1%

POW 1 0% 0 0% 1 100% 1% POW 1% 0%

Total 480 100% 313 65% 167 35% 100% Total 100% 35%

Summary of Wetland Failures by Criterion

ROW Cowardin 80% Cover

Class

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

PSS/PFO 0 0% 0 0% 0 0%

PSS/OW 2 1% 0 0% 2 1%

PEM/PSS 0 0% 1 1% 4 2%

PEM/PFO 0 0% 0 0% 0 0%

PEM/OW 20 12% 1 1% 0 0%

PEM 84 50% 26 16% 54 32%

PSS 7 4% 0 0% 7 4%

PFO 3 2% 1 1% 2 1%

POW 1 1% 0 0% 0 0%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.
COWARDIN CLASSIFICATION

Summary of Wetland Failures By Ecoregion

ROW 

Cowardin 

Class

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

PSS/PFO 0 0 0% 0 0 0% 2 0 0% 0 0 0% 0 0 0% 0 0 0%

PSS/OW 0 0 0% 0 0 0% 1 1 100% 0 0 0% 1 1 100% 0 0 0%

PEM/PSS 0 0 0% 1 0 0% 28 4 14% 1 0 0% 0 0 0% 1 1 100%

PEM/PFO 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0%

PEM/OW 6 5 83% 1 1 100% 8 8 100% 2 2 100% 3 3 100% 1 1 100%

PEM 73 6 8% 77 7 9% 30 3 10% 74 22 30% 63 39 62% 77 50 65%

PSS 1 0 0% 1 1 100% 7 0 0% 1 0 0% 10 8 80% 0 0 0%

PFO 0 0 0% 0 0 0% 4 0 0% 2 0 0% 3 3 100% 0 0 0%

POW 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0% 1 1 100%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%

Summary of Wetland Failures By Landscape Position

ROW Cowardin Vegetated Swale

Class

Number Percent

Sidehill

Number Percent

Bottom

Number Percent

Riparian

Number Percent

Other

Number Percent

PSS/PFO 0 0% 0 0% 0 0% 0 0% 0 0%

PSS/OW 0 0% 0 0% 1 0% 1 0% 0 0%

PEM/PSS 0 0% 1 0% 2 0% 2 0% 0 0%

PEM/PFO 0 0% 0 0% 0 0% 0 0% 0 0%

PEM/OW 0 0% 0 0% 15 3% 5 1% 0 0%

PEM 36 8% 3 1% 68 14% 11 2% 9 2%

PSS 0 0% 0 0% 4 1% 5 1% 0 0%

PFO 0 0% 0 0% 0 0% 3 1% 0 0%

POW 0 0% 0 0% 1 0% 0 0% 0 0%

Total 36 8% 4 1% 91 19% 27 6% 9 2%
ATYPICAL CLIMATIC CONDITIONS AT TIME OF SURVEY

Restoration Summary

Abnormal Passing Wetlands

Conditions

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

Normal 345 72% 236 68% 109 32% 65%

Drought 134 28% 77 57% 57 43% 34%

Flooding 1 0% 0 0% 1 100% 1%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Abnormal 80% Cover

Conditions

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

Normal 68 41% 21 13% 42 25%

Drought 48 29% 8 5% 27 16%

Flooding 1 1% 0 0% 0 0%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.

Summary of Wetland Failures By Ecoregion

Abnormal 

Conditions

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

Normal 50 10 20% 57 8 14% 80 16 20% 80 24 30% 0 0 0% 78 51 65%

Drought 30 1 3% 23 1 4% 0 0 0% 0 0 0% 80 54 68% 1 1 100%

Flooding 0 0 0% 0 0 0% 0 0 0% 0 0 0% 0 0 0% 1 1 100%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
ATYPICAL CLIMATIC CONDITIONS AT TIME OF SURVEY

Summary of Wetland Failures By Landscape Position

Abnormal Vegetated Swale

Conditions

Number Percent

Sidehill

Number Percent

Bottom

Number Percent

Riparian

Number Percent

Other

Number Percent

Normal 31 6% 3 1% 58 12% 10 2% 7 1%

Drought 5 1% 1 0% 32 7% 17 4% 2 0%

Flooding 0 0% 0 0% 1 0% 0 0% 0 0%

Total 36 8% 4 1% 91 19% 27 6% 9 2%
CONSTRUCTION YEAR

Restoration Summary

Construction Passing Wetlands

Year

Number Percent

Failing Wetlands

Number Percent

Overall

Number Percent

Percent of All 

Failures

1995 25 5% 22 88% 3 12% 2%

1996 90 19% 35 39% 55 61% 33%

1998 174 36% 132 76% 42 24% 25%

1999 151 31% 96 64% 55 36% 33%

2000 10 2% 4 40% 6 60% 4%

2001 30 6% 24 80% 6 20% 4%

Total 480 100% 313 65% 167 35% 100%

Summary of Wetland Failures by Criterion

Construction 80% Cover

Year

Number Percent

Diversity

Number Percent

Jurisdictional Wetland

Number Percent

1995 0 0% 0 0% 3 2%

1996 40 24% 4 2% 29 17%

1998 24 14% 15 9% 6 4%

1999 46 28% 7 4% 28 17%

2000 5 3% 2 1% 0 0%

2001 2 1% 1 1% 3 2%

Total 117 70% 29 17% 69 41%

Note: Sums for wetland failures by criterion may not equal total wetland failures due to 

some wetlands failing for more than one of the success criteria.
CONSTRUCTION YEAR

Summary of Wetland Failures By Ecoregion

Construction 

Year

Warm Continental

Total Failed 

Wetlands

% Failing

Hot Continental

Total Failed 

Wetlands

% Failing

Subtropical

Total Failed 

Wetlands

% Failing

Prairie

Total Failed 

Wetlands

% Failing

Temperate Steppe

Total Failed 

Wetlands

% Failing

Mediterranean

Total Failed 

Wetlands

% Failing

1995 0 0 0% 25 3 12% 0 0 0% 0 0 0% 0 0 0% 0 0 0%

1996 0 0 0% 0 0 0% 10 2 20% 0 0 0% 0 0 0% 80 53 66%

1998 38 10 26% 16 0 0% 40 8 20% 80 24 30% 0 0 0% 0 0 0%

1999 42 1 2% 39 6 15% 0 0 0% 0 0 0% 70 48 69% 0 0 0%

2000 0 0 0% 0 0 0% 0 0 0% 0 0 0% 10 6 60% 0 0 0%

2001 0 0 0% 0 0 0% 30 6 20% 0 0 0% 0 0 0% 0 0 0%

Total 80 11 14% 80 9 11% 80 16 20% 80 24 30% 80 54 68% 80 53 66%
WETLAND RESTORATION SUMMARY

Total Number of Wetland Records (80 Wetlands Per EcoRegion) 480

Number Wetlands Per Eco-Region 80

Wetlands Failing FERC Criteria (only need to fail one criterion) 167

Wetlands Failing Diversity Criterion Only 20

Wetlands Failing 80% Vegetative Cover Criterion Only 73

Wetlands Failing 50% Relative Cover by Hydrophytes (RCH) Criterion Only 30

Wetlands Where Reference Wetland Failed RCH Criterion and On-ROW Failed 31

Wetlands Where Reference Wetland Passed RCH and on On-ROW Failed 38

Wetlands Failing Diversity and Vegetative Cover Criteria Only 5

Wetlands Failing Diversity and RCH Criteria Only 0

Wetlands Failing Vegetative Cover and RCH Criteria Only 35

Wetlands Failing All Three Criteria 4

Wetlands Passing FERC Criteria (passing all three criteria) 313

Wetlands Failing Diversity Criterion 29

Wetlands Failing 80% Vegetative Cover Criterion 117

Wetlands Failing 50% Relative Cover by Hydrophytes (RCH) Criterion 69
Appendix B

Statistical Analysis Summary Report
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Statistical Analysis

All statistical tests were set at a 0.05 significance level. Significant factors are highlighted in 

yellow. Df = Degrees of Freedom, SS = Sum of Squares, MS = Mean Square, F= F Statistic, P = 

calculated level of significance. 

I. All Ecoregions

A randomized complete block design was used to reduce experimental error by blocking on the 

variable ecoregion. A factorial design ANalysis Of VAriance (ANOVA) (F Statistic) was used 

with the dependent variable success (1 = yes success, 0 = no success) and nine independent

variables. Interaction terms were not possible because of the presence of empty cells. 

Multiple factor ANOVA effects table on success (the whole model was significant [F = 6.95, P < 

0.0001]):

Source Df SS MS F p

Ecoregion 5 12.0580 2.4116

Construction Debris 1 0.0425 0.0425 0.25 0.6159

Evidence of Erosion 1 0.0006 0.0006 0.00 0.9518

Meets Preconstruction Grade 1 1.0100 1.0100 5.99 0.0148

Water Bar within 100 Feet 1 0.0766 0.0766 0.45 0.5007

Evidence of Human Disturbance 1 1.6755 1.6754 9.93 0.0017

Wetland Position in Landscape 4 0.6179 0.1544 0.92 0.4545

Soil Texture 13 3.0706 0.2362 1.40 0.1551

Top Soil Mix 1 0.0007 0.0007 0.00 0.9505

Error 451 46.0699 0.1686

Total 479 Grand Mean 1.47 CV 27.88

Notes: SS are marginal (Type III) sums of squares.

Similar results were obtained using grouped soil texture categories (e.g., sands, 

clays).

A Tukey HSD all-pairwise comparisons test was used to examine differences between successes 

for each ecoregion (unlike letters indicate a significant difference between the two groups):

Ecoregion Mean Success % Successful

Homogeneous 

Groups

Hot Continental 0.72 86% A

Warm Continental 0.71 86% A

Subtropical 0.63 80% A

Prairie 0.55 70% A

Mediterranean 0.32 34% B

Temperate Steppe 0.23 32% B
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Wetland restoration was significantly more successful in the Hot Continental, Warm

Continental, Subtropical, and Prairie Ecoregions than the Mediterranean and Temperate Steppe 

Ecoregions (P < 0.05). 

The multiple factor ANOVA test above also indicates two groups in which the means for success 

were significantly different from one another; evidence of human disturbance and meets

preconstruction grade (unlike letters indicate a significant difference between the two groups). 

Evidence of Human 

Disturbance Mean Success % Successful

Homogenous 

Groups

Yes 0.46 37 A

No 0.59 63 B

Evidence of human disturbance was a significant factor in determining the success of wetland 

restoration (P = 0.0148). More evidence of human disturbance was associated with less

success.

Meets Preconstruction 

Grade Mean Success %Successful

Homogenous 

Groups

Yes 0.64 67 A

No 0.41 35 B

Meets preconstruction grade was a significant factor in determining the success of wetland 

restoration (P = 0.0017). Wetlands not restored to preconstruction grades were less successful. 

II. Grouped Ecoregions

Based on the above analysis in Section I the ecoregions were pooled into “East” and “West” 

categories to examine if any of the variables could explain the difference in wetland restoration 

success between eastern and western located wetlands. The eastern category included the Hot 

Continental, Prairie, Subtropical, and Warm Continental ecoregions. The western category

included the Mediterranean and Temperate Steppe ecoregions.

One-way ANOVA on Success:

Source Df SS MS F P

Ecoregion (East/West) 1 24.704 24.7042 1.40 0.0000

Error 478 84.194 0.1761

Total 479 108.898 Grand Mean 0.6521 CV 64.36

Location N Mean Success %Successful SE

East 320 0.81 83 0.0235

West 160 0.33 17 0.0332
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As expected the one-way ANOVA results indicates a significant difference in success for the 

pooled ecoregion categories:

Analysis of Variance Table on success with the grouped ecoregion covariate (the whole model 

was significant [F = 7.76, P < 0.0001]):

Source Df SS MS F P

Soil Texture 13 3.2656 0.2512 1.48 0.1211

Construction Debris 1 0.0705 0.0705 0.42 0.5196

Sign of Erosion 1 0.0073 0.0073 0.04 0.8355

Preconstruction Grade 1 0.9127 0.9127 5.38 0.0209

Water Bar within 100 Feet 1 0.2196 0.2196 1.29 0.2561

Evidence of Human Disturbance 1 1.9157 1.9157 11.28 0.0008

Wetland Position in Landscape 4 0.6243 0.1561 0.92 0.4525

Topsoil Mix 1 0.0021 0.0021 0.01 0.9116

Location (East/West) 1 10.8743 10.8743 64.05 0.0000

Error 455 77.2536 .1698

Total 479 Grand Mean 0.5117 CV 80.53

Evidence of Human Disturbance was a significant factor in determining the success of wetland 

restoration (P = 0.0008). More Evidence of Human Disturbance was associated with less 

success.

Meets Preconstruction Grade was a significant factor in determining the success of wetland 

restoration (P = 0.0209). Wetlands not restored to preconstruction grades were less successful. 

III. Chi-Square Tests

Contingency tables and the Chi-square test (X2 Statistic) were used to test for homogeneity of the 

proportions between east and west groups for each of the variables in the ANOVA preformed in 

Section I:

Meets Preconstruction

Grade East West

No 10 (3%) 13 (8%)

Yes 310 (97%) 147 (92%)

Total 320 (100%) 160 (100%)

There is a significant difference between the proportion of wetlands that met preconstruction 

grade between the east and west groups (?2 = 5.85, P = 0.0156, Df = 1). However, this 

proportion is only separated by five percentage points (97% of the eastern wetlands met

preconstruction grade, whereas 92% of the western wetlands met preconstruction grade). A 

greater proportion of eastern wetlands were restored to meet preconstruction grade and this 

could potentially be an explanatory variable as to why the east group wetlands were more 

successful. This finding is further supported by the ANOVA model test in Section II.
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Evidence of Human 

Disturbance

East West

No 210 (66%) 45 (28%)

Yes 110 (34%) 115 (72%)

Total 320 (100%) 160 (100%)

There is a significant difference between the proportion of wetlands that exhibited evidence of 

human disturbance between the east and west groups (?2 = 60.24, P = 0.0000, Df = 1). A 

smaller proportion of eastern wetlands exhibited evidence of human disturbance and this could 

potentially be an explanatory variable as to why the east group wetlands were more successful. 

This finding is further supported by the ANOVA model test in Section II.

Evidence of 

Construction

Debris East West

No 299 (93%) 154 (96%)

Yes 21 (7%) 6 (4%)

Total 320 (100%) 160 (100%)

A significant difference was not found between the proportion of wetlands that exhibited 

evidence of construction debris between the east and west groups (?2 = 1.59, P = 0.2074, Df = 

1). 

Evidence of 

Erosion East West

No 298 (93%) 146 (96%)

Yes 22 (7%) 14 (4%)

Total 320 (100%) 160 (100%)

A significant difference was not found between the proportion of wetlands that exhibited

evidence of erosion between the east and west groups (?2 = 0.541, P = 0.4622, Df = 1). 

Water Bar 

Within 100 Ft

East West

No 189(59%) 121 (76%)

Yes 130 (41%) 39 (24%)

Total 320 (100%) 160 (100%)

There is a significant difference between the proportion of wetlands that had a water bar within 

100 feet between the east and west groups (?2 = 12.35, P = 0.0004, Df = 1). A larger proportion 

of eastern wetlands had water bars within 100 feet of the wetlands and this could potentially be 

an explanatory variable as to why the east group wetlands were more successful. However, the 

existence of a water bar within 100 feet in the context of all of the other variables analyzed was 

not a significant factor in determining the success of a wetland as indicated by the ANOVA and 

ANCOVA models in Sections I and II. Therefore these results should be viewed with caution.
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Wetland Position 

in Landscape

East West

Bottom 198 (62%) 90 (56%)

Other 0 12 (8%)

Riparian 45 (14%) 21 (13%)

Sidehill 12 (4%) 2 (1%)

Vegetated Swale 65 (20%) 35 (22%)

Total 320 (100%) 160 (100%)

There is a significant difference between the distribution of the proportions of the wetland 

positions between the east and west groups (?2 = 27.04, P < 0.0001, Df = 21). These results 

should be viewed with caution because there are cells with expected values less than 5.

Soil Texture East West

Clays 77 (24%) 106 (66%)

Inundated 9 (3%) 2 (1%)

Loams 85 (27%) 1 (.6%)

Organic 20 (6%) 6 (4%)

Rock 2 (6%) 0

Sands 115 (36%) 36 (6%)

Silt 12 (4%) 9 (33%)

Total 320 (100%) 160 (100%)

There is a significant difference between the distribution of the proportions of the soil types 

between the east and west groups (?2 = 100.19, P < 0.0001, Df = 21). These results should be 

viewed with caution because there are cells with expected values less than 5.

Top Soil Mixing East West

No 274 (86%) 146 (91%)

Yes 46 (14%) 14 (9%)

Total 320 (100%) 160 (100%)

A significant difference was not found between the proportion of wetlands that exhibited

evidence of top soil mixing between the east and west groups (?2 = 3.09, p = 0.0790, Df = 1). 
Appendix C

Vegetation and Diversity Summary Reports

(Included in Appendix E on CD)
Appendix D 

Wetlands Monitoring Dataform
Pipeline Company:

Docket Number: Construction Year:

Wetland Name or Location:

Proposed Construction Method:

Cowardin Wetland Classification: Latitude/Longitude:

General Condition of Wetland:

Vegetation: Hydrology:

Total Percent Veg. Cover: Percent Open Water:

Vegetation Vigor: Dead/Dying Depth of Surface Water: 0" 1 to 6" 6 to 12" 12"+

Low Medium High Saturated Soil: Yes No

Percent Bare Ground: Drainage Patterns: Normal Blocked Altered

Evidence of Resprouting: Yes No Drought Normal Flooding

Resprouting Species:

Wetland Position in Landscape: Bottom Vegetated Swale

Sidehill Wetland Riparian Other:

Soil Textural Class (Top 12 inches): Rock

Sand Sandy Loam Loam Loamy Sand Waterbar Within 100 Feet: None Upgradient Downgradient

Sandy Clay Loam Sandy Clay Clay Clay Loam

Silty Loam Silty Clay Loam Silty Clay Silt Evidence of Human Disturbance: None

Topsoil/Subsoil Mixing: Yes % Topsoil No ATV % Farming %

Paved/Fill % Lawn %

Rock Fragments at the Surface: None Logging % Other: %

Gravel (<3" dia.): % Stone (11-24" dia.): %

Cobble (3-10" dia.): % Boulder (>25" dia.): % Evidence of Construction Debris: None Timber %

New or Existing ROW: New Existing Blast Rock % Rip-Rap %

Meets Pre-Construction Grade: Yes No Wood Chips % Slash %

Evidence of Erosion: Yes % of Wetland No Mats % Other: %

Strata of 

Vegetation Species Code

Wetland 

Indicator % Cover Plot Number Species Code % Cover Cover Class

COMMENTS/RECOMMENDATIONS

Class Percent

t <1

1 1-5

2 5-25

3 25-50

4 50-75

5 75-100

Wetland Monitoring Form

Construction Season:

Town/County/State:

Photographic Documentation:

QUALITATIVE ASSESSMENT QUANTITATIVE ASSESSMENT

Percent Cover Class

Pipeline Right of Way

Field Crew:

O Horizon Thickness (inches):

Abnormal Conditions:

Survey Date:

Federal Energy Regulatory Commission 2002-2003
Pipeline Company:

Wetland Name:

Cowardin Wetland Classification:

General Condition of Wetland:

Vegetation Hydrology

Total Percent Veg. Cover: Depth of Surface Water: 0" 1 to 6" 6 to 12" 12"+

Vegetation Vigor: Saturated Soil: Yes No

Low Medium High Drainage Patterns: Normal Blocked Altered

Percent Bare Ground: Drought Normal Flooding

Percent Open Water:

Other Wetland Position in Landscape: Bottom Vegetated Swale

O Horizon Thickness (inches): Sidehill Wetland Riparian Other:

Soil Textural Class (Top 12 inches): Rock

Sand Sandy Loam Loam Loamy Sand Evidence of Human Disturbance: None

Sandy Clay Loam Sandy Clay Clay Clay Loam ATV % Farming %

Silty Loam Silty Clay Loam Silty Clay Silt Lawn % Paved/Fill %

Logging % Other: %

Rock Fragments at the Surface: None

Gravel (<3" dia.): % Stone (11-24" dia.): % % No

Cobble (3-10" dia.): % Boulder (>25" dia.): %

Strata of 

Vegetation Species Code

Wetland 

Indicator % Cover Plot Number Species Code % Cover Cover Class

COMMENTS/RECOMMENDATIONS

Class Percent

t <1

1 1-5

2 5-25

3 25-50

4 50-75

5 75-100

QUALITATIVE ASSESSMENT QUANTITATIVE ASSESSMENT

Percent Cover Class

Evidence of Erosion: Yes

Dead/dying

Abnormal Conditions:

Wetland Monitoring Form

Reference Area Wetland

Field Crew:

Date:

Photographic Documentation:

Latitude/Longitude:

Federal Energy Regulatory Commission 2002-2003
Appendix E

Wetlands Monitoring Database and Technical 

Documentation
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Wetland Monitoring Database

Technical Documentation

March 25, 2004

Introduction

The Wetland Monitoring Database is a Microsoft© Access 2000 database. It is a single 

file database (Wetland Monitoring.mdb) with forms designed for display on a screen with

area settings of 1024 by 768 pixels. All database objects and source code are open for 

modification. 

Wetland Data Tables

Data regarding wetland monitoring is stored in six normalized tables that are linked to 

enforce referential integrity. The structure will support multiple visits to the same

wetland (subsequent year monitoring) without duplication of data. Cascade updates and 

cascade deletes have been enabled on the relationships to maintain integrity. The table 

structure is displayed in the database’s relationship window (see below).
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The Project table stores information for each project including data field specifications. 

The Wetland_Master table stores static information for each wetland. The Wetland_Visit 

table stores a short header record for each trip to the wetland. 

The Wetland_Conditions table stores the single-entry data from the wetland monitoring 

dataform. The OnRightOfWay yes/no field allows this table to store records for both the 

on right of way and it's reference wetland. This field and data structure is repeated in the 

Wetland_Qualitative and Wetland_Quantitative tables, which store the qualitative and

quantitative data respectively.

Lookup Tables

The database contains 21 lookup tables that govern data entry in corresponding wetland 

data fields. The tables are named to indicate their purpose. With the exception of the 

LkpSpecies and the LkpNonNative table, the text following the “Lkp” prefix corresponds 

to the wetland data field(s) that the lookup table governs. All tables using this naming 

convention are listed below:

LkpAbnormalConditions LkpSociability

LkpCoverClass LkpSoilTexturalClass

LkpCowardinWetlandClassification LkpStates

LkpCrew* LkpStrataOfVegetation

LkpDepthOfSurfaceWater LkpType

LkpDocketYearNumberAndSub LkpVegetationVigor

LkpDrainagePatterns LkpWaterbarGradient

LkpPipelineCompany LkpWetlandIndicator

LkpRegion LkpWetlandPositionInLandscape

LkpRockFragmentsAtSurface

*LkpCrew is used for the Crew field and the Team Leader field

The LkpSpecies table is used for the SpeciesCode field, but it also contains important

reference information for each species. The table contains Yes/no fields and

WetlandIndicator text fields with the prefix “Region_” followed by a number or letter 

indicating a region. The region referenced in this section corresponds to the U.S. Fish 

and Wildlife Service's (FWS's) jurisdictional regions, and not ecoregions. This link is 

required because the same plant species may have a different wetland indicator status 

depending on the FWS region in which it is found. The Yes/no field indicates whether 

the species should be listed in the particular region and the WetlandIndicator field gives 

the respective wetland indicator status for that plant within the identified U.S. Fish and 

Wildlife Service region.

The LkpNonNative table is used in a coded procedure behind the data entry form. The 

procedure automatically populates the Wetland Indicator on the data entry form with a 

zero value if the species is considered non-native for the particular region. The 
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LkpNonNative table supports a state-based lookup that overrides the Wetland Indicator 

with a Non-Native flag where appropriate. This supports the exclusion of non-native 

species in diversity, and relative cover by hydrophytes, calculations within the database.

Wetland Monitoring Data Entry Form

The Wetland Monitoring Data Entry Form allows for data entry in the five data tables 

that have the prefix “Wetland_”. The form uses subforms to mimic the normalized

structure of the data. The lookup tables support the drop-down menus on the form. The 

SpeciesCode drop-down menus adjust according to the designated region. Users can add 

species from the Add New Species pop-up form that is launched from this form.

Please Note: In order to maintain data integrity, records must exist in the

Wetland_Conditions table before corresponding records are created in the

Wetland_Qualitative and Wetland_Quantitative tables. During data entry, the users must 

enter some data on a conditions tab before they attempt to enter qualitative or quantitative 

data for the respective portion of the wetland (right of way or reference). The simplest 

way is to enter a Cowardin Wetland Classification for the given portion of the wetland 

before proceeding to either of the assessment tabs.
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The Navigation Bar at the very bottom of the screen lists the number of records in the 

Wetland_Master table. The Navigation Bar at the bottom of the Fieldwork Data subform 

lists the number of visits to the given Wetland. 

Project Specification Form

The Project Specification form allows data entry to the project table as well as

customization of the Wetland Monitoring Data Entry form for each project. Users can

deselect or select the fields they wish to be displayed on the Wetland Monitoring Data 

Entry form. The default is for all fields to be displayed. The fields that are grayed out on 

the Project Specification form cannot be hidden due to the fact that they are the first

fields in their given form.
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Main Menu Form

The Main Menu provides access to the forms, reports, and the database window. The 

menu is automatically displayed when the database is opened.
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Wetland Monitoring Summary Report 

The Wetland Monitoring Summary Report displays success criteria for each wetland with 

indication as to whether the success criteria were met. Two versions of the report exist in 

the current database: A version for one year of data and a version for two years of data. 

Using the models given for years 1 and 2, users can create additional query and report 

objects to support additional years (see the Adding A Year section below).

In order for a wetland to meet its success criteria, the following three conditions must

exist:

1. Qualitative Percentage Cover is greater than or equal to 80%

2. Relative Cover by Wetland Species is greater than or equal to 50%

3. The Shannon Weiner Diversity Index of the Right of Way is at least 50% of 

the Shannon Weiner Diversity Index of the Reference Area.

The Qualitative Percentage Cover is equal to the Total Percent Vegetative Cover for the 

right of way portion of the wetland. 

The Relative Percent Vegetative Cover for Wetland Species is equal to the sum of the 

Cover Class midpoints for the wetland species divided by the sum of Cover Class

midpoints for all species (based on quantitative assessment records). Wetland species are 

defined as species with the following wetland indicators: "FAC","FAC+", "FACW",
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"OBL", "FAC>wetter". The FAC>wetter status is used in instances where dominant

plants can not be identified to species level at time of survey due growing season

limitations, absent plant parts necessary to make the identification, or human or animal 

alteration (i.e., mowing or grazing). To avoid these plants being discounted in

calculations and possible "false failure" of the wetland, this provision was added to the 

database. However, this requires the biologist in the field to make a "best professional 

judgment" call as to whether the plant would be considered to have a "faculative or

wetter" wetland indicator status. The Relative Percent Vegetative Cover for Wetland 

Species is calculated in the queries with the name pattern qry_RelativeCover_*.

The Shannon Weiner Diversity Index is defined below.

Shannon Weiner Diversity Index Calculation

Glossary and explanation of the equation:

N = Total Number of Individuals of all Species

This value is calculated as the sum of the midpoint of the cover class of all 

species.

Pi = Proportion of all individuals in the sample which belong to species i. 

For calculation purposes this is the Midpoint of the cover class percentage range 

as defined in the LkpCoverClass table. 

Log10( ) = A function that returns the base-10 logarithm of the value in the following ( ).

Log2( ) = A function that returns the base-2 logarithm of the value in the following ( ).

Sum( ) = A function that sums all the records in a given recordset. 

The queries with the name pattern qryDiversity_*_Base perform the summation 

of each midpoint for each species for each wetland grouped by reference and 

right-of-way records (* is the wild card symbol; right-of-way and reference 

records have separate queries.)

H’ = Diversity Index. 

You cannot store apostrophes in database field names, so the database uses the 

variable DiversityIndex. Defined as follows:

DiversityIndex = Log2( 10 ) * ( Log10( N ) – (Sum( Midpoint * Log10( Midpoint ) ) / N)

The Shannon Weiner Diversity Index is calculated in the queries with the name pattern 

qry_Diversity_*.
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Adding A Year to the Wetland Monitoring Summary Report (for tracking specific 

wetlands over time)

The following process will create a Wetland Monitoring Summary report with an 

additional year. 

1. Create a copy of the query qry_Success_Criteria_Year_1 and rename it 

qry_Success_Criteria_Year_X where X is the number of the year you 

wish to add.

2. Modify qry_Success_Criteria_Year_X so that the fields with the suffix 

Year_1 have the suffix Year_X. Also change the criteria on the 

SurveyYear field from 1 to X. 

3. Create a copy of the query qry_Success_Summary_Two_Year and 

rename it qry_Success_Summary_X_Year.

4. Modify qry_Success_Summary_X_Year by adding 

qry_Success_Criteria_X joining it with the Wetland_Master table on 

the WetlandNameOrLocation field. The join should show all records in 

Wetland_Master and only those in qrySuccess_Criteria_X that match. 

5. Add all the fields with the suffix Year_X to the result set of the 

modified query. To prevent the display of blank records, add “Is Not 

Null” criteria to the Date_Year_X field. Add this criteria on a new line 

so that it functions as an Or criteria rather than And criteria. This 

allows each wetland with any data to be displayed even if it does not 

have record in each year.

6. Create a new report with qry_Success_Summary_X_Year as the 

recordsource. The report named rpt_Success_Summary_Two_Year 

provides a basic model of the layout for a multiple year report.

Security

The following procedure allows users to add a password to a copy of the database:

1. From the File>Open Dialog in Microsoft Access, open a copy of the database 

using the Open Exclusive option available as a drop-down from the Open 

button.

2. From the Tools menu select Security>Set Database Password and proceed to 

enter and confirm the Password. 

To remove or change a password, the database must be opened in Exclusive mode.
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Additional Report:

Vegetative Cover Summary Report

The Vegetative Cover Summary report displays the detail records from the quantitative 

assessment of right of way wetland portions as well as summary statistics on the

percentage of cover for wetland species and all species. The report also displays general 

wetland information, comments, and reference tables for cover class and indicator status.

Each page of the report represents one wetland.

The Relative Percent Vegetative Cover value for All Species comes directly from the 

Total percent vegetative cover field on the Wetland Dataform for the right-of-way portion 

of the wetland. The Relative Percent Vegetative Cover value for Wetland Species is 

calculated as follows, using right-of-way data: 

 S mid point of the cover class wetland species 

=S mid point of the cover class all species 

The Vegetative Cover Summary Report also displays an image for each wetland per 

survey year visit. The file paths for the image files are stored in the database. Image file 

paths are added to wetland records on the Right Of Way Image tab of the Wetland 

Monitoring data entry form.
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Additional Report:

Diversity Index Summary Report

The Diversity Index Summary report displays the detail quantitative assessment records 

for both the right of way and reference portions of the wetland. The calculated Shannon 

Weiner Diversity Index for each is also displayed with an indication as to whether the 

right of way diversity index is at least half of the reference area diversity index. This 

criteria is only one component of the success criteria given in the Wetland Monitoring 

Summary report. The report displays one page for each wetland.
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Additional Report:

Data Analyses Summary Report

The Data Analyses Summary Report is a multiple page report with tables that summarize 

the conditional trends in the wetlands relative to their success. Wetlands are analyzed 

based on the following eight data elements:

Evidence of Human Disturbance Landscape Position

Soil Textural Class Wetland Hydrology

Waterbar Placement Cowardin Classification

Atypical Climatic Conditions Construction Year

For each element, there is a Restoration Summary table, a Summary of Wetland Failures 

by Criterion table and a Summary of Wetland Failures by Ecoregion. There is an 

additional Summary of Wetland Failure by Landscape Position for Waterbar Placement, 

Cowardin Classification and Atypical Climatic Conditions. The final page of the report 

displays overall summary data. The report design is based on the nationwide survey 

conducted by NEA, which surveyed 80 wetlands in 6 ecoregions for a total of 480 

wetlands.