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Compensating for Wetland Losses Under the Clean Water Act (2001)

Chapter: Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures

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Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Appendix H

Selected Attributes of 40 Common Wetland Functional Assessment Procedures

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

TABLE H–1 Selected Attributes of 40 Common Wetland Functional Assessment Procedures

Assessment Procedure1

Scale2 Non-tidal

Habitat Type3

Functions4

Social Values, Red Flags

AREM

SS

TW

HA

+

Coastal method

SS, WS

NT

HY,WQ,HA

+

CT method

SS

TW

HY,WQ,HA

+

Descriptive approach

SS

NT,TW

HY,WQ,HA

+

EPW

SS

NT,TW

HY,WQ,HA

+

HAT

SS

NT,TW

HA

+

HEP

SS

NT,TW,UP

HA

 

HGM approach

SS

NT,TW

HY,WQ,HA

+

Hollands-Magee method

SS

TW

HY,WQ,HA

+

IBI

SS,LS

NT,TW,UP

5

 

Interim HGM

SS

NT,TW

HY,WQ,HA

+

IVA

SS

NT,TW

HY,WQ,HA

+

Larson method

SS

NT

HY,HA

+

MDE method

SS

NT

HA

+

ME Tidal method

SS,WS

TW

HA

+

MNRAM

SS

NT

HY,WQ,HA

+

MT form

SS

NT

HY,WQ,HA

+

NBM

SS,WS

TW

HY,WQ,HA

 

NC-CREWS

LS

NT,TW

HY,WQ,HA

 

NC guidance

SS

NT

HY,WQ,HA

+

NEFWIBP

SS

NT

WQ(?),HA

+

NH method

SS

NT

HY,WQ,HA

+

NJ watershed method

LS

NT

HY,WQ,HA

 

OFWAM

SS

NT

HY,WQ,HA

+

PAM HEP

SS

NT,TW,UP

HA

 

PFC

SS

NT,TW,UP

HY,WQ,HA

 

RA

SS

NT,TW

HY,WQ,HA

+

Rapid Assessment Procedure

WS

NT

HY,WQ,HA

+

Synoptic Approach

LS

NT,TW,UP

HY,WQ,HA

+

VIMS Method

SS

NT

HY,WQ,HA

+

WAFAM

SS

NT,TW

HY,WQ,HA

 

WCHE

SS,LS

NT

HA

 

WET

SS

NT,TW

HY,WQ,HA

+

WEThings

SS

NT,TW

HA

 

WHAMS

SS

NT,TW,UP

HA

 

WHAP

SS

NT,TW,UP

HA

 

WI RAM

SS

NT

HY,WQ,HA

+

WQI

SS

NT

HY,WQ,HA

 

WRAP

SS

NT,TW

HY,WQ,HA

 

WVA

SS

NT,TW

HA

 

1 AREM = Avian Richness Evaluation Method (Adamus 1994); Coastal Method (Cook et al. 1993); CT Method = Connecticut Method (Ammann et al. 1996); Descriptive Method = Wetland Functions and Values: A Descriptive Method (USACE 1995); EPW = Evaluation for Planned Wetlands (Bartoldus et al. 1994); HAT = Habitat Assessment Technique (Cable

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Weighting Applied

Scaled by Area

Functional Categories Assessed6

Method Description7

Factor Measured8

Number States Where Used9

+

+

AV,HS,SC

M

I

3

   

F

M

Q

3

 

+

FV

M

Q

3

+

 

F,V

L

Q

5

 

+

F

M

E

5

 

+

HQ

M

BS

3

 

+

HS

M

V

50

 

+

F

M

V

6

   

F

M

E

8

   

BC

M

M

5

 

+

F

M

V

9

+

+

F,V

M

 

2

+

+

RF

C

C,V

11

+

+

F

M

I

1

+(?)

 

EI,F,V

M

Q

1

   

F

L

Q

1

+

+

F,V

M

FM

1

 

EH,TR

L

Q

4

   

SF,F,ES

M

V

1

+

 

F,V

FC

F

2

   

BI

M

I,M

6

 

+

FV

M

Q

7

+

 

EI,PI

M

I

1

+(?)

 

F

AC

Q

2

+

+

HS

M

V

3

   

PFC

CL

E

15

   

F,V

BPJ

 

10

 

+

F

M

V

15

+

+

F,V,FL,RP

M

I

15

   

F

L

F

2

 

+

F

M

V

1

 

+

PS,TS,NR

M

V

1

+

 

F,V

L

Q

50

   

HP

M

Q

7

 

+

HS

M

V

1

+

+

HQ

FC

E

1

   

FV

L

Q

5(?)

+

 

WQ

EM

V

1

 

F

RI

V

1

   

HS

M

V

1

et al. 1989); HEP = Habitat Evaluation Procedure (USFWS 1980); HGM Approach = Hydrogeomorphic Approach (Smith et al. 1995); Hollands-Magee Method = A Method for Assessing the Functions of Wetlands (Hollands and Magee 1985); IBI = Index of Biological Integrity (Karr 1981); Interim HGM (NRCS 1997); IVA = Indicator Value Assessment (Hruby

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

et al. 1995); Larson Method = Methods for Assessment of Freshwater Wetlands (Golet 1976); MDE Method = Method for the Assessment of Wetland Function (Fugro East, Inc. 1995); ME Tidal Method = Maine Citizens Tidal Marsh Guide (Bryan et al. 1997); MNRAM = Minnesota Routine Assessment Method (MBWSR 1998); MT Form = Montana Wetland Field Evaluation Form (Berglund 1996); NBM = Narragansett Bay Method (Lipsky 1996); NC-CREWS = North Carolina Coastal Regional Evaluation of Wetland Significance (Sutter and Wuenscher 1996); NC Guidance = Guidance for Rating the Values of Wetlands in North Carolina (NCDENR 1995); NEFWIBP = New England Freshwater Wetlands Invertebrate Biomonitoring Protocol (Hicks 1997); NH Method = New Hampshire Method (Ammann and Stone 1991); NJ Watershed Method = Watershed-Based Wetland Assessment Methodology (Zampella et al. 1994); OFWAM = Oregon Freshwater Wetland Assessment Methodology (Roth et al. 1996); PAM HEP = Pennsylvania Modified 1980 Habitat Evaluation Procedure (Palmer et al. 1985); PFC = Process for Assessing Proper Functioning Condition (Pritchard et al. 1993); RA = Wetland Assessment: A Regulatory Assessment Method (Kusler 1997); Rapid Assessment Procedure = Rapid Assessment Procedure for Assessing Wetland Functional Capacity (Magee 1998); Synoptic Approach = Synoptic Approach for Wetlands Cumulative Effects Analysis (Leibowitz et al. 1992); VIMS Method = Technique for the Functional Assessment of Virginia Coastal Plain Nontidal Wetlands (Bradshaw 1991); WAFAM = Washington State Wetland Functional Assessment Method (Hruby et al. 1998); WCHE = Wildlife Community Habitat Evaluation (Schroeder 1996); WET = Wetland Evaluation Technique (Adamus et al. 1987); WEThings (Whitlock et al. 1994); WHAMS = Wildlife Habitat Assessment and Management System (Palmer et al. 1993); WHAP = Wildlife Habitat Appraisal Procedure (Frye 1995); WI RAM = Wisconsin Rapid Assessment Methodology (WDNR 1992); WQI = Wetland Quality Index (Lodge et al. 1995); WRAP = Wetland Rapid Assessment Procedure (Miller and Gunsalus 1997); WVA = Wetland Value Assessment Methodology (LDNR 1994).

2 SS = site specific, which assesses functions at all parts of wetlands; WS = wetland system, designed to look at entire wetland system as compared to site-specific projects; LS = landscape, wherein functions of wetlands are assessed within the mosaic of wetlands and uplands at the landscape scale.

3 NT = nontidal wetlands, TW = tidal wetlands, UP = uplands.

4 HY = hydrological, WQ = water quality, HA = habitat, O = other.

5 IBI measures biological condition using samples of living organisms. Biological condition is expressed as the divergence from biological integrity. Most other procedures use measures of habitat structure to assess habitat suitability (Bartoldus 1999).

6 AR = avian richness, BC = biological condition, BI = biological integrity, EH = ecological health, EI = ecological integrity, ES = ecological significances, F = function(s), FL = functional loss, FV = functional value, HP = habitat potential, HQ = habitat quality, HS = habitat suitability, NR = native richness, PI = potential impact, PFC = proper functioning condition, PS = plot suitability, RF = resource factor (function), RP = replacement potential, SC = species composition, SF = subfunction, TR = tidal restrictions, TS = tract suitability, V = value, WQ = wetland quality.

7 AC = assessment criteria, BPJ = best professional judgment, C = classification, CL = checklist, EM = evaluation matrix, FC = flow chart or evaluation key, L = list of considerations or questions, M = assessment, functional or habitat relationship model, RI = rating index.

8 BS = bird species, C = assessment criteria, E = element or component, F = factor, FM = field measurement, I = indicator, M = metric, Q = evaluation question or considerations, V = variable or parameter.

9 Including adapted or considered applicable.

10 RA has not been used in any state but reflects the overall approach applied in many.

SOURCE: Adapted Bartoldus (1999).

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
References

Adamus, P.R. 1994. User's Manual Avian Richness Evaluation Method (AREM) for Lowland Wetlands of the Colorado Plateau. EPA/600/R93/240. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR.

Adamus, P.R., E.J.Clairain, R.D.Smith, and R.E.Young. 1987. Wetland Evaluation Technique (WET), Vol. II: Methodology. NTIS ADA 189968. Vicksburg, MS: Department of the Army, Waterways Experiment Station.

Ammann, A.P., and A.L.Stone. 1991. Method for the Comparative Evaluation of Nontidal Wetlands in New Hampshire. NHDES-WRD-1991-3. Concord, NH: New Hampshire Department of Environmental Services.

Ammann, A.P., R.W.Frazen, and J.L.Johnson. 1996. Method for the Evaluation of Inland Wetlands in Connecticut. DEP Bulletin 9. Connecticut Department of Environmental Protection, Hartford, CT.

Bartoldus, C.C. 1999. A Comprehensive Review of Wetland Assessment Procedures: A Guide for Wetland Practitioners. St. Michaels, MD: Environmental Concern, Inc. 196 pp.

Bartoldus, C.C., E.W.Garbisch, and M.L.Kraus. 1994. Evaluation for Planned Wetlands (EPW): A Procedure for Assessing Wetland Functions and a Guide to Functional Design. St. Michaels, MD: Environmental Concern, Inc.

Berglund, J. 1996. MDT Montana Wetland Field Evaluation Form and Instructions. Prepared for the Montana Department of Transportation, Helena. (July 1, 1996; Appendix A revised 9/23/1997). 19 pp+ appen.

Bradshaw, J.G. 1991. A Technique for the Functional Assessment of Nontidal Wetlands in the Coastal Plain of Virginia. Special Report 315 in Applied Marine Science Ocean Engineering. Gloucester Point, VA: Virginia Institute Marine Science, College of William and Mary.

Bryan, R.R., M.Dionne, R.Cook, J.Jones, and A.Goodspeed. 1997. Maine Citizens Guide to Evaluating, Restoring, and Managing Tidal Marshes. Brunswick, ME: Maine Audubon Society.

Cable, T.T., B.Brack, Jr., and V.R.Holmes. 1989. Simplified method for wetland habitat assessment. Environ. Manage. 13(2):207–213.

Cook, R.A., A.J.L.Stone, and A.P.Ammann. 1993. Method for the Evaluation and Inventory of Vegetated Tidal Marshes in New Hampshire: (Coastal Method). Concord, NH: Audubon Society of New Hampshire.

Frye, R.G. 1995. Wildlife Habitat Appraisal Procedure (WHAP). PWD RP N710-145 (2/95) Texas Parks and Wildlife Department, Austin, TX. [Online]. Available: http://www.tpwd.state.tx.us/conserve/whap/body.html [May 20, 2001].

Fugro East, Inc. 1995. A Method for the Assessment of Wetland Function. Prepared for Maryland Department of the Environment, Baltimore, by Fugro East, Inc., Northborough, MA.

Golet, F.C. 1976. Wildlife wetland evaluation model. Pp. 13–34 in Models for Assessment of Freshwater Wetland, J.S.Larson, ed. Pub. 32. Water Resource Research Center, University of Massachusetts, Amherst.

Hicks, A.L. 1997. New England Freshwater Wetlands Invertebrate Biomonitoring Protocol (NEFWIBP). The Environmental Institute, University of Massachusetts at Amherst.

Hollands, G.G., and D.W.Magee. 1985. A method for assessing the functions of wetlands. Pp. 108–118 in Proceedings of the National Wetland Assessment Symposium, J.Kusler and P.Riexinger, eds. Association of Wetlands Managers, Berne, N.Y.

Hruby, T., W.E.Cesanek, and K.E.Miller. 1995. Estimating relative wetland values for regional planning. Wetlands 15(2):93–107.

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Hruby, T., T.Granger, K.Brunner, S.Cooke, K.Dublanica, R.Gersib, L.Reinelt, K.Richter, D.Sheldon, A.Wald, and F.Weinmann. 1998. Methods for Assessing Wetland Functions. Vol. I. Riverine and Depressional Wetlands in the Lowlands of Western Washington. Washington State Department of Ecology Pub. 98–106. Olympia, WA: Department of Ecology.

Karr, J.R. 1981. Assessment of biotic integrity using fish communities. Fisheries 6(6):21–27.

Kusler, J. 1997. Wetland Assessment: A Regulatory Assessment (RA). Association of State Wetland Managers, Institute of Wetland Science and Public Policy, Berne, NY.

LDNR (Louisiana Department of Natural Resources). 1994. Habitat Assessment Models for Fresh Swamp and Bottomland Hardwoods within the Louisiana Coastal Zone. Louisiana Department of Natural Resources, Baton Rouge, LA.

Leibowitz, S.G., B.Abbruzzese, P.R.Adamus, L.E.Hughes, and J.T.Irish. 1992. A Synoptic Approach to Cumulative Impact Assessment: A Proposed Methodology EPA/600/R-92/167. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR.

Lipsky, A. 1996. Narragansett Bay Method: A Manual for Salt Marsh Evaluation. Save the Bay, Providence, RI.

Lodge, T.E., H.O.Hillestad, S.W.Carney, and R.B.Darling. 1995. Wetland Quality Index (WQI): A Method for Determining Compensatory Mitigation Requirements for Ecologically Impacted Wetlands. Proceedings of American Society of Civil Engineers South Florida Section Annual Meeting, Sept. 22–23, 1995, Miami, FL.

Magee, D.W. 1998. A Rapid Procedure for Assessing Wetland Functional Capacity based on Hydrogeomorphic (HGM) Classification. Berne, NY: Association of State Wetland Managers.

Miller, R.E., and B.E.Gunsalus. 1997. Wetland Rapid Assessment Procedure (WRAP). Tech. Pub. REG-001. West Palm Beach, FL: South Florida Water Management District, National Resource Management Division.

MBWSR (Minnesota Board of Water and Soil Resources). 1998. Minnesota Routine Assessment Method for Evaluating Wetland Functions (MinRAM). Draft Version 2.0. Minnesota Board of Water and Soil Resources, St. Paul, MN.

NCDENR (North Carolina Department of Environment and Natural Resources) 1995. Guidance for Rating the Values of Wetlands in North Carolina. North Carolina Department of Environment and Natural Resources, Raleigh, NC.

NRCS (Natural Resource Conservation Service). 1997. Interim Guidance for Making Wetland Minimal Effect/Mitigation Decisions for USDA Programs in Alaska. August 1997. [Online]. Available: http://159.189.24.10/wlistates/alaska.htm. [May 10, 2001].

Palmer, J.H., M.T.Chezik, R.D.Heaslip, G.A.Rogalsky, D.J.Putman, R.W.McCoy, and J.A. Arway. 1985. Pennsylvania Modified 1980 Habitat Evaluation Procedure Instruction Manual. U.S. Fish and Wildlife Service, State College, PA.

Palmer, J.H., R.H.Muir, and T.M.Sabolcik. 1993. Wildlife Habitat Assessment and Management System: Habitat Evaluation Procedure Technology for Wildlife Management Planning. Pennsylvania Game Commission, Bureau of Land Management, Harrisburg, PA.

Pritchard, D., H.Barrett, J.Cagney, R.Clark, J.Fogg, K.Gebhart, P.L.Hansen, B.Mitchell, and D.Tippy. 1993. Riparian Area Management: Process for Assessing Proper Functioning Condition. TR 1737-9. BLM/SC/ST-93/003+1737+REV95+REV98, U.S. Dept. of Interior, Bureau of Land Management, Service Center, CO.

Roth, E., R.Olson, P.Snow, and R.Sumner. 1996. Oregon Freshwater Wetland Assessment Methodology, 2nd Ed., Oregon Division of State Lands, Salem, OR.

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Schroeder, R.L. 1996. Wildlife Community Habitat Evaluation: A Model for Deciduous Palustrine Forested Wetlands in Maryland. Tech. Report WRP-DE-14. Vicksburg, MS: U.S. Army Engineers Waterways Experiment Station.

Smith, R.D., A.Ammann, C.Bartoldus, and M.M.Brinson. 1995. An Approach for Assessing Wetland Functions Using Hydrogeomorphic Classification, Reference Wetlands, and Functional Indices. Tech. Report WRP-DE-9. Vicksburg, MS: U.S. Army Engineers Waterways Experiment Station.

Sutter, L.A., and J.R.Wuenscher. 1996. NC-CREWS: A Wetland Functional Assessment Procedure for the North Carolina Coastal Area. Draft. Division of Coastal Management, North Carolina Department of Environment and Natural Resources, Raleigh, NC. 61 pp + appen.

USACE (U.S. Army Corps of Engineers). 1995. The Highway Methodology Workbook Supplement. Wetland Functions and Values: A Descriptive Approach. NENEP-360-1-30a. Waltham, MS: U.S. Army Corps of Engineers, New England Division.

USFWS (U.S. Fish and Wildlife Service). 1980. Habitat Evaluation Procedure (HEP) Manual (102ESM). Fort Collins, CO: U.S. Fish and Wildlife Service.

WDNR (Wisconsin Department of Natural Resources). 1992. Rapid Assessment Methodology for Evaluating Wetland Functional Values Wisconsin Department of Natural Resources.

Whitlock, A.L., N.M.Jarman, and J.S.Larson. 1994. WEThings: Wetland Habitat Indicators for Non-game Species. Vol. II. TEI Pub. 94–2. Amherst, MA: The Environmental Institute, University of Massachusetts.

Zampella, R.A., R.G.Lathrop, J.A.Bognar, L.J.Craig, and K.J.Laidig. 1994. A. Watershed-based Wetland Assessment Method for the New Jersey Pinelands Pinelands Commission, New Lisbon, NJ.

Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 285
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 286
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 287
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 288
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 289
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 290
Suggested Citation:"Appendix H Selected Attributes of 40 Common Wetland Functional Assessment Procedures." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 291
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Recognizing the importance of wetland protection, the Bush administration in 1988 endorsed the goal of “no net loss” of wetlands. Specifically, it directed that filling of wetlands should be avoided, and minimized when it cannot be avoided. When filling is permitted, compensatory mitigation must be undertaken; that is, wetlands must be restored, created, enhanced, and, in exceptional cases, preserved, to replace the permitted loss of wetland area and function, such as water quality improvement within the watershed.

After more than a dozen years, the national commitment to “no net loss” of wetlands has been evaluated. This new book explores the adequacy of science and technology for replacing wetland function and the effectiveness of the federal program of compensatory mitigation in accomplishing the nation’s goal of clean water. It examines the regulatory framework for permitting wetland filling and requiring mitigation, compares the mitigation institutions that are in use, and addresses the problems that agencies face in ensuring sustainability of mitigated wetlands over the long term.

Gleaning lessons from the mixed results of mitigation efforts to date, the book offers 10 practical guidelines for establishing and monitoring mitigated wetlands. It also recommends that federal, state, and local agencies undertake specific institutional reforms. This book will be important to anyone seeking a comprehensive understanding of the “no net loss” issue: policy makers, regulators, environmental scientists, educators, and wetland advocates.

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