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

Chapter: Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands

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Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Appendixes

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
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Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Appendix A

Survey of Studies: Comparison of Mitigation and Natural Wetlands

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

TABLE A–1 Survey of Studies: Comparison of Mitigation and Natural Wetlands

Region

Time Period

# Sites

Scope

Massachusetts

1983 to 1994

114

Vegetation (% cover) Size Hydrology If project was built

Portland, Oregon

1987 to 1993

95

Freshwater emergent and open-water wetlands, soil organic matter (SOM), hydrology

Orange County, California

1979 to 1993

70

Vegetation, hydrology

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Findings

Reference

79.9% mitigated for impacts <5000 ft2

54.4% noncompliant

Brown and Veneman (1998)

70.1% involved impacts to forested wetlands

61.4% designed to produce scrub/shrub

38.6% actually produced no wetlands

36.8% actually produced open wet meadows

 

Plant communities at replication sites differed significantly from wetlands they were designed to replace. Similarity did not increase between new and 12-year-old projects.

 

Compliance but not similarity between replicated and impacted plant communities increased with greater completeness of the replication plan and Order of Conditions.

 

Mean SOM concentrations were higher in naturally occurring wetlands (NOWs) than in mitigating wetlands.

Shaffer and Ernst (1999)

No significant change in SOM concentration in soils in mitigating wetlands (MWs) sampled.

 

For a subset of wetlands measured for hydrology, there was a significant negative relationship between SOM and the extent of inundation by standing water.

 

Success of mitigation, in terms of SOM, could be improved by better project design and better management of soils during project construction.

 

Thirty of the 70 (43%) met all of their permit conditions and were considered successful; these projects comprised 195 ac.

Sudol (1996)

Six sites (9%) comprising 52 ac did not meet any of their permit conditions and were considered failures.

 

Mitigation in Orange County has been unsuccessful. There has been a net loss of wetland and riparian habitat.

 
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Region

Time Period

# Sites

Scope

Portland, Oregon

1993

45 natural

51 mitigation 1–11 years; mean 5 years

Small (≤ 2 ha) Freshwater, palustrine wetlands in rapidly urbanizing area

Plant species richness (presence/absence) and composition of natural and mitigation wetlands

Relationships between floristic characteristics and variables describing land use, site conditions, and mitigation activities

Susquehannah River watershed, Pennsylvania

1993

20 reference; 44 created

Soil organic matter, matrix chroma, bulk density, total nitrogen, pH

Iowa, Minnesota, South Dakota

1989 to 1991

62

Restored prairie potholes

Basin morphometry, hydrology, and vegetation zone development

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Findings

Reference

Overall species richness was high (365 plant taxa), but >50% of species on both natural and mitigation wetlands were introduced.

Magee et al. (1999)

Wetlands surrounded by agricultural and commercial/ industrial/transportation corridor uses had more introduced species per site than those surrounded by undeveloped land.

 

Wetlands in the urbanizing study area are floristically degraded.

 

Current wetland management practices are replacing natural marsh and wet meadow systems with ponds, changing composition of plant species assemblages.

 

Compared to reference wetlands, wetland creation projects contained less SOM at 5 cm and unlike reference sites, SOM content was uniform between 5 and 20 cm. Created wetlands contained less silt at 5 cm and more sand and less clay at 20 cm. Wetland creation projects had higher pH, bulk density, and matrix chroma and lower total nitrogen.

Bishel-Machung et al. (1996)

No relationship was found between time elapsed since construction and soil organic matter content in wetland creation projects.

 

Earthen dams installed on 73% restoration sites.

Galatowitsch and van der Valk

About 60% of basins had predicted hydrology or held water longer than predicted.

(1996)

Twenty percent were hydrological failures and either never flooded or had significant structural problems.

 

Most had developed emergent and submersed aquatic vegetation zones, but only a few had developed wet prairie and sedge meadow vegetation zones.

 
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Region

Time Period

# Sites

Scope

Florida

1990

40 projects

Surface hydrology, vegetation

Central Florida

1993

10 natural, 10 created

Dipterans in freshwater herbaceous wetlands

Galveston Bay, Texas

Fall 1990, spring 1991

10 created, 5 natural

Densities of nekton and infauna in salt marshes

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Findings

Reference

Forty of 195 permitted projects had undertaken some type of mitigation activity. Only four of those 40 projects met all the stated permit goals. Twenty-four of the 40 projects contained success criteria, but for 23 (57.5%) of the projects the success criteria were inappropriate.

Erwin (1991)

Of the 1,058 acres required by permit to be created for all 40 projects, only 530.6 (50%) acres had actually been constructed.

 

Location and persistence were not in the criteria. Twenty-three (57.5%) of the 40 projects were located where surrounding existing or future land uses may prevent the wetlands from providing their intended functional values. Only three projects had a long-term management plan.

 

Twenty-five (62.5%) of the projects had hydrological problems.

 

32 (80%) projects were colonized by undesirable plant species. Permits for 22 projects required removal of problematic plants, but attempts to control them were undertaken in only 13 (59%) projects. Postconstruction monitoring was required for 39 projects, but adequate monitoring had been undertaken in only 15 (38%).

 

No convincing evidence of differences in natural and created wetland dipteran communities.

Streever et al. (1996)

Densities of daggerblade grass shrimp were not significantly different among marshes, but the size of these shrimp was significantly smaller than in natural marshes.

Minello and Webb (1997)

Densities of the marsh grass shrimp and of three commercially important crustaceans were significantly lower in created marshes than in natural marshes.

 

Fish densities in vegetation were significantly lower in created marshes than in natural marshes.

 

Natural and created marshes did not differ in species richness of nekton.

 

Marsh elevation and tidal flooding are key characteristics affecting use by nekton and should be considered in marsh construction projects.

 
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Region

Time Period

# Sites

Scope

Ohio

1994 to 1995

5 replacement

Hydrology, soils, vegetation, wildife, water quality

Texas

 

10

Invertebrates, fish

North Carolina

 

6

Sediment/soil, invertebrates

North Carolina

 

5

Sediment/soil

North Carolina

Marshes established 1971 to 1974 and monitored for 25 years

2 constructed marshes

2 natural marshes

Above-ground biomass, soil, benthic infauna, carbon, total nitrogen

South Carolina

 

2

Sediment/soil, plants, invertebrates, fish

Texas

 

3

Plants, invertebrates, fish

California

 

2

Sediment/soil, plants, fish, topography

North Carolina

 

Multiple

Plants, invertebrates

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

Findings

Reference

Eighty percent were in compliance with legal requirements and demonstrated medium-to-high ecosystem success

Wilson and Mitsch (1996)

 

Minello and Webb (1997)

 

Sacco et al. (1994)

 

Craft et al. (1988)

Constructed marshes: macrophyte community developed quickly and within 5 to 10 years, above-ground biomass and MOM were equivalent or exceeded corresponding values in the natural marshes.

Craft et al. (1999)

After 15–25 years, benthic infauna and species richness were greater in the natural marshes.

 

Soil bulk density decreased and organic carbon and total nitrogen increased over time in constructed marshes.

 

Nitrogen accumulation was much higher in constructed marshes than in natural marshes.

 

Different ecological attributes develop at different rates, with primary producers achieving equivalence during the first 5 years, followed by the benthic infauna community 5–10 years later.

 
 

LaSalle et al. (1991)

 

Minello and Zimmerman (1992)

 

Haltiner et al. (1997)

 

Seneca et al. (1976)

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×

REFERENCES

Bishel-Machung, L., R.P.Brooks, S.S.Yates, and K.L.Hoover. 1996. Soil properties of reference wetlands and wetland creation projects in Pennsylvania. Wetlands, 16(4):532–541.

Brown, S., and P.Veneman. 1998. Compensatory wetland mitigation in Massachusetts. Research Bulletin Number 746. Amherst, MA: Massachusetts Agriculture Experiment Station, University of Massachusetts

Craft, C, J.Reader, J.N.Sacco, and S.Broome. 1999. Twenty-five years of ecosystem development of constructed Spartina alterniflora (Loisel) marshes. Ecol. Applic. 9(4):1405– 1419.

Craft, C.B., S.W.Broome, and E.D.Seneca. 1988. Nitrogen, phosphorus and organic carbon pools in natural and transplanted marsh soils. Estuaries 11(4):272–289.

Erwin, K.L. 1991. An Evaluation of Wetland Mitigation in the South Florida. Water Management District, Vol. 1. Methodology. West Palm Beach, FL: South Florida Water Management District.

Galatowitsch, S.M., and A.G.van der Valk. 1996. Characteristics of Recently Restored Wetlands in the Prairie Pothole Region. Wetlands 16(1):75–83.

Haltiner, J., J.B.Zedler, K.E.Boyer, G.D.Williams, and J.C.Callaway. 1997. Influence of physical processes on the design, functioning and evolution of restored tidal wetlands in California (USA). Wetlands Ecol. Manage. 4(2):73–91.

LaSalle, W.M., M.C.Landin, and J.G.Sims. 1991. Evaluation of the flora and fauna of a Spartina alterniflora marsh established on dredged material in Winhay Bay, South Carolina. Wetlands 11(2):191–208.

Magee, T.K., T.L.Ernst, M.E.Kentula, M.E. and K.A.Dwire. 1999. Floristic comparison of freshwater wetlands in an urbanizing environment Wetlands 19(3):517–534.

Minello, T.J. and J.W.Webb, Jr. 1997. Use of natural and created Spartina alterniflora salt marshes by fishery species and other aquatic fauna in Gavelston Bay, Texas, USA. Mar. Ecol Prog. Ser. 151(1/3):165–179.

Minello, T.J., and R.J.Zimmerman. 1992. Utilization of natural and transplanted Texas salt marshes by fish and decapod crustaceans. Mar. Ecol. Prog. Ser. 90(3):273–285.

Sacco, J.N., E.D.Seneca, and T.R.Wentworth. 1994. Infaunal community development of artificially established salt marshes in North Carolina. Estuaries 17(2):489–500.

Seneca, E.D., L.M.Stroud, U.Blum, and G.R.Noggle. 1976. An Analysis of the Effects of the Brunswick Nuclear Power Plant on the Productivity of Spartina alterniflora (smooth cordgrass) in the Dutchman Creek, Oak Island, Snow's Marsh, and Walden Creek Marshes, Brunswick County, North Carolina, 1975–1976. 3rd Annual Report to Carolina Power and Light. Raleigh, NC: Carolina Power and Light Com.

Shaffer, P.W., and T.Ernst. 1999. Distribution of soil organic matter in freshwater emergent open water wetlands in the Portland, Oregon metropolitan area. Wetlands 19(3):505– 516.

Streever, W.J., K.M.Portier, and T.L.Crisman. 1996. A comparison of dipterans from ten created and ten natural wetlands Wetlands 16(4):416–428.

Sudol, M.F. 1996. Success of Riparian Mitigation as Compensation for Impacts Due to Permits Issued Through Section 404 of the Clean Water Act in Orange County, California. Ph.D. Dissertation. University of California, Los Angeles.

Wilson, R.F., and W.J.Mitsch. 1996. Functional assessment of five wetlands constructed to mitigate wetland losses in Ohio. Wetlands 16(4):436–451.

Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 187
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 188
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 189
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 190
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 191
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 192
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 193
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 194
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 195
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 196
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 197
Suggested Citation:"Appendix A Survey of Studies: Comparison of Mitigation and Natural Wetlands." National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. Washington, DC: The National Academies Press. doi: 10.17226/10134.
×
Page 198
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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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