Technical Report Merrimack River Watershed Wetland Restoration Strategy Prepared for NH Department of Environmental Services 29 Hazen Drive Concord, New Hampshire 03302 Prepared by /Vanasse Hangen Brustlin, Inc. Six Bedford Farms Drive, Suite 607 Bedford, New Hampshire 03110 In association with: Society for the Protection of NH Forests and naturesource communication March 2009 C:\Documents and Settings\pwalker\Desktop\WatershedReport_rev5.docx Acknowledgements Special thanks go to Lori Sommer of the NHDES Wetlands Bureau and Emily Brunkhurst of the NHF&G Nongame and Endangered Wildlife Program whose technical knowledge, collaborative spirit and patient leadership made this project successful. Dan Sundquist of the NH Society for the Protection of NH Forests shared his salient insights as a special technical advisor to the team, and Michele Tremblay of naturesource communication assisted with the public involvement process. The following individuals and organizations provided valuable guidance during the development of this project through their participation on the project Technical Advisory Group: Collis Adams, Department of Environmental Services, Wetlands Bureau Mary Ann Tilton, Department of Environmental Services, Wetlands Bureau Mike Stanley, Department of Environmental Services, Wetlands Bureau Paul Currier, Department of Environmental Services, Watershed Management Bureau Ted Walsh, Department of Environmental Services, Watershed Management Bureau Ken Edwardson, Department of Environmental Services, Watershed Management Bureau Steve Gaughan, Department of Environmental Services, Watershed Management Bureau Eric Williams, Department of Environmental Services, Watershed Management Bureau Rick Chormann, Department of Environmental Services, State Geologist’s Office George Hastings, Department of Environmental Services, Watershed Management Bureau Mike Marchand, Department of Fish and Game, Nongame and Endangered Wildlife Program Steve Couture, Department of Environmental Services, Rivers Management and Protection Program Steve Landry, Department of Environmental Services, Watershed Management Bureau Minda Shaheen, Southern NH Regional Planning Commission Don Kent, Department of Resources and Economic Development, Natural Heritage Bureau Tracey Boisvert, NH Office of Energy and Planning Funding for this project was provided by a Wetland Program Development Grant from the US Environmental Protection Agency, Region 1 to the NH Department of Environmental Services. C:\Documents and Settings\pwalker\Desktop\WatershedReport_rev5.docx Table of Contents 1. An Overview of Wetland Restoration 1.1 Introduction ......................................................................................................................... 1 1.2 Methods of Wetland Restoration ........................................................................................ 3 1.3 Implementing a Wetland Restoration Project ................................................................... 10 2. Development of a Wetland Restoration Assessment Model 2.1 Watershed Geodatabase .................................................................................................. 14 2.2 Site Identification Model .................................................................................................... 15 2.3 Site Prioritization Model .................................................................................................... 19 2.4 Model Evaluation .............................................................................................................. 24 3. Conceptual Restoration Plans 3.1 Selection of Example Sites for Field Review .................................................................... 28 3.2 Field Review Procedures .................................................................................................. 29 3.3 Conceptual Restoration Plan Elements ............................................................................ 29 3.4 Description of Example Restoration Sites ........................................................................ 30 3.5 Cost Estimates .................................................................................................................. 51 3.6 Net Functional Benefits ..................................................................................................... 52 4. Findings & Recommendations 4.1 Suggested Model Improvements ...................................................................................... 54 4.2 Recommendations to Communities .................................................................................. 56 5. Literature Cited ............................................................................................................... 59 6. Glossary ............................................................................................................................ 60 Appendices Appendix A - ARM Fund Documents Appendix B - Watershed Maps (Under Separate Cover) Appendix C - Functional Evaluation Detailed Methodology Appendix D - Model Output Appendix E - Conceptual Restoration Cost Estimates Appendix F – Functional Benefit Scores for Example Sites C:\Documents and Settings\pwalker\Desktop\WatershedReport_rev5.docx Table of Contents i Tables Table 2-1 Site ID Model Base Data ........................................................................ 16 Table 2-2 Site Identification Model Attributes ......................................................... 17 Table 3-2 Site Identification Results by Watershed Community ............................ 18 Table 2-4 Ecological Integrity (NH Method) ........................................................... 22 Table 2-5 Restoration Sustainability Scoring ......................................................... 23 Table 2-6 Landscape Position Scoring ................................................................... 23 Figures Figure 1-1 HUC-8 Watersheds Figure 2-1 Wetland Restoration Assessment Model - Site Prioritization Model Schematic Figure 2-2 Wetland Restoration Assessment Model - Functional Evaluation Components C:\Documents and Settings\pwalker\Desktop\WatershedReport_rev5.docx Table of Contents ii 1 An Overview of Wetland Restoration 1.1 Introduction Wetlands are widely known to be critical to protect water quality, to provide wildlife habitat, to mitigate floods, and to provide many other important natural functions. Although New Hampshire has been relatively successful in protecting wetland resources, many have been degraded by past and current land uses and more are impacted each year as the state grows. Restoration of these degraded areas holds great potential to help improve New Hampshire’s water quality, wildlife habitat and general quality of life. 1.1.1 The ARM Fund The recent development of the “Aquatic Resource Mitigation Fund” (ARM Fund) has provided a promising new source of grant money to help with wetland restoration efforts. These funds are available to New Hampshire cities and towns to implement programs to restore, protect or create aquatic habitats. The fund accepts payments (“in-lieu fees”) made by applicants for state wetland dredge and fill permits under RSA 482-A, who pay into the fund to help offset (“mitigate”) the impacts of their proposed projects. These funds are then pooled on a watershed basis and managed by the NH Department of Environmental Services (NHDES) and a Site Selection Committee made up of watershed stakeholders. The intent of the fund is to provide grants to environmental and community organizations to conduct worthwhile projects that will yield environmental benefits in the watershed.1 Figure 1-1 shows a map of the sixteen “HUC-8” watersheds in NH. The ARM Fund comprises 16 accounts which correspond to each one of the watersheds; the law requires that in-lieu fee payments made by a project within a particular watershed be 1 Appendix A contains the portion of RSA 482-A which references the establishment of the ARM Fund, as well as the Memorandum of Understanding between the NHDES and the US Army Corps of Engineers that allows use of “in-lieu fee” payments to be used for wetland mitigation. C:\Documents and Settings\pwalker\Desktop\WatershedReport_rev5.docx An Overview of Wetland Restoration 1 \\nh-bed\projects\51955.00\reports\Draft_Report\Figures\Fig_1-1.indd Source: NH Department of Environmental Services Figure 1-1 HUC-8 Watersheds Merrimack River Watershed Wetland Restoration Strategy spent within that same watershed [RSA 482-A:31,III(c)]. The Merrimack River Watershed contains the largest amount of funds collected to date (more than $650,000 through the end of January 2009), and it is also the first watershed for which ARM funds are available.2 1.1.2 Development of a Wetland Restoration Assessment Model (WRAM) Conservation organizations have developed a tremendous amount of information on ecologically important areas in New Hampshire over the years - with a focus on preservation. Additionally, excellent progress has been made in NH’s coastal region on restoring salt marsh habitat. But relatively little is known about potential wetland restoration sites in the Merrimack River Watershed and other watersheds in the state. To address the need, The NHDES, working with its partners at the NH Fish and Game Department, the US Environmental Protection Agency and other state and federal partners, have commissioned this study of the Merrimack River Watershed. A thorough and systematic study of wetland restoration opportunities in the basin will