Characterization, Design, Construction, and Monitoring of

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Mitigation Wetlands

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stron

4183

ID

Interstate Technology and Regulatory Council

2005

rok

TABLE OF CONTENTS

ACKNOWLEDGEMENTS. i

EXECUTIVE SUMMARY . iii

1. INTRODUCTION .1

1.1 Historic Concerns with Mitigation Success2

1.2 Problem Statement2

1.3 Wetlands Overview.3

2. WETLAND MITIGATION OVERVIEW 11

2.1 National Mitigation Action Plan.12

2.2 When to Mitigate 13

2.3 Types of Mitigation 14

2.4 On-Site, Off-Site Mitigation and Credit .16

2.5 In Kind and Out of Kind .17

2.6 Buffers 17

2.7 Mitigation Banking.17

2.8 Mitigation Fund 17

3. PREDESIGN ASSESSMENT.18

3.1 Desktop Data Collection.18

3.2 Functional Evaluation of the Wetlands.19

3.3 Collection of Field Data in Support of Wetlands Characterization 22

4. MITIGATION DESIGN AND PLANNING.27

4.1 Mitigation Ratios for Design Purposes.28

4.2 General Design Sequencing29

4.3 Site Protection.42

4.4 As-Built Reports .42

5. CONSTRUCTION.42

5.1 Soil Erosion and Sediment Control 43

5.2 Preparation of the Appropriate Grade.44

5.3 Plants and Plant Installation45

5.4 Post-Construction .46

6. MONITORING.46

7. WETLAND CREATION IN LAND RECLAMATION.51

7.1 Mined Land.51

7.2 Oil and Gas Drilling Sites.53

7.3 Use of Dredged Material for Wetland Restoration.53

8. ISSUES .54

8.1 Oversight54

8.2 Regulatory55

8.3 Incidental Wetland55

8.4 Constructed Treatment Wetlands56

8.5 Mitigation Banking.56

8.6 Functional Equivalency 57

8.7 Replacement Ratios and No-Net-Loss57

8.8 In-Kind vs. Out-of-Kind .57

8.9 Off Site vs. On Site.58

9. STAKEHOLDER ISSUES58

9.1 Ecological Considerations Surrounding Wetland Mitigation.58

9.2 Mitigation Banking.59

9.3 Monitoring Duration.59

9.4 Wetland Buffers59

9.5 Small Wetland Exclusion59

9.6 Deed Restrictions and Conservation Easements.59

9.7 Performance Standards .60

9.8 Public Considerations and Public Involvement 60

10. BIBLIOGRAPHY.61

11. OTHER RESOURCES 65

APPENDICES

Appendix A. Acronyms

Appendix B. Glossary

Appendix C. Case Study Survey

Appendix D. Sample Conceptual Wetland Mitigation Plan: Restoration Site

Appendix E. Sample Detailed Wetland Mitigation Plan: Creation Site

Appendix F. National Mitigation Action Plan

Appendix G. U.S. Corps of Engineers Regulatory Guidance Letter No. 02-2

Appendix H. Response to Comments

Appendix I. ITRC Contacts, Fact Sheet, and Products List