Asili Stream AMERICAN SAMOA WETLAND/STREAM RESTORATION AND ENHANCEMENT PLAN Vatia Wetland AMERICAN SAMOA WETLAND/STREAM RESTORATION AND ENHANCEMENT PLAN Prepared for: American Samoa Environmental Protection Agency and American Samoa Coastal Management Program Pago Pago, American Samoa 96799 Prepared by: Pedersen Planning Consultants P. O. Box 1075 Saratoga, Wyoming 82331-1075 Tel: (307) 327-5434 Fax: (307) 327-5210 E-mail: [email protected] February 2001 American Samoa Wetland/Stream Restoration and Enhancement Plan TABLE OF CONTENTS Chapter No. Title Page No. One INTRODUCTION 1-1 Purpose 1-1 Scope 1-1 Organization of the Report 1-3 Plan Methodology 1-3 Public Consultation 1-6 Two TULA WETLAND 2-1 Location 2-1 Wetland Hydrology 2-1 Wetland Vegetation 2-5 Aquatic Fish and Invertebrates 2-6 Land Uses in the Vicinity of Tula Wetland 2-7 Wetland Restoration and Enhancement Strategies 2-7 Three ALAO WETLAND 3-1 Location 3-1 Wetland Hydrology 3-1 Wetland Vegetation 3-4 Aquatic Fish and Invertebrates 3-7 Land Uses in the Vicinity of Taufusi Marsh 3-8 Wetland Restoration and Enhancement Strategies 3-9 Four AOA WETLAND 4-1 Location 4-1 Wetland Hydrology 4-1 Wetland Vegetation 4-5 Aquatic Fish and Invertebrates 4-8 Land Uses in the Vicinity of Aoa Wetland 4-9 Wetland Restoration and Enhancement Strategies 4-10 Five VATIA WETLAND 5-1 Location 5-1 Wetland Hydrology 5-1 Wetland Vegetation 5-5 Aquatic Fish and Invertebrates 5-7 Land Uses within Southeast Wetland and Faatafe Stream 5-9 Wetland Restoration and Enhancement Strategies 5-9 Six VAIPITO STREAM 6-1 Location 6-1 Stream Hydrology 6-1 Vegetation 6-5 Aquatic Fish and Invertebrates 6-7 Land Uses Adjacent to Vaipito Stream 6-10 Riparian Restoration and Enhancement Strategies 6-10 - i - American Samoa Wetland/Stream Restoration and Enhancement Plan TABLE OF CONTENTS (continued) Chapter Title Page No. No. Seven PAPA STREAM 7-1 Location 7-1 Stream Hydrology 7-1 Vegetation 7-7 Aquatic Fish and Invertebrates 7-8 Land Uses Adjacent to Papa Stream 7-9 Riparian Restoration and Enhancement Opportunities 7-9 Eight SAUINO STREAM 8-1 Location 8-1 Stream Hydrology 8-1 Vegetation 8-5 Aquatic Fish and Invertebrates 8-6 Land Uses Adjacent to Lower Sauino Stream 8-7 Riparian Restoration and Enhancement Opportunities 8-7 Nine LEAFU STREAM 9-1 Location 9-1 Stream Hydrology 9-1 Vegetation 9-5 Aquatic Fish and Invertebrates 9-7 Land Uses Adjacent to Vaipito Stream 9-9 Riparian Restoration and Enhancement Opportunities 9-9 Ten ASILI STREAM 10-1 Location 10-1 Stream Hydrology 10-1 Vegetation 10-6 Aquatic Fish and Invertebrates 10-7 Land Uses Adjacent to Asili Stream 10-9 Riparian Restoration and Enhancement Opportunities 10-10 Eleven FUSI WETLAND 11-1 Location 11-1 Wetland Hydrology 11-1 Wetland Vegetation 11-4 Aquatic Fish and Invertebrates 11-5 Land Uses in the Vicinity of Fusi Wetland 11-6 Wetland Restoration and Enhancement Strategies 11-7 Twelve FUTURE PROGRAM MANAGEMENT 12-1 Recommended Program Participants 12-1 Individual Project Assignments 12-1 Selected Agency Assignments 12-3 Potential Participation from Other Community Organizations 12-3 APPENDIX A – Summary of Plants, November 1999 APPENDIX B – Summary of Aquatic Macrofaunal Organisms, November 1999 APPENDIX C – Summary of Aquatic Macrofaunal Organisms, July 1981 REFERENCES - ii - American Samoa Wetland/Stream Restoration and Enhancement Plan LIST OF FIGURES Figure No. Title Page No. 1-1 Location Map 1-2 Potential Wetlands and Streams Enhancement Opportunities 2-1 Location Map, Tula Wetland 2-2 2-2 Existing Conditions, Tula Wetland 2-3 2-3 Option 2: Detention of Stormwater Within Tula Wetland 2-9 2-4 Option 3: Expansion of Taro Production Within Tula Wetland 2-11 2-5 Resource Monitoring Stations and Areas, Tula Wetland 2-20 3-1 Location Map, Alao Village Wetland 3-2 3-2 Existing Conditions, Taufusi Marsh 3-3 3-3 FEMA 100-Year Flood Plain, Alao Village 3-5 3-4 Option 2: Restore Taro Production 3-10 4-1 Location Map, Aoa Village Wetland 4-2 4-2 Existing Conditions, Aoa Wetland 4-3 4-3 Option 4: Clear Puna Stream Culvert, Plant Trees 4-12 4-4 Resource Monitoring Areas 4-18 5-1 Location Map, Southeast Wetland in Vatia 5-2 5-2 Existing Conditions, Vatia Wetland 5-3 5-3 Option 1:Restore Mangrove Forest Upstream of Faatafe Stream Mouth 5-10 6-1 Location Map, Vaipito Stream Drainage 6-2 6-2 Existing Conditions, Vaipito Stream 6-3 6-3 Fish and Invertebrate Survey Locations 6-8 6-4 Option 1:Restore Mangrove Forest Along Lower Vaipito Stream 6-11 7-1 Location Map, Leele-Papa-Tauese Stream Drainage 7-2 7-2 Existing Conditions, Papa Stream Segment 7-3 7-3 Option 2: Clean Stream, Improve Stream Hydrology, and 7-12 Reduce Bank Erosion 8-1 Location Map, Sauino Stream Drainage 8-2 8-2 Existing Conditions, Sauino Stream 8-3 8-3 Option 1: Construct Detention Pond 8-8 8-4 Option 2: Plant Native Riparian Trees Along Stream Bank 8-10 9-1 Location Map, Leafu Stream 9-2 9-2 Existing Conditions, Leafu Stream 9-3 9-3 Option 1: Restore Stream Bank in Vicinity of L2 9-10 9-4 Option 2: Construct Basaltic Wall, Stabilize Stream Bank, and Enhance 9-12 Riparian Vegetation 9-5 Option 3: Stabilize East Stream Bank and Enhance Riparian Vegetation 9-13 10-1 Location Map, Asili Stream 10-2 10-2 Existing Conditions, Asili Stream 10-3 10-3 Option 1: Clean Asili Stream and Enhance Riparian Vegetation 10-11 11-1 Location Map, Fusi Wetland 11-2 11-2 Existing Conditions, Fusi Wetland 11-3 11-3 Option 1: Remove Solid Waste Material and Plant Wetland Marsh 11-8 Vegetation - iii - American Samoa Wetland/Stream Restoration and Enhancement Plan LIST OF TABLES Table No. Title Page No. 2-1 Potential Stormwater Discharges into Tula Wetland 2-4 2, 10, 50 and 100-Year Storm Events 2-2 Comparative Evaluation 2-13 Wetland Restoration and Enhancement Opportunities Tula Wetland 2-3 Preliminary Cost Estimate 2-14 Development of Channel and Detention Pond Vailoa Stream Drainage and Tula Wetland 2-4 Preliminary Cost Estimate 2-15 Planting of Wetland and Fruit Trees Along Tula Wetland Margin 2-5 Long-term Resource Monitoring Requirements, Tula Wetland 2-17 2-6 Field Monitoring Worksheet, Tula Wetland 2-18,19 3-1 Potential Stormwater Discharges into Taufusi Marsh 3-4 From Mulivaitele Stream and Its Tributaries 2, 10, 50 and 100-Year Storm Events 3-2 Summary of Macrofaunal Organisms, Mulivaitele Stream 3-8 3-3 Relative Abundance and Diversity of Fish and Invertebrates 3-8 Mulivaitele Stream Segment on East Side of Taufusi Marsh 3-4 Comparative Evaluation 3-12 Wetland Restoration and Enhancement Opportunities Alao Wetland 3-5 Preliminary Cost Estimate 3-12 Procurement and Distribution of Taro Plant Cuttings Alao Village 3-6 Long-Term Resource Monitoring Requirements, Alao Wetland 3-14 3-7 Field Monitoring Worksheet, Alao Wetland 3-15,16 4-1 Median Stream Flow Estimate, Lepa Stream 4-1 4-2 Potential Stormwater Discharges into Aoa Wetland 4-4 From Tapua and Puna Streams 2, 10, 50 and 100-Year Storm Events 4-3 Summary of Macrofaunal Organisms 4-9 Alao Wetland and Lepa Stream 4-4 Relative Abundance and Diversity of Fish and Invertebrates 4-9 Tapua Stream and Lepa Stream 4-5 Comparative Evaluation 4-13 Wetland Restoration and Enhancement Opportunities Aoa Wetland 4-6 Preliminary Cost Estimate 4-14 Initial Clearing of Puna Stream Culvert 4-7 Preliminary Cost Estimate 4-14 Planting of Mangrove and Riparian Trees Upstream of Tapua and Puna Stream Mouths 4-8 Long-Term Resource Monitoring Requirements, Aoa Wetland 4-16 4-9 Field Monitoring Worksheet, Aoa Wetland 4-17 - iv - American Samoa Wetland/Stream Restoration and Enhancement Plan LIST OF TABLES (continued) Table No. Title Page No. 5-1 Potential Stormwater Discharges Along SE Side of Vatia Bay 5-4 2, 10, 50 and 100-Year Storm Events 5-2 Summary of Macrofaunal Organisms 5-8 Vatia Wetland 5-3 Relative Abundance and Diversity of Fish and Invertebrates 5-8 Faatafe Stream 5-4 Comparative Evaluation 5-12 Wetland Restoration and Enhancement Opportunities Vatia Wetland 5-5 Preliminary Cost Estimate 5-12 Clearing of Faatafe Stream Mouth, Culvert, and Upstream Area 5-6 Preliminary Cost Estimate 5-13 Planting of Mangrove and Riparian Trees Upstream of Faatafe Stream Mouth 5-7 Long-Term Resource Monitoring Requirements, Vatia Wetland 5-15 5-8 Field Monitoring Worksheet, Vatia Wetland 5-16,17 6-1 Median Stream Flow Estimates, Tributaries of Vaipito Stream 6-4 6-2 Stormwater Runoff Discharges into Inner Pago Pago Harbor 6-4 From Vaipito Stream Drainage 2, 10, 50 and 100 Year Storm Events 6-3 Estimated Vaipito Stream Capacities 6-5 6-4 Summary of Macrofaunal Organisms 6-9 Vaipito Stream Drainage 6-5 Relative Abundance and Diversity of Fish and Invertebrates 6-9 Vaipito Stream 6-6 Comparative Evaluation 6-13 Riparian Restoration and Enhancement Opportunities Lower Vaipito Stream 6-7 Preliminary Cost Estimate 6-14 Clearing of Lower Vaipito Stream Mouth and Upstream Area 6-8 Preliminary Cost Estimate 6-14 Planting of Trees Upstream of Vaipito Stream Mouth 6-9 Long-Term Resource Monitoring Requirements, Vaipito Stream 6-16 6-10 Field Monitoring Worksheet, Vaipito Stream 6-17,18,19 7-1 Median Stream Flow Estimate, Papa Stream 7-5 7-2 Stormwater Discharges from Papa Stream Into Pala Lagoon 7-6 2, 10, 50 and 100 Year Storm Events 7-3 Cross-Sectional Analysis 7-6 Along Papa Stream Segment 7-4 Summary of Macrofaunal Organisms 7-8 Papa Stream 7-5 Relative Abundance and Diversity of Fish and Invertebrates 7-9 Papa Stream - v - American Samoa Wetland/Stream Restoration and Enhancement Plan LIST OF TABLES (Continued) Table No.