american samoa - University of Hawaii at Manoa Botany Department

Comparative Benefits and ImpactsPPC’s evaluation of the three alternate restoration and enhancement strategies is summarized inTable 10-6.TABLE 10-6COMPARATIVE EVALUATIONRIPARIAN RESTORATION AND ENHANCEMENT OPPORTUNITIESLOWER ASILI STREAMOptionProjectCostResidentialLand UsesSubsistenceAgricultureFish &InvertebrateHabitatWetland/RiparianVegetationStreamBankStabilityFloodHazards &PropertyDamage1 LC LB SB NBC SB MB NBC2 MC LB LB NBC NBC SB LBNotes: Potential project benefits were rated by PPC as follows:SB Significant project benefitsLC Limited undesirable consequencesMB Moderate project benefitsMC Moderate undesirable consequencesLB Limited project benefitsSC Significant undesirable project impactsNBC No anticipated project benefits orundesirable consequencesSource: Pedersen Planning Consultants, 2000Option 1 provides an initial cleanup of lower Asili Stream. The greater benefits associatedwith this option include the planting of ifi and falaga trees that will help stabilize stream banks,particularly in adjacent subsistence plantations. Greater stabilization of stream banks wouldhelp reduce bank erosion along lower Asili Stream. Project costs would be somewhat less thanthose required to implement Option 2.Option 2 would also address significant bank erosion and changes in stream hydrology in thevicinity of station 10+00. This project would provide needed stream stabilization along thewest bank of the stream and help restore the flow path of Asili Stream in this area. Oneresidence immediately downstream of this proposed improvement would benefit from potentialproperty damages that may occur if needed stream bank stabilization is not constructed.Recommended Option and Estimated Project CostThe cleaning of the 1,000-foot segment of Asili Stream and the planting of additional riparianvegetation (Option 1) is recommended for implementation. This wetland restoration project isrecommended because the project can enhance wetland vegetation and stabilize stream banksadjacent to smaller subsistence plantations.The costs associated with this project would primarily be associated with the initial clearing,removal and disposal of solid waste material from the lower reach of Asili Stream, as well asthe subsequent collection and planting of ifi and falaga tree cuttings by the ASCC Land GrantProgram.The estimated cost associated with the initial clearing of the 1,000-foot segment of lower AsiliStream is $3,126 (Table 10-7). The propagation and planting of 50 native riparian trees willcost an estimated $2,2 41 (Table 10-8). Consequently, the total estimated project cost would be$5,367.TABLE 10-7PRELIMINARY COST ESTIMATEAmerican Samoa Wetlands/Streams Restoration and Enhancement PlanFebruary 2001, Asili Stream, Page 10-12