T.F. Green Airport Improvement Program - FEIS Chapters - PVD

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationTable 6-10Alternative B4: Wetland Functions and Values Impacted (acres)ProgramElementGWR/D­SWGWFFAS/T/P R­WQNR/R/T­WQ PE S&S S F&SHRunway 34 2.2 2.9 2.9 2.9 2.9X.XX.XGWR/DSWGWFFAS/T/P RNR/R/TWQPEPrinci pal Wetland Functi on or Value.Additi onal Wetland Function or Value likely provided by wetl and.Groundwater Recharge/Di scharge.Surface Water and Groundwater.Floodflow Alterati on.Sediment/Toxicant/Pathogen Retenti on.Nutrient Removal/Retention/Transformati on.Water Quali ty.Production Export.S&S SF&SHWLHWWHT&E SHRECED/SVU/HAESVQ/AWLH­WWHT&ESHRECSediment and Shoreline Stabilizati on.Fish and Shellfi sh Habitat.Wildlife Habitat.Wildlife and Wildlife Habitat.Threatened and Endangered Speci es Habitat.Recreati on.Educational/Scientifi c Value.Uniqueness/Heri tage.Aesthetic. Visual Quality/Aestheti cs.U/H­AESVQ/A-AESThe USACE New England District provides guidance for recommended minimum compensatory mitigationratios based on the wetland cover types impacted (e.g., emergent wetland 2:1, forested wetland 3:1, etc.). 484 ThePreferred Alternative would fill 5.0 acres of federally regulated wetland with a recommended minimumequivalent of 10.2 acres of mitigation based on the USACE New England District guidance.Some activities such as the replacement of a culvert under Lakeshore Drive to improve anadromous fishpassage and correct flooding problems and the removal of the security fence Airport property along BuckeyeBrook and Wetland A5 to restore wetland wildlife habitat continuity are difficult to evaluate in terms of amitigation acre equivalent. According to the Final Rule: “The district engineer must determine the compensatorymitigation to be required in a Department of the Army permit, based on what is practicable and capable of compensating forthe aquatic resource functions that will be lost as a result of the permitted activity.” 485 The compensatory mitigationprovided in this program achieves this goal of compensating for aquatic functions lost due to the project.Based on Table 6-11, the mitigation program will provide compensatory wetland areas (creation andrestoration) which provide 4.3 acres flood storage as a principal function and 3.0 acres of wetland with waterquality as a principal function. Some of the potential mitigation sites will be incorporated into a program tomitigate for aquatic resources functions that will be lost. Approximately 1.5 acres of wetland wildlife habitatwill be restored or enhanced. In addition, replacement of the culvert at Lakeshore Drive will enhance fishpassage along an anadromous fish run, facilitate wildlife passage, and correct a localized flooding problem thatleads to frequent road closures. Wetland wildlife habitat is proposed to be preserved in two off-site locationsthat are facing threats of encroachment by development. Table 6-11 provides a summary of potential wetlandmitigation sites in the program and the conceptual wetland mitigation estimated acreages for the PreferredAlternative. These are further described in the following section.484 USACE New England District July 20, 2010. New England District Compensatory Mitigation Guidance: Compensation for Impacted Aquatic HabitatResource Functions.485 Federal Register, 40CFR Part 230. Compensatory Mitigation for Losses of Aquatic Resources; Final Rule. April 2008.Chapter 6 – Mitigation 6-26 July 2011\\Mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH06_Mitigation_JUL_2011.doc