EXH1127042630

m. REFINED IDENTIFICATION OF AFFECTED WETLANDS AND STREAMS ......... 14 I.WetlandIdentificationProcess..................................................................................................................14 2. Wetlands m the Study Area - Comparison of Original Identification of Affected Wetlands With Refined Identification of Affected Wetlands ............................................................................................. 15 3. Characterization of Wetlands ..................................................................................................................... 26 4. Location of Miller Creek ........................................................................................................................... 28 IV. REFINED WETLAND IMPACT ANALYSIS ................................. 30 1. Permanent Impacts ..................................................................................................................................... 32 2. Temporary Consu'uction Impacts .............................................................................................................. 38 3. Indirect Impacts ......................................................................................................................................... 42 4. Cumulative Impacts ................................................................................................................................... 44 5. Impact Avoidance and Mitigation ............................................................................................................. 44 V. HYDROLOGY AND SEISMIC STABILITY .................................................................. 47 1. Mechanically Stabilized Earth ................................................................................................................... 47 2. Fill Zones and Stability .............................................................................................................................. ,*7 3. Impact on Hydrology ................................................................................................................................. 49 4. Mitigation of Post-Construction Hydrogeologic Impacts .......................................................................... 51 VI. MITIGATION PROGRAM ................................................................................................... 53 1. On-Site (In-Basra) Mitigation .................................................................................................................... 53 2. Off-Site Avian Habitat Miugation ............................................................................................................. 59 VII. CONCLUSION ......................................................................................................................... 66 Draft - Seattle-Tacoma International Airport i 0S/19/_ Wetlands Re-evaluation Document 50111601.03 AR 042631 Seame-Taconwinterna_l _rlx_f WetlandsR_--E%_!:.'_ionDocument ChapterI INTRODUCTION AND SUMMARY This Wetlands Re-evaluation Document addresses new information on wetlands and other aquaticresources that would be affected by the planned new runwayand other improvements at Seattle-TacomaInternationalAirport. This informationwas not available during preparation of the 1996 Final Environmental Impact Statement for the Proposed Master Plan Update Development Actions (1996 FEIS) and the 1997 Final Supplemental Environmental lmpact Statementfor the Master Plan Update Development Actions (1997 FSEIS). This document was preparedby the Port of Startle (Port) to report the Port's assessment of the new information on affected wetlands and determination that the existing environmental analyses under…

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Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]