RP04009646

5808 Lake Washington Blvd. N.E., Suite 200 Kirldand,Washington 98033-7350 December 2000 556-2912-001 (03) AR 009649 TABLE OF CONTENTS Page EXECUTIVE SUMMARY ................................................................................................................. xii 1. INTRODUCTION ................................................................................................................ 1-1 1.1 PURPOSE AND NEED FOR THE PROJECT....................................................... 1-2 1.2 PROJEGT LOCATION............................................................................................ 1-3 1.3 PROJECT DESCRIPTION...................................................................................... 1-6 1.3.1 Runways and Taxiways ............................................................................. 1-10 1.3.2 Runway Safety Area Extensions / South 154thStreetRelocation ............. 1-10 1.3.3 The South Aviation SupportArea (SASA) ............................................... 1-12 1.3.4 On-Site Borrow Source Areas.................................................................... 1-12 1.3.5 Other SupportFacilities ............................................................................. 1-14 1.4 RESPONSIBLE PARTIES. ................................................................................... 1-14 1.5 DOCUMENT ORGANIZATION ......................................................................... 1-14 2. EXISTING CONDITIONS IN THE PROJECT AREA ...................................................... 2-1 2.1 WETLANDS ............................................. ............................................................... 2-1 2.1.1 Wetland Delineation Methodology .............................................................. 2-1 2.1.2 Wetland Descriptions ................................................................................... 2-7 2.2 STREAMS ................................................................................................................ 2-7 2.2.1 Miller CreekBasin ....................................................................................... 2-7 2.2.2 Des Moines Creek Basin ............................................................................ 2-15 2.2.3 Gilliam Creek ............................................................................................. 2-16 3. NATURAL RESOURCE IMPACTS SUMMARY ............................................................. 3-1 3.1 WETLANDS ............................................................................................................ 3-1 3.2 STREAMS .............................................................................................................. 3-10 3.3 FLOODPLAINS ..................................................................................................... 3-10 3.4 DRAINAGE CHANNELS ..................................................................................... 3-10 3.5 WATER QUANTITY AND WATER QUALITY................................................ 3-13 4. MITIGATION, MONITORING, MAINTENANCE, AND CONTINCENCY OVERVIEW ........................................................................................... 4-I 4.1 MITIGATION .......................................................................................................... 4-I 4.1.1 On-Site In-Basin Mitigation ....................................................................... 4- I I 4.1.2 Off-Site Mitigation..................................................................................... 4-15 4.1.3 Replacement of Functions by the Mitigation Plan..................................... 4-16 4.2 MONITORING PLAN AND CONTINGENCY MEASURES ............................ 4-16 4.2.1 Monitoring Approach................................................................................. 4-16 4.2.2 Adaptive Management Approach .............................................................. 4-22 5. IN-BASIN MITIGATION PROJECTS ............................................................................... 5-1 5.1 VACCA FARM MITIGATION .............................................................................. 5-2 Natural Resource Mitigmfon Plan i AR 009650 D_,,._ 2o00 Seattle-Tacoma International Airport 556-2912-001 (03) Master Plan Update a:_ra_zgn_2fnotm,c,u_omtumc_,_ _2a... TABLE OF…

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PSCAA Advisory Council Meeting Agenda
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 [...]