
COMMISSION AGENDA
Tay Yoshitani, Chief Executive Officer
February 1, 2011
Page 2 of 5
BACKGROUND:
The Port was issued two environmental permits which allowed for impacts associated with the
MPU Projects. The MPU Projects included the Third Runway that is in operation, as well as the
South Aviation Support Area which was never constructed. Soil borrow sites that would have
impacted wetlands were also not used by the MPU Projects. In order to compensate for planned
impacts, the permits required the Port to provide mitigation by enhancing existing and creating
new wetlands. This original mitigation package included approximately 15 acres of wetland and
wetland buffer site development on the Tyee Golf Course.
The Tyee Golf Course mitigation site was to be constructed in 2006 as part of the overall MPU
mitigation program under capital improvement project CIP # C100172. However, the Port
requested the Tyee site be eliminated from the MPU mitigation program on account of reduced
impacts. After extensive discussions, US Army Corps of Engineers (Corps) concluded that the
original planned MPU mitigation site functions were interdependent and the elimination of the
Tyee site could only be assessed after extensive study. In lieu of initiating a costly study which
contained a high degree of uncertainty in terms of methods and outcome, the Corps, Washington
Department of Ecology (Ecology), and Port Staff agreed that a reduced 10 acre wetland
development at the Tyee Golf Course would satisfy the MPU Projects’ mitigation requirements.
In consideration of this reduced mitigation project, Port staff evaluated the existing wildlife
hazard presented by the proposed mitigation site. This area had formerly been used by the Golf
Course operator. In September 2009, this area was excluded from the tenant’s lease due to
conflicts with the Des Moines Creek Basin Committee Regional Detention Facility Projects. The
unmaintained open grass area lies directly under aircraft flight path and is frequently used by
grazing geese and other water fowl. The conversion of this open grass area to a dense scrub-
shrub habitat was seen as a significant benefit to the Airport Operation’s Wildlife Hazard
Mitigation Program.
PROJECT JUSTIFICATION:
The completion of the Tyee Golf Course Mitigation will fulfill the outstanding Port wetland
mitigation permit obligations associated with the MPU Projects. In addition the project would
mitigate a significant wildlife attractant by converting an open grass area to a dense scrub-shrub
habitat.
PROJECT STATEMENT AND OBJECTIVES:
Project Statement:
The purpose of the project is to design and complete the Tyee Valley Golf Course Area
Mitigation which includes removing golf cart paths, removing abandoned culvert, soil
amendments as needed, new wetland planting over approximately 7 acres, updating
approximately 3 acres of existing wetlands to environmental permit standards, and installing a
temporary irrigation system, all as required by Natural Resource Mitigation Plan for the Master
Plan Update (MPU) and as required by the MPU 404 and 401 environmental permits and in
support of the Airport Operation’s Wildlife Hazard Mitigation Program.