TagKing County(412)

In August 2001, King County's Department of Natural Resources wrote to the Washington Department of Ecology confirming that the Port of Seattle's Comprehensive Stormwater Management Plan for Sea-Tac International Airport Master Plan improvements met the technical requirements of the 1998 King County Surface Water Design Manual. The review found that the plan demonstrated a feasible conceptual strategy for managing stormwater from proposed airport construction projects. Reviewers noted that while the plan showed compliance with design standards, additional oversight and monitoring would be needed as individual projects moved from planning into construction.

In August 2001, King County's Department of Natural Resources submitted a technical review letter to the Washington Department of Ecology evaluating the Port of Seattle's Low Flow Impact Analysis and proposed offset facilities for stormwater management near Sea-Tac Airport. The review found the proposal goes well beyond the basic requirements of the King County Surface Water Design Manual and represents substantial mitigation for low flow impacts in affected drainage basins, including Miller and Walker Creeks. Reviewers noted several inconsistencies and data gaps in the documentation and recommended that a final consolidated document be prepared incorporating all corrections and technical memoranda.

Letter dated August 3, 2001 from King County Department of Natural Resources Director Pam Bissonnette to Ann Kenny, Senior Permit Specialist, Washington Department of Ecology Northwest Regional Office, transmitting King County’s technical review comments on the Port Of Seattle’s Low Flow Impact Analysis – Low Flow Impact Offset Facility Proposal (July 2001). The enclosure provides

These draft meeting notes from a July 9, 2001 technical meeting cover low flow analysis related to the 401 Permit decision-making process for Sea-Tac International Airport's Third Runway project. Attendees from the Department of Ecology, King County, Port of Seattle, and several consulting firms discussed methods for determining low stream flow impacts and mitigation requirements across affected watersheds. Key topics included biological effects on fish habitat, a proposed 0.1 cfs mitigation flow for the Des Moines Watershed, and the use of 2-year 7-day low flow rates to guide mitigation planning.

Final draft meeting notes from July 5, 2001 technical meeting on 401 Permit Decision-Making for the Sea-Tac Airport Third Runway, prepared by Rachel McCrea of Floyd & Snider Inc. Attendees include Ann Kenny (Dept. of Ecology), Kelly Whiting (King County), Keith Smith (Port of Seattle), Felix Kristanovich (Foster Wheeler), Paul Fendt and Tom Atkins (Parametrix),

In a July 2, 2001 email chain, Kelly Whiting of Metro King County raises concerns about the analysis of 'non-hydrologic' effects related to water rights relinquishments and their impact on summer low flows in a Sammamish River watershed study. Whiting questions the assumptions made about non-respondents to a water withdrawal survey, arguing that the rates assigned to them appear disproportionately high compared to trends shown by actual survey respondents. The email requests a walkthrough during an upcoming Thursday meeting to clarify how these figures would be incorporated into a low-flow mitigation plan.

A July 2001 email from King County engineer Kelly Whiting summarizes ecological recommendations regarding proposed stream flow mitigation measures. A lead stream ecologist advised that mitigation plans be compared against existing stream hydrology to avoid abrupt changes that could disrupt biological processes, such as sudden summer flow increases confusing fish behavior. The ecologist also emphasized that water quality factors like temperature and dissolved oxygen are as important as flow rates, and suggested introducing reserved water gradually through ponds or wetlands rather than directly into streams.

Final draft meeting notes prepared by Rachel McCrea of Floyd & Snider Inc. for 401 Permit Decision-Making technical meetings on June 25 and June 27, 2001, regarding Sea-Tac International Airport Third Runway. Attendees included Ann Kenny and John Drabek (Dept. of Ecology), Kelly Whiting (King County), Keith Smith (Port of Seattle), Paul Fendt and Tom