TagDes Moines Creek Basin Plan(28)

This April 2023 presentation by Erin Nelson outlines options for the Des Moines Creek Basin Committee moving forward, focusing on decisions to be included in the next Interlocal Agreement (ILA). The meeting agenda covers a review of past studies and committee accomplishments, discussion of what has worked and what needs improvement, and selection of workable options for the basin's future management. The document includes maps and imagery related to infrastructure features such as the Northwest Ponds, Tyee Pond, sediment traps, and flow bypass pipes within the Des Moines Creek watershed.

This April 2023 presentation by Erin Nelson outlines options for the Des Moines Creek Basin Committee as it prepares to renew its Interlocal Agreement (ILA), a cooperative arrangement among local jurisdictions managing the creek basin near Des Moines, Washington. The meeting agenda covers a review of past studies and committee accomplishments, a discussion of what has worked and what needs improvement, and a decision on workable paths forward. While focused on stormwater and creek basin management rather than airport noise policy directly, the Des Moines Creek basin is located adjacent to Sea-Tac Airport and its management is relevant to the broader environmental context of the surrounding area.

A University of Washington case study examines whether the Des Moines Creek Regional Detention Facility (RDF), a 30+ acre stormwater management site near Sea-Tac Airport, can serve as a model for understanding how projected Pacific Northwest climate changes—wetter winters, drier summers, and stronger storms—may affect local wetland ecosystems. Researchers found potential hydrologic similarities between the RDF's altered water patterns and regional climate change projections, though no clear vegetation shifts were observed. The study recommends further hydrologic modeling and a comprehensive plant monitoring program to better assess long-term wetland impacts.

A Port of Seattle resolution authorizing the Chief Executive Officer to execute version two of an Interlocal Agreement with the Cities of Des Moines and SeaTac, Washington State Department of Transportation and King County to fund, construct, operate and maintain capital projects necessary to implement the Des Moines Creek Basin Plan. The projects include construction

This 2002 staff report from the City of SeaTac and City of Des Moines addresses an appeal by King County Water District #54 challenging an environmental (SEPA) determination related to the Des Moines Creek Basin Restoration Projects, a multi-agency effort to reduce stormwater damage and protect water quality near the Tyee Golf Course. The water district argued that the environmental review failed to adequately address potential impacts to the Highline aquifer, which serves as its sole water supply source. The hearing was scheduled before a Hearing Examiner on October 10, 2002.

These are the official draft meeting notes from October 13, 2000 negotiations between the Port of Seattle, the Washington Department of Ecology, and King County regarding the 401 Water Quality Permit for Sea-Tac Airport's proposed third runway. The meeting covered technical issues including stormwater management, natural resource mitigation planning, and a master list of permit issues tracked by resolution status. Representatives from multiple agencies worked to resolve outstanding questions about detention sizing, wetland hydrology, and environmental compliance requirements.

A water resources consultant submitted comments to the Washington State Department of Ecology in September 2000, raising serious concerns about the Port of Seattle's proposed Des Moines Creek Flow Augmentation Facility, which was intended to mitigate water quality impacts from SeaTac Airport's third runway expansion. The consultant argues the plan is vague and incomplete, lacking secured water sources, hydrologic analysis, and finalized design details. Key technical problems identified include unreliable water temperature from one proposed source, dependence on continuous technological systems, and a disputed well design that may violate state groundwater protection guidelines.

In August 2000, the Port of Seattle submitted a revised implementation plan to the Washington Department of Ecology for a flow augmentation facility on Des Moines Creek, near Seattle-Tacoma International Airport. The plan outlines two potential water sources — a Port-owned well used to irrigate the Tyce Valley Golf Course, or water purchased from Seattle Public Utilities — along with details on pipeline construction, dechlorination treatment options, and pump configurations. Construction of the facility was scheduled to begin in June 2002, with the well preferred as the lower-cost option pending resolution of water rights issues.