Consultant Tour for Landsburg Debris Passage Project

Seattle Public Utilities (SPU) is hosting a consultant tour for the Landsburg Debris Passage Project on December 19th, 2024, from 10 AM to 1 PM, located at 28700 SE 252nd Place in Ravensdale, Washington, within King County. The three-hour tour will provide an opportunity for consultants to inspect the Landsburg Diversion Dam and Fish Passage Facility, as well as the Cedar River Hatchery. Participants will receive a comprehensive overview of the site's history, current functions, and details about the upcoming Landsburg Dam Debris Passage Project. The attached final report from URS and Herrera Environmental Consultants indicates the project's primary objective is to manage large woody debris accumulation and mitigate risks during high-flow events, particularly focusing on preventing potential dam blockage that could disrupt Seattle's water supply. The technical report evaluates six alternative approaches for managing debris, with estimated capital costs ranging from $720,000 to $3,220,000 and present value life cycle costs between $310,000 and $4,430,000.

No specific set-aside designations or restrictions on vendor participation were explicitly detailed in the provided documentation. The project appears to be open to qualified engineering and environmental consulting firms with expertise in dam safety, watershed management, and large woody debris mitigation strategies. The existing infrastructure involves the Landsburg Diversion Dam, which currently serves 1.3 million customers and provides approximately 60% of Seattle's water supply. The technical report projects that unstable large woody debris within the watershed is expected to increase over the next 100 years, potentially doubling in volume by 2105, which underscores the critical nature of this project. While precise budget allocations are not definitively stated, the cost analyses in the attached report suggest a potential project investment range between $720,000 and $3,220,000, depending on the selected debris management approach.