Cedar River Landsburg Mitigation Hatchery
Operated jointly by Seattle Public Utilities and the Muckleshoot Indian Tribe to mitigate the impact of Landsburg Diversion Dam, the hatchery produces sockeye and Chinook supplementation stock for the Cedar River — supporting one of the largest remaining Lake Washington sockeye runs.
Project Overview
The Cedar River has been substantially altered since Seattle began using it as a municipal water source in the early 1900s. Landsburg Dam, constructed in 1901, blocks salmon passage to approximately 90% of the Cedar River's historic spawning habitat. A diversion structure at Landsburg routes water into the Cedar River watershed but limits the flow available to salmon below the dam.
In 1984, Seattle Public Utilities (SPU) established the Landsburg Mitigation Hatchery under a formal agreement with the Muckleshoot Indian Tribe to offset these permanent habitat losses. The hatchery incubates sockeye eggs from adult broodstock collected at a weir, rearing juveniles through their first year before releasing them as smolts into the lower Cedar River. A smaller Chinook supplementation program targets the winter Chinook run, which spawns in the main stem Cedar below Landsburg.
The hatchery's sockeye production has contributed to a Lake Washington sockeye run that regularly exceeds 500,000 fish in strong years — one of the largest sockeye runs remaining in the contiguous United States. SPU and the Muckleshoot Tribe continue to jointly manage the hatchery and negotiate the annual broodstock collection and release targets under their operating agreement.
Project Details
1984
Year Started
City of Seattle, Muckleshoot Indian Tribe
Partner Organizations
active
Project Status
Watershed Data
This project operates in the Lake Washington/Cedar/Sammamish watershed (Central Sound). View current salmon health indicators and environmental conditions.