Lake Washington Ship Canal
Canal linking Lake Washington to Puget Sound via Seattle.
The Lake Washington Ship Canal is a canal that runs through the city of Seattle, linking the fresh water body of Lake Washington with the salt water inland sea of Puget Sound. It connects Union Bay, the Montlake Cut, Portage Bay, Lake Union, the Fremont Cut, Salmon Bay, and Shilshole Bay. The Hiram M. Chittenden Locks accommodate the approximately twenty-foot (6.1 m) difference in water level between Lake Washington and the sound.
- length_of_canal
- runs east–west through Seattle
- water_level_difference
- approximately 20 feet (6.1 m)
- key_structure
- Hiram M. Chittenden Locks
- original_name
- Salmon Bay Waterway
Lore & Background
Prior to construction, water exited Lake Washington via the Black River which flowed from the south end of Lake Washington into the Duwamish River. For centuries, people had been dragging boats between the lakes. Pike tried to dig a ditch by himself at Montlake to transport logs. The Army Corps of Engineers investigated Puget Sound for military defense purposes and chose Lake Washington as the best location for a Naval base, though delays led to the Navy building the Puget Sound Naval Shipyard in Bremerton.
Reader's Guide
The Lake Washington Ship Canal is significant as a major infrastructure project that connected two large water bodies, enabling commercial and recreational navigation through Seattle. Its construction involved decades of planning, debate over routes, and engineering challenges, including the need for locks to manage the water level difference. The canal's history reflects competing interests—military, commercial, and local—and the eventual adoption of Hiram M. Chittenden's design for concrete locks over earlier wooden proposals. The canal remains in use today, with regulated traffic and ongoing environmental concerns regarding stormwater and wastewater spills into the waterway.
Did You Know?
- The canal runs east–west and connects Union Bay, the Montlake Cut, Portage Bay, Lake Union, the Fremont Cut, Salmon Bay, and Shilshole Bay.
- Prior to construction, water exited Lake Washington via the Black River into the Duwamish River.
- The U.S. Navy built the Puget Sound Naval Shipyard in Bremerton instead of on Lake Washington due to delays in canal planning and construction.
Frequently Asked Questions
How does the Lake Washington Ship Canal manage the water-level gap?
The canal spans roughly a twenty-foot (6.1 m) difference between Lake Washington and the Sound. That drop is handled by the Hiram M. Chittenden Locks, which raise and lower vessels between the two levels.
Which water bodies does the Lake Washington Ship Canal pass through?
The route threads sequentially through Union Bay, the Montlake Cut, Portage Bay, Lake Union, the Fremont Cut, Salmon Bay, and Shilshole Bay before opening into Puget Sound.
Why is the Lake Washington Ship Canal significant to Seattle?
It provides the city's only practical maritime corridor linking its inland freshwater lakes to the Pacific via Puget Sound. Without the canal and its locks, vessels could not move between the two water systems through Seattle.
More in Canals And Waterways 1-24
Elsewhere in the Canals And Waterways universe
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record