South Sound Properties Undressed

South Puget Sounds Colvos Passage

A lot of folks don’t know a little secret about the tide direction through the Colvos Passage in the South Sound area between Vashon Island and the Olympic Peninsula.  In all of the Puget Sound, the tide comes in and out from the Pacific Ocean.  There is only one water passage where regardless of an incoming or outgoing tide, the tide is always outgoing.  That one area is the Colvos Passage that borders the West side of 13 mile long Vashon Island, and the Olympic Peninsula neighborhoods of Gig Harbor, Olalla, and Southworth (part of Port Orchard).

Because of this, the many barges headed north from Olympia at the Southern end of the South Sound and from Tacoma intentionally head straight up the middle of the Colvos Passage to take advantage of that constant outgoing tide.  They sort of get a partial free ride from mother nature, and save fuel.

Here’s the reason.  The tidal flow through the Colvos Passage on the west side of Vashon Island has a unique unidirectional pattern flowing only in a northern direction. This unusual tidal flow pattern in the Passage is probably caused by the ebbing current from the Narrows, west of  Tacoma, that is naturally directed into the Passage by the land formation at Point Defiance State Park in Tacoma.

So, for all the neighborhood communities that border the Colvos Passage, they get an optical illusion.  Though the water rises 4 to sometimes 20 feet on an incoming tide, the flow of water through the Colvos Passage always heads north.  When you look at it, your mind tells you its flowing south, but it’s not.  Definately a unique South Sound feature that benefits barge traffic.