Building Strong® at the Old Mouth of the Cowlitz River

Aerial view of the Old Mouth of the Cowlitz River, courtesy of Google Earth ProThe Old Mouth of the Cowlitz River channel at Longview, Wash. is authorized to 8 feet deep and 150 feet wide, from deep water in the Columbia River through the Old Mouth of the Cowlitz River, to a point about 3,000 feet upstream from the old harbor line.

 

The navigation channel supports commercial barges shipping 288,000 tons of wood chips per year. Those chips are used to produce 144,000 tons of products worth over $84 million.

 

For more information

Contact us:

Phone: 503-808-4510

Email us about the Old Mouth of the Cowlitz River

Latest News Releases

Columbia River locks shut down for annual maintenance
2/1/2024
The $23 billion of commerce that flows along the Columbia River will pause for two weeks beginning March 2 as the U.S. Army Corps of Engineers (USACE), Portland District closes three navigation locks...
The Dalles Dam Hosts 14th Annual Eagle Watch
1/17/2024
The Dalles Dam invites the public to their 14th annual Eagle Watch event on Jan. 27 from 10 a.m. to 3 p.m. During the month of January, The Dalles Dam Visitor Center will be open every Tuesday through...
Corps seeks public input for Willamette Valley hydropower report to Congress
10/30/2023
The Portland District, U.S. Army Corps of Engineers will gather the public’s perspective and opinions on the future of hydropower across the Corps’ Willamette Valley system of dams during three...

Operations: Old Mouth of the Cowlitz River

Collapse All Expand All
 General information

The vertical plane of reference is adopted low water. The project is subject to tidal influences and annual river freshets. A large shoal regularly forms at the Old Mouth of the Cowlitz River where it meets the Columbia River. Dredging by a contract clamshell dredge is required every 2-to-3 years to allow adequate depth for commercial barge traffic.

This shoal was last dredged by the Corps in 2002 and the material was placed at an in-water site. Limited advanced maintenance width dredging outside the authorized channel width and up to 2 feet of advanced maintenance dredging below the authorized channel depth is practiced in order to maintain adequate depth for commercial barges between dredging events.

 Project description
The authorized channel is 8 feet deep and 150 feet wide, and spans from deep water in the Columbia River at Columbia River Mile 67.5 through the Old Mouth of the Cowlitz River, to a point about 3,000 feet upstream from the harbor line at the time of authorization.
 Authorization

The Rivers and Harbors Act of March 2, 1945, as part of the overall Columbia and Lower Willamette Rivers Project.