The Mouth of the Columbia River Project is made up of three jetties and a navigation channel. The project is bordered by the State of Washington to the north, the State of Oregon to the south, and the Pacific Ocean on the West. The north jetty is 2.5 miles long and spur jetty “A” is 0.3 miles long. Both of these jetties are on the Washington side of the Mouth. The south jetty is 6.6 miles long and is on the Oregon side of the Mouth.
The 6 mile long federal navigation channel at the Mouth of the Columbia River lies between the two jetties and was first authorized in 1884.
The navigation channel is important to the regional and national economy. The Port of Portland estimates more than 40,000 jobs along the lower Columbia River are dependent upon seaport activity. On average, marine activity in the lower Columbia River creates $1.8 billion in personal income. Seaport activity in the regions of the lower Columbia generates $208 million in state and local tax revenue and contributes 10 percent toward the state of Oregon’s gross product. About 1,000 firms export goods via the lower Columbia River and all of these goods must exit the Mouth of the Columbia River.
The Columbia River bar is the second most treacherous in the world and the most treacherous in the United States. By maintaining the channel to its authorized depth, the work ensures safer passage for commercial and recreational vessels. Hopper dredges are used to maintain the navigation channel to its depth of -55 to -58 feet Mean Lower Low Water by removing restricting shoals that are made up of naturally occurring sedimentary materials. The project can only be dredged during the calmer weather between June and early November. Up to 5 feet of allowable over-depth dredging may be accomplished in order to ensure authorized project depth in between dredging cycles. In some locations 1-2 feet of additional depth may be removed or otherwise disturbed during the dredging process.
There are 3 disposal sites to place dredged material: 2 Ocean Dredged Material Disposal Sites (designated by the Environmental Projection Agency) and 1 North Jetty Site in Washington (a designated Clean Water Act Site).
AUTHORIZED BY:
Rivers and Harbors Act of 05 JUL 1884
Project Description:
Main Channel:
Channel A (north reach) is 6 miles long, 2,000 feet wide and 55 feet deep.
Channel A (south reach) is 6 miles long, 640 feet wide and 48 feet deep.
Jetties:
North Jetty is 2.5 miles long.
South Jetty is 6.6 miles long.
Spur Jetty A is 0.3 miles long.
To go to the Mouth of the Columbia River Project Page click here.