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About our pile dikes

The Corps has 233 pile dikes (also known as wing dams) in the 145 miles between the Mouth of the Columbia River and Bonneville Dam. Pile dikes were constructed in stages from 1885 to 1969. If each pile dike was placed end to end, they'd span more than 45 miles! Other privately owned pile structures are also in the Columbia River, but most Corps pile dikes are recognizable by the features shown here. The structure consists of alternating timber piles supported by a horizontal spreader. The king pile is a tall bundle of piles marking the end of the pile dike for better visibility. Stone blankets the entire length of the pile dike around the base. Corps pile dike structures in the Columbia River are authorized as part of the navigation projects, and help maintain navigation channels by directing river flow toward the main channel, resulting in:

  • Reduced dredging requirements
  • Increased channel stabilization
  • Increased bank protection, including protection of dredged material placement sites

SAFETY MESSAGE:  The tops of Corps pile dikes in the Columbia River are frequently just below the river surface during high water events and can seriously damage to vessels trying to transit over them. Many pile dikes are missing the tall king piles which increase visibility to boaters. Pile dike locations are shown on publicly available NOAA navigation charts and Corps hydrosurvey charts. Mariners should use these charts in addition to visual observation when boating around pile dikes in the Columbia River. 

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Phone: 503-808-4510

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Columbia River pile dikes

four pictures of pile dikesThe pile dike structures are very old and have increasingly deteriorated, damaged by high flows. A structural and functional assessment of the Columbia River pile dikes in 2011 determined that 100 pile dikes are in poor structural condition; nearly 80 pile dikes are missing king pile safety markers.

 

Repairing missing safety markers is the first priority for pile dike maintenance. While this need is critical, pile dike maintenance hasn't been funded in recent years. Instead of waiting for increased funding, we're seeking ideas to lower repair costs and repair pile dikes in phases. We're partnered with the U.S. Coast Guard and boating safety groups to improve safe navigation around pile dikes and increase public awareness. 

 

After the king piles are repaired, major maintenance studies and design reports will prepare for major maintenance to restore pile dike functions. The 2011 assessment prioritized pile dike systems for repairs in phases.

 

An interesting finding from the 2011 assessment was how many pile dikes actively help create and/or protect shallow water habitat, which benefits juvenile salmon. But without major maintenance repairs, pile dikes' navigation functions and shallow water habitats are at risk.

 

The Corps is currently studying the relationship between pile dikes and shallow water habitat, and recognizes opportunities to combine efforts and resources between navigation and juvenile salmonid recovery. Further research may help us better understand how juvenile salmonids interact with different pile dikes and adjacent habitats.

 

Click each picture for a larger version with text descriptions.

Lists parts of pile dikes: dolphin, spreaders, connecting hardware, piles and stone. Click to see larger version with text descriptions. Lists parts of pile dikes: dolphin, spreaders, connecting hardware, piles and stone. Click to see larger version with text descriptions. Lists parts of pile dikes: dolphin, spreaders, connecting hardware, piles and stone. Click to see larger version with text descriptions. Lists parts of pile dikes: dolphin, spreaders, connecting hardware, piles and stone. Click to see larger version with text descriptions.