The Jamestown S’Klallam Tribe has been preparing a one-mile section of a dike within the lower Dungeness River for a major setback, preparing to open up the historic floodplains to water and salmon once again.
‘We’ve planted 58 acres of former pastureland outside the dikes with 16,000 native plants, which helps create good salmon habitat,’ said Byron Rot, the tribe’s habitat manager.
For the past five years, the tribe has planted trees and shrubs such as Grand fir, Douglas fir and western red cedar and wild rose and snowberry bushes on the lower floodplain of the river.
‘Establishing native plants now increases their chances of survival when the dike is set back and the river naturally gets into the floodplain,’ Rot said.
Setting back the dike will return the river to a more natural state, allowing it to meander and efficiently move sediment downstream. Sediment buildup creates poor salmon habitat because salmon need clean river gravel to build egg nests.
Studies are being conducted to figure out the best way to remove the dike, which was built by the U.S. Army Corps of Engineers in 1964 to prevent flooding in the community of Dungeness. The various properties behind the dike have been purchased by Washington Department of Fish and Wildlife and Clallam County for habitat restoration efforts.
‘We are moving away from dredging the riverbed, which has been a common solution to reduce the gravel buildup,’ Rot said. ‘Across western Washington, where dikes confine relatively flat river channels, there is also almost certainly a buildup of sand and gravel. This often causes the riverbed to be much higher than the surrounding floodplain, increasing flooding risk to communities behind the dike.
‘Rivers transport this sediment into marine waters if we give them room to move and meander and not dike them into a narrow corridor,’ Rot said. ‘After all, since time immemorial, rivers have functioned quite well without our ‘management.”
The Washington Conservation Corps is a partner in the effort.