SEQUIM — Clallam County commissioners will host an open house Thursday to hear public comment on whether to end Towne Road near Dungeness Bay in a cul-de-sac and parking area or maintain it as a through street during Dungeness River floodplain restoration.
The open house will be from 6 p.m. to 8 p.m. at the Dungeness River Audubon Center, 2151 W. Hendrickson Road in Sequim.
Comments can be made at the open house or sent to the county by March 31.
Between 2,133 feet and 2,753 feet of Towne Road — about two-thirds of a mile — are slated for removal or relocation.
Additionally, a portion of the nearby levee installed by the Army Corps of Engineers also will be removed and relocated.
Construction of the new levee is expected to begin in 2016 or 2017. The project is estimated to cost $11,877,000.
Officials will provide background information about the project, share locally developed designs and gather public comments about two separate courses of action under consideration as part of the restoration process.
Towne Road now extends from Old Olympic Highway to Sequim Dungeness Way.
Public participation will assist the county in making a design choice between ending Towne Road just north of Dungeness Valley Creamery or keeping it as a through street, said County Engineer Ross Tyler.
“If the Board of Commissioners eventually determines that a through route should be maintained, then options to accomplish that will need to be explored,” Tyler said.
“At this point, no through route connection alternative has been selected, or even explored in any detail,” he added.
Public input will help the Road Department “make a recommendation [to county commissioners] that best represents the interests of current and future users,” Tyler said.
Written comment can be sent to Clallam County Public Works, 223 E. Fourth St., Suite 6, Port Angeles, WA, 98362; or email roads@co.clallam.wa.us.
For more information call 360-417-2379.
Clallam County has been working since the late 1990s to reconnect the lower Dungeness River with its floodplain by setting back a portion of the east bank levee of the river.
A levee setback would circumvent the need for emergency repairs in the aging, existing levee, officials have said.
Design of the levee setback and floodplain reconnection was funded by the state Legislature through Floodplains by Design.
When completed, this large-scale ecosystem restoration project will reconnect about one mile of river channel with 112 acres of the floodplain on the east bank, much of which has been reforested.
The expanded floodplain and reconnected habitat has been designed to reduce flood risk, reduce peak water velocities, and increase the volume of woody debris in the channel, officials said.
According to county officials, flooding in the lower Dungeness has been a community concern since at least the 1940s.
To address the flood threat, in 1963 the Army Corps of Engineers constructed the levee on the Dungeness River’s east bank from the mouth to river mile 2.6.
However, the levee increased flooding on the west side of the river.
In response, a private levee was built in that location from river mile 1.5 to 2.6.
As a result, these two levees “have substantially altered the channel and floodplain conditions of the lower Dungeness River,” according to a report submitted to the state Department of Ecology.
“As physical processes have adapted to the levees, flood risk has increased while in-river and floodplain habitat quality and quantity have decreased.”
Currently, the main channel is disconnected from side channels and unable to develop meanders, the report said.
That increases flood flow velocities and associated scouring of the riverbed, it said.
Also, coarse sediments are distributed on the channel bed and fine sediments carried to Dungeness Bay, impairing water quality, the report said.
Further, the levee precludes the ability of high flows to access the historic floodplain to reduce stream energy and to store sediment.
Cross sections have revealed aggradation —- the increase in land elevation due to the buildup of sediment —- up to eight feet in places.
Aggradation occurs in areas in which the supply of sediment is greater than the amount of material that the system is able to transport.
“As the levee constricts the river it creates backwater conditions and, in turn, forces water depths to increase,” according to the report.
“In this reach, it is important to note that the channel bottom has aggraded so severely that it perches above the surrounding landscape, in essence flowing at an elevation that is higher than the surrounding landscape.”
For more information, see http://tinyurl.com/PDN-DungenessRiver.
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Sequim-Dungeness Valley Editor Chris McDaniel can be reached at 360-681-2390, ext. 5052, or at cmcdaniel@peninsuladailynews.com.
