Dynamic revetment — the placement of cobble rock along coastal shorelines to protect them from erosion — is the official “preferred choice” to stave off the shoreline erosion that has been gobbling up property and houses in the North Cove area for decades.
The selection of the preferred design after a year-long demonstration project is a step toward a more permanent solution to the erosion problem that has cost the area more than 3 miles of coastline land since the late 1800s. North Cove is in Pacific County along Highway 105, near the northern entrance to Willapa Harbor but without much of the harbor’s protection. It’s been referred to as Washaway Beach.
Vladimir Shepsis, technical lead for the project’s engineering firm Mott MacDonald, told a packed house at the Shoalwater Community Center April 17 that revetment rose to the top of the list after considering factors ranging from construction and maintenance costs to environmental, shoreline and recreational impacts and, of course, effectiveness.
The options were considered by the engineering firm in conjunction with two advisory committees working together to come up with the preferred option: A technical committee, comprised of scientists and engineers from several agencies including the Army Corps and Engineers, the Department of Ecology, the Pacific County Drainage District, the Department of Transportation and the Pacific Conservation District; and a steering committee made up of policy, permitting and funding experts from many of those same agencies and the Shoalwater Bay Tribe.
“We are going to proceed with dynamic revetment and continue to evaluate the dynamic revetment plus groin option, which may become part of the master plan,” he said. A “groin” is basically a short jetty, said Shepsis, running perpendicular to the shoreline.
Shepsis showed a preliminary cost estimate, breaking down the five options. The preferred option has an initial capital cost of $6 million; the combination dynamic revetment and groin option $8 million. Maintenance costs for both run $13 million and $11 million respectively. The maintenance cost of the revetment itself is based on major maintenance performed every five years during the life cycle, said Shepsis.
The revetment runs from just north of the end of the Old State Route 105 south to the mouth of drainage ditch #1 — near where State Route 105 runs right alongside the shore — a total of about 3,500 feet of coastline. The “groin,” if implemented, would run south and west off the south end of the revetment.
Currently each linear foot of shoreline is protected by 1-5 cubic yards of cobble. Shepsis said the preferred design would call for 15 cubic yards of material for each linear foot.
Pacific County Administrator Kathy Spoor said now that the preferred design has been selected, funding for construction and maintenance of the revetment can be pursued.
“We will submit for construction permits this summer,” said Shane Phillips, Vice President of Mott MacDonald. “It’s hard to estimate how long that will take. It could take at least a year to get construction permits.”
A 2016 state capital budget item of $650,000 paid for the demonstration project and the work to this point, including the project design and recently-completed analysis, and the construction permit applications. Now it’s up to local stakeholders to go back to the table to find more money to fund the construction itself.
“Currently the project is not funded for construction, so project partners are pursuing options for finding funding through a variety of sources, both state and federal,” said Phillips. Those sources could include the Legislature and grants from the Army Corps of Engineers and other sources.
Just a few years ago, North Cove residents had more or less lost hope after decades of watching its historic town and their own homes disappear under the unrelenting sea. That attitude has shifted to a sense of optimism after seeing what they as a community have been able to do over the past few years.
Local cranberry farmer and Pacific County Drainage District #1 commissioner David Cottrell researched the revetment — in which cobble-sized rocks placed along the shoreline move with the pounding of waves, diffusing their energy — and began working with South Willapa Harbor Grange, the county commission and conservation district, the drainage district and local landowners to find ways to get the project started.
In the winter of 2015-16, the Pacific County Conservation District provided a $50,000 grant to the drainage district to build the first 300 feet of revetment. A little later, another $50,000 was applied to extend that project. In 2016, after a lengthy budget battle and with the support of Rep. Brian Blake, who has family that has lost property in North Cove, the Legislature earmarked $650,000 for the current demonstration project.
A big test came in the form of high tides and 60 mph gusts Dec. 20, 2018. The Department of Ecology, funded by the Army Corps of Engineers, the county and the conservation district, surveyed the beach that day and the day after. “It does appear the dynamic revetment held up fairly well,” said coastal engineer George M. Kaminisky.
Cottrell said after that storm, “Yes, that was a pretty good pounding, but I didn’t see any significant losses along our whole mile and quarter of cobble.”
Connie Allen, a local resident with the nonprofit group Wash Away No More, which has been working to fund the fight against shoreline erosion, said after the storm she reckoned a foot of two or shoreline was lost, but “likely the loss would have been over 100 feet if we had no defenses.”
The South Beach is lined with talented and unique artists, many of whom in the North Cove area have lent their skills to promote and support shoreline preservation efforts.
John Jones has produced steel cutout statues of some local personalities, including photographers Van Adam Davis, Marcy Merrill and her dog Hawkeye, and Marguerite Garth, and Jaenette Bush-Hudson. These statues each feature a hole through which visitors can focus their cameras on a particular portion of the revetment at several viewpoints along the project. Photographers can then post their photos to mycoast.org and be part of tracking the changes that take place over time in the revetment.
The artistic talent and passion for the revetment project were on display at the April 17 meeting. Allen made a cake incorporating the elements of the revetment project. Clare Conlan, Master of the local Grange, walked visitors through an interactive display showing how revetment works and the benefits of using cobble. Cottrell stood at another illustrating the importance of the tidal gates on the drainage ditch to local cranberry farmers.