Corps of Engineers replenish eroding shoreline near Cathlamet

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Courtney Talak, The Daily News

Posted October 10, 2019

Wahkiakum County Commissioner Cothren, center, gets a closer look at the new sediment placed on the shore of Cape Horn Tuesday morning. Cothren is accompanied by Col. Aaron Dorf, right, and resident engineer Travis Davidson, left, of U.S. Army Corps of Engineers' Portland District.

CATHLAMET — Just months after moving into the Cape Horn home they planned to retire in, Randy and Trish Shroyer noticed the beach on their riverfront property was less beach and more rock.

Not long after, the couple watched as nearly four-foot waves pounded the Columbia River shoreline in the wake of passing ships, wiping away pieces of land.

The river began encroaching their property, eating away at the bank of their backyard and cutting unstable outcroppings in the shoreline.

“We gauged (the erosion) by our stairs (to the beach). All of the sudden they were underwater,” Trish Shroyer said. “It was scary.”

The Shroyers soon learned their neighbors were also concerned. In one year, the beach had shrunk nearly 10 feet a few houses up the road, Trish Shroyer said. Sandra Davis, another neighbor, told The Daily News she could “feel our home settling” and had to move her fishing shack inland at least three times as the river widened.

But now the residents of Cape Horn can rest easy because the Portland District of the U.S. Army Corps of Engineers has replenished the beach. Crews with the Corps and the Port of Portland’s Dredge Oregon added enough sand to about half a mile of the cape to extend the beach by about 125 feet into the river.

“We feel really blessed to see the security of our banks reinforced,” Trish Shroyer said Tuesday afternoon as a backhoe smoothed down the new sandy shore outside her home. “We both teared up when we saw it. … We had wondered if we’d ever see it.”

The so-called beach nourishment project is about five years in the making, though Wahkiakum County Public Works Director Chuck Beyer said the county permitted similar projects on the Puget Island in the early 2000s. And concerns about eroding river banks in the Cathlamet area date back at least a decade and a half.

It’s a problem created by the natural process of erosion, said Wahkikaum County Commissioner Dan Cothren. As water moves by the shore and beaches in the river, the current sweeps away pieces of sand and rock. Sometimes that erosion undercuts the shoreline, leaving an unstable outcropping that can drop into the river all at once.

“It’s just a natural thing. … We get so much flow from the river, that it robs the sand that’s already been put there and takes it away,” Cothren said.

The erosion process is compounded by river traffic and southwest winds, which create waves that can batter the shore and break off more dirt, Cothren said.

As the bank wears away, the water gets closer to the riverside properties. This can damage building foundations, water and sewer lines and other property for homeowners.

“We weren’t doing this for a volleyball court … or landscaping,” Trish Shroyer said of the beach nourishment project. “The sand is to protect your house.”

Neighbors say the Shroyers spearheaded the push to get the Corps to deposit sand on the shore. Trish Shroyer said she was a “cheerleader” for the neighborhood, but that it “took a tribe” to solve the problem.

“It was passion, persistence and unity,” she said.

The initiative started when the Shroyers started gathering their neighbors to discuss their concerns. The group banded together to petition county commissioners, the Corps and congressional leaders to ask for help.

Karla Ellis, the Corps’ Chief of Waterways Maintenance for the channel and harbor project, said she started working on the project about five years ago when the Corps got letters from worried citizens.

“It’s at that point that we started pursuing what that process for the project would look like,” Ellish said. “We use this (beach nourishment) methodology up and down the river, but this is the first time in a while that we’ve worked at this site.”

In 2016, the county and Corps signed a 10-year agreement that allowed the Corps to deposit sand on private lands if the county received the appropriate environmental and legal permits.

That can be a slow moving process, Cothren said, because it requires getting several organizations together at the same table and “government moves so slowly.”

Shroyer said the permitting process was also bogged down by special interests groups, including environmentalists concerned about native wildlife. The county and the Corps worked with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service to address those concerns.

“We’ve been working on this really steady for about three years and paying for the permitting process,” Cothen said, noting that the county has spent more than $200,000 to date.

Even after all the permits are in place, the county still has to wait for the Corps to find available sand. Cothren said the groups “lucked out” because the Corps found enough material at Shoal West Port to complete the project this month.

“We have a lot of goals in this community, and this is one we can check off. It’s been a long time,” Cothren said. “Hopefully this is the start of a domino effect for the whole (Puget) Island.”

The 10-year agreement also covers shorelines at Pancake Point, North Welcome Slough and Ostervold Road. It includes a “maintenance agreement,” under which the Corps can add more sand in later years to replace regularly eroded sand.

“The river is dynamic,” Ellis said. “But we have had a team of experts look at this, and we will watch it as time unfolds.”

Source: tdn.com