_{Thumbnail photo: Crescent City Harbor’s H Dock took the brunt of the impact from the Kamchatka tsunami on July 30. | Photo courtesy of the Crescent City Harbor District}

Though a 10-day window for an emergency declaration is drawing to a close, coastal engineer Rob Sloop urged Crescent City Harbor commissioners to factor the area’s vulnerability to tsunamis into their losses following last week’s surges.

“You’re suffering now from a long-term bias that this is a dangerous harbor so that needs to go into your equation of loss,” he said Friday. “When we talk about how much this may cost, there’s the structure. But there’s the people and then there’s the loss of revenue — all of those things compound.” 

Sloop, vice president for Moffatt & Nichol, the architect firm spearheading the rebuild of Citizens Dock, sought to help harbor commissioners figure out their next steps after the magnitude 8.8 Kamchatka earthquake produced a tsunami that barreled into the harbor in the wee hours of July 30.

The coastal engineer discussed bathymetric surveys and sonar scanning to determine how much sediment the tsunami deposited into the harbor as well as changes to the ocean floor. He pointed to the harbor’s H Dock which bore the brunt of the damage, saying that an underwater inspection is necessary to make repairs.

Sloop also urged commissioners to think about how the harbor could be even more resistant to tsunamis, urging them to consider widening the entrance to the inner boat basin to make the surges less intense. 

“Start thinking about grants, reach out to regulatory agencies and start talking to them about emergency permits for repairs,” he said. “Take the spotlight and use that to help advance other projects you have going on in the harbor and try to bundle some of that funding when those things come in.”

Sloop said that because the disaster was localized primarily to Del Norte County, he didn’t expect the community would receive much in disaster relief funds from the state or the federal governments.

Sloop’s visit to Crescent City comes after Harbormaster Mike Rademaker stated that the tsunami wrought nearly $1 million in damages to H Dock, including its potable water, fire suppression lines and intra-dock utilities. As a result, the Harbor District is unable to accommodate large vessels seeking to moor at the port, Rademaker said.

According to a Tuesday press release from Rademaker, preliminary damage assessments doesn’t include the amount of sediment the tsunami may have deposited into the harbor. Extensive dredging may be necessary to restore access to the harbor’s navigation channels, Rademaker said.

The Del Norte County Director of Emergency Services proclaimed the existence of an emergency on Thursday. A resolution and a proclamation confirming the existence of a local emergency will go before the Board of Supervisors on Tuesday.

On Thursday, Mike Bahr, CEO of Community System Solutions, which manages the port’s Hazard Mitigation Grant Program dollars, said that he and Rademaker have prepared an email to the California Office of Emergency Services “for exactly the type of studies that Mr. Sloop just presented.”

Bahr said he’ll be asking CalOES representatives about using some of the Harbor District’s Hazard Mitigation Grant Program dollars to pay for those studies.

“We still have unallocated about $800,000,” he said. “We’re waiting for the final reports and the final sign off.”

Sloop’s report also comes after University of Southern California Coastal Engineering professor Patrick J. Lynett conducted a preliminary analysis of the damage based on review of video footage and data modeling.

According to Rademaker’s news release, the USC professor stated that the currents driven by the tsunami accelerated beneath H Dock creating a drop in pressure strong enough to overcome the dock’s buoyancy.

“In this fashion, the dock wasn’t buried by the tsunami wave,” Rademaker wrote. “It was pulled under before the wave overtopped it. This ‘negative lift’ effect coupled with the possibility of overtopping weight load — where water surges over the dock and adds further downward pressure — resulted in the structural separation of dock segments.”

On Thursday, Sloop suggested filling 55 gallon drums with water and slowly lower them onto the dock segments from a boat to relieve the pressure. He noted, however, that the dock segments needed to be redesigned.

The Harbor District may also consider using H Dock as a case study, Sloop said. In the hours following the first surges, Rademaker said that H Dock was sacrificial and did its job, keeping the tsunami from causing even more damage.

“Use its failure as a basis for this kind of sacrificial design,” he said. “Frame the upgrades as a proactive”

Following Sloop’s presentation, Commissioner Annie Nehmer suggested creating a written policy for how to respond to a tsunami event. She said she received calls from fishermen who weren’t notified that they needed to get their boats out of the harbor to prevent damage and that the United States Coast Guard stopped some vessels from entering the harbor while surges were continuing.

“Luckily all disasters were avoided, but guys almost hit the jetty, almost hit the ice plant, almost hit the sand bar,” Nehmer said. “There should have been an internal advisory from the harbormaster saying that it’s still not safe to come in yet.”

Nehmer and Board President Gerhard Weber volunteered to sit on an ad-hoc committee focusing on a written emergency policy.

The first tsunami surges rolled into Crescent City at about 12:50 a.m., roughly eight hours after the earthquake hit. The first surge measured about 1.2 feet, according to Rademaker.

The largest surge in Crescent City came in at about 1:39 a.m. accordig to Ryan Aylward, coordinating meteorologist with the National Weather Service’s Eureka office and c-chair of the Redwood Coast Tsunami Work Group.

The surge that lifted H Dock off its pilings came in at about 2:40 a.m., according to Rademaker. 

He compared the 2025 tsunami to the tidal waves that rolled into Crescent City following the Great East Japan Earthquake in 2011, saying that tsunami created $50 million in damages. The Crescent City Harbor District constructed its inner boat basin after that tsunami with a loan from the U.S. Department of Agriculture.