FOR IMMEDIATE RELEASE

Date: August 5, 2025

CRESCENT CITY, CA — In the early morning hours of July 30, the Crescent City Harbor District experienced a tsunami surge event that caused significant damage. Harbor officials are now coordinating closely with Deborah Otenburg, Emergency Services Manager for the Del Norte County Office of Emergency Services, and the California Governor’s Office of Emergency Services (Cal OES) to complete a Preliminary Damage Assessment, the first step in accessing state and federal recovery assistance.

“The visible damage only tells part of the story,” said Mike Rademaker, Harbormaster and CEO of the Crescent City Harbor District. “We are looking at extensive internal damage to critical infrastructure: utilities running beneath the docks that serve both safety and operational needs.”

“The infrastructure built after 2011 saved vessels and lives,” the Harbormaster stated. “Now we have a chance to take the design to the next level. We’re not asking for a blank check to return to the status quo, we’re taking the opportunity to use what we’ve learned to build smarter. Every time we rebuild better, we safeguard more than concrete and steel, we protect jobs, family businesses, and taxpayer dollars,” he said. “With the right design, the next time a tsunami rolls in, Crescent City won’t just survive it, we’ll be a model to the world of what resilience looks like.”

Hidden Damage and Operational Consequences

The tsunami surge caused a noticeable separation of dock segments along the harbor’s “H” Dock. At first glance, the damage appeared modest. However, ongoing assessments have revealed that the majority of the damage occurred beneath the waterline, in vital infrastructure that supports the safe and functional operation of the harbor.

The Crescent City Harbor District now estimates nearly $1 million in damages to submerged systems, including potable water and fire suppression lines, and intra-dock electrical utilities. However, one of the most costly aspects of the recovery may be the significant sediment deposition left behind by the wave surges. This may demand extensive dredging to restore the operational capacity of harbor navigation channels.

This damage estimate is being prepared within a critical timeframe. Under California Government Code § 8630, local governments have 10 days to proclaim a local emergency if they determine that the effects of an incident exceed their ability to respond with existing resources. The Del Norte County Board of Supervisors is expected to issue such a proclamation later this week. Once adopted, that proclamation may lead to a Gubernatorial State of Emergency Proclamation under Government Code § 8625, if state authorities concur that the conditions require resources beyond local and regional mutual aid capabilities.

The most immediate operational impact has been the loss of large-vessel moorage capacity along H Dock. While A Dock can accommodate vessels up to 77 feet and B Dock up to 66 feet, neither offers the extended linear footage that H Dock provided. Compounding this issue, A Dock is already operating at full capacity.

“While our harbor remains open and functional, we’ve lost an essential piece of infrastructure that gave us the flexibility to accommodate our largest vessels,” the Harbormaster noted.

Fortunately, no vessels were damaged and no lives were lost—an outcome attributed to infrastructure upgrades made in the aftermath of the 2011 tsunami, which caused an estimated $50 million in damages. However, this recent event has illuminated a new vulnerability in floating dock design: a previously underrecognized hydrodynamic failure mechanism.

Engineering Insights: Understanding the Unseen Forces at Play

Shortly after the tsunami event, the Crescent City Harbor District engaged in collaboration with coastal engineering experts across academia and industry to better understand the nature of the structural failure. Among the most significant contributions to this effort has come from Dr. Patrick J. Lynett, Professor of Coastal Engineering at the University of Southern California, whose nationally recognized work in tsunami and coastal wave dynamics has shed light on a subtle yet powerful phenomenon that may explain what occurred.

Dr. Lynett’s preliminary analysis, based on review of video footage and data modeling, points to a hydrodynamic failure mode known as negative lift—a fluid dynamics effect on docks that has rarely been captured on video (see attached PowerPoint file provided courtesy of Dr. Lynett). In this case, the strong tsunami-driven currents accelerated beneath the floating dock structure, creating a zone of low pressure. This drop in pressure produced a downward force strong enough to overcome the dock’s buoyancy, pulling the structure downward into the water. In this fashion, the dock wasn’t buried by the tsunami wave, it was pulled under before the wave overtopped it.

“This is similar to the way an airplane wing generates lift—but in reverse,” the Harbormaster explained. “Instead of lifting the structure up, the water moving rapidly under the dock actually sucked it down. It’s a dramatic and underappreciated mode of failure.”

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. Fortunately, the robust post-2011 construction of the dock helped prevent complete disintegration, but the implications are clear: simply rebuilding the same design risks repeating the same failure.

Dr. Lynett has proposed low-cost engineering remedies to mitigate these risks, including retrofitting the dock with buoyancy-enhancing closed-cell tanks or reconfiguring the dock’s vertical cross-section to disrupt the negative lift conditions. These insights offer Crescent City Harbor the opportunity not just to repair the damage, but to lead the nation in designing tsunami-resilient harbor infrastructure.

Geological Vulnerability: The Mendocino Fracture Zone

Crescent City’s geographic vulnerability to tsunamis is well documented. The Harbor lies adjacent to the Mendocino Fracture Zone, a major offshore tectonic boundary where the Pacific Plate, Gorda Plate, and North American Plate interact. This region is highly seismically active and capable of producing both near-field and distant-source tsunami events.

Due to the harbor’s unique bathymetric characteristics and orientation to offshore faults, Crescent City experiences amplification effects—where incoming tsunami waves grow significantly in size and energy as they refract and concentrate within the harbor entrance. These factors make Crescent City one of the most tsunami-prone communities on the West Coast.

“This harbor has faced more tsunami events than almost any other on the Pacific Coast of the continental U.S.,” said the Harbormaster. “We don’t have the luxury of ignoring edge-case engineering scenarios. For us, they’re not edge cases. They’re recurring events.”

A Model for Smart Investment and Resilient Design

Even with the damage estimate approaching $1 million, the Crescent City Harbor District emphasizes that the investments made since 2011 have already paid dividends. There was no damage to vessels and no catastrophic structural loss. This outcome stands in stark contrast to the devastation experienced in 2011.

“We see this not as a setback, but as an opportunity,” the Harbormaster said. “We now have evidence of a failure mechanism that’s rarely been documented. And we have some of the brightest minds in the field working with us to solve it.”

The Harbor District plans to continue its collaboration with Cal OES, academic institutions, and professional engineers to refine its rebuilding approach and serve as a national model for tsunami-resilient maritime infrastructure.

“Most of the damage isn't obvious to the naked eye,” said the Harbormaster. “But responsible management requires looking beyond the surface. It requires making incremental improvements, and being even more prepared for the next one.”

By committing to that principle—and integrating groundbreaking engineering insights—Crescent City Harbor aims to emerge not only stronger, but smarter, continuing a long tradition of safeguarding its harbor, its economy, and the public resources entrusted to its care.

Mike Rademaker, CEO/Harbormaster

Phone: 707.464.6174

Email: mrademaker@ccharbor.com

Website: https://www.ccharbor.com/