Honolulu’s tsunami after-action report is out—what the city’s findings say about evacuations and communications

Honolulu’s Department of Emergency Management (DEM) has released an after-action report evaluating how the city responded to the July 29, 2025 tsunami warning that triggered evacuations and major traffic congestion across Oʻahu. The report looks at both what worked and what didn’t—especially public confusion about evacuation zones, how “vertical evacuation” should be used, and how emergency alerts and maps were delivered.

What DEM says went right

DEM credits strong coordination early in the event for getting warning information to emergency officials quickly, including alert protocols linking the Pacific Tsunami Warning Center, the Hawaiʻi Emergency Management Agency, and county emergency management points. The report also highlights that DEM’s activation plans helped the Oʻahu Emergency Operations Center stand up rapidly after the Tsunami Watch was issued.

On the evacuation itself, DEM says evacuations of the Primary Tsunami Evacuation Zone were accomplished by the time of anticipated impact, and that roads within the evacuation zone were clear of traffic by then. The report also points to a traffic-management “bridge” operation: the Joint Traffic Management Center bridge helped coordinate tactical evacuation operations among agencies present.

Where residents got tripped up: zones, vertical evacuation, and “unnecessary” car trips

DEM’s biggest public-facing concern is that many people did not clearly understand tsunami evacuation procedures—especially the differences between evacuation zones and when vertical evacuation could be an option. The report says public messaging did not adequately emphasize early and often that vertical evacuation was an option, the zone that needed to evacuate, and the importance of staying off the roads if you were not in the evacuation zone.

The report also cites initial findings from an HDOT (Hawaiʻi Department of Transportation) study on traffic congestion during the evacuation period: 92% of trips by vehicle on Oʻahu were unnecessary because they were not related to moving people from the Primary Evacuation Zone to a safe area. DEM says many citizens left safe areas or evacuated farther than needed, and that many businesses outside the evacuation zone closed. The report says this confusion drove unnecessary travel and was a significant contributor to traffic congestion.

The report also says statewide emergency alerts missed Oʻahu-specific details. Specifically, it finds that Emergency Alert System (EAS) and Wireless Emergency Alerts (WEA) sent by the state did not include localized guidance on vertical evacuation or links to evacuation maps. And it says the city’s HNL Alert tsunami-watch messaging did not include robust readiness actions to prepare people for what to do if the warning was upgraded.

What the report says needs work inside the emergency operations center

DEM also evaluated internal operations inside the EOC and found gaps that affected clarity and coordination. The report says the City Emergency Operations Plan tsunami annex lacked detailed timelines, decision points, and operational tasks.

It also finds staffing and role clarity problems. DEM says it did not have sufficient emergency management staffing to support sustained 24/7 operations for a tsunami event, and it reports that some EOC staff were unclear on their roles and responsibilities—particularly because several key personnel were new to their positions during the event.

On coordination, DEM says statewide coordination calls during the response occurred too frequently and without a clear agenda, occupying Oʻahu EOC staff while adding limited operational value. The report also identifies public-information coordination issues, saying city and state press briefings were not synchronized—interrupting one another—and that the City’s Joint Information Center (JIC) lacked a clear messaging cadence with the state.

Corrective actions DEM recommends

DEM organizes improvement items into an improvement plan tracked through the city’s incident management program. The report treats these as recommended corrective actions, not as proof that every change has already been implemented.

• Update tsunami planning documents and training: revise the tsunami annex with time-phased decision points and operational tasks, and train EOC staff on tsunami-specific threat decision points.
• Strengthen staffing and surge capacity: increase professional emergency management positions and expand reservist or other trained surge options.
• Improve zone and vertical evacuation guidance: update public-facing evacuation maps so only the zone that needs to evacuate shows during a tsunami warning; create graphics and templates focused on vertical evacuation; and improve preparedness education to reduce over-evacuation.
• Fix alert content and links: develop an Oʻahu-specific WEA template that supplements state alerts with localized vertical-evacuation guidance and links to evacuation maps.
• Improve public access to information: address website capacity during surge traffic; provide printable evacuation-zone information and printable/accessible formats for assembly-area and other public materials; and ensure ADA-compliant information.
• Clarify public-information and coordination roles: update JIC guidance to clarify roles/positions and improve messaging synchronization between the City and the state.

What residents can do before the next warning

Even when a tsunami does not end up producing damage, the after-action report suggests preparedness choices can reduce congestion and improve safety. Residents can start with these actions:

• Know your evacuation zone and what it means for your address. Use the kind of hazard-lookup tools referenced in local coverage of the report and confirm what you should do when alerts come.
• Understand your evacuation options: if you live or work in a high-rise or other building where vertical evacuation may be an option, learn what vertical evacuation is and when it should be used before any alert.
• Expect clearer instructions—and plan for a “stay off the roads” moment: DEM’s report frames unnecessary trips as a safety and traffic-management problem that can slow or block those who do need to move quickly.
• Make sure your emergency alerts are enabled and that your household knows where to find evacuation guidance during an event.
• If you manage a business or support vulnerable customers in an evacuation area, build an approach for staff and visitors so evacuation/vertical-evacuation procedures are understood ahead of time.

Sources

• City & County of Honolulu / Hawaiʻi DEM: July 2025 Tsunami Warning After Action Report (PDF)
• Hawaiʻi Public Radio: “New report lays out highs and lows of Honolulu tsunami response”
• Honolulu Civil Beat: “Hawaiʻi Tsunami Panic: Most Who Evacuated Shouldn’t Have, Report Says”