This article, contributed by David Moynihan of the Washington Department of Fish and Wildlife (WDFW), is a follow-up on the massive landslide and subsequent tsunami that occurred in November 2024. This event triggered investigations into preparedness for these kinds of events in the future.
We live in a beautifully deadly land. Wildfires can rage while cold waters run like liquid crystal, bears can eat your garbage while the wind catches the smell of orchard blossoms. Most of us know what hazards we face every day spent living and working on this land. If we get caught in a blizzard, evacuated due to fires, or hit a deer while driving on the highway, we aren’t surprised. We might be annoyed, angry, even elated, but it’s all from known hazards that are semi-ordinary.
A tsunami wasn’t on the expected list of hazards for us inlanders. Such phenomena are for our soggy and rugged western siblings to side-eye. However, the gods of geology, hydrology, and comedy have conspired to get a good laugh at us via landslides on Lake Roosevelt. Last November many of us saw a video on social media, heard a news snippet on the radio, or got a phone call about a tsunami 400+ miles inland from the ocean. Most of us didn’t believe it – until we did. As a safety manager for the WDFW, I have seen many risks in the region. Often you can train, equip, prepare, study, and analyze to feel that you’re prepared for every hazard … and sometimes you just get hit with cold sweats and terror over what nature has dished out.
While we were well prepared to prevent drowning via a robust Personal Flotation Device (PFD) and wilderness first aid training program, we found that due to the size and temperature of landslide-induced tsunamis, exposure and hypothermia are the greater risks on Lake Roosevelt. Using a team of cold-water experts and people who do daily work on the lake, we came up with a strategy and assembled a kit of required personal protective equipment (PPE) that can address the major concerns of future winter tsunamis – even if they are unlikely. Waterproof GPS units are critical, as they can be attached to each person on a boat and that person can be tracked if thrown overboard. A flow chart of PPE was also created based on rain events and air temperature, allowing staff to scale up protection against exposure. The chart ranges from woolen undergarments all the way up to cold water exposure suits like those used in Alaska. Processes were changed to include tsunami drills, checking for weather events of a particular type, and noting changes in the landscape that could indicate a hazard.
We have lots to fear and love in one place, in this inland paradise. There are many things that can hurt us on Lake Roosevelt. But now at least we know when that next tsunami hits, our people might be a little shaken and a little cold, but also alive enough to be annoyed, angry, or even a bit elated.
