The Oregon coast is well known for its spectacular scenery and natural resources. However, because the coast lies at the interface between land and the Pacific Ocean, it also is a zone of great instability and vulnerability. Over time, we are gaining a greater awareness of our coast’s geologic hazards and its risks to people and property there.
Coastal Oregon is not only vulnerable to chronic coastal hazards such as coast erosion from winter storms and sea level rise, but it is also subject to potential catastrophic hazards such as a Cascadia earthquake and tsunami. It is for this local catastrophic tsunami event that this Land Use Guide has been developed. These types of powerful and devastating earthquakes of magnitude 9+ can be generated at the Cascadia Subduction Zone where the eastward- moving Juan de Fuca tectonic plate dives under the westward-moving North American plate just off the Oregon coast. These large earthquakes will occur under the ocean just offshore of our coast and can cause destructive tsunamis that can strike the coast 15 to 20 minutes after the earthquake. It is likely that in most Oregon coast communities, the only warning will be the earthquake itself.
DLCD has prepared a Land Use Guide for Oregon Coastal Communities to assist with preparing for a Cascadia Subduction Zone Tsunami. The goal of this Land Use Guide is to help local coastal communities become more resilient to a catastrophic tsunami event through community land use options and strategies. The guide is focused on a local tsunami event as these events will likely be far more destructive to an entire community and much harder to prepare for. Generally, in preparing for a local event a community should also be well prepared for a distant event. The guide is focused on land use planning approaches to reduce tsunami hazard risk, and is not intended to address the full range of efforts needed for overall disaster preparedness. Adequately preparing for a catastrophic event, such as a Cascadia earthquake and tsunami, requires a comprehensive community effort and must include preparation in many areas including education, outreach, individuals and family, emergency services, evacuation, economic, and land use. This guide can be used to develop land use strategies and options as one part of a community’s comprehensive preparedness effort.