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Tsunami Planning

The greatest hazard facing the Oregon coast is a Cascadia Subduction Zone (CSZ) earthquake and tsunami that could occur at any time. It is important that all Oregonians understand and are prepared for this. The Oregon Coastal Management Program (OCMP) is coordinating with coastal communities to help them prepare for a local CSZ tsunami through land use planning. OCMP is administered by the Oregon Department of Land Conservation and Development.

From 2016 through 2021, OCMP conducted a project with many coastal cities and counties focused on reducing the potential negative impacts of a tsunami through local mapping, the adoption of Tsunami Hazard Overlay Zones, development of Tsunami Evacuation Facility Improvement Plans (TEFIPs), and more. The resources posted here are the results of this work. Coastal cities and counties that have not yet done this type of planning can benefit from these lessons learned and plan for tsunami resilience in their own communities.
Jurisdisctions with Tsunami Hazard Overly Zones


Maps from the Oregon Department of Geology and Mineral Industries (DOGAMI) are the best source of information for identifying areas that may be subject to tsunami inundation. DOGAMI has produced several map products depicting tsunami inundation for the Oregon coast, all of which can be found on their Tsunami Clearinghouse webpage.

  1. Tsunami Inundation Maps (TIM's) depict the projected tsunami inundation zone from five different seismic events and their resulting tsunamis: small, medium, large, extra-large, or extra extra-large (S, M, L, XL, XXL). These different modeled events are associated with differing levels of risk in terms of the relative likelihood of tsunami inundation.
  2. Tsunami Evacuation Maps are public products designed to direct visitors and residents away from low-lying areas in the event of a tsunami. They depict three color zones: orange for the largest expected distant tsunami (an earthquake occurs elsewhere but we receive a tsunami); yellow for the largest expected local tsunami (from a CSZ earthquake); and green for safety (or high ground). These maps come in brochure format, as an online viewer, a phone app, or you can make a custom brochure to print for a specific area of interest.
  3. Beat the Wave​: DOGAMI has completed detailed tsunami evacuation modeling for most coastal communities to determine the best routes to "beat the wave" to safety for a local tsunami event. These maps show areas of expected tsunami inundation, the most efficient routes to reach safety, and how fast one must travel to get there.

These maps allow communities and planners to understand the risk and vulnerability to a local tsunami event. With this information, they can look for ways to improve evacuation and implement land use strategies to improve community resilience. Visit www.oregontsunami.org​ for more information about maps and map products available for your area.

All coastal cities and counties are free to adopt tsunami resilience land use regulations created by and for their community. This kind of land use planning can influence where and how people build or use land over time. When tsunami hazards are considered and understood as communities develop, both short- and long-term resilience can improve.

OCMP created a Tsunami Land Use Guide​ that provides model code and comprehensive plan policy language as a starting point. It is important to note that the model code does not apply to single family homes on existing lots or parcels, nor does it apply to existing development.

The provisions suggested in the Land Use Guide focus on three main areas:

  1. Building new critical and special occupancy buildings, such as hospitals, police and fire stations, schools, and large gathering facilities away from areas at high risk for tsunami inundation (such as the “Large” or "Medium" tsunami inundation zones on the DOGAMI maps). This is to allow those buildings and services to function post-event. There is a “Use Exception” process to allow critical and special occupancy buildings to be permitted in the tsunami inundation zone based on specific criteria.
  2. Require new land divisions within areas at higher risk of tsunami inundation to include evacuation improvements in their overall development design, such as evacuation route signs, educational materials, or pedestrian pathways. This is to help ensure evacuation success to the maximum possible extent.
  3. Provide an optional flexible permit process which would allow a development proposal to modify underlying code standards (such as density requirements, height limitations, or setbacks) to achieve higher degrees of risk reduction than is required, similar in concept to a planned development. For example, waiving height limitations for a hotel that is built as a vertical evacuation structure.

Tsunami Land Use Guide – provides a path for communities to address tsunami risk through tailored land use planning. The Guide includes:

  • Sample comprehensive plan policies (for Goals 7, 11, 12, and 14)
  • Model code for a Tsunami Hazard Overlay Zone (THOZ) – tailorable to meet a community's risk tolerance
  • Steps to develop a Tsunami Evacuation Facilities Improvement Plan (TEFIP)
  • Financing and incentive concepts (such as how to finance evacuation improvements)

How to Implement Goal 7: Areas Subject to Natural Hazards​ – fact sheet about the post-acknowledgement plan amendment process a community can use to integrate new natural hazard data in their land use program.

Tsunami building code standards – As a result of the 2021 Legislative Session, there are now building code requirements for certain types of critical and essential facilities that are built within the tsunami inundation zone (as mapped​ by the American Society of Civil Engineers). These rules are different, but related, to any tsunami land use regulations in a local community.

Examples from Oregon Communities

Use the good work of others! Communities listed from north to south below have partnered with DLCD in tsunami resilience planning. Below is a selection of plans, maps, fact sheets, notices, and other resources, which may be useful to you or your community. Many communities, businesses, and organizations on the Oregon coast are working to prepare for a CSZ earthquake and tsunami. What is listed below is focused on land use planning work done with DLCD through two federally funded grants.

Gearhart

Transportation System Plan, which includes tsunami evacuation routes and tsunami evacuation improvement projects.
THOZ Map
Gearhart Tsunami Exposure Snapshot

Rockaway Beach

Tsunami Resilience Project Case Study
Open House Posters & Presentation Slides
THOZ Fact Sheet
Tsunami Evacuation Facilities Improvement Plan & Appendices
Rockaway Beach Tsunami Exposure Snapshot

Tillamook County

Comprehensive Plan​ Policies

Manzanita

Community survey about evacuation signs and blue lines

Lincoln City

Staff Memo to City Council about tsunami project
Lincoln City Tsunami Exposure Snapshot

Newport

Beach Access Resilience Report
Comp Plan Policies & THOZ
THOZ Map
Newport Tsunami Exposure Snapshot

North Bend

TEFIP – the City incorporated and adopted this into their Transportation System Plan
THOZ Map

Port Orford

Day of Action Press Release
Landowner Notification Notice (Measure 56)
Evacuation Route Map
Port Orford Tsunami Exposure Snapshot

Coastwide

Earthquake and Tsunami Community Disaster Cache Planning Guide​

​Many of the coastal communities doing this work received a technical assistance grant from OCMP. Click here for more information about our coastal planning grant program.

​Funding for this important work was made possible through grants from the National Oceanic and Atmospheric Administration's (NOAA) Office for Coastal Management and National Tsunami Hazard Mitigation Program.

Learn more about earthquake and tsunami hazards.
Learn more about natural hazard mitigation planning.​

 

Contact

Meg Reed
Coastal Shores Specialist
meg.reed@dlcd.oregon.gov
Phone: 541-514-0091

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