Thinking Ahead to the Next Really Big One

Overview of Oregon’s Resilience Plan

A splendid 2015 New Yorker magazine article woke a lot of people up to the fact that here in Oregon, we’re overdue for a catastrophe of Biblical proportion, an civilization-leveling earthquake likely to run from magnitude 8.0 or even ten times or more powerful at 9.0+ (quake magnitudes are logarithmic, so each ordinal step, such as 1 to 2 represents an increase in earthquake strength of 10 times).

The paper below is a good overview of the situation, with recommendations for response.

For more than 300 years, Cascadia subduction zone off America’s northwest coast has lain dormant. Not until the 1980s did scientists recognize it as an active fault that poses a major geological  hazard  to  Oregon as well as northern California and  Washington.

In  1993, the building codes in Oregon were updated to address this newly revealed earthquake threat to the built environment. Since then, geologists have discovered that over 40 great earthquakes of magnitude 8 and larger have struck Western Oregon during the past 10,000 years (see Fig. 1).

The most recent event occurred on January 26, 1700 AD, and was a great earthquake with a magnitude of 9.0. The time interval between previous earthquakes has varied from  a few decades to many centuries, but most of the past intervals have been shorter than the 313 years since the last event.

The current calculated odds that a Cascadia earthquake will occur in the next 50 years range from 7-15 percent for a great earthquake affecting the entire Pacific Northwest to about 37 percent for a very large earthquake affecting southern Oregon and northern California. Many state and local officials have been concerned about potential widespread vulnerability of the buildings and lifeline infrastructure in Oregon.
In 1999, the Oregon Department of Geology and Mineral Industries (DOGAMI) published a preliminary statewide damage and loss study identifying the dire consequences of a Cascadia earthquake and tsunami for Oregon’s infrastructure and for public safety.

In the following ten years, the Oregon legislature passed several bills that directed the state to launch a statewide assessment of public schools and emergency response facilities and established a state grant program to help fund seismic upgrades to hazardous schools and other critical emergency response facilities.

Meanwhile, the state and local transportation agencies and some forward thinking utility providers have taken voluntary steps to assess seismic vulnerability of their systems and conduct limited seismic rehabilitation. However, the systems in different infrastructure sectors were assessed and/or rehabilitated by their public operators and private owners without coordination and without consistent understanding of their interdependencies on other systems let alone the consequences of their systems’ failure on the overall pace of the community recovery. There has been growing desire to break down the “silo” mentality and take a holistic look at comprehensive steps to mitigate the Cascadia earthquake risk to our economy and to our businesses, homes, and communities.


Figure 1. The 10,000-Year History of Cascadia Subduction Zone Earthquakes

In January 2011, three Oregon earthquake safety advocates suggested in the pages of the Oregonian [1] that Oregon should take new steps to make itself resilient to a big earthquake.

The March 11, 2011 Tohoku Japan earthquake and tsunami provided the occasion for Oregon’s House Representative Deborah Boone to introduce House Resolution 3 that was unanimously adopted by the state legislature in April 2011. The House Resolution 3 (HR 3) directed Oregon Seismic Safety Policy Advisory Commission (OSSPAC) to “lead and coordinate preparation of an Oregon Resilience Plan that reviews policy options, summarizes relevant reports and studies by state agencies and makes recommendations on policy direction to protect lives and keep commerce flowing during and after a Cascadia earthquake and tsunami”.

The focus of the HR  3 is on the state’s physical infrastructure. The plan and recommendations were scheduled to be delivered to the 77th Oregon Legislative Assembly by February 28, 2013. As the goal of the Oregon Resilience Plan is consistent with the aim of President Obama’s Presidential Policy Directive / PPD-8: National Preparedness issued on March 30, 2011, Richard Reed, President Obama’s Senior Director for Resilience Policy, Oregon Governor John Kitzhaber, and Cascadia Region Earthquake Workgroup (CREW) acknowledged the resilience planning efforts and provided their endorsement prior to the kickoff of the project.

Resilience Definition and Expected Earthquake Scenario 

Resilience as defined in the HR 3 means that Oregon citizens will not only be protected from life-threatening physical harm, but because of risk reduction measures and pre-disaster planning, communities will recover more quickly and with less continuing vulnerability following a Cascadia subduction zone earthquake and tsunami. For the Oregon Resilience Plan, OSSPAC defines the Cascadia earthquake (as mentioned in the HR 3) to be a Magnitude 9.0 Cascadia subduction earthquake with an average recurrence of once every 550 years. We believe that a Magnitude 9.0 earthquake is a very real possibility that would affect all of Oregon and is directly comparable to the 2011 Tohoku earthquake and tsunami, the effects of which are all too well known.
To achieve the goal of rapid recovery, we need arrangements in place for government continuity, resilient physical infrastructure, and business and workforce continuity. Resilient physical infrastructure is the foundation, and will help the state enhance its sustainability and other aspects of community resilience such as social, environmental, and economic resilience.


Figure 2. Resilience Triangle [2]

The definition of (physical) resilience can be better illustrated with the resilience triangle diagram as shown in Fig. 2.

Higher resilience is characterized with minimal reductions in critical lifeline services after a disaster, speedy recovery of those services, and an overall improved service level as a result of rebuilding damaged systems and implementing better systems. The resilience triangle diagram indicates that Chile and Japan have high levels of earthquake resilience. At the current stage, Oregon’s infrastructure has low resilience and is expected to have significant loss of sector services and an excessively long recovery time.

This is partly due to the sheer size and power of a magnitude 9.0 earthquake, but it is also the result of the inherent vulnerability of our buildings and lifeline systems. Another major factor that amplifies the effects of a Cascadia earthquake and delays the pace of recovery is the co-location and interdependencies of various lifeline infrastructure systems, coupled with the wide geographic spread of a Cascadia disaster as virtually all of the resources required for  the recovery of lifeline systems would have to come from outside the affected states.
Resilience Planning Methodology and State Response/Recovery Strategy 

OSSPAC identified existing earthquake resilience planning from San Francisco, California by the San Francisco Planning and Urban Research Association (SPUR) as a good model to follow. The SPUR developed a method that

(1) defines performance metrics for buildings and lifeline infrastructure based on what a community needs in the context of response and recovery stages and

(2) helps the community identify where the resilience gaps are.

The SPUR method focuses on the speed of infrastructure recovery, which is critical for Oregon’s economy as 50- 60% of our state work forces are employed by small businesses which do not have sufficient financial resources to survive lengthy business disruption.


Figure 3. Four Impact Zones for the Magnitude 9.0 Cascadia Earthquake Scenario

To apply the SPUR method to a state level, OSSPAC decided to divide the state into four distinct zones based on expected pattern of damage in combination with Oregon’s mountainous geography:

(1) Tsunami Zone;
(2) Coastal Zone (outside the Tsunami affected area);
(3) Interstate 5/Valley Zone; and
(4) Central/Eastern Zone (see Fig. 3 for these four impact zones).

In addition, this would allow the state to implement the statewide response and recovery effectively and efficiently.
In the Tsunami Zone, we anticipate that severe shaking and tsunami inundation would cause near total damage of buildings and lifeline infrastructure, and threaten the lives of thousands of residents and tourists. Thus, our focus is simply to save lives.
In the Coastal Zone, severe shaking and landslides that will cause damage to transportation systems would severely disrupt and isolate communities. Thousands of people displaced from the Tsunami Zone are expected to evacuate here. Thus, in the Coastal Zone, keeping the population sheltered, fed and healthy is critical to avoid humanity crises.
In the I-5/Valley Zone where we have majority of the state population and businesses, widespread moderate damage would severely disrupt daily life and commerce. It is clear that restoring services to businesses and residents will be the main priority.
The Central/Eastern Zone, light damage would allow rapid restoration of services and functions, and communities would become critical hubs for the movement of response, recovery and restoration personnel and materials for the rest of the state.

This requires the state to develop an efficient and cost-effective multimodal transportation system to maintain statewide connectivity and provide the highest level of mobility to the largest area and the highest population centers. This multimodal transportation system involves a lifeline backbone highway system supplemented with air transportation and marine ports.

The backbone highway system (after strengthened) will move goods and people from the Central/Eastern Zone to the Valley to the Coastal Zone. In addition, we believe that the Redmond Municipal Airport in the Central/Eastern Zone could be hardened to remain fully operational without much investment. From there, goods and people would be easily distributed to commercial airports in the Valley via fixed-wing aircrafts. Then, goods and people would access coastal areas by helicopters. An alternative redundant transportation system would serve Oregon from the west  from ships. Goods and people would have access to the ships either through selected ports shortly after the event or helicopters.
Advisory Panel and Eight Task Groups 

To complete the plan without funding and on a fourteen-month schedule, OSSPAC decided to lead and coordinate the preparation through its Resilient Oregon Steering Committee and chose to tap into volunteer expertise from Oregon’s academic, professional, governmental and public communities. Almost one hundred seventy volunteer experts drawn from a broad section of Oregon society were organized into one Advisory Panel and eight work groups to complete this planning task. The eight task groups include

(1) Earthquake/Tsunami Scenario,
(2) Business and Workforce Continuity,
(3) Coastal Communities,
(4) Critical/Essential Buildings,
(5) Transportation,
(6) Energy,
(7) Information and Communications, and
(8) Water and Waste Water.

The Advisory Panel consisted of representatives from the state and federal government, the state legislature, universities, and local businesses. It augmented OSSPAC’s overall capability and capacity, and provided strategic advice to the OSSPAC’s Resilient Oregon Steering Committee on an as-needed basis throughout the development of the Resilience Plan. Through its interaction with the Advisory Panel, OSSPAC was able to keep the state government, legislature, and businesses informed of overall statewide earthquake risk and necessary steps to mitigate it.
The OSSPAC’s Resilient Oregon Steering Committee provided leadership and direction to the eight task groups and helped coordinate the planning efforts among different groups to address interdependencies of various lifeline infrastructure sectors. Each task group was charged with three primary tasks for four affected zones (Tsunami, Coastal, I-5/Valley, and Central/Eastern Zones):

(1)  Determine the likely impact of the scenario earthquake on the assigned sector and estimate the time required to restore functions in that sector if the earthquake were to happen under current conditions;

(2)  Define performance targets for the sector. The targets represent the desired timeframes for restoring functions in a future Cascadia earthquake — in other words, the timeframes within which functions must be restored if Oregon is to be resilient;

(3)  Provide a series of recommendations to OSSPAC for changes in practice and policy that, if implemented, would ensure that Oregon reaches the desired resilience targets over the next 50 years.
The products from the various task groups were reviewed by the Advisory Panel  to ensure that the material was accurate, complete, and up-to-date. OSSPAC then reviewed the recommendations and selected and endorsed those that the commission felt offered the most effective way to achieve resilience to a great Cascadia disaster.
The Oregon Resilience Plan

After fourteen months of extensive planning, coordination, and meetings, OSSPAC assembled eight chapters that make up the plan titled The Oregon Resilience Plan: Reducing Risk and Improving Recovery for the Next Cascadia Earthquake and Tsunami [4] (See Fig.  4 for the report cover), and delivered it to the Oregon’s 77th Legislative Assembly on February 28, 2013. Below lists a brief summary of what each task group produced for the plan.
The Cascadia Earthquake Scenario Task Group (Chapter One) reviewed current scientific research to develop a detailed description of the likely physical effects of a great (magnitude 9.0) Cascadia subduction zone earthquake and tsunami, providing a scenario that other task groups used to assess impacts on their respective sectors.
The Business and Workforce Continuity Task Group (Chapter Two) sought to assess the workplace integrity, workforce mobility, and building/infrastructure systems performance – along with customer viability – needed to allow Oregon’s businesses to remain in operation following a Cascadia earthquake and tsunami and to drive a self-sustaining economic recovery. Resilience is primarily about the timely re-occupancy of residents as employees and businesses.

The Coastal Communities Task Group (Chapter Three) addressed the unique risks faced by Oregon’s coast, the region of the state that will experience a devastating combination of tsunami inundation and physical damage from extreme ground shaking due to proximity to the subduction zone fault.

The Critical and Essential Buildings Task Group (Chapter Four) examined the main classes of public and private structures considered critical to resilience in the event of a scenario earthquake, and sought to characterize the gap between expected seismic performance (current state) and desired seismic resilience (target state). The group also assessed buildings deemed vital to community resilience, and addressed the special challenges posed by unreinforced masonry (URM) and non-ductile concrete structures.
The Transportation Task Group (Chapter Five) assessed the seismic integrity of Oregon’s multi-modal transportation system, including bridges and highways, rail, airports, water ports, and public transit systems, examined the special considerations pertaining to the Columbia and Willamette River navigation channels, and characterized the work deemed necessary to restore and maintain transportation lifelines after a Cascadia earthquake and tsunami. The group’s scope included interdependence of transportation networks with other lifeline systems.
The Energy Task Group (Chapter Six) investigated the seismic deficiencies of Oregon’s energy storage and transmission infrastructure, with a special emphasis on the vulnerability of the state’s critical energy infrastructure (CEI) hub, a six-mile stretch of the lower Willamette River where key liquid fuel and natural gas storage and transmission facilities and electricity transmission facilities are concentrated.
The Information and Communications Task Group (Chapter Seven) examined the inherent vulnerabilities of Oregon’s information and communications systems and  the consequences of service disruptions for the resilience of other sectors and systems. The group explored the implications of co-location of communications infrastructure with other vulnerable physical infrastructure (e.g., bridges), and specified the conditions needed to accomplish phased restoration of service following a Cascadia earthquake and tsunami.
The Water and Wastewater Task Group (Chapter Eight) reviewed vulnerabilities of the pipelines, treatment plants, and pump stations that make up Oregon’s water and wastewater systems, discussed the interventions needed to increase the resilience of under-engineered and antiquated infrastructure at potential failure points, and developed strategies to address fire following the earthquake to minimize secondary damage to buildings. The group proposed a phased approach to restoration of water services after a Cascadia earthquake and tsunami, beginning with a backbone water and wastewater system capable of supplying critical community needs.
Major Findings of the Oregon Resilience Plan 

Oregon is far from resilient to the impacts of a great Cascadia earthquake and tsunami today.

The scenario Cascadia earthquake would be an unprecedented catastrophe for Oregon and for the United States. It would impact every aspect of life for all Oregonians and for the residents of northern California, Washington, and British Columbia.

The effects of a Cascadia subduction earthquake will be greatest on the coast, which is right next to the subduction zone fault, and will diminish as one goes inland. This, in combination with Oregon’s mountainous geography, divides the state into four impact zones: within the Tsunami Zone, damage will be nearly complete. In the Coastal Zone, shaking will be severe, liquefaction and landsliding will be widespread and severe, and damage will be severe. In the I-5/Valley Zone, shaking will be strong, liquefaction and landslide will be common but less severe, and moderate damage will be widespread. In the Central/Eastern Zone, shaking will be mild, landslides and liquefaction sporadic, and damage generally light.
Fatalities and Economic Loss

Available studies estimate fatalities ranging from 1,250 to more than 10,000 due to the combined effects of earthquake and tsunami, tens of thousands of buildings destroyed or damaged so extensively that they will require months to years of repair, tens of thousands of displaced households, at least $30 billion in direct economic losses (close to one-fifth of Oregon’s gross state product), and more than one million dump truck loads of debris.
Extreme Vulnerability of Liquid Fuel Supply 

A particular vulnerability is Oregon’s liquid fuel supply. Oregon depends on liquid fuels transported into the state from Washington State, which is also vulnerable to a Cascadia earthquake and tsunami. Once here, fuels are stored temporarily at Oregon’s critical energy infrastructure (CEI) hub, a six-mile stretch of the lower Willamette River where industrial facilities occupy liquefiable riverside soils. Disrupting the transportation,  storage, and distribution of liquid fuels would rapidly disrupt most, if not all, sectors of the economy  critical to emergency response and economic recovery.
Large Resilience Gaps Business Communities Can’t Afford 

Business continuity planning typically assumes a period of two weeks to be the longest disruption of essential services (i.e., utilities, communications, etc.) that a business can withstand, and service disruptions lasting for one month or longer can be enough to force a business to close, relocate, or leave the state entirely. Analysis in the Oregon Resilience Plan reveals the following timeframes for service recovery under present conditions as shown in Table 1. As shown on Table 1, row 1, basic electricity services are expected to be down for over three to six months in the Coast Zone and between one and three months in the Valley Zone, and so on.
Resilience gaps of this magnitude reveal a harsh truth: a policy of business as usual implies a post-earthquake future that could consist of decades of economic and population decline – in effect, a “lost generation” that will devastate our state and ripple beyond Oregon to affect the regional and national economy.


Based on the findings in the Oregon Resilience Plan, OSSPAC recommends that Oregon start now on a sustained program to reduce our vulnerability and shorten our recovery time to achieve resilience before the next Cascadia earthquake inevitably strikes our state.
OSSPAC urges systematic efforts to assess Oregon’s buildings, lifelines, and social systems, and to develop a sustained program of replacement, retrofit, and redesign to make Oregon resilient. Sector-by-sector findings and detailed recommendations are presented in each chapter of the Oregon Resilience Plan. Overarching priorities, illustrated with examples selected from the chapters, include new efforts to:
1.     Establish a State Resilience Office to provide leadership, resources, advocacy, and expertise in implementing statewide resilience plans;

2.     Undertake comprehensive assessments of the key building structures and critical infrastructure systems that underpin Oregon’s economy;

3.     Launch a sustained program of capital investment in Oregon’s public school buildings, emergency response facilities, and lifeline transportation routes;

4.     Craft a package of incentives to engage Oregon’s private sector in efforts to advance seismic resilience;

5.     Update Oregon’s public policies, including

(a) revising individual preparedness communications to specify preparation from the old standard of 72 hours to a minimum of two weeks, and possibly more;

(b) developing a policy and standards for installation of temporary bridges following earthquake disruption; and

(c) adopting a two‐tiered ratings system that indicates the number of hours/days that a citizen in a community can expect to wait before major relief arrives, and the number of days/months that a citizen can expect to wait before the community itself achieves 90 percent restoration of roads and municipal services.

published under a CreativeCommons Attribution License by three Oregonians, Kent Yu, Jay Wilson, and Yumei Wang. Cite as

Yu Q.-S., Wilson J., and Wang Y. Overview of the Oregon Resilience Plan for Next Cascadia Earthquake and Tsunami. Proceedings of the 10th National Conference in Earthquake Engineering, Earthquake Engineering Research Institute, Anchorage, AK, 2014. 

Yu is Principal, SEFT Consulting Group, Beaverton, OR 97005. Email:; Wilson is Emergency Manager, Clackamas County Emergency Management, Oregon City, OR 97045; Wang is Principal Engineer, Sustainable Living Solutions LLC, Portland, OR 97214