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Hello everyone, welcome back. It's Loma Prieta part 2 time. So we said when we were thinking back on the Loma Prieta earthquake, there were two questions that really came up in our mind.

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One was to think about what we learned from liquefaction from 1989 earthquake. The other one was just that was the last time we had a major earthquake in the Bay Area.

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And that was a long time ago. That was 35 years ago. Presumably, if another earthquake would happen in the Bay Area today 

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things would be completely different. Response would be completely different. The people involved would be completely different.

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Oh, would it? Let's find out. And to take us on this journey, we have the wonderful Tom Brother and Ruth Harris.

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Take us away!

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Thank you. Sarah. This is Tom Broker and our first speaker in this session will be Cynthia Kroll.

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Who's a retired chief economist at the Association of Bay Area Government. So Cynthia.

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Thank you for inviting me to join this panel. I've enjoyed looking back on several decades of work and thinking about how it informs the issues we face today.

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My background is in city original planning with an emphasis on regional economics. In 1974 I was at Stanford Research Institute.

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Now SRI International. Working on a technology assessment of earthquake prediction systems responsible for explaining the planning and social science impacts of the system.

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Two of the leading forecasters on the state's economy looked at the economic implications. What would it take for prediction to make us safer at what cost given the basic uncertainties surrounding earthquake occurrence, strength and impact even with prediction.

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By 1989 when Loma Prieta happened, I was at the Center for Real Estate and Urban Economics at UC Berkeley's Haas School of Business.

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The UCB Transportation Center received a large grant from NSF to look at the impacts of the earthquake on the region and with several planning colleagues, I looked at aggregate economic impacts as well as critical factors for small business.

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By the time USGS began crafting their HayWire Scenario, I had moved on to the Association of Bay Area Governments (ABAG).

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The Bay Area regional planning agency, which had its own website to inform communities of their levels of seismic risk.

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My work there involved implementing a new economic forecasting model, one with impact analysis capabilities. So when, Anne Wein approached me from USGS with the idea of integrating HayWired into our modeling, I was excited.

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Also, ABAG after the Napa quake I became involved with EERIs learning from earthquakes program in their business resilience working group.

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That was designing and piloting a survey for understanding the effects on businesses, not just initially, but over time.

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Since then the focus of this working group has expanded in composition and activities, and my short presentation today, I want to talk about how these experiences apply to the scenario building of USGS and others 

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and how the lessons not just from earthquake research, but also from experiences and policies forming around other disasters inform us on what we can expect going forward.

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Since the panel theme is the Loma Prieta earthquake let me start with some comments on the economic effects of that earthquake.

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It was a "wake-up" call with very costly physical damage but also highlighted the survivability of most of the structures in the area.

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Casualties were very low compared to what might have occurred in less wealthy parts of the world. Using different building techniques with one freeway interchange collapse responsible for the bulk of fatalities.

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The most concentrated damage in terms of the business community was in downtown Santa Cruz. But portions of Oakland and San Francisco also had serious problems 

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and Santa Cruz much was related to building structures in Oakland and San Francisco, ground conditions, and liquefaction were major contributors highlighting questions of where we should be building.

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Here are some illustrations of the economic impacts of the earthquake. There was damage to some major Bay Area highways and the Bay Bridge, but alternatives were restored quickly and disruption to most Bay Area businesses was measured in days or at most a month.

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The time frame was longer in Santa Cruz, but still for a minority of firms and in a much smaller geographic area.

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The quick restoration of infrastructure and utilities is a story of resilience that I think our other panelists will touch on.

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Impacts did not go just one way. There was redistribution among sectors and locations and probably over time, although not illustrated here.

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The Santa Cruz Watsonville area was most heavily affected, but Watsonville, for example, had a surge in sales in eating and drinking places.

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Probably capturing some business normally in Santa Cruz and partly from recovery activities. Santa Cruz saw a surge in building material sales, a sign of rebuilding and reconstruction already underway.

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Hotel employment dropped sharply in Santa Cruz and a bit in San Francisco while Oakland and San Jose saw increases.

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Our study included a survey of businesses that we're Chamber of Commerce members in the affected cities; small businesses in Santa Cruz reported more severe effects,

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but these differences were reduced within a month.

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More recently, the Business Resilience Working Group at EERI is learning from the earthquakes program began with a collaborative group of structural engineers and social scientists to look at how damage affects businesses.

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This working group now includes representatives from several U.S. agencies involved in tracking disasters in their response. Our efforts showed that survey responses often list some key points, such as the depth of loss to individual businesses and communities and the role of informal networks in recovery.

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The working group task have expanded to include more virtual reconnaissance but also to focus on case studies and individual interviews most recently in Turkey.

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The HayWired economic studies covered subareas, counties, the entire region, and the state and nation.

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Data availability was greatly improved from 35 years ago. USGS had developed extensive information on seismic factors as well as on infrastructure strength in government and utility responses.

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The data was used in several different studies to identify firm vulnerability, bisector and size. As well as the impacts of commute patterns on overall risk to businesses.

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Population behavior from recent earthquakes and other disasters helped inform migration patterns and labor availability in the ABAG analysis.

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Resilience factor assumptions were included for individual firms and sectors, supply chain and production adjustments, for example.

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And for employers and workers in response to transportation bottlenecks. Finally, the models are rough generalization, so sensitivity tests were applied after reality checks by reviewers to show how the conclusions could change with tweaks and assumptions.

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These showed not only both opportunities and vulnerabilities in the construction sector, but also relocation possibilities in the tech sector.

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So what have we learned? A few key points stand out. Damage to buildings needs to be viewed in broad terms, structural and non-structural within buildings and in adjacent space.

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Infrastructure restoration is key and how quickly businesses are restored to operation. Many different business strategies can make firms resilient after the fact and advance preparation can determine how successful resilience efforts are.

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Many regions recover from these events and the Bay Area would be one of them. However, there are businesses and communities within these areas.

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They are much more vulnerable and may find recovery very challenging. Low-income levels, loss of tax base, a business base of small firms, older residents and owners can all make recovery more difficult.

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When I look back over the work, I've been involved in for the past 50 years, I'm impressed with how much has changed in the basic conditions we face in the response capabilities.

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In terms of basic conditions, our population is demographically more diverse and also older. There have been several rounds of experience with displacement highlighting the need for approaches to protect the vulnerable.

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Our response agencies have many more tools and strategies to draw from and lessons learned and other disasters are helping to shape our understanding of what works.

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We continue to see efforts to make mitigation a reality, updating building codes, soft story retrofits, while we learn more all the time about resilience approaches.

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So what do we need to do now? We need to put what we have learned into action. We need to plan to make as many buildings as possible earthquake and fire resistant.

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We need to plan how to house people who will certainly be displaced. And how to keep vital businesses and services in operation.

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Plans for viable transportation alternatives following the damage we can expect from an earthquake. And for how to quickly restore other infrastructure crucial to resilience,

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telecommunications, power, and water, for example. We also need to build community capacity.

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Effective business networks today will provide resources for cooperative support tomorrow. Empowering traditionally disenfranchised communities today will provide local residents with resources to be part of the rebuilding rather than targets for relocation.

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Governments need cooperative agreements too for mutual aid. These work well already in many parts of the state.

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We also need to recognize some of the tough questions. Unlike other types of disasters the state is excessively underinsured for earthquakes.

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In addition, the jurisdictions that will be most in need of resources will also be the ones that see the greatest drops in revenues,

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as their property values drop. The Learning from Earthquakes Program can play an important role in developing, coordinating, and communicating information.

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There's much more to say perhaps in our discussion time. Thank you for your time.

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Thank you, Cynthia. I think Ruth will introduce our next 

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speaker.

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Yes, thank you, Cynthia. Our next speaker is Jack Bachhuber 

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Director of Geosciences at the Pacific Gas & Electric Company or PG&E. Here to present on the impacts of the 1989 Loma Prieta earthquake on the PG&E electric system.

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The earthquake occurred in the central part of our service territory. In adjacent to our area of highest customer density, and also system.

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I speak from personal experience. As I was an in-house contract geologist at the time and I was based in an office in San Ramon for PG&E.

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I experienced quite a bit of swaying and then after the event was involved in system inspections in seismic geology observations.

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The earthquake effects highlighting important lessons learned and also discussed how this influenced current in future planning in actions to make our system more resilient against future earthquakes.

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The Loma Prieta earthquake is the largest and most damaging earthquake experienced by the company since the 1906 Great San Francisco earthquake.

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The earthquake caused significant system damage, which resulted in outages affecting 1.4 million customers 

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through parts of nine counties included distribution systems as well as our gas distribution system. Rapid understanding and assessment of system damage was essential to plan initial emergency response.

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This had a start as night approached and into the darkness since the earthquake happened just after 5 p.m.

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Damage impacted the electric energy supply. The power plants tripped off line due to damage and perturbations in the transmission grid.

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Power within the plans for operations was cut off, forcing workers to respond by backup power from generators or by flashlight.

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Power coming in from power plants outside of the affected area, such as the Diablo Canyon power plant which was far away and undamaged 

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provided the central feed energy to the area for undamaged parts of the transmission system that were still operating.

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One equipment cut off power to Monterey in Santa Cruz. Even though some of the switch art equipment had been seismically retrofit

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previously other equipment with low seismic design standards failed at the higher level of shaking that occurred.

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A key finding from the earthquake is how differential movement between interconnected equipment caused failure due to insufficient slack or accommodations between components against this movement.

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Some towers generally perform well through the earthquake. But equipment failure and some substations interrupted electric transmission.

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Similar to the Moss Landing switch yard, equipment toppling and connection failures were responsible for the greatest damage.

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This system helped to quickly restore power transmission through damaged substations. An example of this is that the Metcalf Substation where partial energy flow could still be transmitted through undamaged 230Kv system components.

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when the 500Kv equipment failed. PG&E repairs and life-cycle replacement for the type of equipment that failed has largely eliminated the kinds of vulnerability exposed from the Loma Prieta earthquake.

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This is a good example of learning from earthquakes, building back better, and progressive system reliability improvements.

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[indiscernible] and do not have significant damage. Localized damage is were sustained, however, for the low pressure gas distribution system, notably in the San Francisco Marina District and

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in the Watsonville area from a combination of ground motion shaking and possible liquefaction. Cast iron pipes experience failure.

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Here the entire grid of this vulnerable type of pipe was replaced during repairs by new plastic pipe. On order of 10 miles of pipe replacement performed in 4 weeks by 400 workers.

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The vulnerability of this cast iron pipe was known previously to the earthquake and was being replaced.

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But a localized area in the Marina District had not yet been addressed. There is no remaining cast-iron pipe in the PG&E system.

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It has all been replaced by a much more resilient modern pipe. Electric distribution system: it was most severe in the South Bay area around Los Gatos, Saratoga, and Santa Cruz County in the epicentral area.

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Typical damages were down wires and broken cross arms due to areas of highest ground velocity. There were few cases of drop transformers as PG&E had already applied lessons learned from the 1952 White Wolf earthquake in southern California and since practice solid bolt connections of transformers to pull so they perform well 

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In the Loma Prieta earthquake. Right after the earthquake to direct respiration from the company Emergency Operation Center 

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in the San Francisco main headquarters building. Hundreds of employees made their way to the office, some having difficulties.

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You did the closure and damage to the Bay Bridge, Cypress structure, and other transportation corridors.

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An important takeaway lesson from the earthquake was for PG&E to improve the emergency response process by further distributing reporting locations.

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Workers were called from all across PG&E.  An augmented with field crews from sister utilities in southern California and the Western States through Mutual Aid agreements.

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State, local and federal agencies assisted in the response. An interesting example was transportation of replacement electrical equipment by military airlift.

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Mutual Aid crews assisted a major gas relight effort, which required the combined workforce of over 1,000 gas technicians 

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so work through the backlog to inspect and return service for customers who proactively shut off their own gas.

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Transportation closures complicated in extended restoration for some more isolated in rural communities. Yeah, electric supply was restored to all but 26,000 of the 1.4 million affected customers within 48 hrs and 

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the system and operations were generally back to normal within 4 days.

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This earthquake has been the most significant event since the 1906 San Francisco earthquake. Other more recent earthquakes have been significantly smaller in magnitude 

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or outside of dense population areas, reducing damage and impact. We can continue to plan for a future large earthquake with greater potential impacts than the Loma Prieta event.

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Including a potential Hayward fault event captured by the U.S. Geological Survey HayWired Scenario.

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Notification and response tool called Dash. The Dash program combines ShakeMap and Asset map layers with damage models to identify the location, severity, and initial response for an earthquake within 15 minutes of the event.

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The tool also can run scenario earthquake events to use for emergency response planning exercises and training.

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Better earthquake. PG&E is similar to other power utilities, has a dedicated emergency response group that directs some plans earthquake responses including developing detailed response plans and training.

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System component, infidelity models, and are used to test the electric grid. The model output is used to identify remaining vulnerabilities and prioritize studies and mitigations.

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On an annual basis this includes life cycle replacements with improved more resilient equipment. And specific targeted mitigations.

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So some hardening micro-grids in undergrounding performed for storm and fire mitigation also provide benefits for seismic performance.

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Learning from earthquakes continues to be an important way to improve our risk models and mitigations.

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As well as a component of seismic testing in improved standards.

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It includes increased outreach and collaborations between lifeline utilities. Such as occurring during this workshop.

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We are excited with new developments and progress on earthquake research that are being supported by PG&E and our collaborators.

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This will be integrated to improve our risk models.

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Thank you for inviting me to give this presentation and I look forward to any questions that you may have.

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Thank you, Jeff. That's great and lots of questions for later.

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Yes, thank you, Jeff that was a really interesting presentation. Our next speaker is Roberts McMullen 

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And he's a senior civil engineer. With the East Bay Municipal Utility District.

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So, Roberts.

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Oh hi, I'm Roberts with Mullen and I'm a senior civil engineer from East Bay Municipal Utility District (EBMUD).

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And I'll be presenting on the impacts on EBMUD then, now, and in the future based upon the 1989 Loma Prieta earthquake.

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Okay, the agenda for today includes giving information related to the damage following the Loma Prieta earthquake on EBMUD's infrastructure.

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The development of the Seismic Improvement Program or the SIP. Our collaboration with USGS and others on the HayWired Report.

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Our current seismic program that we have in place today at EBMUD and then what we're looking for into the future.

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Following the number, EBMUD reported 135 pipe repairs in total;

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52 on cast iron; 46 on steel; 13 on asbestos cement; 2 on PVC, and 22 on service repairs.

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The figure on the right shows the location of pipe repairs in the EBMUD system, where a majority of the repairs are located in artificial fill 

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located closer to the San Francisco Bay.

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EBMUD teamed up with American Lifelines Alliance to review the collective main break repairs, the repair base.

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Using this information with American Lifelines Alliance (ALA). We were able to develop damage trends of pipelines and  develop a fragility formulas that could be used for damage or prediction.

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An example of this is the chart showed here on the right which shows the repair rates per 1,000 feet of pipeline 

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versus peak ground velocity inches per second and we were able to develop this relationship that could estimate the number of breaks for a 1,000 feet of pipe.

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Using input of PGV and PGA, the pipe characteristics of what type of material the pipe is made of, and then whenever scenario earthquake event you wanted to review.

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The district has always been committed to hazard mitigation. In 1995, the district launched this 12 year, 189 million SIP to retrofit facilities and minimize earthquake impacts on the water system.

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The program, the first of its kind in the Bay Area, was then completed in 2007.

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The program scope included improvements to storage reservoirs, pumping plants, clutter not tunnel improvements, Southwood pipeline installation,

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4 crossing improvements, building and equipment anchorages, and water treatment points, where 3 of the major components focused on pipelines alone.

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However, the pipeline focus on critical facilities and some pipelines the focus was not on the distribution system.

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Starting around 2014 EBMUD collaborated with USGS and Keith Porter on the development of the HayWired Scenario Report that evaluated the hypothetical yet scientifically realistic depiction of a scenario earthquake event on the Hayward fault.

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USGS estimated mainshock following aftershocks. Total property damage and business disruption is estimated at $86 billion and an additional $30 billion is estimated for fire damage.

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And as said, EBMUD support with the development of the report and a lot of the assumptions needed for estimating pipe damage and the

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return of service that I'll get into later.

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Okay, now to discuss the results of the HayWire Report. The key map on the left shows the concentration of repairs per square kilometer for both the mainshock and aftershocks 

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with concentrations shown in parts of Oakland, Berkeley, San Leandro, and Alameda.

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The graph on the right shows the number of repairs remaining versus time for the Oakland Hills region of our distribution system.

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It would take about 6 months to repair all the breaks in the store; all of the districts; 380,000 services under "as is" conditions.

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The graph also shows that if the districts 2,400 miles of brittle, asbestos and cast iron pipe could be replaced. It would reduce the number of breaks from about 3,500 to 2,300 

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and the time it would take to restore the system would be reduced to 3 months.

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Currently, the district is promoting the Resilient Network Concept that is shown in this figure.

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The concept would focus on installing resilient pipes and isolation valves so a minimum level of service is restored quickly 

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to a vast majority of critical customers such as hospitals or post-earthquake event shelters. The goal of the program is to strategically replace pipelines in order to build a resilient grid or network system and keep critical customers and service after an earthquake event.

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Our current pipeline replacement program called "Rebuild" has goals to increase a number of miles of pipelines to replace each year.

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We've more than doubled our replacement rate since 2014 when the "Rebuild Program" was initiated.

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Main breaks are still gradually tending upwards, which justifies the need to continue our ramp-up as we head towards 30 miles of pipelines that we replace per year.

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Brittle pipelines such as asbestos cast iron pipelines are now being replaced with more resilient pipeline materials.

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For all of our replacement projects for pipelines, we are installing pipes that lock together at the joints,

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thus improving the resiliency in our system. All tightly installed including fittings and vowels have joints that lock together, resist pull apart.

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Earthquake resistant ductile iron pipe can move back and forth inside the joint that can accommodate some ground movement.

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Our primary pipe that we install here at EBMUD is ductile iron pipe and is discussed and has rocking joints.

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Within our Geohazardous areas, earthquake resistant ductile iron pipe is what we design.

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For our larger diameter transmission means that are 20 inches and greater, we still use steel pipelines. So either with beam and fuel hazardous areas or outside.

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And then we are also looking into using trenches rehabilitation methods such as cast and voice pipelines to use within areas where we have asbestos in that pipe or cast iron.

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EBMUD has teamed up with UC Berkeley to launch a new research in an innovation center to address infrastructure challenges such as natural hazards.

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The center is capable of testing pipelines and connections to help innovate the pipeline industry to install more resilient systems.

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EBMUD helped to teach an undergraduate course in the fall providing a broad background in water and waste water operations, engineering, and maintenance.

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This collaboration is imperative to better understanding new pipe materials to build a resilient network of pipelines as well as teach and inspire a new generation of engineers to continue the effort.

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Well that wraps up my presentation for today. Thank you.

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Thank you, Roberts. Looking forward to our discussion at the end. Thank you for a really good talk.

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Our next speaker is Tim Dawson from the California Geological Survey.

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Good morning. My name is Tim Dawson and I am the manager of the Seismic Hazards Program at the California Geological Survey.

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The theme of this session of the 2024 Northern California Earthquake Hazards Workshop 

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is impacts on stakeholders then, now, and in the future from the Loma Prieta earthquake.

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I will spend the next 10 minutes or so discussing how the 1989 earthquake changed the course of the California Geological Surveys (CGS) activities.

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Geotechnical practice in California and what lies ahead in terms of improvements to seismic safety related to CGS's focus on ground deformation hazards such as liquefaction and earthquake induced landslides, and

00:29:54.000 --> 00:29:58.000
strong motion instrumentation on climate change.

00:29:58.000 --> 00:30:07.000
This is important to remember the earthquake safety improvements to building construction practices related to seismic issues in California are driven by significant earthquakes.

00:30:07.000 --> 00:30:14.000
Subsequent legislation takes the lessons learned from these earthquakes and is intended to better protect the public from earthquake hazards.

00:30:14.000 --> 00:30:31.000
One of the earliest examples of this is the 1933 magnitude 6.4 Long Beach earthquake which severely damaged over 200 public schools in southern California many of them constructed as unreinforced masonry buildings such as the one shown here on the upper left.

00:30:31.000 --> 00:30:39.000
Fortunately, the earthquake occurred after school hours averting what could have been a much larger tragedy than it already was.

00:30:39.000 --> 00:30:46.000
The Field Act was enacted shortly after the earthquake and mandates earthquake-resistant construction for public schools in California.

00:30:46.000 --> 00:30:54.000
The 1971 San Fernando earthquake was the next earthquake where the lessons learned from this earthquake resulted in legislation.

00:30:54.000 --> 00:31:07.000
This time addressing the hazards, related to surface fault rupture known as Alquist Priolo Earthquake Fault Zoning Act and hospital construction, the Alquist Hospital Safety Act.

00:31:07.000 --> 00:31:10.000
The 1989 Loma Prieta earthquake

00:31:10.000 --> 00:31:20.000
resulted in the Seismic Hazards Mapping Act, which addressed the hazards of liquefaction and earthquake induced landslides, which I will discuss later in this presentation.

00:31:20.000 --> 00:31:33.000
Most recently, although it's hard to believe that it was over 30 years ago this year; the 1994 magnitude 6.7 Northridge earthquake resulted in additional modifications to acute care facilities at hospitals in California.

00:31:33.000 --> 00:31:44.000
The impacts which are still being felt today as hospitals throughout California are working towards meeting current seismic safety requirements by 2030.

00:31:44.000 --> 00:31:54.000
Similar to the Alquist Priolo Earthquake Fault Zoning Act, the seismic hazards mapping act was response to a significant earthquake and included a broader group of ground deformation hazards.

00:31:54.000 --> 00:32:02.000
Embedded within the legislation, the Act initially covered liquefaction, earthquake induced landsides and amplified shaking.

00:32:02.000 --> 00:32:08.000
Later, tsunamis were added following a minor tsunami triggered by the 1992 Petrolia earthquake

00:32:08.000 --> 00:32:18.000
and amplified shaking was dropped because it was determined by an advisory group that the building code at the time captured the hazard.

00:32:18.000 --> 00:32:36.000
Listed here are the key elements of the Seismic Hazards Mapping Act. The State Mining and Geology Board sets the mapping priority, produces guidance documents with help from CGS for implementing the requirements of the Act and promulgates the regulations requirements related to the legislation.

00:32:36.000 --> 00:32:49.000
The California Geological Survey creates earthquake zones of required investigation for liquefaction and earthquake induced landslides using available geologic geotechnical and seismological data.

00:32:49.000 --> 00:32:53.000
USGS products such as the National Seismic Hazard Model is a key ingredient in these maps, providing estimates of expected ground motion 

00:32:53.000 --> 00:33:09.000
that can trigger liquefaction and earthquake induced landslides. Other existing data such as high resolution topography, geologic mapping including mapping by CGS, USGS, and academic sources.

00:33:09.000 --> 00:33:21.000
As well as data from technical investigations performed for construction projects and collected from city and county building departments also provides a vital role in the projection of these zone maps.

00:33:21.000 --> 00:33:34.000
Finally, local governments cities and counties implement the requirements of the act by requiring geotechnical investigations and mitigation for construction projects within their jurisdictions.

00:33:34.000 --> 00:33:45.000
Guidance to CGS on the best approaches to delineate zones was published internally in 1992 is required by the act and then officially in 1999 a special publication 118.

00:33:45.000 --> 00:33:53.000
These guidelines were last updated in 2004. Guidelines for lead agency reviewers consulting geologists 

00:33:53.000 --> 00:34:01.000
and consulting engineers was published first in 1997 as Special Publication 117 and last revised in 2008.

00:34:01.000 --> 00:34:13.000
The release of Special Publication 117 was significant because for the first time there was a document that presented the best practices in evaluating and mitigating seismic hazards throughout the state.

00:34:13.000 --> 00:34:22.000
It emphasized the importance of read agency review of engineering and geotechnical reports by engineering geologist and geotechnical engineers.

00:34:22.000 --> 00:34:40.000
It presented information on how investigation should be conducted and reports prepared. The Seismic Hazards Mapping Act Advisory Committee was challenged to find a balance between uninforming lead agencies on the state of practice, yet not being too specific to avoid creating underground regulations.

00:34:40.000 --> 00:34:50.000
A result of that caution was that the city and county of Los Angeles convened their own technical committees under the auspices of SCEC and the American Society of Civil Engineers 

00:34:50.000 --> 00:34:58.000
to provide more definitive guidance for the review of geotechnical investigations that address seismic hazards and mitigation.

00:34:58.000 --> 00:35:06.000
The implementation committee documents were released in 1999 for liquefaction and in 2002 for landslide hazards.

00:35:06.000 --> 00:35:19.000
In 2003, a little more than a decade after the Seismic Hazards Mapping Act went into effect a survey of local lead agencies was conducted to evaluate the effectiveness of the act.

00:35:19.000 --> 00:35:32.000
Questions included, how well has the act improved the safety of new buildings in your community? Are ground failure hazards evaluated more thoroughly and has the standard of geotechnical practice increased?

00:35:32.000 --> 00:35:45.000
The majority of responses indicated that the answer was "yes," ranging from slightly improved to greatly approved, suggesting that the Seismic Hazards Mapping Act had a positive effect on the evaluation of hazards 

00:35:45.000 --> 00:36:04.000
at the project level within the state. Since 1990, CGS has prepared 138 zone maps out of 410 quadrangles identified as high risk areas with the mapping largely focused on urban core areas of the San Francisco Bay Area and Los Angeles region.

00:36:04.000 --> 00:36:11.000
Zoning priorities are mostly based on areas of high forecasted ground motion for probabilistic seismic hazard analysis 

00:36:11.000 --> 00:36:25.000
and areas with high population density and population growth projected census data with additional consideration of geologic conditions that make these areas susceptible to the ground deformation hazards addressed.

00:36:25.000 --> 00:36:32.000
CGS is mostly focused on completing mapping for Contra Costa County with new maps scheduled for release in February.

00:36:32.000 --> 00:36:42.000
For Western and Central Contra Costa County. Ongoing work will focus on Sonoma County and the city of Sacramento and preliminary work has begun in Santa Cruz County.

00:36:42.000 --> 00:36:49.000
As you can see from this map, much work remains to be done throughout the state to complete these high priority areas.

00:36:49.000 --> 00:37:02.000
I'd like to take a moment to highlight this report authored by Tom Brocher and others about investments made in earthquake mitigation in the San Francisco Bay Area and focus on investments in schools and hospitals.

00:37:02.000 --> 00:37:10.000
Since, 1989, Brocher and others estimated that $8 to $12 billion dollars were invested in public school retrofits and seismic upgrades.

00:37:10.000 --> 00:37:24.000
Even more impressive is that almost $19 billion dollars were invested in acute care facilities and hospitals. Collectively, these investments accounted for over a third of the total spending on seismic improvements in the Bay Area.

00:37:24.000 --> 00:37:47.000
This amount has almost certainly continued to rise as hospitals and public schools have continued to upgrade their facilities. The reason I point this out is that the review of essential facilities such as public schools and hospitals is one of CGS's core activities and arguably some of the most impactful work that CGS conducts affecting the citizens of California throughout the state.

00:37:47.000 --> 00:37:57.000
Through our essential facilities review unit, CGS works with our partners such as the Division of the State Architect and the Department of Healthcare Access and Information 

00:37:57.000 --> 00:38:19.000
to ensure the seismic safety of public schools and acute care facilities throughout the state of California. This slide highlights the Recent accomplishments, which is typical for any given year of this team in 2023, which includes celebrating 50 years of hospital reviews under contract with our partners at the Department of Healthcare, Access and Information; 

00:38:19.000 --> 00:38:34.000
475 school reviews that were completed and 22 hospital reviews. This is a total of 754 technical review letters that were sent to geologists and geotechnical engineers working on these projects.

00:38:34.000 --> 00:38:41.000
We also published a Geoblog available on the CGS website that highlights the work done by the essential facilities review unit.

00:38:41.000 --> 00:38:47.000
The URL for this story map is highlighted on screen.

00:38:47.000 --> 00:38:55.000
Much of this work is a direct consequence of major earthquakes that have occurred in California such as Loma Prieta, illustrating the long-lasting and substantial impacts that earthquakes have on our society 

00:38:55.000 --> 00:39:07.000
and improvements to protect the public of the adverse effects of earthquakes. We are also working to implement several technological improvements for zoning, including Standardized groundwater mapping procedures.

00:39:07.000 --> 00:39:17.000
The incorporation of Cone Penetration Testing (CPT) data, which is more widely available than in the past for site specific geotechnical studies.

00:39:17.000 --> 00:39:29.000
A revamped online geotechnical report upload and distribution facility. This is similar to the online portal that CGS has developed for the distribution of fault studies done under the AP Act.

00:39:29.000 --> 00:39:36.000
The use of Geologic Strength Index (GSI) Hoek-Brown criteria and the evaluation of regional landslides and fully probabilistic analyses of triggering and ground deformation 

00:39:36.000 --> 00:39:54.000
for liquefaction and landslides. If anyone is interested in these topics or has suggestions, I encourage you to reach out to our landslide and liquefaction unit leads, Erik Frost and Brian Olsen who are attending this workshop.

00:39:54.000 --> 00:40:01.000
Finally, we are looking into the assessment of climate change impacts; sea level rise on areas susceptible to liquefaction.

00:40:01.000 --> 00:40:09.000
As you can see on the map on the right, many of the areas most susceptible to liquefaction are in the low-lying areas surrounding San Francisco Bay.

00:40:09.000 --> 00:40:16.000
The impacts of sea level rise due to climate change have not yet been considered in the production of revision of the Seismic Hazard Zone Maps.

00:40:16.000 --> 00:40:23.000
And yet, sea level rise will almost certainly affect regional groundwater levels in areas that might experience liquefaction.

00:40:23.000 --> 00:40:30.000
This year, CGS will be collaborating with Scott Brandenburg and colleagues at UCLA on a project that will begin to look at these 

00:40:30.000 --> 00:40:41.000
potential impacts of sea level rise on liquefaction. If you have any questions about this presentation or CGS activities, please reach out to myself or any of the CGS team members who are attending this workshop.

00:40:41.000 --> 00:40:52.000
Thank you for watching this presentation and I'd like to thank the convenors of this year's workshop for inviting me to participate in this session.

00:40:52.000 --> 00:40:57.000
Thank you very much, Tim that was a great presentation and summary of the work at CGS.




















00:40:57.000 --> 00:41:06.000
Our last speaker of this session will be Bart Ney who's the Office

00:41:06.000 --> 00:41:14.000
Chief of Public Affairs at Caltrans Bay Area. So Bart.

00:41:14.000 --> 00:41:20.000
Greetings everyone. Thank you for this opportunity to discuss Loma Prieta from Caltrans perspective.

00:41:20.000 --> 00:41:37.000
My name is Bart Ney, I am the Office Chief of Public Affairs for Caltrans in the Bay Area and for almost two decades I worked on the bridges that were rebuilt and retrofited in response to Loma Prieta as a spokesperson as the head of the Communications Department for the Colbridge Oversight Committee.

00:41:37.000 --> 00:41:46.000
So a lot of experience there. So getting right into our talk today, who was Caltrans then, now, and in the future.

00:41:46.000 --> 00:41:52.000
And I think we've always been an agency that's focused on safety. We're here to get you there.

00:41:52.000 --> 00:41:58.000
No matter when it was in time, now in the future, back then we've been a rainbow of cultures and people the entire time.

00:41:58.000 --> 00:42:11.000
Engineers come of every, every asked, but we're not just engineers, we're maintenance people, we're communications folks.

00:42:11.000 --> 00:42:33.000
We have about 20,000 employees statewide and the picture that we're showing here is, Brian Maroney, who had a 36-year career with Caltrans and was one of the premier designers for the bridges that we're going to be discussing today, especially the the Bay Bridge.

00:42:33.000 --> 00:42:41.000
So, Loma Prieta we've probably gone over these stats at nauseam 

00:42:41.000 --> 00:42:46.000
but of course, the anniversaries was upon us on October, 17, 1989,

00:42:46.000 --> 00:42:55.000
5 o'clock is a big commuter time for us, 6.9 magnitude earthquake struck the Bay Area 10 miles away from Santa Cruz Mountains 

00:42:55.000 --> 00:42:57.000
and caused one of the biggest tragedies we've seen in the Bay Area, 63 deaths, almost 4,000 injuries, 

00:42:57.000 --> 00:43:19.000
and estimated $6 billion dollars, 1989 dollars of damage throughout the region. So for us and for just about everybody, one of the most difficult things to see was the collapse of the Cypress structure, almost a mile of freeway.

00:43:19.000 --> 00:43:30.000
The upper deck pancake on the lower deck because the decks were supported by the same columns. And this footage kind of ran at nauseam in the media because its so terrifying.

00:43:30.000 --> 00:43:35.000
The Cypress structure is part of the Nimitz Freeway; it's almost 2 miles long.

00:43:35.000 --> 00:43:43.000
It was constructed between 1955 and 1957. It was built on fill and single columns supported both decks.

00:43:43.000 --> 00:43:52.000
Those columns were not ringed for extra support so, when blasting occurred, we had the failure that you saw and in this location.

00:43:52.000 --> 00:43:57.000
42 people died. It was the largest loss of life in Loma Prieta at that location.

00:43:57.000 --> 00:44:07.000
So we got right after it. Even though it took a while, we had to work with the community and in 1997 the Nimitz Freeway was rerouted.

00:44:07.000 --> 00:44:10.000
Now extra work took it into 2001, but basically we changed that freeway into a single deck with surface streets.

00:44:10.000 --> 00:44:15.000
We worked pretty strongly with the community over those years, we relocated a railyard to get extra space.

00:44:15.000 --> 00:44:41.000
We eliminated the Eighth Street exit. We added two more exits at Seventh Street. And we also helped establish the Cypress Mandela Training Center, which is a community-based organization that teaches youth, some of the trades that they can use in construction.

00:44:41.000 --> 00:44:47.000
And this is just a view of what that alignment looked like after Cypress structure was removed.

00:44:47.000 --> 00:44:51.000
Now there's a beautiful park at this location.

00:44:51.000 --> 00:45:01.000
Then we get to the bridges and we got going with the Carquinez Strait bridges first. The new Alfred Zampa Bridge 

00:45:01.000 --> 00:45:06.000
was opened in 2003. It was a first new suspension bridge built in the United States in over 30 years.

00:45:06.000 --> 00:45:16.000
This really started a bridge building boom that we hadn't seen in a generation.

00:45:16.000 --> 00:45:25.000
New technologies and old trusted skills were used on this. So the control tensioning method we use to place 8,584, 5-diameter wires very carefully as you can see here with that iron worker working on the bridge,

00:45:25.000 --> 00:45:47.000
but it was fascinating to actually see a suspension bridge constructed in the Bay and this particular one was named after a blue collar worker, Al Zampa who had worked on all the Bay Area bridges and was famous for having fallen off the Golden Gate Bridge survived it and got his job back.

00:45:47.000 --> 00:46:10.000
Now the seismic considerations for the Zampa Bridge, basically the building a suspension bridge we eliminate the center tower so there's less mass out there you open up the waterway eventually which is open now we battered the tower legs so the tower legs are coming down at an angle for better support and seismic event the piles that the tower sit on are 10 feet in diameter and there is a center

00:46:10.000 --> 00:46:19.000
time it spanned for that main cable that dissipates energy in an earthquake and this was all done for the secondary emergency route for the Bay Area.

00:46:19.000 --> 00:46:30.000
We're going to talk about the primary route now. So normally suspension bridges are built with about a 500-year return period.

00:46:30.000 --> 00:46:34.000
And what that means is the largest potential earthquakes you'd see within a 500-year time.

00:46:34.000 --> 00:46:46.000
Those ground motions are looked at and that's what we designed for. But a lot of the engineers that work on the Bay Bridge actually responded to the 1989 Loma Prieta earthquake were affected by it.

00:46:46.000 --> 00:46:52.000
And so our decision makers elevated what we would be doing at her to a 1,500 year we call it a safety evaluation earthquake.

00:46:52.000 --> 00:47:02.000
Which means much larger ground motions are being designed for. That required us innovating new structural solutions for this unique bridge.

00:47:02.000 --> 00:47:08.000
There were three key challenges that we saw with building this new bridge. Obviously one is going to be built in the most stringent seismic standards that were developed.

00:47:08.000 --> 00:47:15.000
Specifically for this bridge. It also had to be constructed while we kept traffic running on the old bridge.

00:47:15.000 --> 00:47:31.000
And the community wanted it to be an icon. Which was quite a challenge to figure out with them, but as you can see from this, you know, we got there.

00:47:31.000 --> 00:47:34.000
Now, how do we get there? Well, let's look at what we're talking about.

00:47:34.000 --> 00:47:39.000
The San Andreas and the Hayward faults are on either side of the Bay Bridge location.

00:47:39.000 --> 00:47:48.000
And this new bridge was going to be designed with up to 6 feet of movement at some locations where the old bridge was designed to only 6 inches.

00:47:48.000 --> 00:47:50.000
So the ideology had changed. Instead of trying to stand against an earthquake, we were going to be teaching the structure how to dance with it.

00:47:50.000 --> 00:48:01.000
For the eastern span of the bridge it's composed of different types of structures we would need 

00:48:01.000 --> 00:48:11.000
certain elements in order to allow those bridges to move at different periods, and here you can see the skyway in the self-anchored suspension bridge moving independent of each other.

00:48:11.000 --> 00:48:20.000
One of the elements that we would need is a fusible link. So if we look at the main tower of our self anchored suspension bridge as it dances before you.

00:48:20.000 --> 00:48:23.000
It's composed of four different legs that are independent of each other that are connected by the shear link beams.

00:48:23.000 --> 00:48:32.000
These link beams are the fuses. After a massive earthquake, you can see the bolts there.

00:48:32.000 --> 00:48:40.000
We can unbolt these these beams, replace them that with new ones that accommodate the new spacing for the tower legs after the earthquake.

00:48:40.000 --> 00:48:48.000
Now something similar had to be done inside the deck of the Bay Bridge. So if we look at the Skyway and the SAS transition here, we have hinge pipe beams.

00:48:48.000 --> 00:48:54.000
These are massive diameter steel pipe beams with a fuseable link that allows the bridge to move in and out like you'd see for thermal expansion and contraction, but it would control the lateral movement 

00:48:54.000 --> 00:49:04.000
then we could replace those fuses that would be distorted. Then finally we were going to be battering piles.

00:49:04.000 --> 00:49:19.000
So these 10 foot diameter piles going 300 feet down through different varying base strata. As the third key element to how we were going to be addressing seismic movement on the new Bay Bridge.

00:49:19.000 --> 00:49:27.000
Now during this period of time when we were rebuilding a bridge, the Bay Area was basically a theater for construction.

00:49:27.000 --> 00:49:28.000
And, what we ended up building out there was the world's widest suspension bridge.

00:49:28.000 --> 00:49:40.000
You have two decks connected with beams that allowed for sunlight to come down between them. It's also the world's largest self-anchored suspension bridge,

00:49:40.000 --> 00:49:49.000
and that just means that it anchors into itself instead of those big massive anchorages you see at Beale Street for the West Fans of the Bay Bridge or out on the Golden Gate.

00:49:49.000 --> 00:49:53.000
This main cable is tied into itself. In order to do that, you have to have a temporary bridge that's built that the decks are set on and then you transfer the weight onto the cable system.

00:49:53.000 --> 00:50:01.000
Now the entire bridge just celebrated its 10th Birthday and that basically saw over 1,020,000,000 billion, 20 million safe trips across the Bay.

00:50:01.000 --> 00:50:11.000
It was a race against time for us. It was challenging to get it done. It took over 24 years 

00:50:11.000 --> 00:50:19.000
after Loma Prieta to get this bridge open. But we did it!

00:50:19.000 --> 00:50:29.000
Now what have we learned and where are we going? Well, our largest projects now really have the environment in climate change in consideration.

00:50:29.000 --> 00:50:43.000
So the biggest one we've got in the Bay Area and for the state is State Route 37 which is a 21 mile long corridor that has to be rebuilt for seismic concerns but also sea level rise flooding which is a different thing as you can see here those are flooding conditions and operational concerns like congestion.

00:50:43.000 --> 00:50:55.000
We have to do that while we restore local wetlands because there's a huge opportunity to make improvements there.

00:50:55.000 --> 00:51:02.000
So we're working with with scientists and we're working with local stakeholders and this is the main thing that we learned 

00:51:02.000 --> 00:51:06.000
in the construction that followed the Loma Prieta earthquake is that we learned a lot.

00:51:06.000 --> 00:51:22.000
There are a lot of different things that we we brought into the technology and into our operations. But working with partners and working with communities ultimately led to success in these big projects and we're going to be taking  that with us into the future.

00:51:22.000 --> 00:51:34.000
So thank you for the opportunity to address you today and we'll stop there.

00:51:34.000 --> 00:51:39.000
Thank you very much, Bart. That was a great presentation and, it's very impressive.

00:51:39.000 --> 00:51:51.000
It was very impressive how Caltrans responded to the Loma Prieta earthquake and popped on the strengthening of the vertical columns and the 

00:51:51.000 --> 00:52:04.000
toll bridges. And in our compilation we found out that Caltrans was one of the bigger investors in retrofitting or replacements.

00:52:04.000 --> 00:52:12.000
Following the earthquake. But do we have all the speakers on now with their audio and their cameras.

00:52:12.000 --> 00:52:28.000
So, I had a question. To you all about you know it has been 35 years since the earthquake and initially after the earthquake, of course, there's a lot of enthusiasm about 

00:52:28.000 --> 00:52:38.000
building back better, retrofitting structures, and so on. But that tends to wane over time.

00:52:38.000 --> 00:52:46.000
So what what are the strategies that you have been using to help maintain enthusiasm for 

00:52:46.000 --> 00:52:51.000
continued enthusiasm for earthquake retrofits. Bart?

00:52:51.000 --> 00:53:01.000
Well, one of the ones that was the most impressive that I saw is that 24 years, 25 years, seems like a long time for a project, right?

00:53:01.000 --> 00:53:07.000
Loma Prieta earthquake happens and then we don't get a new Bay Bridge opened until 2013.

00:53:07.000 --> 00:53:17.000
So for the team that had to be out there constructing it for that period of time what the project leaders did is they hung, I'm looking at one right now.

00:53:17.000 --> 00:53:26.000
I kept it because it made such an impact on me. They hung giant posters of peer E9 where the failure was on the Bay Bridge.

00:53:26.000 --> 00:53:35.000
At the front desk of every building on Burma Road where we were constructing the bridge. So when you came in every day, you knew exactly what your job was.

00:53:35.000 --> 00:53:50.000
And that and a picture of competing against time the report that went to the Governor's office that sanctioned building a new bridge there was one of the ways that the department used to keep people fired up while we were working on that big job.

00:53:50.000 --> 00:53:59.000
That's interesting. Any other comments from other organizations, agencies? Go ahead.

00:53:59.000 --> 00:54:00.000
Go ahead, Jeff. I'll go after you.

00:54:00.000 --> 00:54:12.000
Yeah, so for PG&E, we're an investor own utility that's regulated by the California Public Utility Commission.

00:54:12.000 --> 00:54:26.000
And they've implemented a program so whenever we submit and it's usually on a 3 to 4-year basis, our estimate for operating the system called our general rate case that establishes our funding.

00:54:26.000 --> 00:54:37.000
They now require that we perform a risk assessment. So any spin that we propose to make, we have to show how that would potentially reduce risk.

00:54:37.000 --> 00:54:49.000
And so this is a case where regulations is actually keeping that current enforcing utilities to keep considering earthquake resilience.

00:54:49.000 --> 00:54:52.000
Interesting. Cynthia?

00:54:52.000 --> 00:55:03.000
So I guess I have a couple of directions I look at it from. The actually retrofitting buildings like soft-stories has been.

00:55:03.000 --> 00:55:13.000
very difficult to accomplish because it's local government level. There are some local governments that have really been focused on that 

00:55:13.000 --> 00:55:20.000
but many have not and and are concerned about the cost because you're looking at individual property owners.

00:55:20.000 --> 00:55:37.000
In terms of other things like, information available to the public. Organizations that develop that information, everything from what's the seismic risk of your area where your house is?

00:55:37.000 --> 00:55:51.000
To how do you make your home better prepared. Those have improved tremendously over the past 35 years and I think having many different organizations involved has been important 

00:55:51.000 --> 00:55:59.000
because when one loses funding or loses enthusiasm, there's another one to step in.

00:55:59.000 --> 00:56:03.000
And the other thing that's happened is that.

00:56:03.000 --> 00:56:17.000
A lot of the needs from an related to an earthquake in terms of preparation and then recovery afterwards are not that different from other disasters and we've had enough other disasters as "wake-up" calls 

00:56:17.000 --> 00:56:24.000
to keep the momentum going on those kinds of activities.

00:56:24.000 --> 00:56:43.000
Roberts, what's your experience that's keeping your program going.

00:56:43.000 --> 00:56:44.000
Yeah, that's better.

00:56:44.000 --> 00:56:57.000
Yeah, I think, You're talking out for, Jay Wires, No, it's, yeah, we're talking now with various studies like that.

00:56:57.000 --> 00:57:22.000
Thank you, So I think it's, the reminder, And, Every pipeline that we, you know, I think, something where it's, used to, I'm gonna get, to, I'm gonna get through.

00:57:22.000 --> 00:57:33.000
And then you're throwing, it's basically, you know, they're, they're installing something that, isn't joining, and,

00:57:33.000 --> 00:57:44.000
Yeah, continuing on that, theme at Hey Wired. I know that, some of you, briefly mentioned it in your presentations and or also very involved with Hayward.

00:57:44.000 --> 00:57:59.000
Can you talk a little bit about how scenarios such as HayWired? Help design thanks for the feature help plan things for the future and then also what we could do better or differently the next time we generate some big scenarios.

00:57:59.000 --> 00:58:03.000
Of large earthquakes in the San Francisco Bay Area.

00:58:03.000 --> 00:58:09.000
I'll jump in there for hay wired what was really valuable for us, Jenny. Was that it's a standard scenario.

00:58:09.000 --> 00:58:16.000
So all the different agencies are using the same input. And so that really helps give a holistic view.

00:58:16.000 --> 00:58:26.000
Of maybe interdependencies on power dropping from PG&E now affecting East Bay mud pumps for water supply.

00:58:26.000 --> 00:58:36.000
So having those standardized scenarios. They're really important. Something also we do. Is we have a pretty active learning from Earthquakes program.

00:58:36.000 --> 00:58:37.000
So whenever there's an earthquake that potentially affects a country with similar types of infrastructure, we use that.

00:58:37.000 --> 00:58:58.000
And so that helps us also integrate into scenario events. But we run scenario events to cover all the active faults that would potentially impact our system.

00:58:58.000 --> 00:59:06.000
Right, thanks, Chuck. Do other, others of you have, comments, comments on that or things that we could do differently in the future.

00:59:06.000 --> 00:59:17.000
Well, I think, HayWired is in a tremendous, service to the Bay Area for this kind of preparation because It really is.

00:59:17.000 --> 00:59:25.000
It's a wake up call without the actual earthquake. And it's certainly a number of the cities that are doing soft story.

00:59:25.000 --> 00:59:42.000
Retrofits, for example, right now are doing them because of hay wired. But it's also been used For many different kinds of conversations and Also for conversations on how do you bring disadvantaged communities into this.

00:59:42.000 --> 00:59:52.000
Work and help them prepare and become eventually more resilient. So I think. Just as, Jeff said, just having a.

00:59:52.000 --> 01:00:14.000
As scenario that covers the whole area. Really provides. Material for conversation for this kind of work. I think they learned a lot on the fly and it would be great if they could consolidate the lessons that they've learned on how to communicate this.

01:00:14.000 --> 01:00:20.000
And how to then make it useful. Going forward

01:00:20.000 --> 01:00:24.000
Okay, thanks Cynthia.

01:00:24.000 --> 01:00:32.000
One other question we had and I think, Jeff, Minson mentioned to me that you had, some things to talk about.

01:00:32.000 --> 01:00:37.000
And we only, only gave each of you 10 minute to talk and there's so many things to.

01:00:37.000 --> 01:00:44.000
Bring up sleep. I don't include some things and then I'll meet some other stuff. So what about, disparate effects?

01:00:44.000 --> 01:00:55.000
We have, more and more stratification of our populations in the San Francisco area where a lot of new people are always coming in and it just, everything's always changing.

01:00:55.000 --> 01:01:00.000
So I was wondering how things have changed. Since, Luma Preda in terms of our population to our populations live.

01:01:00.000 --> 01:01:10.000
Also the economics, economic impacts are. Perhaps different than they were, back in 1, 1989.

01:01:10.000 --> 01:01:18.000
So I was wondering if, Jeff, I think you had, some things that you wanted to see and also if other people also have things they wanted to say about that.

01:01:18.000 --> 01:01:28.000
Sure, since, the extent of our systems increase dramatically. And also let's expect it from electric supply.

01:01:28.000 --> 01:01:44.000
Now so many things are even more dependent than in the past. And so what we try to do is balance both our initial response will be focused where we expect most damage to occur but making sure that we're covering other maybe disadvantaged areas of communities around the Bay Area.

01:01:44.000 --> 01:01:53.000
That we're sure, you know, to be able to have resourcing address across that whole spectrum.

01:01:53.000 --> 01:02:04.000
Another aspect is things that happen outside of our PG&E control. So after a large earthquake, a wired event, good example of that.

01:02:04.000 --> 01:02:17.000
Is transportation systems will be cut off, supply chain, and so those are things that we more and more really have to account for in our emergency response planning.

01:02:17.000 --> 01:02:18.000
Yeah.

01:02:18.000 --> 01:02:22.000
Yeah, thank you. And I really like, thank you, Jeff. That's really good.

01:02:22.000 --> 01:02:31.000
It's so important. And in, I also really like how you discussed some of these topics in your in your presentation directly discuss them.

01:02:31.000 --> 01:02:33.000
On top.

01:02:33.000 --> 01:02:42.000
Yeah, I had a question for Tim. That came up in the chat. You had a nice history of legislation that's been passed after each event.

01:02:42.000 --> 01:02:48.000
So what's the legislation going to be after the next earthquake in the Bay Area?

01:02:48.000 --> 01:02:56.000
Yeah, that's been sort of a question that garnered a bunch of responses and I had initially just said, start to foresee it is.

01:02:56.000 --> 01:03:07.000
Incremental changes because really Yeah, in California, we haven't had a major urban earthquake since all the, in North Ridge, Southern California.

01:03:07.000 --> 01:03:15.000
We live in a different world and we subsequent to that. We've had all this legislation, you know, and improvements to building codes to test this.

01:03:15.000 --> 01:03:26.000
So really the next big earthquakes going to be the I think I see it as the test of all these improvements and then after that I would see sort of changes.

01:03:26.000 --> 01:03:35.000
Taking the lessons for and from those earthquakes to changes to building codes and things like that

01:03:35.000 --> 01:03:40.000
Thanks, Tim. And Keith, you had a question in the chat. Did you want to?

01:03:40.000 --> 01:03:44.000
On mute. And to ask it.

01:03:44.000 --> 01:04:02.000
Sure, thanks, Ruth. On the same theme, it's been a long while since, Loma Prieta occurred attention and perhaps even investments have waned a little bit since then, in addressing seismic resilience,

01:04:02.000 --> 01:04:13.000
But other hazards have gotten the public's attention at least. And I'm wondering if there are ways that your agencies are capitalizing on attention to 

01:04:13.000 --> 01:04:19.000
climate change, the related hazards. Fire and flooding, sea level rise and what have you.

01:04:19.000 --> 01:04:31.000
Is there a way to capitalize on investments in mitigation for those hazards and at the same time address earthquake hazards?

01:04:31.000 --> 01:04:43.000
I could take a crack at that. Although I wish the answer was better. I think sea level rise is one of the most difficult ones to communicate to various different audiences.

01:04:43.000 --> 01:04:46.000
Because there's members of the public that don't believe in it. Some members believe that it's way more catastrophic than than what our sciences is saying.

01:04:46.000 --> 01:05:00.000
So sometimes it starts an argument just looking at that that topic. And then when you look at the difference, so Cal Trans, we're kind of going through everybody.

01:05:00.000 --> 01:05:09.000
We're working with all the different constituencies. And many cities aren't ready to address some of these, these impacts.

01:05:09.000 --> 01:05:15.000
And so when we have to take on a project like say for instance state route 37 and North Bay.

01:05:15.000 --> 01:05:28.000
Their significant predicted sea level rise for that project. That also sort of when we start communicating it because we need to get billions of dollars of funding in place.

01:05:28.000 --> 01:05:36.000
We have to be careful because some of the cities that are also going to be very affected don't have their plan in place yet for how they're going to do that.

01:05:36.000 --> 01:05:43.000
And then the material that we show sometimes could be counterproductive to us all working together.

01:05:43.000 --> 01:05:54.000
So there's a big challenge in that aspect of it, but I think the way that we are trying to work on it by educating as many audiences as possible.

01:05:54.000 --> 01:06:04.000
So we've been upgrading our communications effort on that particular project and bringing more partners. As a matter of fact, you're going to hear a little bit of that from our secretary this week.

01:06:04.000 --> 01:06:14.000
We're bringing more partners in earlier on. In the planning for that that project and projects like that.

01:06:14.000 --> 01:06:17.000
Yeah, he, something we've found. Is right now there's a really heavy focus on fire mitigation.

01:06:17.000 --> 01:06:43.000
Improving our system to reduce potential triggering. You know, events. For and a lot of the work done to harden our system for fire also has a site benefit for So for example, undergrounding or distribution electric lines right there is a really good benefit that we also get.

01:06:43.000 --> 01:06:52.000
So double benefit. Establishing more control points, so micro-gridding our system. So if a fault occurs on one part,

01:06:52.000 --> 01:07:05.000
the effect is more localized. Again, target it for fire, but it really has a significant impact on seismic response or resilience too.

01:07:05.000 --> 01:07:09.000
Cool, thanks.

01:07:09.000 --> 01:07:10.000
Yeah, go ahead.

01:07:10.000 --> 01:07:40.000
Yeah, that's good. Yeah, it's the big

01:07:48.000 --> 01:07:51.000
Hey, thank you, Tom. And

01:07:51.000 --> 01:07:57.000
yes, thank you. I think Keith, first of all, thanks everyone for a very good session.

01:07:57.000 --> 01:08:08.000
I think Keith Nison has put his finger on a very good question. About the climate change funding but particularly funding versus earthquake.

01:08:08.000 --> 01:08:24.000
Risk reduction. And I think that climate change is really kind of stealing all the thunder recently. And, the opportunities for multi hazard mitigation are being lost, although part.

01:08:24.000 --> 01:08:31.000
Pointed out that the State Route 37 is an opportunity where they're gonna address all these things.

01:08:31.000 --> 01:08:36.000
But in many other cases they're not. And a good example is the seawall in San Francisco.

01:08:36.000 --> 01:08:44.000
Which is in the paper the other day for a $13 billion dollar project and it's as far as I know, it's entirely focused on.

01:08:44.000 --> 01:08:52.000
Sea level rise and they're missing the opportunities for improving the infrastructure behind the seawall.

01:08:52.000 --> 01:09:01.000
Course that's in very early stages so that may change. So therefore an opportunity. Response to Sarah's question about legislation following an event.

01:09:01.000 --> 01:09:10.000
An opportunity I think now is for legislation that would. In some way require a multi hazard approach.

01:09:10.000 --> 01:09:25.000
Or that or to do that. Emphasize not just for climate change projects that they address climate change but also address the other relevant hazards and not just by code approach.

01:09:25.000 --> 01:09:32.000
But a more performance based approach. That's my comment. Thank you so much.

01:09:32.000 --> 01:09:41.000
That's a great comment, Charlie. Are you aware of, And, any such proposed legislation for multi hazard analysis?

01:09:41.000 --> 01:09:47.000
No, I'm not. I'm saying that. This is an opportunity.

01:09:47.000 --> 01:09:51.000
Vis-a-vis Sarah's question about. Post earthquake or post earthquake legislation.

01:09:51.000 --> 01:09:57.000
Let's get some pre earthquake legislation in there.

01:09:57.000 --> 01:10:05.000
And there are there are other examples of that by the way in I think it was Tim's.

01:10:05.000 --> 01:10:20.000
Presentation about. The California legislation, the Field Act. He didn't mention the Riley Act, which is the same time, which prohibited.

01:10:20.000 --> 01:10:36.000
You around construction after 1933 but also there was Senate Bill 5 47 in 1985 I believe which required all jurisdictions to address there remaining a legacy.

01:10:36.000 --> 01:10:43.000
Unreinforced Masonry buildings. So that was an example of legislation. That was not, spurred.

01:10:43.000 --> 01:10:45.000
I mean, I have been a Morgan Hill earthquake and the cold linger is quite just prior in a couple years prior to that.

01:10:45.000 --> 01:10:56.000
But that legislation really didn't come out of an earthquake. It just came out of the common sense recognition.

01:10:56.000 --> 01:11:04.000
That 50 years after the Long Beach earthquake, we had 24,000 on reinforcement buildings in California.

01:11:04.000 --> 01:11:12.000
And, and actually we still have. A number because the legislation only required the local jurisdictions to address it.

01:11:12.000 --> 01:11:21.000
They didn't require them to mitigate it. And in some jurisdictions, the dressing required a postcard notification to the owner.

01:11:21.000 --> 01:11:25.000
But I don't wanna go into this too much. Thank you so much for a great session.

01:11:25.000 --> 01:11:35.000
You made it. You also made a comment in the chat about Cynthia's presentation on the the uptake of earthquake insurance in the Bay Area.

01:11:35.000 --> 01:11:39.000
Being much higher than 9%. You wanna. Exemplify that. Could you apply in that?

01:11:39.000 --> 01:11:55.000
Sure, I'm sorry. Oh, you wanted to amplify? Sure. Well, I'm basing that on to Data points following the 1994 Northwards earthquake I wrote an article in for the American Institute of Actuaries.

01:11:55.000 --> 01:12:05.000
On why the. The the estimates of insured loss. Were grossly underestimated the losses in North earthquake.

01:12:05.000 --> 01:12:12.000
There's a number of factors, but one of the factors was the adverse selection. Which means that.

01:12:12.000 --> 01:12:28.000
If you take the state of California, there are areas of low and moderate seismicity and people don't buy earthquake insurance there because They really don't need it and the areas of high risk such as the Bay Area in Southern California have much higher uptake of.

01:12:28.000 --> 01:12:35.000
Earthquake insurance. That's called adverse selection. And for example, Southern California in 1995.

01:12:35.000 --> 01:12:43.000
40% of the homes had earthquake insurance. That was the Department of Assurance. Statistic.

01:12:43.000 --> 01:12:55.000
I looked at those numbers maybe 5 or 6 or 7 years ago and again that adverse selection still exists. So the 9% is a correct statistic that Cynthia quoted for the state of California.

01:12:55.000 --> 01:13:07.000
But, it is as, as Ashley, yeah, I think Cynthia made the point about regional estimates are or only give you one perspective and you need to drill down on local impacts.

01:13:07.000 --> 01:13:13.000
The same thing with regard to insurance coverage. It varies significantly within the state. And the 9%.

01:13:13.000 --> 01:13:14.000
Is, is what is this correct statistics, but it may not give us the full picture.

01:13:14.000 --> 01:13:25.000
And I'd be happy to. Here Cynthia's perspective on that.

01:13:25.000 --> 01:13:30.000
Well, that's a really good point and I'm sure we need to look at that in more.

01:13:30.000 --> 01:13:45.000
depth. I would be surprised if it was as high as 40% in the urbanized areas because most of the urbanized areas in California are also earthquake prone.

01:13:45.000 --> 01:13:46.000
Yes.

01:13:46.000 --> 01:13:55.000
And so if we were 40% in those areas where the bulk of the buildings are it would just be surprising to me that it was only 10% statewide but

01:13:55.000 --> 01:14:06.000
definitely leads more careful look. The other thing is that there's definitely a differential between residential, single family residential, and commercial property.

01:14:06.000 --> 01:14:07.000
Yeah.

01:14:07.000 --> 01:14:12.000
And the commercial properties do have a higher uptake.

01:14:12.000 --> 01:14:18.000
I agree. I agree with that. And I don't have the current statistics on my fingertips.

01:14:18.000 --> 01:14:21.000
Department insurance will provide that. And we were shocked.

01:14:21.000 --> 01:14:29.000
Right. But if you compare it to a wildfire situation where most homes have fire insurance and are insured for that.

01:14:29.000 --> 01:14:35.000
That really gives you the money for rebuilding in a way that even if you have earthquake insurance 

01:14:35.000 --> 01:14:39.000
you may not have enough to rebuild.

01:14:39.000 --> 01:14:40.000
Oh, this is the fifth. Sorry.

01:14:40.000 --> 01:14:43.000
And we. No, go ahead.

01:14:43.000 --> 01:14:49.000
I was gonna agree with you simply. Earth's back insurance has a 10 or 15, typically 10 or 15% deductible.

01:14:49.000 --> 01:14:52.000
So on a typical house today, it's a hundred $1,000 deductible.

01:14:52.000 --> 01:15:02.000
Right. And then we were talking then I think the topic was brought up. About how the demographics have changed.

01:15:02.000 --> 01:15:10.000
We have a much more diverse population, but also a larger cohort of older people and those.

01:15:10.000 --> 01:15:22.000
That's a population also that that we found in at least other disasters tends to be more reluctant to spend the time rebuilding they simply don't feel like.

01:15:22.000 --> 01:15:29.000
They have the time to do that and if They're caught short on money. They're much more likely to just move out of the area.

01:15:29.000 --> 01:15:35.000
Find a less expensive place. To relocate rather than try and rebuild in this area.

01:15:35.000 --> 01:15:41.000
That's a good segue to one of my reactions to your talk, Cynthia, that there's always a migration after an earthquake.

01:15:41.000 --> 01:15:56.000
We saw it in 1906 people moved from San Francisco to Oakland and Los Angeles and we saw it and we see it after every earthquake.

01:15:56.000 --> 01:16:03.000
Well, your comment also was that you know, somebody else's loss is somebody else's gain.

01:16:03.000 --> 01:16:12.000
Yeah, some. How much thinking is going into them, like, potential for migration following.

01:16:12.000 --> 01:16:14.000
In the next pay area at riskake.

01:16:14.000 --> 01:16:24.000
Well, we certainly discussed that and included it in the HayWired model. And

01:16:24.000 --> 01:16:35.000
Laurie included that in her paper on the more of the social impacts rather than the economic. I think she

01:16:35.000 --> 01:16:51.000
was more pessimistic about the amount of displacement that would happen outside the Bay Area, whereas we included in our estimates the assumption that a certain amount of it would be relocation within the region.

01:16:51.000 --> 01:16:59.000
The bottom line is who knows? There's a lot of uncertainty around that.

01:16:59.000 --> 01:17:13.000
The other thing is that you have As I said, the older, we had a larger share of the older population moving out, but you also have other people moving in for whom the rebuilding is an opportunity.

01:17:13.000 --> 01:17:17.000
And so you often have for the remaining housing of which will be most of it and hotels and things like that.

01:17:17.000 --> 01:17:33.000
Those costs often go up as people come in. Even temporarily to be active in the rebuilding process.

01:17:33.000 --> 01:17:39.000
I'll be speaking to migration very briefly in the next session.

01:17:39.000 --> 01:17:52.000
But just in the last few days, a very interesting paper has come out. In nature called actually the nature cities of publication called depopulation associated challenges for U.S. cities 2,100.

01:17:52.000 --> 01:17:58.000
I, sutra, at all. I'll put the citation in the chat.

01:17:58.000 --> 01:18:03.000
It's published in January, 2024. He's from the University of Chicago.

01:18:03.000 --> 01:18:13.000
And it speaks to this question from a not from an earthquake point of view but from a larger socioeconomic point of view.

01:18:13.000 --> 01:18:16.000
Including climate change.

01:18:16.000 --> 01:18:27.000
Yeah, the other thing I wanted to add was that there are certainly huge equity differences and how all of this plays out.

01:18:27.000 --> 01:18:33.000
And I mean, it's mentioned very briefly in our slides, but it certainly needs to be a focus of 

01:18:33.000 --> 01:18:43.000
public policy preparation for earthquakes and disasters just trying to build capacity among the populations that otherwise don't have the resources.

01:18:43.000 --> 01:18:50.000
To built and stay. And to maintain some aspect of their community.

01:18:50.000 --> 01:18:51.000
Absolutely. Yes. So thank you. Thank you so much.

01:18:51.000 --> 01:19:03.000
To our speakers. Learned a time thank you to Cynthia, Jeff, Roberts, Tim, and Bart for your presentations.

01:19:03.000 --> 01:19:17.000
And thank you also for the really good discussion afterwards. And we will meet again I guess in about an hour and Sarah will come back online and give us all the updates and what we're doing next.

01:19:17.000 --> 01:19:18.000
Thank you.

01:19:18.000 --> 01:19:19.000
So thank you so much to our speakers.

01:19:19.000 --> 01:19:20.000
Thanks for the opportunity.

01:19:20.000 --> 01:19:21.000
Yeah, good deal.

01:19:21.000 --> 01:19:22.000
Thank you, everyone.

01:19:22.000 --> 01:19:27.000
Thank you everyone. Thank you to our speakers. Thank you to our moderators. That was really great!

01:19:27.000 --> 01:19:37.000
And it is so interesting to think about what happens between now and the next earthquake. So as Ruth just hinted, this is our lunch break on the West Coast and it's for whatever meal you like in any other time zone.

01:19:37.000 --> 01:19:46.000
We are scheduled to come back at 1:30pm. As always we invite all speakers and moderators to come back about 15 minute early at 1:15p.m.

01:19:46.000 --> 01:19:53.000
West Coast time so that we can help them get set up and test their microphone and their cameras.

01:19:53.000 --> 01:20:01.000
So that means, Lori Dengler, Mike Furniss, Daniel Swain, Deepti Singh, Charles Scawthorn, Noah Patton, Daniel Swain, Steve Ingebritsen, and Jia Wang-Connelly. 

01:20:01.000 --> 01:20:03.000
If you want to come back at 1:15pm (Pacific), that's great. Otherwise, we will see you all at 1:30pm.

01:20:03.000 --> 01:20:09.000
Thank you so much