Assessing Seismic Risk and Mitigation Efforts

A Conversation with Ralph Dorio

Ralph Dorio Verisk Review recently spoke with Ralph Dorio, community mitigation manager at ISO Community Mitigation, about the need for well-enforced, up-to-date building codes.

Verisk Review: What are some common misconceptions regarding seismic activity?

Ralph Dorio: When speaking about seismic activity, most people think of the West Coast. And many identify strong winds with the Atlantic and Gulf Coasts. However, both hazards are also prevalent in other parts of the country, and many of those areas are largely unprepared for the risks. Decision makers in Midwestern states, in particular, must address those hazards in their local building codes.

The New Madrid Fault is a prolific source of intraplate seismic activity — and it’s not in California. It’s a 150-mile-long fault running through seven states: Illinois, Indiana, Missouri, Arkansas, Kentucky, Tennessee, and Mississippi. In 2008, the Federal Emergency Management Agency (FEMA) warned that a major earthquake along the New Madrid Fault would cause widespread damage to tens of thousands of structures, including vital infrastructure that would displace more than 7 million people. Despite that threat, in six of the seven New Madrid states (Arkansas being the exception), the adopted codes have been amended to actually reduce the requirements for seismic-resistant construction.

Verisk Review: How can communities adequately assess seismic risk and mitigation efforts?

Dorio: You need three pieces of information: the edition of the adopted building code, the extent to which the code has been amended, and the quality of the enforcement efforts. Recently, we analyzed data in our Building Code Effectiveness Grading Schedule (BCEGS®), which considers all three pieces of information and more. Verisk’s BCEGS evaluation is far-reaching and covers the quality of a jurisdiction’s adopted building code, including its appropriateness for the peril facing that locality, certifications of code officials, and staffing levels and workloads for residential and commercial construction plan review and inspection. We analyze the data and assign the community a classification from 1 to 10. Class 1 represents exemplary commitment to building code enforcement.

Verisk Review: What did ISO discover by studying the West Coast and the New Madrid zone, both seismically active regions?

Dorio: Our comparison showed a stark difference in commitment to code enforcement between the West Coast and the New Madrid Fault area. I should note that our study included South Carolina, not technically a New Madrid state but an area that has significant seismic potential and amended codes that reduce mitigation requirements.

The accompanying two charts (see Figures 1 and 2) show the BCEGS percentage of communities in each classification in the Western states and the New Madrid states. Class 1 represents the most favorable BCEGS classifications. The charts clearly indicate that in both commercial (first chart) and one- and two-family construction (second chart) the Western states have more favorable BCEGS classifications than the New Madrid states. That information can help insurers decide where to focus attention related to underwriting, selection, and pricing their products. And if there’s any doubt that this is important, remember that after 1994’s Northridge earthquake, California insurers paid out more than three times the $3.4 billion collected in direct earthquake premiums over the prior 25 years.

Figure 1
Commercial Property BCEGS Classifications

Figure 2
One- and Two-Family BCEGS Classifications

As noted, seismic risks aren’t the only unacknowledged hazard across large swaths of America. Insured wind losses have steadily approached — and in some years surpassed — fire losses. Such losses were a driving force for the development of our Enhanced Wind Rating Program. The French writer Victor Hugo once said, “There is nothing more powerful than an idea whose time has come.” The time was ripe for the program. Under Enhanced Wind, our trained field staff collects relevant building features to help determine commercial property resilience to the wind peril.

Verisk Review: How are states and communities dealing with the challenges of repetitive high-wind events?

Dorio: The BCEGS database and State Fact Sheet information reveal some drastic differences among states. For instance, in many states, certification is not required for code officials until three or five years after hiring. That means an uncertified code enforcer can conduct inspections and approve plans for quite some time. Some states recently began requiring certification from the inception of employment but allow “grandfathering,” where having some code experience allows an enforcer to skip the certification process. Training and certification are prime indicators of an employee’s ability to enforce the adopted code rigorously.

Verisk Review: Can you provide examples?

Dorio: If you look at New Jersey, the state has enforced a mandatory statewide building code since 1977. Now, think about the ­difference between the reaction to recurring high-wind events in Texas, Oklahoma, and Florida.

Texas prohibits structural building code enforcement in unincorporated counties. Therefore, although Houston has a building code enforcement department and meets the minimum requirements of the BCEGS program, the remainder of Harris County is covered by the Harris County Public Infrastructure Department. That department is not permitted to enforce structural building code provisions and does not qualify for a BCEGS classification.

In Oklahoma, more than 95 percent of all tornadoes have a rating of EF1 or EF2, which have maximum wind speeds of 135 miles per hour. Yet in most of Tornado Alley, current construction standards are for winds up to only 90 miles per hour. Communities build to withstand 135-mile-per-hour winds in many of the Atlantic Coast states. Why not in Tornado Alley?

Wind-resistant construction and retrofitting is not rocket science. The technique is simply to form a continuous load path in the building, where the structure is secured to the foundation. The first-story walls are connected to the second-story walls, and the roof is attached to the second-story wall. That can be accomplished by anchor bolts in the foundation and straps or by sheeting that crosses the story connections and clips to hold the roof framing to the top plate.

One hard-hit town in Tornado Alley has had four tornadoes in the last 15 years. After a 1999 tornado, a local official was quoted in a Reuter’s news article1 as saying that the community didn’t change the building code because residents on a limited income felt the probability of being in a tornado was not that great. However, that doesn’t even touch the level of enforcement. The most recent BCEGS survey for Moore, Oklahoma, indicated that not all the enforcement staff is certified and they did not conduct as many inspections as our benchmarks require. In the same news article, Leslie Chapman-Henderson, chief executive of the Federal Alliance for Safe Homes, said that it’s insane to suffer the effects of a storm and then rebuild the same way.

Verisk Review: What steps can communities take to protect themselves from seismic and wind events?

Dorio: Some communities learn ways to stop, or at least ease, the cycle — albeit the hard way. Florida, for example, took steps to toughen its building standards following Hurricane Andrew. And it has paid off in fewer losses ever since the state adopted more rigorous building code enforcement.

Localities that do not consider themselves vulnerable to seismic and wind events are unaware and unprepared. Adopting strong, effective building codes commensurate with the local exposures, as reflected in our BCEGS criteria, obviously doesn’t prevent earthquakes and tornadoes, nor does it prevent all damage. But it does help limit the loss of life, property, and associated business interruption. Just look at the experience in California and Florida.

1. http://news.yahoo.com/insight-tornado-alley-building-practices-boost-damage-110444131.html