Hurricanes Harvey, Irma, and Maria

September 19, 2017
The past several weeks have seen unprecedented hurricane impacts across the Caribbean islands, Texas, and Florida. These areas have suffered billions of dollars in wind and water damage. Our hearts and prayers go out to everyone affected by Harvey, Irma, and Maria, including the staff at our Houston and Miami offices whose lives have been disrupted by these terrible storms.

As a consulting firm whose employees spend a great deal of time analyzing “disasters,” we understand that recovery will be a long process for everyone involved, fraught with unique challenges and complications. Exponent staff have assisted insurers, utilities, corporations, and public agencies with hurricane response issues for 25 years, participating in recovery efforts following Hurricanes Andrew, Katrina, Sandy, Rita, Ike, and others. With expertise spanning more than 30 disciplines and industries, our engineers and scientists in 20 U.S. offices stand ready to support our clients in this time of crisis.

Read more about the challenges the recent hurricanes have posed.

Challenges – Infrastructure Damage and Resiliency

Of all the environmental loads on buildings and structures, wind is perhaps the most damaging. Almost three-fourths of all catastrophe claims paid by insurance carriers in the last 20 years have been for wind damage from tornadoes and hurricanes. For Hurricane Harvey, we see that most of the damage in the Houston area was due to inland flooding caused by record breaking amounts of rainfall in Southeast Texas. Structures located along the coastlines of hurricane-prone regions such as the U.S. Gulf Coast and Eastern Seaboard are at great risk during large storm events (including hurricanes) because of high water levels, which have the potential to inundate vast areas.

While infrastructure damage can have enormous costs, its full extent isn’t always readily apparent even after the winds have died and the waters have receded. Exponent’s engineers work with catastrophe adjusters to determine the nature and extent of damage, evaluate the contributions of multiple causal factors, and identify the most appropriate repairs. Because we have offices across the country, our staff can respond quickly to catastrophes in any region affected. Our structural engineers and building technologists meet adjusters in the field, and our teams will remain as long as required. Our experience applying Geographic Information Systems (GIS) to disaster response can be of great value to insurance catastrophe managers, who require full information to manage the carrier’s response in an inherently chaotic situation.

Challenges – Cranes and Construction

As Irma bore down on the Florida Coast, media outlets covering the storm in Miami captured cranes swaying or even collapsing under gale-force winds. Unfortunately for contractors, lenders and insurers, there are often limited options available for protecting cranes deployed at construction sites. While cranes are designed for winds that might be expected during a short construction period, Hurricane Irma winds in many areas exceeded these speeds. As a result, many are now in the process of determining how their cranes fared during Irma.

In the event of crane damage or collapse, immediate action may be necessary to prevent further property destruction and loss of life.

  • Stabilization plans to prevent further damage to any nearby buildings and structures in the fall zone.
  • Investigation of cranes to identify any damage not readily visible and ensure proper stability.

Once the site is secured, further work may be required to determine the causes and responsibility for the damage. Additional work may include:

  • Failure analysis of damaged cranes to determine the nature, extent, and cause/origin of damage.
  • Review of crane design and installation to assess compliance with appropriate regulations and industry standards.

Exponent consultants have a wide variety of experience investigating crane failures. By leveraging our inter-disciplinary knowledge, Exponent is able to provide the expertise necessary to assess the situation, recommend stabilization options, identify failure causes, and testify in litigation. An example of Exponent’s work can be found in an article published in the Proceedings of the Forensic Engineering Congress reviewing potential hazards and regulations for cranes.

Challenges – Potential Risks and Issues of Oil and Gas Pipeline Facilities Due to Flooding

As the energy capital of the country recovers from flooding caused by Hurricane Harvey, the oil and gas industry will begin to assess the impacts to its infrastructure and ask the question: What additional threats need to be considered due to Hurricane Harvey? The unfortunate truth is that multiple threats may have been created and/or magnified by Harvey, some of which may require an immediate response. Others issues and risks are time dependent and may require a comprehensive long-term assessment and mitigation plan.

Flooding dramatically changes the threats affecting a pipeline. The immediate condition change is exposure to water, which can leave many facilities inoperable, such as valves, regulators, relief sets, pressure sensors, etc. Furthermore, floating debris, excessive water currents, and watercraft operations around exposed pipelines and facilities increase risk of catastrophic damage by outside forces during flooding [1]. A 1996 NTSB investigation reported that water velocities measured in the San Jacinto River during a 1994 flood exceeded 13 ft/sec, which generates sufficient force to move 5,000 lb rocks.

Underground pipelines are not exempt from damage by outside forces as flooding negatively impacts all damage prevention methods:

  • Erosion of land and river beds reduce depth of cover 
  • Damage to line markers reduce their visibility and/or accuracy
  • Reduced usage of “call before you dig” practices during operations by flood response teams
  • Increased traffic outside of normal roadways due to rescue and restoration operations

Flooding can cause river bottom scour, leaving large spans of previously buried pipeline exposed to additional stresses caused by the lack of underlying support, lateral water forces, or impacts from waterborne debris. According to PHMSA’s accident investigation, an ExxonMobil Pipeline near Laurel, Montana failed due to such conditions [2]. Furthermore, vibration from water rapidly passing over pipelines, called vortex-induced vibration (VIV), can also increase the potential for pipeline failures [3]. A metallurgical report from the 2011 Enterprise Products Operating, LLC pipeline failure in the Missouri River identified fatigue crack growth due to VIV [4]. Even if pipelines exposed to such conditions do not fail during flooding, sub-critical cracks and corrosion can grow after flooding subsides, leading to increased susceptibility to time-dependent threats.

Many oil and gas pipeline operators have, as a preventative measure, determined where pipeline integrity is at risk in the event of flooding and have contingency plans to shut down and/or isolate pipelines as needed. Many of these plans have been put into effect due to Harvey. Next steps may include integrity assessments of impacted pipelines before returning to normal operations. Exponent has extensive experience investigating failures of pipelines, fittings, and facilities. We can provide assistance in assessing current conditions of pipelines or development and implementation of integrity assessment plans.


  1. NTSB, "Evaluation of Pipeline Failures During Flooding and of Spill Response Actions, San Jacinto River Near Houston, Texas, Oct 1994," NTSB, Washington, DC, 1996.
  2. PHMSA Office of Pipeline Safety, "ExxonMobil Silvertip Pipeline Crude Oil Release into the Yellowstone River in Laurel, MT on 7/1/2011," DOT, 2012.
  3. Exponent, Inc., "The Dangers of Flood Scouring on Buried Pipeline River Crossings," Exponent, Inc., 2017. [Online]. Available:
  4. PHMSA, "Pipeline Safety: Potential for Damage to Pipeline Facilities Caused by Flooding, River Scour, and River Channel Migration," DOT, Washington, DC, 2016.

Challenges – Electrical and Mechanical Equipment Failures

Hurricane Irma is responsible for wide spread power outages to over 5 million customers in Florida alone. Every piece of equipment impacted either by wind or water damage needs to be inspected and evaluated for potential repair. Electrical system failures can create hazardous situations that can generate shock and arc-flash risks to customers, employees, and maintenance personnel.

It is imperative to identify and address potential failures and dangerous situations before they cause physical harm and/or property damage. It is also critical to analyze hazardous situations following a failure or loss to determine how the danger arose so that future safety may be improved. Hazardous situations can be created through failures of electrical equipment including high-power transmission equipment, switchgear, consumer products, and consumer electronics.

Mechanical systems must be reviewed as well to evaluate damage caused by wind loading or flooding. These stresses can have significant consequences for mechanical systems, damaging property, resulting in financial loss, or rendering a system unsuitable for its intended use.

Exponent’s electrical and mechanical engineers provided technical support to clients that dealt with these issues following Hurricane Sandy and are available to provide reviews of electrical and mechanical equipment to assess damage and determine repair or replace options.

Challenges – Construction/Reconstruction Concerns

As efforts to repair and rebuild after Hurricanes Harvey and Irma move forward in the coming months—and in some cases, the coming years—the project management and control-related actions taken by stakeholders now will impact long-term outcomes. To complete projects or bring facilities back online while mitigating overall losses and minimizing litigation risks, costs resulting from these catastrophes, including delays, need to be properly quantified and documented.

For those projects under construction at the time of the loss and already under acceleration, it is important to have the ability, at a later date, to identify what elements of the asā€built and forecast plan were part of the accelerated efforts when the hurricane struck. Accurate determinations of actual cost incurred at the time will be needed, and project participants will need to establish a realistic estimate of the cost for the scope of work remaining when the event occurred. If the estimate for the work remaining does not already do so, it should have the capability of distinguishing between the base (or adjusted) contract scope of work remaining and those costs directly related to the then-accelerated efforts.

Exponent combines its Construction Consulting and Forensic Engineering Services to provide an integrated team of schedule, cost, and technical professionals to help clients address their most challenging construction issues.

Challenges – Water, Food Contamination, and Public Safety

The health impacts from Hurricanes Harvey and Irma, or from the disruption of services they’ve created, can have lasting effects. The forces of wind and water associated with major storms often cause releases of chemicals or materials used in industrial processes or public works (e.g., sewers and water treatment operations) into the ground, aquifers, or the air. Once released into the outdoor environment or into indoor spaces, they may affect or create concerns about food and water supplies or even consumer products.

Potential releases caused by large storm events require investigations to determine if such releases actually occurred and, if they did, to characterize the likely extent of those releases.

Some releases may be of sufficient magnitude (level and or toxicity) to require investigation to estimate the level of contamination associated with the release, determine any health risks posed, and evaluate possible remedial actions that might be needed. Careful considerations of release components and potential exposure pathways benefit greatly from the combined skills of health professionals, engineers, and environmental scientists knowledgeable in risk assessment methodologies and related analyses that are critical in many regulatory decisions made during various community disruptions.

One of the most significant challenges after the water has receded is mold. Damage to structures and health effects to individuals can be significant if not assessed properly. Exponent’s industrial hygienists perform site visits, collect multimedia samples, and evaluate laboratory and industrial hygiene reports that may already have been produced by others. Exponent’s physicians review medical records to discern the validity of claims of injury secondary to alleged inhalation exposure to “black mold” or other mold genera. We also work with our Building Technology and Mechanical Engineering professionals to evaluate the source of water that may contribute to this issue.

Exponent has one of the largest health consultancies with expertise in human health risk assessment, exposure assessment, toxicology, epidemiology, and meteorology to support health claims resulting from hurricanes.

Challenges – Environmental Concerns and Ecological Modifications

Devastation from Hurricanes Harvey and Irma have created enormous environmental concerns, some immediate and some that may not manifest themselves for months or years to come. In the Houston-area in particular, multiple media outlets reported fires and explosions in chemical processing and storage plants impacted by Harvey, potentially releasing millions of pounds of chemicals into water and air, and the U.S. Environmental Protection Agency (EPA) confirmed the inundation of 13 Superfund sites, creating the potential for contaminants to leak into floodwaters and leading to runoff concerns for local residents and wildlife.

Incidents at chemical plants and flooding at petroleum storage facilities and Superfund sites highlight the two-pronged environmental challenge facing the responses to Harvey and Irma. Not only is it necessary to remediate new environmental impacts, but existing cleanup sites of all kinds—some already under remedy—will need to be reassessed to determine new potential risks and new baseline conditions.

These challenges require thinking both tactically and strategically, simultaneously pursuing an understanding of short-term consequences to guide the immediate response while developing frameworks to address long-term liabilities and regulatory compliance.

Potential response actions include:

  • Assessing spills and spill impacts, including transport and fate analysis
  • Re-evaluating existing environmental initiatives and cleanup sites (i.e., Superfund sites)
  • Surveying/sampling surrounding areas to determine new baseline conditions
  • Redoing due diligence for plant or facility expansions
  • Re-examining Environmental Impact Statements (EIS), Ecological Risk Assessments (ERAs), and state and national pollutant discharge permits
  • Monitoring water quality impacts
  • Planning for future natural disasters and spill prevention.

For More Information, Please Contact:

Construction Damage/Claims

  • John D. Osteraas, Ph.D., P.E.
  • Brian M. McDonald, Ph.D., S.E.
  • David B. Peraza. P.E.
  • Joel M. Wolf, P.E., LEED AP
  • James R. “Bob” Bailey, Ph.D., P.E., F.ASCE
  • Morgan Griffith, P.E.


  • David B. Peraza. P.E.
  • Jeffrey A. Travis, P.E., S.E.

Oil and Gas Pipeline Facilities

  • Wen Tu, Ph.D.

Electrical/Mechanical Issues

  • Shukri J. Souri, Ph.D.
  • John D. Martens, Ph.D., M.B.A., P.E., CFEI
  • John R. Fessler, Ph.D., P.E., GSLC
  • Maher Saleh, P.E., CFEI, CFII
  • Scott A. Wright, Ph.D., P.E., CFEI

Health and Safety

  • Mark A. Roberts, M.D., Ph.D.
  • Renee M. Kalmes, M.S.P.H., CIH
  • Jeffrey B. Hicks, M.P.H., CIH, QEP, FAIHA
  • Arthur J. Miller, Ph.D., CFS


  • Robert I. Haddad, Ph.D.
  • William L. Goodfellow, Jr., BCES
  • Susan C. Paulsen, Ph.D., P.E.

Local Contacts

  • Miami: Lee A. Swanger, Ph.D., P.E.
  • Houston: James R. “Bob” Bailey, Ph.D., P.E., F.ASCE