Flood Risk

Protecting Dam Breach Inundation Zones

Dam failures are a ‘low probability but high consequence’ event best addressed by preparation and maintenance.
By: | February 28, 2017 • 7 min read

After a five-year drought, the rains finally returned to California this winter. Lake Oroville, which was formed in 1967 at the foot of the Sierra Mountains by the nation’s tallest dam, began to refill.

An atmospheric river, colloquially known as a “Pineapple Express,” continued dropping water at such a pace that it replenished the reservoir and then some. The swollen lake forced the excess water onto an emergency spillway alongside the Oroville Dam for the first time in half a century.

The spillway cement crumbled and sent a cascade of water down the mountainside. Engineers feared the erosion compromised not only the spillway but also the 770-foot-tall earthen dam.

An emergency evacuation was hastily ordered and nearly 190,000 residents were forced to flee their homes. Traffic clogged roads. Fortunately, no life was lost and water levels eventually receded.

“There has to be a more robust conversation around flood.” — John Dickson president, NFS Edge Insurance Agency

For many, this crisis is a wake-up call for renewed assessment of the aging infrastructure of the U.S. dam system and the emergency response plans drawn to prevent loss of life in the event of a failure.

Dams Exceeding Effective Dates

Nearly all of the 700 dams managed by U.S. Army Corps of Engineers are more than 30 years old. More than half have reached or exceeded the 50-year service lives for which they were designed. Oroville Dam turns 50 next year.

Tim McCarty, risk control manager, Trident Public Risk Solutions

Tim McCarty is a risk control manager at Trident Public Risk Solutions, which insures a wide range of municipalities including those in close proximity to a dam. His statistics on the aging dam system in the U.S. are even more alarming.

“The average age of our dams nationwide is 56 years,” he says. “And, the average age of a failed dam is 62 years.

“So we’re kind of reaching that point where we’re starting to have some very old infrastructure and if it’s not properly maintained we may see repeats of this type of an incidence,” McCarty said.

The Federal Emergency Management Agency says dam failures are a “low probability but high consequence” event.

Since they rarely occur, many people who live downstream in “dam breach inundation zones” are completely unaware of the potential hazard. But they are, in fact, at the mercy of the dam’s ongoing health.

“The only time the concept is front and center is when water is rushing over the dam,” said John Dickson, president of NFS Edge Insurance Agency.

“I worry constantly that that’s a total disservice to the American people. We need to have the conversation when the sun is shining.”

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Dams are a vital part of the U.S. infrastructure. They provide flood protection, water supply, hydropower, irrigation and recreation. But all it takes is one busy muskrat to compromise the integrity and cause a breach.

The operators of the Oroville Dam were advised in 2005 to shore up the spillway with concrete. For a dozen years, the expensive recommendation was tabled. The reasoning was the emergency spillway was never used because the lake water never rose high enough.

“With a dam breach, when it fails, it fails quickly, the water comes out quickly and there’s a limited amount of time.” — Dr. Louis Gritzo, vice president and manager of research, FM Global.

But when it finally did, the emergency response — mass evacuations and helicopters conducting air drops of dirt and boulders to fortify the dam —averted a catastrophe.  But it also was an expense way beyond the cost of maintenance.

Perhaps most alarming, not all people received the emergency notification when the evacuation was called, according to the Associated Press.

Dams Fail Quickly

Every four years, the American Society of Civil Engineers issues a “Report Card for America’s Infrastructure.” Bridges, roads, tunnel systems are evaluated on capacity, condition, funding, future need, operation and maintenance, public safety, resilience and innovation.

Dams received a “D” grade in the 2013 report. The next report is due March 9, and there is no expectation for a major shift in that grade. The Army Corps of Engineers estimated it would currently take $24 billion to fix all dams that need repairs.

State agencies regulate most of the nation’s 84,000 dams. Unlike bridges and roads, the U.S. government may inspect the dams but they don’t maintain most of them. More than 65 percent are privately owned and those owners may lack the money needed for adequate maintenance.

Louis Gritzo, vice president and manager of research, FM Global

Experts say dam owners need to know how their structures are aging and prepare for the repairs that need to be done. Develop a timeline for a replacement and how to respond if the dam fails.

“We’re chasing an aging population,” said Louis Gritzo, vice president and manager of research with FM Global.

It is most important to conduct regular inspections and deal with what seems to be minor issues immediately.

“Many people just think you build a dam and it’s just there and fades into the background,” McCarty said.

“But it really is an active system that has to be maintained just like a road or a bridge.”

Gritzo said he discusses with clients opportunities to retrofit facilities and fill in the weak spots. More often than not, an engineer looks at an aging structure and weighs when it is best for a new build. The cost of that is often too challenging, Gritzo said.

Unlike a river flooding over its banks, a dam breach may occur with little to no warning. For that reason, an emergency response plan is needed to lay out how much time is required to get mitigation efforts in place and who is responsible for completing each task.

Conduct Hazard Assessments

“With a dam breach, when it fails, it fails quickly, the water comes out quickly and there’s a limited amount of time,” said Gritzo.

Risk managers need to conduct a very good hazard assessment in the event one of these dams has a catastrophic failure. FM Global uses tools such as complex computer models to calculate different breach scenarios and determines where the water might go and how much flooding might occur when it gets there.

As of 2015, a quarter of dams designated “high hazard” don’t have an EAP.

The insurer works with clients to decide if that amount of water is something they can protect a facility against, or if it’s too large.

“If it’s a meter of water or less you can protect against it,” Gritzo said. “That’s an easy cut-off point.”

More than a meter of water and there’s much fewer protection measures available.

The risk manager that is associated with the facility needs to know the risk exposure, how to react and who to contact in an emergency.

As of 2012, there were 13,991 dams classified as “high hazard,” up 3,000 from a decade earlier.

When a dam is designated a “high hazard,” it means there’s a potential for loss of life if it fails. All high hazard dams require an emergency action plan (EAP). Dams with a “low hazard” or “significant hazard” may have a low expectation for loss of life but still carry potential for damage to surrounding terrain, roads or buildings.

As of 2015, a quarter of dams designated “high hazard” don’t have an EAP. Sometimes, the owners don’t even know they are labeled high hazard, McCarty said.

Risk managers should contact the authority or municipality that creates the EAP to start an ongoing communication and organize emergency drills.

“The time to be swapping business cards and introducing yourself is not when there’s an emergency,” Gritzo said.

John Dickson president, NFS Edge Insurance Agency

McCarty periodically reviews the state assessments of dams in his clients’ communities to try to ascertain the condition of the dams and what kind of ongoing maintenance has been required. He also checks to make sure each community has an EAP in place should something occur.

“Our clients are doing a great job with it, but we know that there are a lot of dams that aren’t getting the attention they need,” McCarty said.

“There has to be a more robust conversation around flood,” said Dickson of NFS Edge.

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“The way we do that is not responding in the face of imminent disaster but having the conversation when the levee is not about to be breached or the spillway is not being activated because the dam is at historic highs.”

Municipal leaders should prepare to address the ongoing maintenance that is needed, the EAP they have in place and the responsibilities that go along with having a dam, McCarty said.

“We’ve had an incident here that has heightened our awareness. Those things tend to tail off as time passes,” McCarty said.

“We really need to keep this in our collective memories otherwise we’ll see more and more of these incidents occur.”

Juliann Walsh is a staff writer at Risk & Insurance. She can be reached at [email protected]

More from Risk & Insurance

More from Risk & Insurance

Catastrophe Risk

Material Resiliency

New materials, methods and ideas are empowering property owners to rein in their catastrophe risks.
By: | October 12, 2017 • 11 min read

The 2017 hurricane season is one for the record books. Rebuilding efforts are underway, with builders working to make insureds whole again as soon as possible … at least until the next storm comes along.

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And therein lies the problem with recovery in disaster-prone regions. It evokes the oft-quoted definition of insanity: Doing the same thing over and over again and expecting a different result.

So what if we did it differently? What if instead of rebuilding to make structures “like new,” we rebuilt to make them better, more resilient, less prone to damage?

The reality is, we don’t really have a choice. Climate change is ushering in weather systems that are increasingly volatile. Wildfires are raging like never before. Sea-level rise is threatening our coasts, and there’s no way to dial any of it back.

Nevertheless, people will continue to build homes and businesses along the coast. Real estate developers will continue to nestle luxury homes into wooded foothills.

That means communities need to come to terms with the risk and plan for it intelligently.

Michael Brown, vice president and property manager, Golden Bear Insurance

“Natural disasters are going to happen,” said Michael Brown, vice president and property manager with Golden Bear Insurance. “But if we plan and build communities around the idea that something bad may happen someday, then that community can bounce back faster afterward.”

In any natural disaster, he added, “the property damage is extreme. But the biggest portion of the losses, both insured and uninsured, are the time element pieces. How long was the business closed? How long were homeowners unable to occupy their homes? Those are the pieces that drag on for months — years in some cases — and really drive the economic loss.”

That’s the motivation behind new materials, designs and strategies being implemented in the construction and repair of at-risk residential and commercial properties.

Powerful Flood Solutions

Newer building products move the needle significantly in terms of efficacy.

For new or restored structures in flood-prone regions, Georgia Pacific produces gypsum panels that incorporate fiberglass mats instead of paper facings and comply with the latest FEMA requirements for flood damage resistance and mold resistance. Wall boards made from magnesium oxide (MgO) don’t absorb water at all and have the added benefits of being environmentally friendly and non-flammable.

In the UK, advanced flood-resilient structures built with water-resilient concrete-block partitions are being fitted with not only MgO wallboards, but also wood-look porcelain or ceramic flooring that’s non-permeable and fire-resistant — without sacrificing aesthetics. Drains are installed in the flooring, along with sub-flooring gullies and submersible pumps that push the water back outside. Outlets and appliance motors are all situated above expected flood levels. Doors are equipped with sliding flood panels.

In the event of flooding that exceeds a depth of two feet, automatic opening window panels (flood inlets) are triggered by sensors to allow flood water to enter the property slowly, to reduce external pressure that could damage the structure.

Carl Solly, vice president and chief engineer, FM Global

Controlled inflow buys time for a homeowner to raise furniture up on blocks, or for a business owner to raise pallets of goods up to higher shelves or move equipment to a higher elevation.

Water intrusion is reduced dramatically, and even when it happens, there is little to no damage. Water is pushed into the floor drains, surfaces are allowed to dry, and then it’s back to business as usual in days rather than months — likely with no insurance claim filed.

Dramatic improvements are happening on this side of the pond as well. For entities that need permanent on-site flood solutions, barriers like flood gates and retractable flood walls are the most sophisticated they’ve ever been.

After suffering $4 billion in damage during Superstorm Sandy, New York’s Metropolitan Transit Authority invested heavily in flexible fabric flood panels that are made with Kevlar® and can be unrolled quickly and easily. Additional flood gates hinged to air grates are passively activated by the weight of incoming water entering the grates.

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The transit authority is also testing a prototype “resilient tunnel plug” — essentially a giant air bag that can be deployed quickly to seal off sections of subway tunnel. The plug is designed to withstand not only flood but also biochemical attack.

Even temporary solutions are leaps and bounds beyond the days when sandbagging was typically the best option. New as-needed barrier methods include inflatable bladders that can be placed around a building’s perimeter and filled with water to keep floodwater and flood debris at bay.

“People have always said, ‘Well, I’m in a flood plain, it’s inevitable. It’s an act of God,’ ” said Carl Solly, vice president and chief engineer, FM Global. “In the last several years, we’ve really been trying to deliver the message that you can do something about your flood risk.”

Shake, Pummel and Burn

Flood is far from the only problem benefiting from smart engineering. FM Global is working with manufacturers to develop and certify roofing material designed to better withstand the localized hailstorms that often plague southeastern and midwestern states.

Current materials rated for severe hail can withstand hailstones up to 1 ¾ inches in diameter. The new product, rated for “very severe” hail can tolerate hailstones up to 2 ½ inches. The difference sounds small, but it’s far from it.

“It’s about three times the amount of impact energy when it hits the roof [compared to a 1 ¾ hailstone],” explained Solly. “That’s a big difference.”

As for “bouncing back” after a catastrophic fire, Solly said that’s a fairly tall order. But even there, technology is helping to reduce the severity of fires so that disruption is minimal.

FM Global researchers recently pioneered the concept of SMART sprinklers — shorthand for Simultaneous Monitoring and Assessment Response Technology — which can sense a fire earlier than traditional systems and activate targeted sprinkler heads when needed and shut off once the fire is out.

“You’ll catch it with less water, so from a water usage perspective, a water damage perspective and a smoke damage perspective, we think that has an opportunity to be a big difference-maker in the fire protection industry, particular with high-challenge fires,” said Solly.

“You’ve got a better chance of stopping what normally would be a really tough fire to catch.”

In addition, added Brown, smarter sprinkler systems, much like burglar alarms, could be programmed to notify the fire department instantly, even when a structure is unoccupied.

For earthquake risk, said Brown, resilient building efforts are less about new materials than they are about more strategic ways of using traditional materials.

“Here in California we wrap homes in stucco around the wood frame to help the whole building move as a unit. Stucco is concrete so it does crack. I end up with a building that’s got some cosmetic damage … but you don’t have to rebuild the building. It does its job in terms of absorbing a lot of the ground motion before it pushes the building beyond its design tolerances.”

Using stronger, larger steel brackets where the walls meet the roof or the floor or each other, said Brown, “keeps the north wall from moving in one direction while the west wall moves a different direction.”

Those kinds of stress points can push modest earthquake damage to catastrophic levels, he said.

One earthquake innovation still in the beta phase is a project out of the U.C. Berkeley Seismological lab, using the accelerometers in smartphones as virtual seismometers. Participating phones have an app that detects certain types of ground motion. As phones pick up earthquake wave patterns, they ping the server which checks nearby smartphones to see if they sensed the same pattern, all in microseconds. If an earthquake pattern can be confirmed, an alarm will be sent to every cellphone within a logical radius.

That might only buy people an extra two to five minutes before the event, said Brown, “but if you are the operators of Bay Area Rapid Transit commuter trains, that’s enough time to slow all the trains down to five miles an hour. If you are Google, that’s enough time to park a bunch of hard drives in your server farm so that they’re better able to resist shaking and not be damaged too badly.”

Raising Standards

Cost, of course, will impact the take-up of resilient materials and tools. If it’s three times more expensive to build a home out of the resilient materials, a lot of builders aren’t going to want to because the home will be tougher to sell.

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FM Global’s Approvals division tests and certifies a variety of products aimed at mitigating disaster peril. That can help increase property owner confidence in these materials, particularly for commercial structures.

“When you’re betting millions of dollars and the future of your business — or at least the near-term future of your business — you really need to know that it’s going to work,” said Solly.

With just-in-time manufacturing, a company may have a few days’ worth of stock on hand rather than three months’ worth.

“So you can’t afford to be out of business for weeks, because your customers are going to go somewhere else for your product,” he said.

Building standards and codes can help drive adoption of resilient measures in both commercial and residential construction. But more work needs to be done to raise standards to meet the goal of resilience.

Effecting real resilience is something leaders across the spectrum should be talking about, including brokers and carriers, government and research agencies, building products manufacturers, and corporate executives.

If lives are saved in an earthquake, but a building is still damaged to the point where it needs to be torn down, said Brown “that building owner, that community, is going to have a much longer path to full recovery. We want the building codes strengthened to an immediate occupancy [goal] — we want people to be able to move right back into that building so there’s a much shorter window of disruption.

“It’s certainly better for me as the insurer,” he said, “but it’s even better for the guy that owns the building or runs his business out of it because now his employees still have a place to come to work and they can still get paid.”

Every single business able to minimize its downtime in this way helps the entire community be more resilient, he added. It creates that snowball effect in a good way. When businesses are able to stay open or reopen quickly, he said, workers don’t lose a meaningful amount of pay. Everybody’s in a better position to continue shopping and supporting the local economy.

“If you just shorten the line of people who are looking for some sort of federal aid, or state aid because they’ve had a massive financial disaster — maybe we can turn those into moderate to small financial disasters. That’s the key, I think, to communities being more resilient.”

Driving Demand

As the likelihood increases that property owners will experience a second loss or even third loss, some insurers are looking at ways to invest in resilience — a smarter long-term business plan than paying to rebuild again and again.

One new initiative is Lex Flood Ready, the product of a partnership between Lexington Insurance and The Flood Insurance Agency (TFIA). Flood Ready is a coverage enhancement for Lexington Private Market Flood clients that will not only indemnify property owners that suffer flood damage but will also provide the funds to rebuild them to a higher standard of resiliency when replacing floors and walls.

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Resilience proponents advocate a variety of approaches to encourage take-up, including tax credits, resilience grants, insurance incentives and other partnerships, as well as encouraging lenders to engage borrowers by making the flood risk assessments part of the mortgage process.

A certification scheme similar to LEED could also help drive resilience efforts. The UK is currently beta-testing a certification program called Home Quality Mark, developed by the Building Research Establishment (BRE). Properties are rated on stringent criteria that considers not just disaster resilience, but energy performance and cost, durability and environmental impact.

“Getting people from diverse perspectives thinking about it and talking about it is going to be the avenue to finding the right answers.” — Michael Brown, VP and property manager, Golden Bear Insurance

That’s something builders would be able to use to add value to their properties, offsetting the cost of building in resilience and driving consumer demand for properties built to the highest standards.

With increased resilience will come questions for insurers, said Brown. “It will open up a can of worms.”

It will create something of an arms race among insurance companies, he said. “Who’s going to be the first one to figure out what’s the right way to insure that? What’s the right price? What are the right terms and conditions?” Admittedly, it’s a good problem to have.

Effecting real resilience is something leaders across the spectrum should be talking about, including brokers and carriers, government and research agencies, building products manufacturers, and corporate executives.

“Getting people from diverse perspectives thinking about it and talking about it is going to be the avenue to finding the right answers,” said Brown.

“That kind of mentality top to bottom in the industry is going to be necessary. It’s not the first time we’ve dealt with disruptive things and we will continue doing it. It’s what keeps the game interesting.” &

Michelle Kerr is associate editor of Risk & Insurance. She can be reached at [email protected]