This article by Avianto Amri, Deanne K. Bird, Kevin Ronan, Katharine Haynes and Briony Towers published in Natural Hazards and Earth System Sciences investigates the implementation of disaster risk reduction education for children in Indonesia. In the last decade, education programmes related to this subject have been promoted as capable of reducing disaster losses and increasing resilience, based on several studies that have identified positive outcomes. Therefore, it is critical to evaluate and address any potential challenges that might impede their success. The article uses a case study in Jakarta, a rapidly growing megacity that is highly prone to disasters and natural hazards, especially floods and fires, to explore the scaling up and sustainability of disaster risk reduction in Indonesian schools. Based on previous studies, a new approach was developed for evaluating the implementation of education programmes related to these subjects. This study captured the perspectives of children, school personnel, and non-governmental organisations on the challenges of scaling up the implementation of disaster risk reduction education in schools. The study revealed seven key issues and suggests several policy recommendations to move forward. These key issues may also be apparent in many other developing and developed countries, and the suggested recommendations may well be applicable beyond Indonesia.
This nicely written and well-researched article by Brooke Jarvis appeared in the New York Times Magazine on April 23, 2017, with the headline: Under Water. It nicely illustrates many of the issues discussed by John and other authors in McAneney et al. (2016) in Government sponsored insurance schemes: a view from down under and other scholars. In particular it points out the role of seal level rise and sinking coastal landscapes — in some cases both together — in changing the vulnerability of coastal communities to flooding, the ‘immoral’ hazard of subsidizing people to live in harms way, the stupidity of building slab-on-ground construction in flood plains, the reality signal sent by risk-informed insurance premiums and how homes with repeated claims are threatening the viability of the National Flood Insurance Program in the US.
In 1909, a group of Virginia developers placed an ad in The Norfolk Ledger-Dispatch announcing the creation of a subdivision that — because it was built on a pair of peninsulas where the Lafayette and Elizabeth Rivers poured into Chesapeake Bay — came to be known as Larchmont-Edgewater. The developers set up private jitney service to downtown and advertised the area as “Norfolk’s only high-class suburb.” People flocked to live by the water’s edge.
Today the neighborhood is known for the venerable crepe myrtles that line its streets, for its fine houses and schools and water views and for the frequency with which it is not just edged by, but inundated with, water. Melting ice and warming water are raising sea levels everywhere. But because the land in the Hampton Roads area of Virginia (which includes Norfolk) is also sinking, relative sea levels there are rising faster than anywhere on the Atlantic coast. Water levels are already as much as 18 inches higher than they were when the developers created Larchmont-Edgewater a century ago, and they are still rising. As a result, it’s much easier for winds, storms and tides to push flood water into streets, yards and homes that once stood high and dry.
When Elisa Staton found a small house a block from the water in Larchmont-Edgewater in 2005, she was thinking of the neighborhood’s grand trees and Tudor-style houses, of the elementary school she hoped to send her kids to, once she had them. She wasn’t thinking much about flooding, though she knew the house was in a hundred-year flood zone, which meant that to get a federally backed mortgage, she was required to pay for flood insurance through the National Flood Insurance Program (N.F.I.P.), a government-subsidized system overseen by the Federal Emergency Management Agency. The insurance was reasonable, and there was no record of the house ever being flooded before. She bought it for $320,000.
A “hundred-year flood” sounds like a factor of time, as if the land were expected to flood only once every 100 years, but what it’s really meant to express is risk — the land has a 1 percent chance of flooding each year. As waters rise, though, flooding in low-lying places without sea walls, like Larchmont-Edgewater, will become more and more common until the presence of water is less about chance and more about certainty. And few insurers are willing to bet against a certainty.
Ten years later, Staton’s rec room had been flooded twice, and her insurance premiums, like those of many coastal property owners, had skyrocketed. She was seeing the effects not only of those local floods but also of rising waters elsewhere. As storm damage becomes more costly, it has left the N.F.I.P. tens of billions of dollars in debt and federal officials scrambling to bridge the divide between the rapidly growing expense of insuring these properties and the comparatively tiny, taxpayer-subsidized premiums that support it.
In 2012 and 2014, Congress responded to the N.F.I.P.’s troubles with bills known, thanks to the accidental aptness of their sponsors’ names, as Biggert-Waters and Grimm-Waters. The first law cut subsidies and phased out grandfathered rates so that premiums would start to reflect the true risk that properties like Staton’s face — reaching what the N.F.I.P. calls “actuarial soundness.” The second tried to slow the rate of those increases when it became clear how hard they would hit property owners.
Staton married and left Norfolk, renting out her house as she followed her husband’s job in the military. But eventually she was paying nearly $6,000 in flood premiums on top of her mortgage every year, nearly always more than she could make in rent. “I decided to cut my losses and get out,” she said. “The flood insurance kept going up, and I was drowning in it.” A real estate agent she consulted told her that she’d be lucky to sell the house for $180,000, barely more than half of what she paid for it and significantly less than what she still owed on the mortgage. Everyone looking at places near the river, the agent said, asked about flood insurance first. It wasn’t the risk of high waters that spooked buyers; it was the certainty of high premiums.
Staton lay awake at night wondering what to do. “I hate that house — that house has been my nightmare for 10 years,” she said last month, on a day when the dogwood and quince were bursting into flower in the front yard and the sun was sparkling off the calm, tidal river biding its time a block away. “I never got to get my head back above water.”
Insurance serves as a bulwark, both financial and mental, against the fact that we live in a fundamentally uncertain and dangerous world. “The revolutionary idea that defines the boundary between modern times and the past,” the financial historian Peter L. Bernstein wrote in his 1996 book, “Against the Gods,” “is the mastery of risk: the notion that the future is more than a whim of the gods and that men and women are not passive before nature.” Calamity can come for us all, but by bundling enough separate peril together we manage to form a general stability, a collective hedge against helplessness. As climate insecurity mounts, though, that math will get harder.
Frank Nutter, president of the Reinsurance Association of America, put it in more direct terms: “Constant risk — that’s not what insurance is about.”
Flooding is the most common, and most expensive, natural disaster in the United States. Private insurers have long declined to cover it, leaving the government on the hook for disaster assistance after floods. (Hence the famous lawsuits after Hurricane Katrina, when people who came home to empty slabs were asked to prove that their losses were a result of wind and not waves.) Congress created the N.F.I.P. in the late 1960s in response to a series of expensive floods caused by hurricanes and overflowing rivers. It offers insurance coverage, some of it subsidized, to communities that meet floodplain-management requirements; requires people who want loans to buy houses in dangerous places to buy it; and also provides grants for mitigation projects meant to reduce flooding damage, like elevating houses or buying out the owners of flood-prone homes. Private insurers including Farmers, Allstate and 68 other companies also sell and administer the policy on the government’s behalf — and take a sizable cut of the premium. If floods do come, though, it’s still the government that’s on the hook.
The N.F.I.P. was meant to encourage safer building practices. Critics argue that instead it created a perverse incentive — a moral hazard — to build, and to stay, in flood-prone areas by bailing people out repeatedly and by spreading, and in that way hiding, the true costs of risk. (In 1998, “repetitive-loss properties,” buildings that flood over and over, accounted for 2 percent of N.F.I.P.’s insured properties but 40 percent of its losses; since then, such losses have only increased.) As Larry Filer, an economist at the Center for Economic Analysis and Policy at Norfolk’s Old Dominion University, explains, “Somebody on a mountain in Colorado is helping the person in Virginia Beach live on the waterfront.”
And then came Hurricanes Katrina, Wilma and Rita, which in 2005 left the N.F.I.P. with claims six times higher than it had seen in any previous year. To cover them, it borrowed $17.3 billion from the Treasury. Hurricane Sandy in 2012 meant another $6.25 billion in debt, along with allegations that insurance companies distributing FEMA funds were shorting policyholders; 2016, when there were floods in Louisiana, Texas, Virginia and elsewhere, managed to be the third-most-expensive year in the N.F.I.P.’s history even with no single standout catastrophe, deepening the hole further. Servicing the debt is expensive, but FEMA sees no way to repay it, Roy Wright, the N.F.I.P. administrator, told Congress last month.
More losses loom. A single major storm-and-flooding event could cause $10 billion in damage in Hampton Roads alone, according to one planning report. AIR Worldwide, which models the risks of catastrophic events for insurance companies and governments, found that $1.1 trillion in property assets along the Eastern Seaboard lie within the path of a hundred-year storm surge. “That’s a very staggering number,” says AIR’s chief research officer, Jayanta Guin — and it represents only the risk on that coast, and only under current sea levels. By the 2030s, according to a 2008 analysis by Risk Management Solutions (R.M.S.) and Lloyd’s of London, annual losses from storm surges in coastal areas around the world could double.
In 2015, the N.F.I.P. asked R.M.S. and AIR Worldwide to update its modeling by running thousands of computer simulations to show what possible storms might mean for the properties it insures, helping it to quantify its financial exposure across the country. In 2016 and 2017, the N.F.I.P. — in a first-of-its-kind action for a federal program — transferred some of its risk to large, private companies known as reinsurers, which pool risk on gigantic scales: insurance for insurance companies.
Although Katrina and Sandy “felt like once-in-a-lifetime events,” Wright wrote in a recent blog post explaining the decision, “there is actually a 50 percent chance within a 10-year period the N.F.I.P. will once again experience Hurricane Sandy-size losses.” Removing subsidies is one partial solution, he told me — “There is no greater risk-communication tool than a pricing system” — but more hard decisions are coming. The N.F.I.P. is up for a reauthorization vote in September, its first since Biggert-Waters was passed; Wright believes the time has come to start limiting coverage for properties that are flooded over and over, a significant shift from the past. Multiple losses, he told me, “should force us to shift our position where we make an offer of mitigation to a homeowner, and if they do not choose to take it, we don’t renew their policy.”
After Biggert-Waters, some private insurers began showing an interest in covering flood insurance for the first time. A major factor is the end of subsidized coverage: As premiums increase, private insurers have a greater incentive to compete. Another, Guin says, is that risk analysis can be much more accurate than even a few years ago, thanks to powerful computers able to run more simulations that include more variables. Making money on insurance, after all, is a game of timing, and most policies are rewritten each year.
Evan Hecht, chief executive of the Flood Insurance Agency, based in Florida, read the details of Biggert-Waters and decided to expand his business. He had sold N.F.I.P. policies for years, but in 2013 he and his wife, Tiara, went out on their own, seeking private underwriting from Lloyd’s of London and an A.I.G. subsidiary. The vast majority of their policies — now totaling 19,000 in 37 states, including some in the Norfolk area, according to Hecht — are on properties that require flood coverage because of their locations, and on which FEMA is raising rates. On average, he estimates, premiums from the Flood Insurance Agency cost 30 to 35 percent less than those bought through FEMA. And the agency plans to offer further discounts for properties with waterproof alternatives to easily damaged materials like wood floors and Sheetrock.
At a congressional hearing on flood insurance reform in March, Hecht asked lawmakers to approve legislation that makes it simpler for private flood insurance to satisfy mortgage requirements. FEMA supports this move as a way of spreading out risk — the bottom line, Wright says, is that “we need more people covered for their flood peril” — but also cautions that it could make things worse for taxpayers if, with the help of better data, private insurers are willing to cover only lower-risk properties, or purposefully price themselves out of high-risk ones, leaving FEMA with an even more dangerous portfolio than it started with.
Hecht believes his company’s interest in policies FEMA considers underpriced for their risk is evidence that such an outcome won’t occur. But private insurance, he noted in the hearings, is “of course” not interested in covering severe-repetitive-loss properties or buildings whose exposure is higher than what can be recouped in premiums. What will happen, I asked him, to houses that flood too often? “Insurance policies aren’t written for 100 years,” he replied, “so we’ll react as it happens.” He described a driver who has had so many speeding tickets and accidents that his auto insurance skyrockets: “Those houses will not exist, just like that driver will no longer have a car. There’s no magic answer.”
Elisa Staton still owns the house in Larchmont-Edgewater. After delivering the painful estimate of the house’s new value, Staton’s real estate agent suggested she call a man named Mike Vernon, an insurance agent in Hampton Roads who brands himself as “the Flood Insurance Guy.” His specialty is finding clever ways to reduce flood premiums. When Vernon visited Staton’s house, he saw a solution right away: The rec room, once a garage, sat lower than the first floor, lowering the minimum elevation level of livable space inside the house, which FEMA uses to calculate premiums. By converting it back to “low-value storage space,” lifting the electrical system to a higher elevation and adding flood vents, Staton could get her premiums close to $800 a year. She paid for the work, Vernon updated her policy and she put the house on the market for $100,000 more than the agent first advised — but it has yet to sell.
We’re often actually making the building worse to bring down premiums,” Vernon told me: filling in basements, or preparing a house to let water flow through it instead of keeping it out (yes, the house may be damaged by moisture, but at least it won’t be pushed off its foundation). “Or we’re eliminating something good, like a sunroom on a slab.”
Vernon’s business is flourishing. A former consultant, he got the idea for his own venture after advising a flood-vent inventor around the time federal flood premiums began to increase: “Biggert-Waters passed, and I’m seeing dollar signs.” He’s hardly alone in looking for the financial silver linings of rising seas — local universities and the city itself are pointing to their growing expertise in flood mitigation and adaptation as a source of future revenue. Vernon gets most of his business from referrals from real estate agents, whose clients, unable to sell their houses, often come to him in tears. “People are getting killed,” he said. “To an appraiser it’s still worth $300,000, but to the real world it ain’t worth nothing, because it’s not going to sell.”
On a recent Wednesday morning, Vernon, seeking new business, described his work in the packed beige meeting room of a Hampton Roads real estate agency. He showed the agents a slide that listed the threats facing the area: changing weather patterns; bigger, stronger storms; rising sea levels; long-term erosion; sinking land mass; and poor building decisions. He got a laugh with a line about the absurdity of building houses with basements in Norfolk. “Was it a bad building decision back in 1900?” he continued. “Probably not, but it has turned into one.”
Vernon described which problems are fairly easy to remedy and which are not. Houses built directly on slabs, which are especially common in low-income neighborhoods, have the fewest alternatives: Basically, raise it up or raze it down. (“If you ever want to make an enemy, or get back at one,” he’ll tell agents, “just sell them a house on a slab in a required flood zone.”) With flood insurance, Vernon said, the agents should be prepared for the three Fs: frustration, fear and foreclosure. “I’ve seen people, they just walk the keys down to the bank and say, ‘You can have it.’ ”
The biggest reaction came when Vernon explained that, because of the effort to make the N.F.I.P. more financially sound, premiums are set to go up by 18 to 25 percent every year, and cited a study that found that each $500 annual increase in flood insurance lowers a home’s value by $10,000. The room filled with gasps and whistles. “What was that ratio again?” an agent named Carmon Pizzanello called out from the back. “In two years,” Vernon replied, “you’ve lost tens of thousands of dollars on your house.”
Pizzanello volunteered that she’d sent one of her clients, living in a below-flood-elevation house on a slab and paying $3,200 annually for N.F.I.P. coverage, to talk to Vernon. Short of options, they looked into private insurance. The lowest quote that came back was $22,000 a year. It was one of those raise-or-raze situations, Vernon told the gathering, saying, “Elevation certificates are literally about tenths of feet.”
Spend a few days talking about floods and real estate in Norfolk, and you’ll quickly learn the importance of even tiny inclines. Locals know where, on what appears to the uninitiated to be a flat street, to park their cars to keep them from flooding past the axles when the wind pushes the tide up. Landscapers build what are essentially decorative earthen dikes around houses. When I asked one man how close storm and tidal surges come to his front porch, he pointed at the bricks under my feet, which I had taken for the wall of a flower bed. “You’re actually standing on a bulkhead,” he said.
In the coming decades, these fine distinctions will mean little, as the risk of flooding becomes the certainty of it. The operative measurement for rising waters in Norfolk is not inches but feet — as many as six of them by the end of the century, according to the Army Corps of Engineers, though estimates vary. City planners are forthright that they’re preparing for a future in which parts of the city do not survive. “We absolutely cannot protect 200 miles of coastline,” George Homewood, Norfolk’s planning director, says. “We have to pick those areas we should armor, and the places where we’re going to let the water be.”
Norfolk now mandates that new construction be built three feet above current base flood elevation (as if the houses were boats, this distance from the waterline is called freeboard), and 18 inches above what Homewood says is “euphemistically known as the 500-year floodplain.” But Norfolk is an old, established city, where changing new construction can only get you so far. In 2008, the city hired a Dutch engineering firm, experienced with life below sea level, to help develop a plan for adaptation. The firm suggested $1 billion in changes, more than half of which would go to simply updating existing infrastructure.
Like insurers, residents are playing a game of risk and timing. “Adaptation is a range,” says Fred Brusso, a former city flood manager. “Do you need to just move your car? Do you have to put your washer and dryer on cinder blocks? Or do you need to get the heck out of town?” Sean Becketti, the chief economist for Freddie Mac, cautioned in a report last year that economists aren’t sure if coastal property values will decline gradually, as the life expectancy of homes shrinks, or precipitously, “the first time a lender refuses to make a mortgage on a nearby house or an insurer refuses to issue a homeowner’s policy.”
Skip Stiles, the executive director of the local nonprofit Wetlands Watch, took me on a tour of frequently flooded areas of Norfolk — when waters are down, Stiles uses rusty storm drains and marsh plants growing in yards and medians to show where they’ve been — and pointed out buildings that had been elevated. Often their awkwardness made them obvious: ordinary, colorful houses perched uncomfortably atop walls of bare concrete blocks. While FEMA does pay to elevate risky houses, it struggles to keep up with demand: Wetlands Watch compared the number of people on the FEMA waiting list in Norfolk with the number of houses raised in a year, and concluded that it would take 188 years to complete them all. By then, of course, waters would be far higher.
This is the hardest reality to discuss, Stiles said, and a reason flood insurance is serving as a kind of advance scout into a more difficult future. “When you go out to the end of the century, some of these neighborhoods don’t exist, so it’s hard to get community engagement,” he said. “Nobody wants to talk beyond where the dragons are on the map, into uncharted territory.”
Carol Stewart, Thomas M. Wilson, Victoria Sword-Daniels, Kristi L. Wallace, Christina R. Magill Affiliated with Risk Frontiers, Macquarie University, Claire J. Horwell, Graham S. Leonard, Peter J. Baxter.
Volcanic ash is generated in explosive volcanic eruptions, dispersed by prevailing winds and may be deposited onto communities hundreds or even thousands of kilometres away. The wide geographic reach of ashfalls makes them the volcanic hazard most likely to affect the greatest numbers of people.
by Andrew Gissing, Katharine Haynes and James O’Brien
Floodwaters arising from the rainfall of Ex-Tropical Cyclone Debbie impacted North, South and Central Lismore from Thursday, March 30, 2017. Hundreds of residential and commercial buildings were flooded; several thousand residents and business operators were evacuated. Central and South Lismore are protected by levees but both of these were overtopped.
The Lismore Rowing Club Gauge measured a flood peak of 11.6 metres AHD, the highest recorded since 1974 (12.2 metres AHD). North Lismore was flooded late on the evening of the 30th of March, whilst South and Central Lismore were flooded in the early morning hours of the 31st of March.
Risk Frontiers visited Lismore on the 3rd of April to undertake unstructured interviews with residents and business operators in order to gain preliminary insights into impacts; responses to warnings; sheltering behaviours; how levees may have influenced risk perceptions; and the initial recovery. Our team was integrated with emergency service Rapid Impact Assessment teams to avoid duplication and burden on those impacted. In total we spoke with 22 residents and 23 business operators. In what follows, we highlight key learnings from these early investigations.
Residential flood damages in the main appear to have been restricted to the ground storey areas of raised dwellings, with peak flood heights reaching just inches below second storey living areas. In many cases it would appear that these ground story spaces were likely occupied at the time of the flood and in some cases rented out. The majority were certainly used for extensive storage. There were a smaller number of lower set dwellings in which flooding impacted main living areas.
Almost every home and business on the floodplain had a large muddy pile of possessions stacked on the roadside awaiting council pick-up (Figure 1). In some areas possessions had floated away and were now scattered across open areas. Common household items damaged were carpets; household appliances — fridges; washing machines; dryers; cupboards and drawers; fabric lounge chairs; tables and chairs; hardware; bedding; doors and outdoor furniture. Some people stacked goods on tables or shelves within the ground storey only for tables to float and shelving to fail. Pets were also lost with one family losing some sixty guinea pigs.
Damage to commercial operations varied widely depending upon the type of business. A large number of businesses had suffered significant losses, such as a Hotel, which estimated its damages at $600,000; a hire-car business in which all vehicles were flooded; a whole foods store that lost most stock; a bakery that had lost its ovens and mixing equipment; and a large clothing retailer that was disposing of all of its stock and fittings. Some reported that they were unable to move large pieces of equipment in time. Most reported that they were uninsured or were hopeful that some losses may be claimed through severe storm coverage.
Most flood-affected businesses were closed at the time of our reconnaissance mission for clean-up and restoration. A small number, however, had recommenced trading, albeit on a reduced scale. In a higher area that hadn’t been flooded, a café operator reported that they had run out of food to serve two days running due to increased customer demand.
One business owner expressed frustration concerning the closed access to the CBD, suggesting that allowing earlier access on presenting identification would help. Concern was also expressed about bow waves, arising from motorists and boats driving through floodwaters, causing further flood damage to homes and businesses.
Significant flood velocities occurred through Browns Creek and the adjacent car park causing substantial erosion in the lower area of the car park, and structural damage to the roller doors of a nearby business. Figure 2 shows two trucks washed from an adjacent business into Browns Creek.
Recent commercial developments, with floor levels set above the 1-in-100 year flood level avoided flooding. These businesses included Hungry Jacks, Woolworths, Aldi, Bunnings and Toyota, who were all able to trade directly after floodwaters subsided. Figure 3 shows the raised floor level of the Aldi Supermarket. The operation of supermarkets in Central Lismore during the initial recovery phase likely helped reduce the scale of emergency relief required.
Given that we saw many dwellings where the floodwaters had come only inches from second storey levels, a flood of 1974 or 1954 proportions would certainly have resulted in significantly higher damages, community panic and displacement. Roche et al. (2013) estimated that the total normalised economic cost of the 1954 floods in 2011 dollars throughout the region would have been of the order of $7.5 billion, although the uncertainty in that figure is high. The 1954 flood affected many more catchments in the Northern Rivers region of NSW and occurred prior to reliable insurance statistics and the recent escalation in property values. 28 lives were lost in that event (Roche et al. 2013).
Community response to warnings
The Bureau of Meteorology and the NSW SES provided warnings and information to the community throughout the event via websites, traditional media, door-knocking and social media. The local Council also utilised flood sirens when levees were over-topped.
As reported in the media the majority of residents interviewed did not evacuate instead opting to shelter in a higher story of their home as floodwaters rose. The reasons for doing so varied and included wanting to save possessions, fear of looting, that they had sheltered previously and to enable clean-up to commence earlier.
Many appeared to have been caught off guard by the scale and speed at which the flood occurred and were not able to save many items. Some told us that earlier warnings of a moderate flood gave them a sense of security, false as it turned out, and which was quickly replaced by panic when flood heights exceeding 11 metres were forecast. Others simply thought the warnings were exaggerated and that the flood heights would be less than predicted given that this had been the case in the past. A few of those interviewed, however, thought that a larger flood than that predicted was likely and had taken action in advance.
Overall, people described flood warnings as “OK”. Suggestions for improvement included providing warnings more regularly, perhaps every two hours and providing regular river height readings. One resident expressed concern that residents may still be confused by a river gauge datum change that occurred some fifteen years ago. Another favoured forecasts provided by locals over those derived from automatic gauges and delivered by officials in Sydney.
Pointing to the success of Lismore City Council efforts to provide such information, most residents knew how to interpret gauge levels in terms of the corresponding flood heights in their homes and businesses. The degree to which this knowledge influenced behaviour requires further exploration.
Although a frightening experience for some, many, who sheltered in place, said that they would do it again. Some prepared by stocking up on food, however, the majority did not as they considered they would only be isolated for a few hours at most. Most were caught off guard when power was lost resulting in an inability to cook and use lighting or hot water. This surprised them as the power had remained on during previous floods and although some did expect the power to fail, the length of outage was a challenge for everybody.
One resident described how his medications needed to be kept in the fridge and he had just bought a three-month supply only days before the flood. Although the supply had been ruined because of the power loss he had just managed to keep a small amount cool enough during the flood to keep him healthy.
Another resident discussed how they had not only stocked up on food but had also bought iceboxes and ice in order to keep their food from spoiling in the event of a power outage.
Another resident with a child who requires lung support to sleep evacuated their lower set home and waded, in the dark, through waist high water to a neighbour’s house. As the power remained off for a couple of days they could not return to their home. Another mother who sheltered with her four children and two other adults discussed how they didn’t know if the tap water had been compromised, and therefore only drank the fluids they had in the home. The family had taken the precaution of filling the bath with water when the flooding began; however, the bath had emptied overnight due to a poorly fitting plug.
Many did not have radios, torches, candles or spare batteries. People talked about the isolation as their phone signals didn’t work, laptops ran out of power and they could not access information. Others enjoyed the camaraderie of neighbours who assisted through the sharing and cooking of food for each other (if they had access to gas), and the passing on of information from neighbour to neighbour.
Specifically those interviewed stated:
We stayed. Not the best idea. We lost power. We couldn’t cook. (North Lismore business owner)
My daughter stayed. She is pretty freaked out. Still hasn’t left the house.” (North Lismore Resident)
Next door neighbour stayed. Said it was interesting, was blacked out, had no hot water. Lucky water didn’t get in the house. (North Lismore Resident)
I had food, water and plenty of warm beer. . . I always intended to stay, stayed in 74 . . . its just life . . . (South Lismore resident)
Decided to shelter but didn’t realise the water would get that high or stay for so long . . . Didn’t realise the power would be off for so long . . . just had enough food (South Lismore resident)
Still lifting when the water came through, so had to stay, but would have stayed anyway . . . Went out and got extra food. House is built for it so would always stay . . . Could stay a week, had batteries for radio, didn’t have a generator but have bought one now (South Lismore resident)
Next time I will evacuate as didn’t like being without power . . . bought extra food but didn’t think about the power going off . . . 1 camp stove and 7 people to feed . . . everything in the fridge went off and I couldn’t cook it . . . if it had lasted another 12 hours we would have been in trouble (South Lismore resident)
Four-year old daughter had an ear ache and we were seeing how bad it got. She had a mild temperature and we were giving her Panadol, we were considering calling the SES to take her to the doctors but only if it had got really bad (South Lismore resident)
We have a gas stove and we even cooked for our next door neighbour . . . we have been in floods too many times to not be prepared . . . bought eskies and ice to make sure were ok with food (South Lismore resident)
Didn’t expect the power to go off for so long, only expected it to go off for an hour or two (South Lismore resident)
Didn’t want to evacuate, we had enough food and lived on sandwiches. We were due to do a shop on Wednesday as we only get paid fortnightly so we just ate what we had . . . could only have lasted another day. We didn’t want to evacuate because of looters, if we lost our contents that would be it . . . I’m on medications that need to be in the fridge and had just picked up a three month supply and they are all spoiled . . . I had just enough to get me through. Such a disappointment that the electricity went out for so long. Because the TV went out we weren’t able to get any information, take that out and we have nothing. Don’t have a radio, have a mobile but it ran out. (South Lismore resident)
Stoked up on food and water but then the power went off and it all went off . . . a bloody waste of time . . . if I’d known the power was going to go off I would have bought a generator in to save the food… we choose to live here and I wouldn’t want to live anywhere else (South Lismore resident)
Didn’t have time to get food and didn’t think it was going to be this bad. Had some food but had to throw it away. Fridge off for a day and a half and it just goes off so quickly (South Lismore resident)
Perception of Flood Levees
Businesses in the CBD thought some may have put too much faith in the Central Lismore levee and got caught out. Some were said not to have packed up to the amazement of other businesses.
Some perceived the Central Lismore Levee as being both a blessing and a curse: it had kept water out previously in 2005 and 2009, however, once overtopped kept water in.
In North Lismore one resident expressed concern that flood behaviour had changed since the CBD levee had been built believing flood levels were now much higher as a result. In other places residents showed us that flood levels were lower than those experienced in 1974.
We observed both formal and informal mechanisms to assist recovery efforts. Emergency services and council staff were assisting with the clean-up, with local volunteer groups such as Rotary provided catering for residents on the street. On an informal level we observed people bringing hot meals for those impacted, and family and friends assisting in the clean-up.
A Facebook Page called Lismore Helping Hands was cited as a fantastic resource, where community members were helping to coordinate the provision of support for others. As at April 7 the page had 6450 members.
Business owners expressed dismay and anger about looting and theft from their clean up piles in the street and were verbally challenging people who were stealing items from shopfronts.
Discussion and conclusions
Though a significant and very damaging event, we were left with a sense that the community was functioning and resilient, getting on with the job of cleaning up.
Much bigger floods are possible in Lismore and there is much to be learned from this event. The physical and social impacts would have been far greater had the floods been only a little higher.
As well as providing more evidence as to the effectiveness of flood mitigation and flood warning systems, the event offers significant opportunities to better understand community risk perceptions, responses to warnings, sheltering behaviours and flood damages.
Several policy and communication issues already apparent include the following:
What should be done to reduce flood damages in enclosed ground floor areas of high set dwellings? These areas should not be rented as habitable space.
Despite evacuation orders being mandatory many residents chose not to leave. This is consistent with other NSW flood events and experience internationally. In larger floods these people could face significant risks. This issue may be difficult to solve: current messages in evacuation warnings mention the possibility of rescue and this in turn implies the availability of rescue resources. This messaging should be reviewed.
The culture of sheltering-in-place during floods requires further in-depth research in order to determine perceptions and beliefs, and, by documenting the experiences in events like this, the risks and challenges. Emergency services must inform people of what they can expect when they shelter-in-place during floods, particularly the likely lack of power and the number of days of isolation. There is a need to ensure people fully understand the possible consequences both physically and emotionally and that it will always be safer to evacuate. The experiences documented to date outline the many risks involved in sheltering and appear to support existing arguments against the adoption of shelter-in-place strategies within green field developments with similar flood risks.
Can levees be raised to reduce the flood risk? Community members are already pushing for increased flood levee protection. However, the original decision to construct the levee to provide protection with a 10% annual chance of over-topping was made based on a study that found larger structural measures were ‘uneconomical, impractical and socially unacceptable’ (Lismore City Council, 2002). In the absence of levee raising or new engineering works, Lismore would be largely reliant on existing non-structural measures including house raising, education, flood warnings and evacuation, and perhaps the voluntary buy back of flood prone properties by the government.
ROCHE K M, MCANENEY K J, CHEN, K AND R.P. CROMPTON, 2011. The Australian Great Flood of 1954: Estimating the cost of a similar event in 2011. Weather Climate and Society DOI: 10.1175/WCAS-D-12-00018.1.
LISMORE CITY COUNCIL 2002. Lismore Floodplain Management Plan. Lismore: Lismore City Council.
Risk Frontiers’ Andrew Gissing joins a panel on RN Radio with Fran Kelly to discuss mitigating disaster and measuring risk in the wake of Cyclone Debbie. Other panel guests include Rob Whelan (CEO, Insurance Council of Australia) and Karl Mallon (Director of Climate Risk).
By Thomas Mortlock, Niyas Madappatt and Matalena Tofa
Severe Tropical Cyclone Debbie made landfall near Airlie Beach on the north Queensland coast at midday on 28th March 2017. It was a slow-moving category 4 system that generated wind gusts exceeding 160 km/hr, heavy rainfall, large waves and storm surge at the coast. 27 hours later, after having tracked inland over the townships of Proserpine and Collinsville, it was downgraded to a Tropical Low. A team from Risk Frontiers travelled to the landfall site and surrounds a day later to assess the damage.
Surface water and river flooding
From the air, the most obvious impact of TC Debbie was floodwater. The slow forward speed of the cyclone (average 9 km/hr) contributed to surface water flooding from large amounts of accumulated rainfall on Tuesday 28th while river levels at the coast peaked a day later as the inland movement of the (then) ex-tropical cyclone released large amounts of rainfall on the hinterland. Speaking to local residents in Mackay, the delayed flooding of the Pioneer River (Figure 2 A) came at a time when most were reeling from the initial passage of the Cat 4 system.
From our observations, most main road and rail lines remained free from floodwater because of the appropriate elevation of both above the surrounding floodplain. The Bruce Highway – the main arterial between Mackay and Proserpine – was temporarily cut at Gunyarra but good gullies and freeboard (visible in Figure 2 B) ensured this was short-lived.
Wind gusts of up to 260 km/hr were recorded at Hamilton Island (50 km due east of Proserpine) and 160 km/hr at Proserpine on 28th March. Further south at Mackay, the maximum gust speed was considerably less (95 km/hr).
Driving north on the Bruce Highway from Mackay the visible signs of wind damage increased. Fallen power lines and trees were common from Seaforth north. Around Proserpine and Hamilton Plains, fields of sugar cane – usually 2 to 3 metres in height – were bent knee-high, demonstrating the severity of near ground-level winds in this area. The importance of local topography was also obvious, with steep relief exhibiting worse impacts than adjacent valleys (Figure 3 A).
With the exception of trees fallen on houses, there were few external signs of wind-induced building damage. The design gust wind speed for typical buildings in this region is 248 km/hr. Most post-1986 buildings around Proserpine, for example, experienced ~75 % of the design ultimate wind speed and faired well (JCU, 2017).
The only area where we witnessed significant structural damage was flying over South Molle Island (Figure 3 B). While this resort was half-abandoned prior to Debbie, it demonstrates what can happen with significantly stronger winds and sub-standard building condition.
Figure 3 A) Contrasting impacts of exposed relief (hill in background, trees stripped) and adjacent valley (foreground, foliage and power lines intact), B) Destruction at South Molle Island.
Storm surge is the rise in the ocean water level associated with strong onshore winds and low atmospheric pressure during a cyclone. The ‘surge’ element is additional to the normal tide. On top of the tide and surge (collectively known as the ‘storm tide’), waves can further contribute to coastal flooding locally by increasing the surface water level (wave setup) and providing momentum for an up-rush of water up the beach (wave runup). At the Mackay wave buoy, for instance, waves reached 8 m around 5 am on the Tuesday morning.
Overall surge impacts were limited because: 1) the strongest winds occurred two hours after the morning high tide and 2) the cyclone made landfall over a section of the coast partially shadowed by the Whitsunday Islands. If Debbie had made landfall two hours earlier, an extra 1 metre of storm tide may have been possible.
As it happened, water levels were able to breach most beaches on Tuesday morning as sheet flow rather than causing any significant inundation. This was largely because of the delayed landfall of Debbie after the highest state of the tide. The largest recorded storm tide was around 4.1 m at Laguna Quays (1.6 m surge), and 2.7 m at Shute Harbour (0.9 m surge). The worst affected areas that we observed in terms of surge and erosion damage were Seaforth, Midge Point, Laguna Quays, Airlie Beach and Shute Harbour.
At Seaforth, the beach was stripped away and waterfront property damaged (Figure 4 A). At Midge Point there was no surge-related damage because property was well set-back from the shoreline and the mangrove swamps dampened inundation velocities and extents. At Laguna Quays, boats were damaged and the storm tide large enough to break concrete-clad pontoons from their moorings and deposit them above the marina on adjacent high ground. At Airlie Beach and Shute Harbour, several boats were washed up onto the beach (Figure 4 B) and sand and saltwater extended onto the promenade.
Figure 4 A) Storm surge damage at Seaforth, B) boats washed up onto Airlie Beach.
Debbie has probably caused more damage after her transition to a Tropical Low than during her time as a Severe Tropical Cyclone. While witnessing the impacts of Debbie first-hand was impressive, the most striking thing we saw was the positive attitude and community spirit of Queenslanders to clean-up and get-by under very stressful circumstances.
Thanks to residents at Seaforth for providing valuable information on surge impacts in the middle of their clean-up operation. Thanks also to the Cyclone Testing Station group at James Cook University for sharing their Severe Wind Hazard Preliminary Assessment, and RegionalAir charter flights from which all aerial photographs were taken.
Lismore has a long history of flooding, with the community known for its ‘flood culture’. The areas of North, South and Central Lismore were flooded on Friday the 31st of March, the worst since 1974. It was the first flood to have overtopped the Central Lismore levee, which protects the CBD comprising some 400 businesses. Built in 2005, the levee provides protection from floods to an average recurrence interval of some ten years.
Many people ignored evacuation orders and later needed help when their properties were directly threatened by floodwater. The SES has reported some 400 rescues, many of them from properties where people chose not to evacuate.
Previous Risk Frontiers research has explored evacuation rates from natural hazards, concluding that they are variable and that is very difficult to achieve complete compliance. As a result authorities need to plan for large-scale rescue operations. Flood risk perceptions and previous flood experience have likely played a part in how individuals responded to warnings, as well as the rapid rise of the Wilsons River that caught some off-guard.
Many previous studies after floods in Lismore have concluded that the community has been well prepared and adjusted to the flood hazard. Smith (1981), for example, found that previous flood experience and flood warnings had resulted in relatively low damages during the 1974 flood.
After the business district last flooded in 2001, Risk Frontiers identified that businesses had avoided major losses as a consequence of preparedness measures they had undertaken and activated once flood warnings were received. These included mitigation measures such as lifting fittings and equipment, use of mezzanine floors and implementation of Flood Action Plans (Gissing and Leigh, 2001).
Recent Research on Lismore Business Flood Risk Perceptions
Risk Frontiers undertook a telephone survey of 50 business operators in the Lismore CBD in November 2016 and February 2017 to understand the impact of the Central Lismore levee has had on risk perception and preparedness of businesses in the area.
Over 70% of businesses surveyed had operated in the Lismore CBD for more than 10 years with some 56% of respondents reporting that they had had experience with flooding. Wilson River floods recalled were those in 1954, 1974, 1984, 1987, 1989 and 2001.
Almost all respondents (95%) were aware of the Lismore CBD levee. Perceptions regarding how often they could expect to be flooded varied from never to once every year. 43% believed they would be flooded on average once every ten years and 22% once every five years. 32% over estimated the protection afforded by the levee believing they would be flooded less often than once in every ten years on average.
Some businesses acknowledged that they had been lucky not to have experienced flooding and acknowledged the value of SES and council efforts to educate communities:
We’re massively lucky that we haven’t had any big floods for so long, new business owners don’t really know what to expect.
I went to an SES meeting for business owners about a year ago about floods and learnt a lot, I think it should be mandatory to go to things like that and listen to what people who have had to deal with full on floods have to say.
Some held unrealistic beliefs about the protection offered by the levee:
A flood would now have to be of biblical proportions with all the work done on the
The levee protects us from floods so we haven’t had to deal with any since it was built, I wouldn’t expect to be flooded in the near future.
Others felt that:
The levee gives a sense of false security, people aren’t really packing up any more when we get flood warnings. In the future when a big flood comes, people might lose a lot.
The majority of people (75%) believe that the levee provides more time for people to evacuate from the CBD in a flood event.
In respect of flood preparedness, the majority of respondents believed that despite the levee, it was still necessary to be prepared for floods with only 9% of respondents believing it unnecessary. However, 34% of respondents believe it is less important to be prepared now than was the case before the levee was constructed. 31% of respondents invoked global warming to mean that it was even more important to be prepared for worse floods.
80% of respondents had a Flood Action Plan. The completion of plans varied slightly with businesses that had experienced flooding 10% more likely to have developed Flood Action Plans than were businesses without prior flood experience. Of those businesses that had developed plans, many had had them in place for some time with respondents stating since moving in and forever. Only 37% of respondents had documented their Flood Action Plan, however, meaning it would be difficult for any new employee to effectively respond to flooding.
The majority of businesses either did not have flood insurance cover (56%) or were unsure if they did (31%). Those that did not have flood insurance believed it was not available to them or that it would be too expensive.
Discussion and conclusions
The construction of the levee in 2005 has likely impacted the perception of flood risk as evidenced by the number of respondents who believed the levee provided more protection than was designed for and the number of respondents who believed it was less important to be prepared for floods than prior to the construction of the levee.
In 2002 Gissing (2003) undertook a similar study. In comparison to the 78% of businesses identified as having Flood Actions Plans today, almost all Lismore businesses in 2002 had Flood Action Plans (97%). This comparison may imply a comparable decline in flood preparedness across business operators following construction of the levee, a decline that may have been worse in the absence of flood education programs offered by the NSW SES and Lismore City Council.
There are already concerns from business owners and residents about the length of time the levee has held floodwater within the CBD area, with some suggesting that consideration must be given to raising the levee to protect against future flooding.
Over the coming weeks Risk Frontiers will visit the area and provide further briefing notes on the outcomes of research.
We wish business operators well in their recovery and acknowledge the incredible efforts of all involved especially emergency service volunteers.
GISSING, A. 2003. Flood action plans-making loss reduction more effective in the commercial sector.
Australian Journal of Emergency Management, The, 18, 46.
GISSING, A. & LEIGH, R. 2001. February 2001 Lismore Flood. Natural Hazards Research Centre Newsletter.
SMITH, D. I. 1981. Actual and potential flood damage: a case study for urban Lismore, NSW, Australia. Applied Geography, 1, 31-39.
Risk Frontiers’ Andrew Gissing was invited to be part of the Channel 10 in-studio television broadcast on Severe Tropical Cyclone Debbie. This gave viewers the opportunity to hear expert insights on the management of the disaster as the cyclone approached the Queensland coast.
This speech was given by Hon Dr Nick Smith, Minister for Building and Construction, Minister for the Environment, on 25 January 2017. Dr Smith’s experience as a civil engineer is manifested in this lucid analysis of policy issues related to earthquake risk in New Zealand.
“A big worry in this Trump era of modern politics is that complex issues are dumbed down to 140 character tweets. The beauty of this annual opportunity you give me as Nelson’s MP is to give a far more considered and thorough account of a topical issue. The focus of this 22nd Rotary address is the steps we are taking to improve New Zealand’s management of earthquake risks.
We were dubbed the Shaky Isles 170 years ago and at two minutes past midnight on November 14 we got another harsh reminder of why. That Kaikoura quake was the largest in New Zealand since 1855. We are one of the most seismically active countries in the world and we need to be at the leading edge of protecting people, infrastructure and the economy from earthquakes.
The challenge in government is that there are all sorts of risks to manage – financial, terrorism, biological, trade, climate change, fire, and cyber-security, as well as the natural risks of floods, volcanic eruptions and cyclones, as well as earthquakes. We cannot pretend that government can eliminate these risks and we will always be limited in the resources we have to reduce them. My long term ambition as a Minister and as a rare engineer in Parliament is to try to ensure as a country we manage these risks and allocate resources based on science-based risk assessment. Politics and rational science are not close relatives, but tonight is an attempt to bring them closer together.
It is worth recalling our history of seismic events. We have had eight fatal earthquakes post-1840, or about one every 20 years. While it is true that two majors inside six years is unusual, we should treat the 40-year lull between Inangahua and Christchurch as unusually long.
There is no evidence the frequency of earthquakes in New Zealand has changed. GNS measures about 15,000 a year, of which 150, or one every three days, is felt. What has been unlucky is that we have had major quakes close to major population centres where the effects are so much greater.
It is useful to compare the risks to life from earthquakes to other risks. Our history points to an average loss of three lives a year from earthquakes, as compared to 300 a year from road accidents, 120 a year from drowning and 30 a year from house fires. You can see in these numbers why I placed huge importance in getting a new law through Parliament last year requiring smoke alarms in rental properties, when the costs are so small in comparison to earthquake strengthening and the number of lives saved so much greater. These stats are not to discount the risks from quakes, but to keep the relative risk in perspective.
Average expected fatalities are just one factor to take into account in determining priorities. Earthquakes will cost New Zealand close to $50 billion in both public and private sector costs this decade, of which the Government’s share is about $20 billion – $18 billion for Christchurch and $2 billion for Kaikoura.
The loss of life from earthquakes in New Zealand pales by comparison internationally. The 185 deaths in Christchurch compares to 230,000 in the 2004 Boxing Day quake and tsunami in Indonesia, the 160,000 killed in Haiti in 2010, the 16,000 killed in the Tohoku quake in Japan of 2011 and the 70,000 killed in Sichuan quake in China in 2008.
It is of note that the last decade has been the deadliest on record for earthquakes globally and that fatalities have been on the rise over the past half century.
The big killers are building failures and tsunamis. The reason for the significant rise is not any increase in seismicity but many more people living in the cities and in coastal areas. Improved building seismic resilience and better managing tsunami risks are the issues we should focus on to reduce future fatalities.
New Zealand’s comparatively low level of fatalities despite being one of the most seismically active areas of the world is due to both our relatively low population density and the huge improvements in building standards over the past century.
The Christchurch and Napier earthquakes were similarly sized quakes but whereas one in 100 died in Napier, in Christchurch one in 2000 died. This 95 percent reduction in fatalities can largely be attributed to the huge improvements in buildings’ seismic resistance. To put it another way, there would have been about 4000 fatalities in Christchurch were building standards left as they were in 1931. The key issue for my Building Minister’s role is how we further improve our engineering and building standards into the future.
It is not my intention to spend too much time on the seismic and engineering sciences, but there are a few core facts needed to explain the Government’s priorities and direction of policy. The first is to communicate the scale of energy release in a seismic event that makes designing and constructing earthquake resistant buildings so challenging. The Richter scale used to report earthquakes is logarithmic. An increase from a 5 to a 6 magnitude quake actually represents a 32-fold increase in the energy being released.
To get some sense of scale, the Christchurch 2011 quake at a 6.3 involved a release of energy equivalent to four Hiroshima atomic bombs. The Kaikoura earthquake at 7.8 was 180 times more powerful and the equivalent of 800 Hiroshima bombs. But the magnitude 9, mega thrust Tohuku earthquake that struck Japan in 2011 was 80 times stronger again and the equivalent of 60,000 Hiroshima bombs. So my first point is that earthquakes involve the release of phenomenal energy and that we cannot make our buildings totally safe.
The Christchurch earthquake was comparatively small and made deadly not by its size but by its location. We need to be prepared for the worse scenario of a Kaikoura or Tohoku scale quake close to a major city.
The analogy I would make to improved building design is the improvements made in vehicle standards.
Cars today are not 100 per cent safe in a crash but the risk of fatality has been made an order of magnitude better by smart design.
The challenge with buildings is more difficult because cars generally last 15 years, whereas buildings last 100, buildings are generally one off designed whereas cars are massed produced and accidents occur far more frequently than earthquakes, enabling design lessons to occur far more frequently. The common feature is that while we can make buildings a lot safer, a big enough crash or quake will still result in fatalities. My greatest concern is about the thousands of vintage buildings still in use that pose the most risk.
The second important scientific fact relates to the cause and probability of earthquakes. We heard all sorts of phantom theories about earthquakes being triggered by the phase of the moon, by oil exploration activity and from Destiny’s Brian Tamaki that sexual sinning was the cause. Earthquakes are caused by the sudden movement along faults of the earth’s tectonic plates and the timing cannot currently be predicted beyond probability estimates.
I was particularly offended by the moon-man, who caused widespread alarm in 2011 when he publically predicted a major shake at the Sign of the Kiwi on Christchurch’s Port Hill’s at a particular date and time. I was part of Skeptics New Zealand’s protest on site to highlight the nonsense of such pseudo-science. Extensive studies have shown no correlation between phases of the moon and earthquakes.
The science does, however, tell us two things about the probability of earthquakes. There are no surprises that the risk of earthquakes varies significantly with geography, i.e. that Wellington is much more prone than Auckland but the scale of difference needs highlighting. We would expect a significant earthquake of intensity MM8 in Wellington about once every 120 years, in Christchurch or Nelson every 720 years, in Dunedin every 1700 years and in Auckland once every 7400 years. For the record, the most high risk earthquake locations are Arthurs Pass, Hanmer Springs, Hokitika, Masterton and Kaikoura. The importance of this is that we need to focus our policies on the areas of greatest risk and avoid imposing excessive costs in areas like Auckland and Dunedin, where the seismic activity is low.
The second factor about the timing of earthquakes that we know is that they are much more likely after a significant quake. One of the worst psychological impacts of earthquakes is the long tail of aftershocks that can last several years. There is nothing more soul destroying than fixing the sewer pipe or removing the liquefied silt only to have it re-break and re-appear time and time again.
The last technical issue I want to cover is an explanation of why some buildings failed and others did not in the Kaikoura earthquake. People have been both mystified and unnerved by the fact that many older buildings labelled as earthquake prone had minimal, if any, damage in Wellington, while other new modern buildings had life-threatening partial failures. The explanation for this lies in the way the frequency of shaking interacts with the natural frequency of a building.
Every building has a natural frequency. If you give it a strong enough shove, it will naturally rock back and forward with a particular frequency. A short building may have a period of 0.2 seconds, but a tall building may be at over 2 seconds per sway. If the frequency of the earthquake’s shaking coincides with the building’s own frequency, it will experience much more extensive damage.
An earthquake will typically release a whole lot of shaking frequencies, but the short sharp shaking abates in close proximity to the quake. So the Kaikoura earthquake in Wellington had strong frequency shakes in the range of 0.8-1.2 seconds that lasted for an unusually long time. That affected buildings in the five to ten storey range. For these buildings, the earthquake was stronger and longer than the design standards required. But these same buildings would not be the most vulnerable in a major quake close to the city. The one and two storey, unreinforced masonry buildings that were untouched by the Kaikoura quake would be more likely to be hugely damaged and cause significant loss of life in a closer quake.
The Government has been severely tested by the challenges of the Christchurch and Kaikoura earthquakes and, while some mistakes have been made, I think history will judge our Government well. I particularly give tribute to Gerry Brownlee who, through the Canterbury and Kaikoura earthquakes, has done the lion’s share of the work.
We have poured in billions of dollars, passed special pragmatic laws to facilitate the rebuild, bailed out failed insurers to protect householders and acted decisively on getting infrastructure quickly fixed.
The responsibility is not just to rebuild but to learn every possible lesson so as to improve our resilience as a country to future earthquakes.
Tonight I want to outline a dozen initiatives we are taking to achieve this.
1. New Earthquake Prone Building Act
2. Adding Natural Hazards To The Resource Management Act
3. Post-Quake Building Act Reform
4. Improving Consistency Of Building Assessments
5. Standards And Training Of Engineers
6. Powers For Addressing Newly Identified Risks
7. Tackling High Risk Parapets And Facades Post Kaikoura
8. Supporting Heritage Buildings Upgrades
9. Improving Tsunami Warning Systems
10. Supporting Innovative Design
11. Investing In Seismic Research
12. National Policy On Natural Hazards”
The full text of these twelve initiatives can be found at: https://riskfrontiers.com/better-managing-new-zealands-earthquake-risks/
Storm Direction Controls Coastal Erosion Risk in New South Wales
By Thomas Mortlock
Between 3 and 7 June 2016, an East Coast Low (ECL) storm caused widespread flooding, wind damage and coastal erosion along the eastern seaboard of Australia. Wave heights measured offshore of Sydney were not exceptional, but beachfront properties experienced some of the worst erosion losses in 40 years. Recent research suggests the major cause of erosion was the unusual north-easterly wave direction, which may have significant implications for future coastal management along the east coast .
Wave direction controls probability estimates
The peak storm wave height measured offshore is a key design parameter for coastal engineers and is commonly used as an indicator of coastal erosion potential. For example, most seawalls are built to prevent overtopping up to a 1 in 100-year storm wave event and erosion hazard planning uses similar design conditions. However, annual return intervals (ARI) of extreme ocean wave heights can change dramatically according to wave direction.
For example, the peak storm wave height measured at the Sydney buoy on 5 June 2016 was approximately 6.5 m which – based on 35 years of observations – is exceeded, on average, once every two years. Coastal wave conditions were clearly less frequent than this (Figure 1), and beach monitoring showed more sand was eroded from Sydney beaches during this storm than the benchmark ‘1 in 100-year’ event, the ‘Sygnia Storm’, of 1974 . Evidently, the peak-wave-height method can grossly under-estimate erosion risk if wave direction is ignored.
When extreme values are recalculated to include wave direction, the June 2016 storm becomes a 1 in 30-year event. While this is a more realistic estimate, it still does not explain why the erosion response in 2016 was larger than other ECL events over (at least) the past 40 years.
Wave power retained across the shelf
There have been many more powerful ECL storms than the 2016 event, but few have produced waves from north of southeast (only 8% over the past three decades at Sydney). Large storms such as those in 1974, 1997 (the ‘Mothers Day Storm’), 2001 and 2008 (the ‘Pasha Bulker Storm’) all produced waves from the south of southeast because of the cyclonic rotation of the low-pressure systems.
While rarer, easterly and north-easterly storm waves retain a higher portion of their offshore wave power by the time they arrive at the NSW coast. This is because they approach normal to the coastline, meaning shorter travel distances across the continental shelf and thus dissipate less energy via friction with the seabed, than do waves approaching from oblique angles.
This means smaller storm waves from the east and northeast can produce more powerful coastal wave conditions – and erosion – than do larger storm waves from the south.
Coastline shape amplifies erosion risk
The present-day NSW coastline has evolved over the past 6,000 years during a period of relatively stable sea level and under a predominantly south-easterly wave climate. As a result, the northern sections of beaches up and down the coast are more exposed to wave energy while the southern ends receive much less, and are often protected by rocky headlands. This south-to-north gradient in wave energy at the coast controls the morphology of the beach and dunes – both being lower and narrower towards the southern ends.
For this reason, NSW beaches are particularly vulnerable to storms from the east and northeast because wave energy is focussed on southern beach sections not equilibrated with high wave exposure under the prevailing south-easterly wave climate.
Collaroy particularly vulnerable
Collaroy, a suburb situated at the south end of the Narrabeen-Collaroy embayment on Sydney’s Northern Beaches, was one of the worst affected areas in June 2016. Six properties, including some multi-unit blocks, were declared structurally unsafe and residents were evacuated.
The shorefront at Collaroy is characterised by years of inappropriate development into the active beach zone, contributing to its reputation as one of the State’s erosion ‘hot-spots’. Our modelling now shows that the geometry of the Collaroy embayment, in particular Long Reef headland, amplifies erosion during east and north-easterly storms.
During most wave conditions, Long Reef shadows Collaroy and Fishermans Beach from wave energy, but during east and north-easterly storms it contributes to a mega-rip circulation which instead focusses erosion at Collaroy (Figure 2). The location of rip currents is well known to correspond to areas of beach erosion as they facilitate the offshore transport of sand during a storm. In areas where the beach is severely lowered, waves can attack adjacent dunes and undermine structural foundations of buildings.
Implications for coastal management
The June 2016 ECL highlighted the importance of storm wave direction for coastal erosion risk in NSW. While an unusual event in the context of the past few decades, extreme wave events from this direction are projected to become more common for Southeast Australia in the future with climate change [3,4].
Regulatory requirements for both shoreline recession and beach erosion planning currently ignore potential changes in wave direction under a warming climate. They also do not consider the significant impact less powerful storms from unusual directions can have on coastal risk. There needs to be a fuller examination of the implications of changes to the storm wave climate for the NSW coast to inform sustainable management practice for the coming decades.