A vanishing land: helping frontline communities plan for climate change

The Alaskan village of Shaktoolik is on the frontline of climate change, its existence threatened by severe storms and flooding. A risk assessment combining traditional knowledge with advanced modelling aims to put the community in control of their future

July 2022

Aerial view of Shaktoolik
Photo: Walter Holt Rose

Words by Katie Puckett

“We’ve always had storms but the ocean never came into town or showered water in on the community. We’re losing land, in other words”

Sophia Katchatag, Shaktoolik tribal coordinator

Regardless of where greenhouse gases are emitted, everyone, everywhere will be affected as weather patterns change and extreme events like storms, flooding and heat waves become more frequent. But not everyone will suffer to the same degree or on the same timeframe. The Native Alaskan village of Shaktoolik is one of the world’s “frontline communities” — those bearing the brunt of climate change and experiencing its first, worst effects.

Built along a narrow sand and gravel spit on Norton Sound in the Bering Sea, Shaktoolik is vulnerable to flooding and erosion from all sides. Fiercer, more frequent storms push the waves further and further up the shore, while destabilizing the ground beneath it and threatening to cut off access to the mainland. “We’re losing land, in other words,” says tribal coordinator Sophia Katchatag. “We’ve always had storms but the ocean never came into town or showered water in on the community.” 

Studies have repeatedly warned that Shaktoolik’s time is running out. In 2009, US federal government agencies considered it to be one of four Alaska Native villages in immediate need of relocation; in 2016, the State of Alaska identified it as one of six top-priority communities at risk from the impacts of climate change. But the other thing that makes Shaktoolik particularly vulnerable to climate change is that the people follow a subsistence lifestyle, drawing what they need from the environment around them. So the villagers have decided that — for now — they would lose more by leaving this rich source of food. They have already relocated once, in 1974, further up the spit from a site two miles south. But the next move will likely have to be a more drastic one, off the spit altogether and further from the water, with much greater implications for their way of life. 

“We are in the land of subsistence, from the river, the ocean and the land, so this spot right here is a good source of subsistence foods,” explains Katchatag. “A lot of people here rely on that. With these climate change erosion issues, some feel that they’re not safe here. But there are still some that don’t want to leave because of the subsistence we have here.” Climate change is already taking its toll: “There is a decline in fish, we noticed last year, a decline in berries. The caribou are further up north than they ever have been. We’re getting news that these wild birds are getting all these sicknesses.” 

Why is Shaktoolik on the frontline?

 

Shaktoolik’s location, aspect and geology all conspire to make it especially vulnerable to climate change. Global temperature changes are amplified at the poles because of the reflectivity of polar ice — as it melts to reveal darker areas of land or sea, more of the sun’s warmth is absorbed. As a result, the Arctic region is warming about twice as fast as the rest of the world. This diminishing ice cover remains a worrying but abstract statistic for most of us, but for the coastal communities of western Alaska, the consequences have been very real and frighteningly rapid. In 2018, the Bering Sea experienced sea ice coverage 47% below the 1976-2016 mean — a record low attributed to climate change and expected to become typical by the 2040s. In the eastern Bering Sea, where Shaktoolik stretches along the coast of Norton Sound, spring sea ice cover could be reduced 58% by 2050. By 2100, there will be no sea ice at all.

Norton Sound itself acts like a lens to focus wind-driven storm surges at the low-lying villages around its rim. Its mouth is wide and opens to the west, exposing it to a long fetch across the Bering Sea, while its average depth is just 20m. The waves are powered up by high winds over several hundred miles before being trapped with nowhere else to go. Shaktoolik lies on the eastern side, placing it directly in the path of the greatest surges from the south and south-west. During the autumn and winter, when the waves are fiercest, it used to be protected by a thick buffer of sea ice. But as the ice cover shrinks, and the ice cover season shortens, the village will be left exposed for much, if not all, of the year to the ravages of a much wilder, angrier climate.

“Right now, the community can be completely inundated by major floods that might occur once or twice in a century,” says Phil Osborne, principal and senior coastal geomorphologist at WSP Golder. “As sea level comes up, the likelihood increases. So those storm events might occur once in 25 or 30 years as opposed to once in 50 or 100 years. The community might be able to deal with a storm every 50-100 years, but as those large floods become more frequent, then they become more vulnerable.”

An engaging process

While other communities around Norton Sound have already chosen to go, Shaktoolik has voted to defend in place for as long as it can, while making a longer-term plan to move inland to the foothills approximately 14 miles away. But to do this, within the constraints of limited resources, it needs to know what it’s up against. Previous plans for this village of around 250 people have tended to time-out, as the impacts of climate change accelerate or funding streams change. Now, as they figure out new priorities and options, the villagers have commissioned a different kind of study — a climate change vulnerability and risk assessment compiled by a team of engineers and scientists from Bristol Engineering and WSP Golder.

"They said, ‘we don’t need another study, we’ve had lots of people come and study Shaktoolik and write a report and a lot of those reports are just collecting dust on the shelf’"

Phil Osborne, WSP Golder

Frontline communities around the world are often those who have historically been marginalized or disempowered. The methodology for this study aimed to address that by fusing scientific modelling with more qualitative inputs that reflect the community’s own perspectives and priorities. It is an attempt to not only quantify the environmental threat, and the costs of repairing damage due to hazards such as flooding and erosion, but to give them a framework for measuring how their situation is changing in the years ahead, and for making their own decisions about how much longer they can hold their ground.

“The first feedback the community gave to us was to ask what we were going to do that was different,” recalls Phil Osborne, principal and senior coastal geomorphologist at WSP Golder. “They said, ‘we don’t need another study, we’ve had lots of people come and study Shaktoolik and write a report and a lot of those reports are just collecting dust on the shelf’. We said to them, ‘you’re going to make the difference: we’re going to incorporate your community experience and knowledge, to help us identify what’s important to you and to identify a good path forward’. There needs to be alignment between what comes out of a technical study and what the community wants, and that’s why the engagement process is the foundation.”

Artwork: Sam Jenkins / Supermassive

Talking to the community isn’t just a way of working out what a desirable outcome would look like. It was also critical to the analysis. The WSP Golder team drew on a range of sources, including information on historical flood events, aerial photography, topographical survey data and modelling. But there was a gap that no amount of technical expertise could fill: the lack of detailed local data. “It is exceedingly difficult — or just impossible — to get reliable long-term design data in these very remote areas,” says Richard Mitchells, principal geotechnical engineer in WSP Golder’s Anchorage office. “So we need to rely on judgement to augment that.”

This is an especially big stumbling block for coastal flooding, says Osborne: “A storm surge is dependent on storm drivers and the pattern of pressure and wind, and then the stretch of open water over which the wind is blowing, so it becomes very site-specific.” The closest regional water level gauge is in Nome, 130 miles away on the other side of Norton Sound. “To get the actual levels, we have to patch together different lines of evidence in order to assemble a historic record of storms.”

One of those lines of evidence is memory, adds Mitchells: “We sit and listen to the elders in the community and gain their traditional local knowledge. They know far, far more about what has happened and in some instances what may happen. It’s very qualitative in nature and it’s often laced in with stories. Our mission to a large extent is to filter that, quantify it and integrate it into our analysis to really understand what’s going on.”

"In many of these communities, there are multiple terms for ice, and each has a very distinct meaning and behaviours that we’re interested in as technologists, and we’re blind to that … It’s a huge plus to have that knowledge"

Richard Mitchells, WSP Golder

To assess how flooding and erosion will affect Shaktoolik in future, the team sought to establish the annual probability that the water would reach a certain level, and from that derive return periods for storms of a particular magnitude — for example, a one-in-20-year storm or a one-in-50-year storm. As the climate heats up, these return periods will shorten, so the aim is to work out what the new extremes look like.

“That concept is a little bit abstract, so we looked at it from the perspective of lifetimes,” explains Osborne. “So maybe the youth of the community are within a lifespan of 10 to 20 years, and then their parents are another generation and the elders are another generation beyond that. If they can remember a particularly big or large event in their lifetime, what was that? Normally with things like storms, people can remember where the water level came up to against a building or if it went right through the village and they had standing water up to the porch decks. If they can remember the timeframe, even if it’s not exact, we can usually go back to the climate and meteorological records and say, okay, that would have been the storm of 1965.”

This allowed them to quantify the depth of flooding associated with different events. “Ultimately, when it comes to risk assessment, what we’re trying to get to is some estimate of depth and velocity as those correspond to damage. If you can get a good cross-section of the community that has those memories, that feedback is very helpful to the modelling process.

Mitchells studies permafrost, so he is more interested in the steadily increasing rate of change. Vegetation, for example, has a distinct impact on the behaviour of permafrost. If a grass-covered area changes to a brush-type cover, it will retain less snow, and therefore be less well insulated. “It starts this cycle of slight warming, ratcheting every year. So it’s just trying to get a sense from local individuals — ‘how has this changed?’” In multilingual communities, this sometimes means communicating through interpreters, coordinated by Bristol Engineering and the community. “We say snow, snow, snow or ice, ice, ice,” says Mitchells. “In many of these communities, there are multiple terms for ice, and each has a very distinct meaning and behaviours that we’re interested in as technologists, and we’re blind to that. We’re experts in what we do, but we’re not experts in everything, so it’s a huge plus to have that knowledge.”

Having built up a picture of how the past and present climate is impacting Shaktoolik, the team then developed scenarios to describe future conditions. Here, they flag up a number of inherent uncertainties: we don’t know what emissions pathway the world will take, or if and when the ice sheets in Greenland and the Antarctic will collapse and what feedback loops this might trigger. Models used to describe future air temperature and climate conditions are based on assumptions that need to be revisited as our understanding evolves and projections are updated. But frontline communities don’t want — and can’t afford — to retain consultants to translate shifting probabilities into on-the-ground predictions. They need to be able to assess their own level of risk based on what they see happening around them.

"At what point do they have to just abandon the location wholesale and move to a new one? That’s the sort of decision you need to make 20 years in advance. You don’t want to get within five years and not have a plan"

Phil Osborne, WSP Golder

WSP Golder has tried to address this by providing what Osborne calls “decision pathways”. “First of all, it’s giving them some understanding of the hazards, how they’re likely to vary over time and what the uncertainty is related to those hazards. Then that helps them to understand the timelines and the different approaches they can take to mitigate, and how much longer they can afford to be in place and to use natural types of shore protection. At what point do they need to start moving pieces of critical infrastructure, and at what point do they have to just abandon the location wholesale and move to another one? That’s a really critical and big decision, and it’s the sort you need to make 20 or more years in advance. You don’t want to get within five years of that point and not have a plan.”

This is an iterative process, he emphasizes: “We want to get across the idea that they have to keep monitoring, collecting observations and data, to improve the assessment for the next round of decision-making. That helps deal with the fact that, with respect to climate, everything is in a state of flux. So rather than being some technical or abstract concept, it makes it something practical that they can take ownership of.”

“An immense hurdle”

This is especially important because as a small community with a subsistence lifestyle, Shaktoolik has no local tax base to pay for major works. Neither is there any single agency it can turn to, so securing grants for adaptations, and ultimately relocation, will be a piecemeal process. “Moving is an incredibly complex question for communities, and funding is an immense hurdle,” says Isaac Pearson, senior civil engineer at Bristol Engineering, an Alaskan Native-owned company that supports them with everything from project planning and technical design to sourcing affordable construction equipment. “Shaktoolik is at threat from the natural environment but then you couple that with the challenges of just being a rural Alaskan community. It’s extremely expensive, not only the cost of living but just the cost of getting anything done. We have a very short window for construction in northern Alaska and there’s only so many people who can do the work, which drives up the cost too. So they need all the help they can get to figure out when they are going to need to spend money and how much.”

Shaktoolik is particularly hard to defend because there is no local source of rock, and materials and often labour need to be imported. In 2014, the community secured a grant from the Norton Sound Economic Development Corporation to build a mile-long berm along the shorefront in front of the town. This was prompted by a storm in late 2013 that was powerful enough to wash driftwood right up the beach and into the village. “That brought scare to the community,” recalls Katchatag. “There were literally logs behind people’s homes from the ocean.” The city hired a foreman, loader operator, two dump truck drivers and a labourer to shift the natural gravel of the spit into a simple berm to protect the community. It took almost two summers to complete, but only lasted until an even more extreme event in 2019. “We had an early fall storm at the beginning of August and it took a good portion of that berm,” she says. “There was water surrounding our community — riverside, oceanside, water everywhere.”

Fortunately, in 2018 the community had hired Bristol Engineering to provide a soft erosion berm design, mimicking what they already installed, to support future funding requests and provide a greater level of protection. These plans were used after the 2019 event, to secure funds for an emergency repair from the Denali Commission, a federal agency that funds infrastructure in Alaska’s remote villages. Katchatag has since secured US$1m from the National Fish and Wildlife Foundation too. “With that, we purchased two dump trucks and a water truck, and the rest was used for wages, equipment rental and supplies and diesel, and we hope to expend the rest of that this season.”

They also got a US$800,000 Indian Community Development Block Grant from the US Department of Housing and Urban Development (HUD), and a further US$450,000 from the HUD’s imminent threat fund. Katchatag says that the first will be used to increase protection for the most important shore-front infrastructure — the school, the tank farm, the clinic — and the second to extend the berm past Shaktoolik’s former site two miles south. “We still have to expend those funds and should be close to finishing this season also.”

Bristol and WSP Golder are continuing to assist the community on how to make the berm more resilient using local materials. “In a perfect engineering world, we would specify material we know is suitable for the intended design and service life,” says Pearson. “But sometimes we have to make economic concessions for the use of local materials, to give them the best that we can with what they have, and then fine-tune it and tweak it for local conditions.”

Bristol works with Shaktoolik using a “force account” methodology. This is where the community provides the equipment and labour, like a contractor, and Bristol provides technical support and works side-by-side with the project foreman to understand the plans and develop proper construction means and methods. “That’s really important for giving communities the power to protect themselves and to get them engaged not only on the construction side but in the planning too. It brings them through that whole project lifecycle. Rather than paying contractors to come and do the work and then take all their stuff and leave, we try to help the community build their own resources.”

"Rather than paying contractors to come and do the work and then take all their stuff and leave, we try to help the community build their own resources"

Isaac Pearson, Bristol Engineering

To translate the climate hazards it has identified into actionable steps, WSP Golder developed thresholds to categorize the risks as either manageable, manageable with adaptations, or unmanageable. Examples of manageable risks include minor damage to the berm or to buildings and utilities that can easily be repaired with locally available materials, a brief intrusion of saltwater into the freshwater intake, or only occasional disruptions to hunting and gathering routes. As the risks increase, potential adaptations include importing building supplies, finding a new source water intake further upstream, using alternate hunting routes when traditional ones are waterlogged, and collecting driftwood and storing it safely so that it doesn’t wash into the community and can be used to reinforce the berm.

An unmanageable risk is one that is not sufficiently reduced with the adaptation options available. At this point, the costs of importing gravel and building supplies for frequent repairs or replacements become unaffordable, and there is no longer a viable location for an emergency shelter. Flooding and erosion from both sides at the neck of the spit turns Shaktoolik into an island, and evacuation must begin well in advance of potentially dangerous storms. The water supply is frequently contaminated by saltwater and subsistence becomes extremely difficult as grounds are frequently left waterlogged by storms. Driftwood and debris washed onto the beach cannot be moved fast enough to avoid further damage in larger storms that follow.

Today, only the borrow pit is in the unmanageable category — this source of gravel is frequently flooded with deep water. By 2050, adaptations will be required for almost everything, and the spit will become an island during storm events. By 2100, the risks to the village’s critical infrastructure will become unmanageable.

But that’s a long-time horizon and as the situation evolves, it will be down to the community to decide what level of adaptation and risk is acceptable. “We don’t parachute in and say ‘here’s what you should do’,” says Mitchells. “We’re there for technical assistance and maybe assistance on financial planning, because at some point the funding agencies are going to want answers to very technical questions. But self-determination is a critical element of the entire process, and that’s really positive because that’s not always the way it’s been in Alaska.”

The art and science of predicting climate risk

 

WSP Golder carried out several layers of analysis to create a decision-making framework for the community that integrates their insights and priorities with advanced scientific modelling.

First, they established a list of significant buildings and infrastructure, and assessed the current vulnerability of each to different natural hazards: coastal and river flooding and erosion, lack of sea ice and permafrost degradation. All of these are predicted to become more frequent with climate change — in a graphical representation of how the risks are changing, there are no downward arrows.

Next, they developed a three-point scale ranking the potential consequences of each of these events. So for coastal flooding, if the beach is flooded but the water level remains below the berm and driftwood is not carried into the community, that would be a category 1 event. If the water level reaches the berm and overtops it due to wave action, inundating low-lying buildings, that would be category 2. A category 3 event would occur if the berm is overtopped, the entire community is inundated and saltwater contaminates the water supply on the river side.

They then determined the likelihood of each interaction by asking the community what had happened in the past. For the purposes of a three-point ranking, they described the timing relative to the youth of the community, aged 13-17. An event that had occurred within their lifetime was assumed to have a return period of ten years, to be “almost certain” to occur again. An event that their parents had experienced and told them about was assumed to have a return period of 20 years, to be “likely” to reoccur. An event that had been experienced in the past and which they had been told about by the elders was considered “possible” with a return period of 50 years.

This was complemented by a second hazard-quantification ranking, based on topographical surveys and surface modelling by the Alaska Department of Geological and Geographical Surveys, as well as statistical analysis and modelling using historic data about tides and storm surges.

When the results of these two scales were presented side by side, there were some key differences. The community perceived a higher likelihood of coastal flooding than the hazard quantification, perhaps influenced by their recent experiences of flooding events. The consequence rankings differed too, because the community value incorporated the perceived importance of each structure and the impact of its loss or damage, whereas the hazard quantification only considered inundation depth and the rate of shoreline retreat. The community ranked the overall risks to facilities such as the school, electrical distribution system, water treatment plant and fuel tank farm higher, whereas they were much less concerned about inundation of the borrow pit, old dump site and sewage evaporation pit, even though the hazard was more severe.

To predict how Shaktoolik will be affected by climate change, the team used the hazard-quantification method, projecting forward the current likelihood and depth of inundation using modelling and statistical analysis. It wasn’t possible to produce a comparable community-based ranking: the consequences of future events have not yet been experienced, and perceptions of their likelihood cannot be measured.

The discrepancies between the two rankings demonstrate the value of qualifying technical analysis through engagement — a purely data-based approach could skew resilience planning by failing to count the full costs of flooding to the community. Statistical analysis and modelling is a valuable tool for predicting future risks, but we need to keep in mind that there may be impacts that are not captured by data alone.

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