Managed retreat — relocating infrastructure (people, businesses, etc.) away from low-lying coastal areas because of sea-level rise — is often met with some resistance.
Although it’s a solid proactive move against climate change, not everyone sees the benefit of it.
Many view it as “uprooting” lives — failing to see how those lives will eventually be impacted by certain natural hazards like floods, wildfires, droughts, etc. down the road.
Everything from legislation, consent, funding, community opposition, and the environment itself becomes a barrier.
Is managed retreat a good option?
Here’s what you should know about it.
1. What is managed retreat?
Managed retreat, also called managed realignment, is a coastal realignment and emergency management strategy that involves the purposeful movement of both people and buildings away from environmental hazards.
These disasters are increasingly the result of climate change.
2. What does managed retreat do?
The goal of managed retreat is to move people and infrastructure out of harm’s way before disasters or threats occur.
This helps to mitigate any damage that may occur as well as minimize the cost for the coastal communities and ecosystems.
Managed retreat is a proactive strategy that state and local government workers and environmental advocates must work together to implement.
3. What is the process of managed retreat?
Here are the components of managed retreat:
The first step of managed retreat is coastal planning.
This is the process that’s used to make better decisions about how we can use the coastal zone.
Coastal planning takes several different uses of the coastal zone into consideration.
This means that various options are considered, and any potential conflicts are reflected on before moving forward.
During this phase, relocation plans are drawn up and executed.
Relocation must not only help communities move to safer parts, but it must also help to meet their needs.
Additionally, sometimes buy-back and buy-out programs are implemented where the government or another investor will buy back people’s land or buy out their interest in it to make it easier for them to move elsewhere.
To protect the land, the government often regulates the type of development that’s permitted after they relocate the inhabitants and businesses in the area.
Why go out of your way to protect the environment from climate change in one way only to allow a business or industry to destroy it in another?
Designating no-build areas is an important part of the process because you want to make sure that new people, communities, and infrastructure aren’t affected in a similar way in the future.
When a drought, wildfire, or flood occurs, it can wreck the habitats in the area in addition to endangering people or businesses.
Taking steps to restore these habitats is an essential part of managed retreat.
Green space improves air quality, enhances biodiversity, and reduces noise.
It can also serve as a barrier to hazards, such as floods.
This is why public green space is often planted after the retreat is complete.
4. What are the benefits of managed retreat?
Managed retreat carries the following advantages for the environment.
If you’re evaluating your land for managed retreat, keep in mind that this process is likely to have a higher net benefit in the following situations:
5. Where is managed retreat used?
Managed retreat can be used in areas where the following conditions are present:
6. Is managed retreat a viable response to climate risk?
Most communities will consider managed retreat as a last resort.
After all, who wants to pick up and move?
No one is the easy answer.
People can be relocated, but it isn’t easy to do.
They have a close attachment to their home as well as their local culture and community.
Relocating communities often comes at a significant financial cost to the governments footing the bill.
While governments like New Zealand are looking into this possibility if climate change continues to progress, it’s still considered a fallback option instead of a mitigation effort.
7. What are the alternatives to managed retreat?
Before managed retreat, most communities will try something in the realm of traditional design.
Here’s what that looks like.
No action is taken to either improve or maintain the existing defenses against the sea level rise and coastal erosion.
Communities will stop all maintenance, repair, renewal, and emergency repair if they choose to go the “do nothing” route.
For health and safety reasons, the defenses can be monitored until they fail, or a new management option may be selected.
Once the “do nothing” approach is implemented, the areas will no longer be protected by the existing defense.
Application of this method often requires a defined exit strategy because of the flood risk.
This approach allows limited intervention.
For immediate health and safety issues, maintenance and repair works are permitted.
However, doing the minimum leads to a reduced standard of defense over time.
When the sea-level rises, doing the minimum can mean essentially lowering the defense level.
The existing defenses are advanced in this approach.
New defenses are built in front of existing defenses — often on emergent coastlines.
If infrastructure is of national importance, then it’s often required to “advance the line” to meet the requirements of the development.
In this scenario, the existing defense is maintained through repair, maintenance, and/or improvements to the existing defenses.
By holding the line, you restrict natural processes, and this is the leading factor in “coastal squeeze.”
Coastal squeeze occurs when coastal habitats and natural features are squeezed and lost between rising relative sea levels and hard sea defenses.
When the sea level rises, the low water mark migrates landward.
Meanwhile, the high-water mark is held stationary by the defense.
Over time, the width of the intertidal habitat is reduced which therefore reduces the buffering effect afforded by the defense.
As the toe is attacked consistently by the waves, the defense becomes more destabilized and potentially undermined.
This can result in large investment repair costs.
8. What are some of the “advance the line” and “hold the line” options?
Managed retreat is not the only option when it comes to protecting the coast.
Here are some other options if you’re worried that managed retreat will have some drawbacks that you’re not prepared to address, or you’re simply not able to move the people or businesses in the way due to time, money, or logistics.
Sea walls are one of the first solutions you will see used when coastal erosion is an issue.
These are large coastal protection structures that can be made from a variety of materials including rubble mounds, reinforced concrete, and granite masonry.
When sea walls are built along the shoreline, it prevents the damaging influence of ocean waves and flooding (often driven by storms) from affecting people and businesses.
The three main types of sea walls are the curved face sea wall, stepped face sea wall, and rubble mound sea wall.
Each has its advantages.
The curved face sea wall is designed specifically to withstand high wave action impacts.
The stepped-face sea wall is good at resisting moderate wave actions.
Finally, rubble mound sea walls are both an easier and cheaper option that can resist substantially strong wave actions.
Bulkheads are a barrier between a property and whatever body of water is nearby.
Their main purpose is to help prevent erosion caused by strong waves.
They’re often made from concrete, steel, or timber.
If you’re considering a bulkhead, there are two main types: gravity structures and anchored sheet pile walls.
Groins are structures that protect shores and decrease erosion.
They help to change the offshore current and wave patterns.
Often, they are constructed out of concrete, stone, steel, or timber.
There are many different types of groins depending on length, height, permeability, etc.
These structures are often built vertically to the shoreline.
Jetties are built from concrete, stone, timber, and steel.
Sometimes, they have asphalt used as a binder.
Jetties are used at estuary or harbor entrances, and they extend into deeper water to oppose the forming of sandbars.
They also help to limit currents.
The three main types of breakwaters are offshore, shore-connected, and rubble mound.
They protect shore areas, anchorage, and harbor from wave actions.
They also provide a safe environment for mooring, operating, and handling ships.
9. How much does managed retreat cost?
There’s no straightforward answer about how much this process costs.
However, depending on the location of the work, the extent of the engineering required, and any associated assessment, implementation, and mitigation requirements, managed retreat can easily climb to the hundreds of thousands, if not millions, of dollars.
10. What are some examples?
The first example of managed retreat is at Ventura Beach near Santa Barbara, California.
This area in the southern part of the state has experienced a chronic shoreline erosion problem.
The second example is at Pacifica State Beach which is near San Francisco.
Both locations have medium human development.
Yet, motivated groups of residents and stakeholders collaborated to create a long-term plan that could ensure that the areas remained healthy.
That said, it’s also important to remember that these were small-scale projects.
Still, while these properties were less than 10 acres, they still provide a much-needed example of how and when managed retreat can be successful.
In both of these situations, the stakeholders focused on the common goal that they had.
They decided that they needed to retreat from the ocean and pull the existing structure inland to make room for the natural beach processes.
The decision was compounded by the fact that other solutions (like a seawall) would impact the surfing conditions.
The decision to move forward with managed retreat helped to rehabilitate the beach ecosystem and enhance the protection of natural land.
Managed retreat can sound like humans are “giving up” in some ways.
They’re yielding land to the sea — land they were very much using for their homes and businesses.
However, while relocation can be inconvenient and costly, the alternative can be disastrous.
And sometimes, it isn’t clear how long until disaster strikes.
Additionally, the land isn’t always completely lost.
Often, it can be used in another form like recreation.
Still, managed retreat isn’t without political and social controversy, and it’s never anyone’s first choice.
If you’re considering managed retreat for an area of your land, recognize that your options may only become worse if you wait.
It’s worth doing your research now and considering all your options.
Would you like to receive weekly emails with our latest blog/properties?
Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.