To move away from the shore, or to 'armour' it — Prince Edwards Islands erosion question
Coastal Property Guide advises against the use of hard rock to protect shoreline. This story is part of a CBC News series entitled In Our Backyard, which looks at the effects climate change is having in Canada, from extreme weather events to how it's reshaping our economy.
When the UPEI Climate Lab first started using drones to survey the Island's coastline in 2016, it was described as a "game changer" in the fight against coastal erosion.
Now in its fourth season, the annual drone flights over the Island coastline have become a valuable tool for the P.E.I. government to manage coastal development, including recommendations on how Islanders should be protecting the shoreline.
"Looking at erosion is a long-term type of endeavour so our partnership with them is intended to give us information that will inform our decisions in the long term," said Erin Taylor, manager of the climate change secretariat of the P.E.I. government.
"Erosion is a process that happens kind of in increments and in order to really understand what's happening you need fairly long stretches of monitoring information."
Taylor said the information the UPEI Climate Lab has provided over the last couple of years reinforces previous findings, that the typical erosion rate on P.E.I. is about 30 centimetres per year.
But the drone's aerial surveys give even more insight.
I think the main message that I'd like to give is that people should not be building so darn close to the shore—Adam Fenech, UPEI Climate Lab
"The drone work lets us see about how all of the sand is moving where it's going, how it's shifting," Taylor said.
"That's important in a place like P.E.I. because we have such dynamic beaches that seeing that shift with the drone work allows us to better understand how sand is moving."
Risks and responsibilities
The P.E.I. government released its Coastal Property Guide in 2016, outlining the rules that apply to properties on the coastline, the risks and responsibilities and what can be done to adapt to those risks.
Taylor said the department gets lots of questions around coastal development that vary, depending on where people are coming from and their experience.
"Some people who have coastal property may not be from Prince Edward Island and they may not have any experience with living in a tidal kind of region," Taylor said.
"So they may think that when they go and view the property for the first time with the realtor, and see where the water is, they may think that's where the water is all the time and that's not the case."
Taylor said there are also questions around the rules on buffer zones on coastal properties.
"For any property that's near a stream or water course, that includes rivers and coastlines, there's a 15 metre kind of no-go zone, so you can't be any closer than that," Taylor said.
"Then there's a development setback on top of that that pushes you even further back."
The department uses the rate of erosion on a property to calculate how far back a structure must be.
"So you have to be 60-times the erosion rate back on that property, plus an additional piece for development, so it's about a 75-foot setback," Taylor said.
'Close to the shore'
The setbacks and buffer zones, Taylor said, are managed by staff in a number of departments, including Agriculture and Environment.
Taylor said there can be the perception, as you drive around the P.E.I. coast, that homes are still too close to the shoreline.
"People may look at properties and say, 'Hey that looks awful close to the shore,'" Taylor said.
"If it's an existing property, when it was built it might have been in full satisfaction of the requirements, it's just an indication that erosion is taking its course."
Advises against armouring
The UPEI Climate Lab was also contracted by the provincial government to do an inventory of all the shoreline structures that Islanders are currently using to protect their coasts.
They found that about five per cent of the entire Island has been armoured, as they call it, in some form of protection, usually a hard stone.
"I think what we've learned is that there is a mish-mash of protection that's out there," Fenech said.
"Some is working, some not so well. If it's more recent, it's usually engineered a lot better. We've learned from from our past mistakes."
In the 2016 Coastal Property Guide, the P.E.I. government actually advises against armouring along the shoreline.
"We say that's not our recommended position for people that are experiencing erosion along the coast," Taylor said.
Instead, Taylor said the government recommends, first of all, not building so close to the shoreline.
The second option, she said, is moving buildings out of harm's way.
"If folks are already there, we encourage people, if they can, to move infrastructure back," Taylor said.
Taylor said that hardening the shoreline can have negative consequences, including an impact on neighbouring properties and changing how sand moves along the whole shoreline.
She says shoreline stabilization can disrupt a habitat for nesting birds and it changes the look of the beach.
"For folks that love to be at the beach and love the natural appearance of the beach, it's not the same when you have these hard structures sitting along the beach," Taylor said.
"I think there are lots of good reasons why not to do it and I think those outweigh the reasons to put it in place."
Taylor points to the government's recent shoreline stabilization project near Souris as an example of a better way to protect the coastline.
"They installed some intertidal reefs, to try and trap sand along the beach while maintaining the aesthetic of the beach," Taylor said.
"Allowing it to be accessible, and actually building habitat in that area, rather than diminishing habitat by placing those hard structures."
- Souris is the spot for the Island's first artificial reef
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Fenech, of the climate lab, said the armouring is also very expensive.
"We don't have any natural hard stone here so we have to import it from off-Island, usually New Brunswick," Fenech said.
"It works in the short term but you're going to have to replace it at some time and it's just getting more and more expensive."
Plan for erosion
Fenech's best advice is to anticipate erosion and plan for it.
"We know erosion will occur, we know what the historical rates are," Fenech said.
"We have an idea that those rates are going to increase because of the rising sea levels and the increase in the frequency and magnitude of storm events."
The P.E.I. government is currently assessing public coastal infrastructure that may be at risk because of climate change.
The study will help government to plan future efforts in shoreline protection.
"I think the main message that I'd like to give is that people should not be building so darn close to the shore," Fenech said.
"And if they do, build in such a way that you can move the infrastructure away from the shoreline when it starts approaching."
Under the province's Climate Change Action Plan, the government is developing coastal hazard maps, incorporating the latest information on future sea level rise, storm surge and coastal erosion.
Those will be released later this year.
More P.E.I. news
ABOUT THE AUTHOR
Nancy Russell has been a reporter with CBC since 1987, in Whitehorse, Winnipeg, Toronto and Charlottetown. When not on the job, she spends her time on the water rowing, travelling to Kenya or walking her dog. Nancy.Russell@cbc.ca