Advocates say nature can be powerful tool in adapting to coastal climate change
Moira Donovan | CBC News | Posted: August 4, 2020 9:00 AM | Last Updated: August 4, 2020
Natural systems can be more effective than hard barriers
With sea levels rising faster in Nova Scotia than almost anywhere in the country, experts say the need for coastal property owners to take action to mitigate against erosion is more important than ever.
Due to a combination of land subsidence and climate change, it is projected that sea levels here will rise between one and 2½ metres by 2100, while storm surges and wave action exacerbate coastal erosion.
In Nova Scotia, there are thousands of properties located on the coast.
"Climate change is here ... and reversing it doesn't look like it's actually going to happen in our lifetime, so if that's not a possibility to fix it from the root end, then we have to take charge of the symptoms and then really engage people at education," said Rosmarie Lohnes, founder of Helping Nature Heal, an ecological restoration company based in Bridgewater, N.S.
Several initiatives are encouraging property owners implement living shorelines — also known as nature-based systems — such as wetlands, tidal flats and revegetating the shoreline, rather than popular hard barriers, such as armour stones.
Lohnes said rock walls "are sort of an old technology and old methodology."
In fact, rock walls come with their own set of problems. Armour stone may protect the individual property, but it causes the wave energy to be deflected to another part of the shoreline, and blocks the natural movement of sediment, exacerbating erosion elsewhere. Waves can also erode around the stone, causing structures to collapse.
Lohnes said she instead encourages people to consider how planting the coast with a particular mix of native species can more effectively slow down erosion. "The right plants in the right place make all the difference, for sure."
Living shorelines are increasingly recognized as an important form of protection for coastal properties and communities. A 2018 report by the Insurance Bureau of Canada, for instance, recommended retaining and restoring "natural infrastructure," such as wetlands, as a way of reducing risks for those on the coast.
Lohnes runs a program called Shore Up, which teaches people about living shorelines. In 2019, the group ran a pilot workshop in St. Margarets Bay.
"Lots of people don't understand the ecosystem that they're living in," she said. "And so this is an opportunity to really talk to them about how the plants work, and how they work together, and then what happens when a storm arrives."
Nancy Anningson, coastal adaptation co-ordinator with the Ecology Action Centre in Halifax, said many Nova Scotians struggle to find information about what to do.
"We don't have good information here at all, in my opinion, and from everything I hear, from the towns I'm working with, and the people I'm working with, it's not easy to figure out what your options are when it comes to adapting to coastal climate change," she said.
New design program coming to Nova Scotia
DG Blair, director of the Stewardship Centre for British Columbia, said the organization is currently in the process of bringing its Green Shores initiative to this province.
Green Shores is a credit and rating system, similar to LEED, the international green building certification system. It encourages property owners to adopt design standards that use natural systems, such as vegetation and wetlands, to manage the shoreline.
"It incentivizes doing a little bit more, or a little differently ... because you've got the design standard in front of you, so it's relatively easy, if that is your intent, to do [a] Green Shores-type project," said Blair.
The design standards provide best "practices guidance" on how to develop the shoreline in a way that conserves the environment and restores natural processes, Blair said. Projects are assessed against credits for which they can receive points, which add up to a bronze, silver or gold rating.
"The data is definitely coming in that a well-designed nature-based solution can be as effective, if not more effective for sea -level rise and increased storm surge, for example," said Blair. "If you can do a nature-based approach, usually it's less expensive and it proves to be more resilient."
Green Shores plans to partner with Saint Mary's University and its TransCoastal Adaptations group, to offer training in Nova Scotia over the coming year.
Looking to government for leadership
In the meantime, Patricia Manuel, a professor in the school of planning at Dalhousie University in Halifax, said education will be an important planning tool as Nova Scotia looks to manage sea level rise and its associated risks. While much of the education thus far has come from companies and not-for-profits, she said local governments can also lead the way.
Manuel said living shoreline projects, such as ones that have been proposed or completed in Nova Scotia communities like Mahone Bay and Shelburne, provide an opportunity for governments to model better approaches to protecting the shoreline.
"That is a huge thing a local government can do, in combination with the province," she said. Instead of armouring the shore, municipalities can restore a wetland or use landscaping, "and then people can see how it works and take some assurance from that."
Nova Scotia is currently developing regulations for its Coastal Protection Act, which will protect new construction from flooding and rising sea levels, by stipulating how close people can build to the coast.
MORE TOP STORIES