Rising sea levels throughout metro Vancouver putting landmarks at risk
Granville Island and False Creek at high risk for negative effects of higher water levels
Vancouver is at risk of losing landmark communities like Granville Island and False Creek unless the city starts taking measures to defend its shoreline against rising sea levels, an urban planner warns.
Andrew Yan, a planner and researcher with Bing Thom Architects, estimates the city will have to spend upwards of $510 million to build and upgrade the dikes and seawalls — plus billions more to buy the land to put them on — over the next century.“What’s under threat in Vancouver is a lot of our identity; our beaches, our seawall … this is what makes Vancouver such a livable place,” Yan said. “We just need to look at Granville Island and its exposure to sea level rise and what may be required to defend it.”
Vancouver isn’t the only city under threat.
Richmond’s Steveston, which has experienced huge residential growth along its waterfront in recent years, will face significant pressures in the future, Yan said, while south Surrey’s Crescent Beach is already being threatened by a more insidious force: increasing groundwater from rising ocean tides.
“It affects every municipality that touches the water,” Yan said. “Sea level rise isn’t going to separate itself from the boundaries of Vancouver, Burnaby, Richmond or Surrey. We’d better be serious about this. It’s important to plan now as opposed to 50 or 70 years from now.”
BTAworks, the research and development division of Bing Thom Architects, has developed a tool kit for Vancouver, after being inspired by the sea level rise work being conducted in places like San Francisco, New York City, Florida and the Netherlands, to deal with the potential fallout from climate change.
The B.C. government estimates the mean sea level rise by 2100 will range from 80 centimetres at Nanaimo to 120 centimetres in the Fraser delta, potentially resulting in more frequent and extreme high water levels, increased erosion and flooding, higher risks to coastal infrastructure and loss of habitat and cultural and historical sites.
Deborah Harford, executive director of Simon Fraser University’s Adaptation to Climate Change Team, noted all of Metro Vancouver is ranked as at high risk for negative effects of climate change because it has so many people, so much infrastructure and so many assets at sea level. And with the region built on river deltas, she said, there’s also risk of the sea encroaching toward the area’s rivers, leading to “salt wedging” or salination of the region’s agricultural lands and the water supply.
“Things are going to happen that we can’t imagine yet,” said Harford, whose team is comparing climate change in coastal areas including Metro Vancouver, Bangkok, Manila and Lagos. “We have a spectacular advantage in that we can predict our future. We can use those [sea level] models to see which scenarios will work.”In Vancouver, which has a shoreline of 51 kilometres, with another 8.5 kilometres in the University Endowment Lands, about $25-billion worth of the city’s real estate could be negatively affected by rising sea levels — either from spray or inundation — along with existing infrastructure such as roads, sewers, and electrical facilities, the BTAworks report warns.
The report illustrated a number of sea level rise scenarios, from one to six metres, which could affect between three and 13 per cent of the city’s land mass. For instance, sea level rise at the three-metre interval, combined with a severe storm in 2100, would affect most of the city’s shoreline, including the harbour, the southern edge of the city and Granville Island.
And it gets worse: At the four-metre interval, False Creek would revert to its 19th-century boundaries, while Gastown, Chinatown and the harbour would be heavily affected. And at five- and six-metre intervals, the report warns, downtown Vancouver would become an archipelago and the city’s coastline would be “unrecognizable” compared to today’s.
Yan noted it’s not just multimillion-dollar waterfront homes that have to be defended before the seas rise. Metro Vancouver’s sewage treatment plants, all located in low-lying areas, are also at risk, along with the region’s industrial lands, which are increasingly tapped by developers for affordable housing or higher density.
“There’s going to be increasing temptation to move into industrial lands,” Yan said. “But should you be putting people on that type of land knowing that it will be under threat in the future?”
Both Harford and Yan are calling for a more comprehensive plan across Metro Vancouver to deal with the issues, noting if Surrey has a plan in place, and nothing is done at Boundary Bay, Surrey’s efforts won’t make a whit of difference.While municipalities are largely responsible for protecting their shorelines, Harford notes dikes and seawalls are expensive and could affect private property if they end up blocking views. She would like to see more collaboration with the provincial and federal governments on addressing sea level rise in Metro as well as how to pay for it.
Richmond, which manages 49 kilometres of dikes on Lulu Island and Sea Island, is considering raising its existing dikes between Garry Point and London Farm, which could cost $200 million.
A Richmond staff report notes raising existing dikes will present challenges because of limited space and conflicts with developments and construction scheduling, while moving the dike closer to the water’s edge would significantly change “the look and feel of the existing harbour and potentially disrupt sensitive shoreline ecology.”
But Harford argues doing nothing will cost more in the end, and “we have to let the public know this is an issue they have to be concerned about.”
In places like Thailand and Manila, which have seen extensive flooding, “there’s no question in their minds that climate change is happening and they are desperate for help,” she said. “But even though there are many warnings here, people are still going, ‘Is it going to happen to me?’”
B.C. has already experienced sudden storms and massive downpours, which have led to river floods and deadly mudslides, such as the one in Johnsons Landing, where four people were killed, she said.
During the peak of the 2006 windstorm, 250,000 BC Hydro customers were without power — many of them for days — while Vancouver spent more than $10 million to deal with the problem. And in September 2010, heavy rainfall in Vancouver prompted 173 claims against the city and an additional 23 flood reports.The situation has prompted Vancouver to develop an “adaptation strategy,” after the province last year issued a series of guidelines to bolster B.C.’s dikes and seawalls. Dikes are considered high risk — or “high consequence” — when they protect urbanized areas.
Vancouver’s nine-pronged strategy, which aims to protect the city against potential increases in street flooding, sewer backups, damaged forests and heat-related illnesses by 2050, doesn’t suggest specific dike upgrades or costs, but acknowledges work will likely have to be done over time. It notes, for instance, the incremental cost to build a section of the existing Stanley Park seawall to a higher level would be negligible compared with the costs of repairing increased damage from wave action or retrofitting to a higher elevation at a later date.
The B.C. government also suggests the Richmond-Sturgeon Bank Sea Dike, which protects the city from inundation by storm surge and associated wave effects, would require a “future degree of protection” and notes that as the sea level rises over the next century, Granville Island “will become exposed to an increasing risk of flooding and … if protection of the existing land use is adopted as the option, a sea dike will be required.”
In Surrey, city officials are in the midst of a study to determine where and when its dikes will have to be upgraded on a priority basis. In the meantime, city officials have started building sewers and are installing a pump station at Crescent Beach after rising winter tides has resulted in increased groundwater pooling in the streets. The city is also looking at gradually raising the community — by building new houses higher and gradually raising roads and boulevards — to avoid the rising waters.
The city is also taking measures to control brackish water from coming into town and affecting homes and facilities. Meanwhile, there are also heightened concerns about increased flooding from the Serpentine and Nikomekl rivers, which could affect not only the city’s agricultural land but neighbouring communities such as Morgan Creek.
“It’s the fringe areas we’re worried about,” said Carolyn Baron, an engineer with the City of Surrey. “We may not be able to drain the rivers like we did in the past.”
Baron notes much is at stake, including the region’s railways and transportation networks, as well as its ports and airport, and the province should be stepping up to help. “Is it right to have cities managing the costs for all the dikes when it serves the greater good for the country?” she asked.
Harford noted while the problems associated with sea level rise aren’t expected to happen overnight, they have to be considered now. “This is the next conversation that has to happen,” she said. “How much is it going to cost and what will happen if we don’t do it?”