Lower Mainland bracing for king tide, possible flooding
Published Friday, November 24, 2017 11:55AM PST
B.C. cities are bracing for the rising waters of a king tide that could put homes in low-lying areas at risk for flooding.
The City of Delta has built a concrete and sand berm to protect homes and streets along Boundary Bay, while Vancouver has laid sandbags along Locarno Beach to stop waters from flooding past Marine Drive when the next king tide hits around December 5.
“It’s hard to say what these storms will bring,” said Steven Lan, Delta’s acting city manager. “But we’re prepared, as you can see. We’ve had lots of experience with it.”
The king tide, also known as a perigean spring tide, happens when the moon and the sun line up, and their gravity pulls water levels higher.
Storms and waves on top of those higher waters can overwhelm coastal defenses and cause property damage.
In 2014, a storm that hit during a king tide washed out a 20-metre section of the seawall along Boundary Bay. One home was evacuated.
Two years before that, a West Vancouver arts centre was flooded, and Vancouver’s Kitsilano Pool was itself under water.
This year, the king tide is predicted to last from Dec. 5 to 9, January 2 to Jan. 7, and January 31 to Feb. 4, according to the B.C. Storm Surge Almanac.
Damage from king tides used to be rarer, but has been more frequent in the past decade. That’s because the average sea level itself is rising, said Vancouver Park Board biologist Nick Page.
“If you add the whole range of sea level increases, from thermal effects, larger storm surges because of climate change and melting of ice, you’re seeing flood elevations that will worsen first by centimeters and higher and higher over time,” he said.
Vancouver’s king tide preparations have cost about $45,000 while Delta has spent some $60,000.
A Richmond spokesperson told CTV News the city believes its existing flood barriers are adequate.