Dikes in Pitt Meadows and across the Lower Mainland are too low to offer protection against the worst Fraser River floods or a potential storm surge of coastal waters.
That was the message brought to Pitt Meadows council by Steve Litke, senior program manager with the Fraser Basin Council on Tuesday night. That group is working on a Lower Mainland Flood Managment Strategy to reduce the risks of a major flood.
The cost of reinforcing flood protection is beyond what local governments can afford. Litke’s non-profit organization does not yet have a price, but cited a cost estimate in 2012 of $9.5 billion to bring up all Lower Mainland dikes to protect against a one-metre rise in sea level.
After hearing the presentation, Pitt Meadows council asked staff to investigate the possibility of a regional approach to dike maintenance and flood management.
Mayor Bill Dingwall, attending electronically, said Metro’s ability to lobby for senior government funding will be important.
Litke thought it was a good motion.
“This is an issue that would benefit from a greater level of coordination,” he said.
Pitt Meadows dikes are built to protect against a flood level established in 1968, but those elevations were increased in 2007, and seismic considerations were later added, calling for wider dikes. With climate change models predicting a rise in sea levels, Litke said the call for higher dikes has been renewed.
Litke said climate change science also predicts larger and more frequent floods on the Fraser River.
The factors are a high snowpack, a hot spring producing a sudden melt, then heavy rains.
Litke said last spring it looked like these conditions were aligning, but the weather cooled and the freshet came more gradually.
His group’s work has also identified the tremendous assets left at risk through inadequate flood protection and a major flood – assuming widespread failure of dikes – would trigger losses estimated at $20 to $30 billion, making it potentially the largest disaster in Canadian history.
Pitt Meadows council watcher William Wild identified that there are low spots on Pitt Meadows dikes which should be brought up to the same standard as the rest of the system.
Litke agreed it may be a prudent first step to address low spots in the short-term, although all the dike infrastructure will need to be upgraded eventually.
The flood management strategy will identify the most important areas where flood protection should be increased, and approximate cost estimates. The Fraser Basin Council expects to have the strategy ready to guide region-wide action by winter 2020.