New provincial design standards for dykes meant to provide protection against earthquakes and prepare for rising sea levels could cost Lower Mainland municipalities hundreds of millions of dollars.
Municipalities say if the province is going to establish new design guidelines for dykes -- which protect billions of dollars in infrastructure -- it needs to provide money to help make the required improvements.
The City of Richmond has already estimated the new dyke design standards will cost $180 million -- $100 million to account for higher sea levels and $80 million to improve the dykes' ability to withstand earthquakes.
Richmond's director of engineering John Irving said even though the expense could be spread over a number of decades, it is difficult to plan for the improvements without dedicated funding.
"It's additional cost the province has created without additional funding,'' he said.
Richmond, Delta and Chilliwack account for nearly half of the 330 kilometres of high-risk dykes to which the new earthquake rules apply.
Dykes are considered high risk -- or "high consequence'' -- when they protect urbanized areas. Chilliwack alone has estimated its 50 kilometres of dykes protect $2 billion in property and infrastructure.
The province is not ordering municipalities to make upgrades immediately to meet the new standards. Instead, the improvements will be required only as new dykes are built, or dykes are upgraded.
The new earthquake standards released last month allow dykes to be upgraded in a number of ways, for example, by widening or compacting the base with methods that include pile driving and injecting mortar into the soil. Dykes would need to be raised to account for expected rises in sea levels from climate change, outlined in new guidelines released in the first half of the year.
Neil Peters, the province's inspector of dykes, said there is no new funding tied to the new standards.
"At least at this point, the guidelines process is separate from any infrastructure-funding process,'' said Peters, who is also head of flood safety for the province.
He likened the new dyke standards to upgrading the building code. "It doesn't mean that somebody building an apartment gets money to comply with the new code,'' he said.
Although Delta has not produced cost estimates, deputy director of engineering Hugh Fraser said the new standards would cost "very large dollars. ''
Fraser noted the provincial and federal governments are putting significant investments into the Lower Mainland to develop its ports and other infrastructure to tap into growing trade with Asia.
"They need to recognize these communities need to be protected if this is going to be the gateway to the Pacific,'' he said.
According to the province's new guidelines, an earthquake creates a number of risks, including a phenomena known as liquefaction which can turn sandy, wet soils into a kind of slurry.
The Fraser River delta had been identified as a prime location for liquefaction, said John Clague, a Simon Fraser University geologist with an expertise in earthquakes.
The liquefied ground can destabilize dykes and can cause sliding and collapsing.
This can be an immediate threat where dykes are holding back seawater, for example, at high tide, or river water, as at the Vedder Canal in the upper Fraser Valley.
Any collapse of dykes from an earthquake is also a significant danger if there is an ensuing tsunami. If an earthquake were to happen when the Fraser River was experiencing high water, the consequences could be more severe.