Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Posts Tagged ‘the delta is sinking

Sinking river delta could mean trouble along Fraser

with 9 comments

Peace Arch News

Steveston Ladner Canoe Pass and Mt Baker 2007_0710_1058

This issue has been bothering me for a while now – as posts to this blog will attest.

The cause in the Fraser delta is that dikes, constructed to prevent flooding, force the river to carry its sediment load out into the Strait of Georgia so that none accumulates on deltaic lands. The delta is also sinking one to two milimetres each year under its own weight.

The survey data suggest that, by the end of this century, it will have sunk by more than a metre (130 centimetres), with the effects reaching as far upstream as Maple Ridge and Fort Langley. As elsewhere, a rise in sea level will accentuate the problem.

The warning about the Fraser river delta is coming from Canada’s Geological Survey but is replicated by  satellite data, coupled with historic records, on many of the world’s deltas. Add rising sea levels due to global climate change, and our vulnerability to seismic activity and we have a recipe for disaster.

Roy Strang raises the same questions I have been asking

If these data are accurate and reliable, and one adds in the consequences of seismic liquefaction in the event of an earthquake, what is the future for the Vancouver airport and Richmond? Were such eventualities considered when expansion of Deltaport or the controversial South Fraser Perimeter Road were being planned? Are there contingency plans, or is the horizon too distant to be a concern for today’s politicians?

He does not answer these questions and the article then drifts off into other things. The only official comments I have seen recently came from Malcolm Brodie, the Mayor of Richmond. Which were simply a recitation of his complacency about the strength of our dykes.

I rather suspect that the boosters who have been so keen on expansion of the port and the airport have been deliberately quiet about these risks. But I do know that when emergency planners at the then GVRD assessed these risks during the period when the LRSP was being drawn up, advised that development should be directed away from flood risk areas. That is why Richmond was not part of the Growth Concentration Area. And of course the fact that the land was of very high agricultural quality was also a reason for not building on it. Indeed, protection of the Richmond farmland which had not already vanished under subdivisions was one of the main reasons for the creation of the ALR.

Of course ALR designation means nothing to the Port of Vancouver, who are happily buying up farmland to store containers on or to sell for industrial development. And the province is so taken with the huge land development profits consequent upon the SFPR that any considerations like food security, critical habitat or even carbon capture by bog lands have been steadily ignored. Or even denied. So flood risk is just another one of those tiresome objections to be swept under the carpet so the BC Liberal party supporters can go on making lots of money – which is all that matters as far as they are concerned.

Written by Stephen Rees

October 1, 2009 at 8:52 am