But if you dredge the s#@t out of it, maybe.
Dredging won't reduce flood risk, report says
Excavation on Fraser not the 'silver bullet,' official says
Peter O'Neil
Vancouver Sun
Monday, June 11, 2007
A massive dredging initiative on the lower Fraser River would likely do nothing to reduce the risk of catastrophic flooding, according to a technical report obtained by The Vancouver Sun.
The federal government commissioned the analysis after getting hammered by critics who say Ottawa could reduce the risk of a catastrophic flood on the river by allowing more gravel dredging.
"It shows that [gravel excavation] isn't the silver bullet for flood mitigation," Greg Savard, director of special projects at the federal Department of Fisheries and Oceans, said last week.
But he said the report does open the door to strategic gravel removal in certain key areas, and therefore provides important feedback for the federal and B.C. governments in considering possible gravel extraction efforts for this summer and in early 2008.
Liberal MLA Randy Hawes (Maple Ridge-Mission) accused the federal government earlier this year of stalling dredging initiatives due to fear of fish habitat damage.
Ottawa, he said, is putting "fish over people."
The report, by Northwest Hydraulic Consultants Ltd. of North Vancouver, was made public as federal, provincial and municipal officials brace for potential flooding along the Fraser.
The company conducted a modelling study looking at excavation removal ranging from 1.4 million cubic metres to 4.2 million cubic metres. A cubic metre is equal to the volume of a cube measuring one metre in each dimension.
That's far in excess of the permissible annual removals under a 2004 B.C.-Ottawa agreement that allowed 500,000 cubic metres in each of the first two years of the deal and 420,000 cubic metres annually in subsequent years.
The initiative would reduce water levels by only five to 15 centimetres, insignificant in preventing floods that would only occur if the river level swelled by several metres, said Barry Chilibeck, an engineer at Northwest Hydraulic
"It does not appear that large- scale gravel removals from the gravel reach of the Fraser River are effective in lowering the flood profile," concluded author Dale Muir in the April report.
"Localized reductions in water surface elevations are possible, but significant, wide-scale reductions at flood flows are unlikely."
The report, commissioned in March, recommends further studies to ensure that large-scale gravel extraction wouldn't result in riverbank erosion.
Both levels of government said in 2004 that dredging is a crucial component in preventing flood disasters.
"Gravel must be removed from the Fraser River on an annual basis to prevent buildup," Shuswap Liberal MLA George Abbott said when the gravel removal deal was struck.
Then-federal fisheries minister Geoff Regan said the deal "addresses the long-standing concerns of Fraser Valley communities to ensure that we are able to act in a timely and environmentally responsible manner to reduce the risk of flooding and erosion."
Only 320,000 cubic metres of gravel have been removed since the accord was struck, according to media reports.
The B.C. government has spent $33 million on flood mitigation measures this spring, primarily involving dike improvements, and recently received $16.5 million back from the federal Conservative government to cover half the bill.
The study's results present "no surprise to people who are knowledgeable about the river," Chilibeck said.
But he said the report's conclusions will be unpopular with some government critics.
"It's much easier to say, 'dig the river out,' because it's a simple solution. But it's really not that effective."
poneil1@hotmail.com© The Vancouver Sun 2007
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