'Gravel grab' or saving graceThe science behind flood protection value along Fraser being questionedPaul J. Henderson, The Times
Published: Tuesday, February 26, 2008
Large scale gravel removal in the Fraser River is now underway near Seabird Island, but opposition from a growing number of groups suggests it's nothing but a "gravel grab."
The science behind the flood protection value of the gravel removal at Spring Bar is also in question.
"The single-site 400,000 cubic metres removal is, in my estimation, much too large," said Michael Church, a sedimentologist and river hydraulics scientist at the University of British Columbia.
"The head of Spring Bar is a notably poor place for such an extraction . . . excavation of a relatively deep hole in the bed is a poor choice for the removal, and the effect on water levels will be small. The latter point has been known for some years from mathematical modelling of various proposed removals."
But Minister of Public Safety John Les stands behind the current gravel removal project on Spring Bar.
"We need to look at the long term," Les told the Times yesterday. "If someone were to say 'removing 400,000 cubic metres won't make much of a difference,' they would be correct. But the cumulative effect over time will be significant.
"One year isn't going to get the job done. We need to be able to do this year after year after year."
In January, the provincial government, through Les's ministry, announced $564,000 to fund a temporary bridge across the river to access the gravel on Spring Bar with an aim to reduce Fraser River flood risk and protect public safety and property.
"Major deposits, including entire islands of gravel that have formed over time, are increasing the flood risk for the millions of people who live and work in the Fraser Valley," Les said in a press release.
The Fraser Valley Salmon Society (FVSS)--backed by the B.C. Wildlife Federation, the David Suzuki Foundation, among other groups--have suggested that not only will the gravel removal damage high-quality salmon rearing habitat, it won't do anything to help to protect communities like Chilliwack anyway.
"I'm convinced by the science I have seen," said Frank Kwak, president of the FVSS. "Removing gravel out of the Fraser River is not going to do anything significant from protecting the city from flooding."
Kwak points to a number of scientific engineering reports including a gravel extraction modelling report done for Fisheries and Oceans Canada by Northwest Hydraulic Consultants that concluded: "It does not appear that large scale gravel removals from the gravel reach of the Fraser River are effective in lowering the flood profile."
Les's ministry has suggested that between 15,000 and 63,000 dump truck loads of gravel wash down the Fraser River each year, coming to rest between Hope and Mission.
But a study prepared in 2006 for the B.C. Ministry of Lands and Agriculture entitled Fraser River Potential Gravel Removals 2007-2011 reported that the area in question is actually a net area of gravel loss, not accumulation as the government has reported.
The study said there was more than four million cubic metres eroding from this stretch of river between 1952 and 1999, and more since then.
"Comparison to the 2006 georeferenced air photographs and the 1999 channel mapping indicates that the bar on the east side of Spring Bar has actually eroded by about 90 metres over the last seven years," the study concluded.
Kwak's main concern is that the area in question is a 10-hectare footprint equivalent to a four-metre-wide salmon rearing stream 25 kilometres long.
Kwak suggested this really is about the valuable gravel being used for the busy construction industry.
Work at Spring Bar has begun and will continue with DFO approval until March 15. For this work the contract provides the contractor with all rights to the gravel removed.
To protect against any environmental damage, the government announced has said an environmental monitor is there, but given the expense and size of the operation, Kwak says the monitor will have no real power.
"Do you really think that man has the capacity to actually say, 'whoa, you are not moving another rock of this gravel bar,'" he said.
Les responded that the oversight at the gravel removal site will be legitimate.
"Does that person have the ability to shut the site down?" Les asked, and then answered: "Yes they do. I've been clear from the beginning I want this to be meaningful oversight."
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Topic: "There are safer places to get gravel" (Read 123214 times)