Fraser River fish habitat threatened by gravel extraction

Approximately 280,000 cubic metres of gravel accumulated in the active channel of the river. This was largely offset by significant losses (4 million cubic meters) of over-bank sand on islands and river edges, resulting in little net gain of sediment. (Credit: janheuninck via Flickr)

B.C.'s Fraser River has become the battleground for the gravel industry and conservation groups fighting to protect one of the world's most productive fish habitats.

The Fraser has been a source of gravel for B.C. construction for decades. However, Fisheries and Oceans Canada (DFO) placed a moratorium on gravel extraction in the mid 1990s due to concerns about fish and fish habitat. Not long after the freeze, the B.C. Provincial government began to argue that gravel removal from the Fraser was necessary for flood protection as "massive" gravel accumulations were, allegedly, causing the river bed to rise. A series of public meetings was held to debate the issue and experts were called in to assess the scope of the problem.

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Dr. Michael Church, a professor of Geography at the University of British Columbia, provided the most compelling testimony on how gravel and sand enter and move through the gravel reach. He estimated that while approximately 280,000 cubic metres of gravel accumulated in the active channel of the river, this was largely offset by significant losses (4 million cubic meters) of over-bank sand on islands and river edges, resulting in little net gain of sediment.

The B.C. government and proponents of the gravel industry incorrectly interpreted this to mean that 280,000 cubic meters of gravel and sand entered the gravel reach each year and merely "piled up" in the river causing a rise in riverbed elevation that would, over time result in increased flood risk. These groups argued that lives and property were at risk and pushed for DFO to lift the moratorium on gravel extraction.

In 2004, a five-year federal-provincial agreement was reached to allow removal of up to 500,000 cubic metres of gravel in each of the first two years and up to 420,000 cubic metres in the following three years. The agreement was touted as a long-term plan for reducing the flood hazard risk in the lower Fraser River.

Critics argued that gravel removal was only taking place in areas where it was easily accessible to industry and that removal from the targeted areas provided no flood protection benefits whatsoever. In addition, fish and fish habitat were paying the price. In one case, at a location known as Big Bar, removal operations undertaken in 2006 resulted in the de-watering of thousands of salmon redds (nests) and the demise of possibly millions of young salmon which were just about to emerge from the gravel. There was evidence to suggest that similar losses of fish had occurred at other sites as well.

The Fraser River is also home to the white sturgeon, listed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as endangered, with gravel removal identified as one of the key threats affecting this species.