Study raises concerns about Flora Bank integrity

A report prepared for the Lax Kw’alaams Band raises new concerns that a terminal on Lelu Island could have on Flora Bank.

A report prepared for the Lax Kw’alaams Band raises new concerns about the impact Pacific NorthWest LNG’s terminal on Lelu Island could have on Flora Bank.

The report, entitled A Sediment Trend Analysis of Prince Rupert Harbour and Its Surrounding Waters, was written by Dr. Patrick McLaren of SedTrend Analysis and notes that Flora Bank is unique in that the sediments are not believed to have been transported and deposited at the site but rather “must have formed in situ or are remnant from a pre-existing environment”.

“If, in fact, the sands are actually part of a larger transport regime in which sand is both arriving and leaving the bank, thereby keeping them maintained, a constantly shifting position of the bank could be expected as the availability of sand arriving could never be constant and the processes to remove it would also be variable,” he wrote.

“The amount of sand on the surface of Flora Bank has remained constant and, to date, there has been little possibility for the complex interaction of river, tide and wave processes responsible for holding the sand in place to have changed since sea level reached its present position 8,000 years ago.”

Based on the idea that Flora Bank is not a feature that is created by sediment transported through the Skeena River, Dr. McLaren said different considerations must be taken into account when examining the impact of industrial development in nearby areas.

“Any change that might alter the wave, river or tidal currents in the waters surrounding Flora Bank will inevitably affect the ability of the processes to hold the sand in place. If such a change results in a loss of sand, there will no longer be any chance either for it to return or be replenished from other sources,” he wrote.

“If, instead of losing the sand, a decrease in energy levels over the Bank increases the deposition of fine sediments the possibility of losing the eel grass will occur.”

Luanne Roth of the Prince Rupert Environmental Society says this information must be considered by the company which she says, despite eliminating the need for dredging through the use of a suspended bridge trestle, would still create “a forest of pilings” that would impact current wave action and flows in the area.

“Pacific Northwest LNG is aware of the erosion problem with the new design. I spoke to them at their last open house and they said they were meeting with Dr. McLaren whose sediment analysis confirmed a serious flaw in the new design which threatens Flora Bank if the Pacific Northwest LNG project is allowed to proceed,” she said.

The company acknowedges they have heard the concern, but say their studies show any impact to the currents and tides around Flora Bank would not be significant.

“Based on extensive studies conducted by our environmental consultants who are experienced in this field, we are confident that the integrity of Flora Bank will be maintained. We have conducted rigorous engineering modelling and analysis, and are confident that changes to waves, river and tidal currents around Flora Bank would be minimal,” said communications advisor Krissy Van Loon.

“We fully understand the importance of, and are committed to protecting, the eel grass and Flora Bank. We have conducted wave, current and tidal studies, sediment dispersion modelling, shading analysis as well as extensive field work to better understand how our marine terminal will impact the area around Lelu Island. The conclusion of this work is that the current marine structure design and terminal operations would not adversely impact eel grass or Flora Bank.”

 

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