From my perspective.... First of all, that's a very good question.
We did not anticipate that we would have the dewatering effects that I think we observed. The issue is we have to tease apart to what effect the causeway was the cause of that versus the natural flow reduction. That being said, we realize that the installation of the causeway clearly affected passage of water through the causeway and we have to determine to what effect that disruption dewatered gravel sites further downstream that ultimately were affected. That is the part of the review we're looking at now.
You asked the question, though—I think a bigger question--which is: in allowing for operations of gravel removal on the Fraser River, do you do so knowing that there may be some impacts? I would shape the question even more broadly. The reality is that when we develop habitat anywhere, we are trying to minimize the impacts of that habitat on the resource; we're always trying to minimize and, where possible, avoid impacts. But there's always a risk. When you develop habitat, whether it's to construct a bridge over a river, a road along the river, a house near a river, or a well that draws water from an aquifer, in all those instances you are managing risk, always.
In the case of gravel removal, what we are trying to do is minimize the risk. We try to have the gravel operation occur at a time of the year where the impact on, in this case salmon, is made as small as possible. We're trying to have the operation occur in such a way that the chances of its affecting fish are low. But short of having no gravel operations, no road development, no bridge crossings, it's hard to say that there is ever zero risk. So we try to manage the risk. We try to come up with something we think makes sense, through a scientific evaluation and a scientific base.
We're always conscious that ultimately we're trying to manage risk and arrive at something we think is reasonable, given that we have conflicting objectives. On the one hand, we have provinces and municipalities that are worried their communities are going to be flooded; that the gravel accumulation will cause the river to divert, to go into channels and into sloughs and into fields and into farmers' areas, and so forth, and disrupt crops and cause huge economic damage. On the other hand, as the Department of Fisheries and Oceans, we're concerned about the preservation and management of Pacific salmon.
So it's a constant balance we are trying to find. We believe we arrived at a reasonable balance with our understanding of the science in this particular case. But as we've noted, we're prepared to learn from that experience.