The issue is that there's a timing window for when the gravel operations can be removed. Typically we want the operations to be discontinued around the middle of March, the reason being that's when young pink fry are emerging from the gravel and migrating downstream. So there's a very narrow window in which the gravel can actually be removed. The flow of the water in the Fraser River has to be sufficiently low that you can construct a causeway across the channel to access the gravel. At the same time, you want them to finish their operation before the middle of March, when these young pink fry are present in the river.
In this particular case, those conditions didn't really arrive until the first week of March. So on March 3, the causeway was completed. Under normal conditions, we would have wanted that operation to continue until the middle of March; in this case it was curtailed earlier, because of the conditions I spoke to, in terms of lack of flow.