I don't know nothing about this issue , but highly dought the gravel was used for concrete, unless they crushed it to certain sized rocks, anyways , besides the point , why the hell wouod they have to extract gravel from one of the rivers that brings in ,probably the most money in the province as far as fishing turisam goes , or what ever you wanna call it ...
Why desturb what already works somewhat good compared to other rivers around the province .
I know it's probably a total nother topic , but WHY?