Dredging in the Fog

The Fraser River is very "silty" and needs continuous dredging to allow ocean going ships to travel upstream.  There is a plan to deepen the channel significantly to allow even bigger ships to enter.  There is a tunnel about 8 km. upstream carrying the main highway from Vancouver to the USA and it would obstruct the larger ships so it will have to be removed and  be replace by a bridge   $$$$$$$$$$$$$$$