Why? So that equipment, and personnel, can be victims of the disaster, instead of responding to it? So they can be isolated in Chilliwack, with no means of resupply? With no means to get anybody to anywhere to do any good?
Even when 1 CER was located in Chilliwack, along with CFSME, there wasn't enough MGB, Bailey, Acrow, or MR to get across the Vedder, the Chilliwack River, the Fraser River.... etc. In short, they aren't able to get themselves the 100 km from CWac to Vancouver.
Those who think that having 800-odd soldiers in the middle of the disaster zone is going to make any difference beyond helping those people in the immediate vicinity of the base are deluding themselves.
I would suggest the best bet for BC after the big one is going to come from 192 AEF located at the Abbotsford Airport, a unit that specializes in Airfield Engineering, and may be in a position to restore operations at an airport or two to get the rest of the relief forces in.
You are right in that the first 72 hrs will be crucial, but it will be the individuals and families, well prepared and equipped to look after themselves, without any outside support, that will reduce the degree of the calamity. You saw the footage of Katrina? Stock up now, cache some food, water and other necessities, have a plan, and think ahead.
As for the "Sea Borne Threat", that's what Maritime Patrol AC are for, and I don't believe they're going away any time soon.
My 2 shekels,
DF