Holy smokes... 8 gallons x 7 days = 56 gallons at one gallon/person/day.

56 gallons x 8.34 lbs/gallon = 467 pounds!

Yeah, I could see how that might cause problems. <img src="/images/graemlins/shocked.gif" alt="" />

How about just stashing a few one gallon jugs of spring water and relying more on filtration and purification? Are there any reliable sources nearby to draw from? (The package store doesn't count!)