I have made a water bag for backpacking out of the 1.1 oz silnylon.
This is a lightweight bag that will hold over 3 gallons of water, allowing me to set up camp well away from my water source. I simply scoop water in the bag, carry it to camp, hang from a tree limb or my walking stick, and then I can pump right out of the bag after particles have settled (easier on my pump).
This bag used to be made by Coghlan's, but they discontinued them!
I tested with 2 gallons of water for 24 hours and there was no seepage