DIY Camelbak Backpack

Well.. this is one of those things that I cheated on. Yes, it's a DIY, and yes, it is a functional Camelbak Backpack, but I cheated on it.
The Camelbak consists of two main parts: the bladder, that actually holds the water, and the backpack, which holds the bladder in a convenient position on your back. I spent $10 on a knock-off brand bladder from Walmart. Though I'm sure it could be DIY-ed, finding food grade materials that I was familiar with was difficult, and outside of my money range, so I cheated and bought a pre-made one.

The rest, however, I DIY-ed. I got an old pair of my brother's too-small jeans (they don't have to fit too snugly or too loosely- I did this part and the next mostly because I was worried that it would rip, tear, get ruined, or pull itself apart once full under the strains of a Via Ferrata that I was putting it through).

I cut off a part of the pants leg a bit longer than the bladder itself.

I then sewed the end shut. I repeated these steps with a pair of sweatpants, which I put inside the jeans/denim layer. this served to both hold the bladder and to provide padding for it against being hit and such.

I cut holes for the fill part of the bladder and the nozzle for the tube, and used paracord to tie the top of the sack closed, and also to tie the bladder to the top of the pack.

As it turns out, all of my concerns about the structural integrity of the bladder were pretty unfounded. It stayed together, and still works even now. Do I regret putting this much time into the padding, though? Not at all.

I then got a really old backpack we had around the house still. I cut a slit at the top for the drinking tube to go through, then cut slits along the sides, behind the zipper, and laced the bladder in.

I then attached velcro to both the strap I wanted the tube to stay on, and the tube itself. When I went to fill it and use it, it just worked. Ta-daa!

This could be accomplished with any size or style of backpack you want to use, and additional straps could be added for additional support.