There is nothing built into this bag for this, it really is no frills. There isn't even a tube hole, I run it through the top of the zip.

Having said that, I run with a 3litre bladder and it pretty well stays where I put it. I also have a jacket in the bag which kind of holds thins in place.

I am nothing short of impressed with this bag.

no

No

No, the 20L has this though

No, there's no internal pocket at all, or padding on the back of the pack to give structure to the pack & stop the bladder be pressed up against your back.

I have this and there is no internal pocket.

Yes,

yes, there's a separate compartment inside that works fine

There are 2 pockets on the waist strap. 1 is water proof, the other isn't. The rest of the rucksack is water proof. So i'd say it's 95% water proof :)

I have used it once when it was raining. The clothes i had inside was perfectly dry.

The zips are waterproof but the bag doesn't seem totally waterproof. My bladder leaked a bit once or twice and the water soaked out from the inside

I think that this product is what exactly you are looking for. Has a good and adjustable fit. the only point that you have to consider is the size Sizes 15 ltrs in terms of carrying clothes to work.

You're pretty small but so is the bag :). The fit is excellent on me, I'm 5 8 but it may fit you fine. Probably worth trying one on if you can.

There is no airflow between the bag and your back so don't get it if you really like your back to stay dry.

It's 15L

15 Liter