I really struggle to wear/carry belts etc.
I have one run which I frequently use that goes through a camp site... so I just pinch a drink directly from the stand-pipes
Other solutions I've used are to secrete a coin on my person, and have a route where there's a shop/pub roughly half way round. Just buy a bottle of water there.
If the other two aren't an option, I've sometimes taken a re-used small bottle (maybe just 200ml) that fits up my (long) sleeve, and I can throw away when finished. I found that less hassle than carrying one, or having one bumping around my waist.