Unless you plan on spending your life drinking by the river in Medieval Dynasty like you're some sort of grazing deer, you'll need to get your hands on a skin of water. You'll also want to do this as early as possible, as this will allow you to roam the area freely and hunt and foraging without needing to stay near a river.
There are two ways to get Water Hide early in the game that won't negatively impact your reputation with others. The first is to take advantage of an early game mechanic that allows you to earn easy coins. You can make a lot of stone axes and stone carving knives and sell them to traders in town. This will earn you money easily and you can buy a water skin from Uniegost for 200 coins when you have enough.
You can also get a water peel for free which is always a better option. If you talk to Uniegost, he'll tell you that a local hunter who doesn't like him has mentioned wolves in the area. This guy really hates Uniegost, so Uniegost will ask you to go find out what he knows. As Castellan, it's important that Uniegost keeps people safe, and he can't do that if he doesn't know wolves.
Follow the waypoint to the hunter's cabin and make sure you stop in an area where the fences are broken on the map above. Go down the embankment to a crashed cart and inside you'll find a skin of water. Because no one has it, you can take it safely without angering anyone or being seen as a criminal.
After that, you can continue to the hunter's home, talk to him, and then report to Uniegost with the information you find out.
