The hut-keepers offer food and beverages and water as well. Also in every hut there is water fountains and you can recharge your bottles. As a whole, in the Bulgarian mountains water is not a problem.
On many spots along the paths there are fountains or small spring with pure and potable water. Of course there are high mountain trails that are waterless. Usually they are passages along high mountain ridges like Koncheto in Pirin or the central part of the main ridge in the Balkan. Usually we carry a bottle of 1.5 L. Depending on the path and the temperatures this quantity could vary. In cold weather we recommend a 0.75 L lightweight thermos with hot water/tea.