The geological composition, with a good proportion of impermeable rocks, in combination with a relatively large amount of precipitation, significantly affect, along with the repentance of the relief, on the rich water map of this spa. In the basin of the Jošanica River, there are about 20 springs of cold water with a release of up to 1 l/sec. With the capture of four springs from Kokorovac, the water supply of Jošanička Banja was solved.

Jošanica River springs at a height of 1,560 m, from a small lake under the mountain Željin. It is 39 km long, up to the mouth of Ibar, and is very fast and cold mountain river in the upper stream, while in the middle flow temperature is warmed by warm springs in Jošanička Banja. The area of the rich basin of Jošanica is 265 km² with 141 tributaries. The waters of this river are rich in brook trout and huchen.

The Samokovka River is the left tributary of the Jošanica River, springs at 1,900 m above sea level and then flows through Ravni Kopaonik. In Jošanička Banja the river flows into the Jošanica River, it has a stream of 11 km long and a 52 km² basin area.

Among the wells in the Jošanica basin, the best known are the thermal springs of Jošanička Banja. With a water temperature of 77ºC, it represents the second spa in Serbia. The spa environment is represented by sixteen springs of low mineralized (320 mg/l) thermal water at three locations. The main spring is in the village on the left side of Jošanica with 11 springs. Second, it is much weaker on the right side of the river and consists of 3 springs, and third, Slanište, at a distance of 1,850 m from the center of the spa, downstream by the river Jošanica. The largest expanse has a group of warm springs located on the left terrace of Jošanice, in the park itself. At the 500 m upstream of the center of the spa lies the Luški potok, the spring of cold iron-carbon water (14ºC) and the volume of 0.08 l/s.