Hydrological conditions

The southern boundary of the Magura National Park (the state frontier with Slovakia) is the European watershed between the drainage basins of the Black See and The Baltic. The territory of the Park lies within the drainage basin of the upper Wisloka river , whose source is located on the slopes of Debi Wierch Mt. (in the protection zone). At first the Wisloka flows by the narrow valley towards the North.

Wisloka river (phot. Slawomir Basista)

The change of the direction of the river’s course is caused by the first bigger tributary – the Zawoja river. This change occurs several times and is always caused by the watercourse flowing into the Wisloka river. The Wisloka is a mountain river and is characterised by the very high index of the discharge irregularity. Not very high water retention value of the river’s source-area causes large runoff in comparison with the precipitation and in consequence the fluctuations of discharges. The maximum discharges take place during the snow melting period (March, April), while the minimum discharges can be seen in September and October. High speed of water flow down the slopes causes strong soil erosion and transport of debris. This process increases in the periods of high water stages and floods. The protection of the forests of the upper Wisloka drainage basin will cause the enlargement of the top age class tree stands area and renaturasing of the planted stands. These changes will increase the water retention value of this area.

In the area of the Magura National Park very complicated systems of mires and springs can be observed. Their occurrence conditions the ground permeability among other things. Very picturesque spring cirques of bigger watercourses are quite characteristic for the area of the Park, the biggest and the best known of them is the spring cirque of the Klopotnica river.