Seasonal lakes of Pivka

Lake Palško is the largest among the Seasonal lakes of Pivka.
Top image: high water in December, after the autumn rains; bottom image: empty area in autumn, two months earlier.

Seasonal lakes of Pivka is a group of 17 seasonal lakes; the most well known are Lake Petelinje and Lake Palčje, which is the biggest of them at about 1.9 square kilometres (0.73 sq mi).^[1][2] They are all located in Pivka Basin, Inner Carniola, Slovenia.^[1] Lake Jeredovce, the northernmost lake, is in Municipality of Postojna, 10 of them (Krajnikov dol, Lake Petelinje, Lake Radohovo, Lake Klenik, Lake Palčje, Lake Parje, Major & Minor Lake Drskovče and Major & Minor Lake Zagorje) are in Municipality of Pivka and the southernmost 6 (Kljunov ribnik, Lake Kalec, Lake behind Kalec (Veliki dol), Lake Bač, Lake Lan and Lake Šembije) are in Municipality of Ilirska Bistrica, all of them are located at altitudes between 549 metres (1,801 ft) and 570 metres (1,870 ft).^[2] There are also two areas (polje) that are only inundated during intense floods, so they are not officially considered Seasonal lakes of Pivka.

The lakes are situated on a rocky terrace in the Upper Pivka Basin at the foothills of the Javorniki range, rising above the Pivka riverbed. The terrace is dotted with a number of depressions with flat bottoms and sharp transitions at the banks, deep enough to reach the level of groundwater fluctuation. Thus, they are inundated after periods of stronger precipitation (late autumn and spring).^[3]