Beli Iskar Reservoir, constructed between 1939 and 1945, that powers a small 16 MW hydro power station. Levi (left) Iskar is the smallest of the three and has its origins at the northern slopes of the Marinkyovistsa Peak (2,636 m). It flows through a deep valley for 18 km until its confluence with Cherni Iskar downstream of the village Mala Tsarkva and has a watershed of 56 km².

Iskar proper is formed by the confluence of Beli