[1] The river takes its source under the name Vodenska reka at an altitude of 482 m in the eastern part of the Dervent Heights, just north of the Bulgaria–Turkey border.

In its upper course until the village of Voden it flows in a narrow forested valley, initially westwards and then northwards.

After Bolyarovo the valley widens, the river makes meanders and changes direction several times — northeast after the town, northwest at Dabovo and southwest downstream of Popovo.

The Popovska reka enters the Elhovo Field after the village of Dobrich.

It flows into the Tundzha at an altitude of 98 m south of the town of Elhovo near the first class I-7 road.