The Topolnitsa ( ) is a river in southern Bulgaria, an important left tributary of the Maritsa. It takes its source from Bich Peak in Sredna Gora close to Koprivshtitsa; it is known as the Shirineyska in its upper course. Its average discharge is 55 m3/s and it is long; its drainage basin covers . The Topolnitsa flows into the Maritsa near Pazardzhik after making a large turn under Trakiya motorway. The Topolnitsa Reservoir has a maximum volume of and serves the area around Pazardzhik. Among the Topolnitsa's tributaries are the Mativir and the Bunovo River. The river's name is derived from the Bulgarian word топола, topola ("poplar"). References Rivers of Bulgaria Landforms of Sofia Province Landforms of Pazardzhik Province