Then it merges with the Bärenbach, becoming the Piesau River, and flows north to the district Bock-und-Teich of the municipality of Lichte, the so-called Piesauknie.

In Wallendorf, close to the Lichte East railway station, it flows under the rail viaduct over the Piesau Valley.

The present-day name of the river appears only after the foundation of the municipality of Piesau in 1627, derived from the name of the founder, Pisa.

[1] Tributaries of the Piesau river are from the left the Kupfertalbach and from the right the Bärenbach, the Kulmbach, and the Taubenbach.

The Piesau and Lichte have unusually steep and deep gorges, the difference between hilltops and valley bottoms often exceeding 100 m. The Piesau and Lichte and their tributaries in the surrounding valleys have been known for centuries for deposits of placer gold and are considered the most significant sources of gold in Germany.