Bilećko Lake, reservoir in Bosnia and Herzegovina

Bilećko Lake is a large artificial reservoir near the town of Bileća, created in 1968 when the Grančarevo Dam was constructed across the Trebišnjica River. The lake covers about 33 square kilometers, reaches depths exceeding 100 meters, sits at roughly 400 meters elevation, and is surrounded by white limestone mountains and rugged terrain.

The Grančarevo Dam on the Trebišnjica, 123 m high and 439 m wide at its crest, was completed in 1968 to feed the Trebinje I hydroelectric plant. Raising the water submerged the villages of Panik, Orah, Čepelica, Zadublje and Miruše, along with the Kosijerevo monastery, later moved to Petrovići in Banjani. The Perović bridge and a Roman settlement at Panik with baths and mosaics also went under. Sources differ on rank: Serbian lists call it among the largest Balkan reservoirs, Croatian calls it the second largest.

The reservoir submerged the village of Panik, where a Roman settlement with baths, thermal rooms and mosaics lay; the site is known as Leusinium. The Kosijerevo monastery was also flooded and later moved to Petrovići in Banjani. The Dobrićevo monastery and Perovića Bridge are the other monuments tied to the drowned valley.

The southern end of the lake is narrower than the northern part and ends at the Grančarevo Dam, 123 m high and 439 m wide at the top, where the Trebinje I hydroelectric plant stands. The lake stretches 18 km in length and 3–4 km in width, with a maximum depth of 104 m at about 400 m above sea level. Water level varies, so the shoreline shifts; the exposed bank on the left of the view is mud and rock.

When the reservoir filled, the Trebišnjica drowned the village of Panik and its Roman settlement, Leusinium, whose villas, baths and mosaics lie under the water. The Kosijerevo monastery was moved to Petrovići in Banjani rather than lost. The Grančarevo dam that holds the lake is 123 m high and 439 m wide at its crest.