Rybinsk Reservoir
The town of Poshekhonye is situated on the left (southern) bank of the Sogozha. Historically, the river received two left tributaries, the Soga (from the east) and the Pertomka (from the south) within the city limits. Due to the water level rise caused by the Rybinsk Reservoir, the Sogozha and the Soga now form a wide bay at their joint entering of the reservoir.