The station began to work in 1981 with normal water level lowered to 63 m above sea level. Most of flooded land belonged to
Mari El Republic. Flooded land included valuable meadows and several hundred acres ( hectares ) of oak forest that was not duly felled. Rising normal water level to the design value of 68 m was hindered first by incomplete reservoir banks protection, then being opposed by
Nizhny Novgorod Oblast and
Mari El Republic. Now the station is operating at 63 m water level, with an actual installed power of 820 MW and an average annual production of 2100 GWh. Also lowered level poses difficulties to navigation on the Volga river between
Nizhny Novgorod and
Gorodets, with allowed draught down to 3 m, whereas it is 4 m on other parts of the Volga. Water quality in reservoir degrades because shallow waters comprise 33% of its area instead of the designed 19%. The water level problem is still being discussed. Further water level rise will cause flood of vast areas of
Nizhny Novgorod Oblast and
Mari El, including most part of
Nizhny Novgorod between the Oka and the Volga rivers. == See also ==