describe the given diagram of hydroelectric power station

The given diagram gives a detailed account of electricity generation in a hydroelectric power station. Two distinct processes are being conveyed through the figure, one which takes place during daytime and contrarily, the other occurring at night. The water flowing in from the river is stored in a high-level reservoir which is bound by a dam on one end. During the day, the dam intake is open for water to flow into a reversible turbine that operates the generator at the same time resulting in energy creation. Both, the generator and the turbine, are enclosed in a structure labelled as the power station. The electricity from the generator then flows to the power lines that further connect to the national grid. Moving ahead, the water overflowing from the turbines accumulates in the low-level reservoir. On the other hand, during nighttime, the direction of the water is reversed. It is released from the low-level reservoir towards the aforementioned turbines that work on pumping it ahead into the high-level reservoir. The dam intake is closed at night, presumably to ensure no overflow of water. In conclusion, it is apparent from the illustration that the given hydroelectric power station is a complex and heavy structure that begins and ends at two different level reservoirs; it also seems like one that could generate a significant amount of electricity.