Errors:  

- five steps start from river water reserve into a dam and end with flow of water during pumping at night

Corrected version:

The process chart illustrates how electricity is generated in a hydroelectric power station. Overall, there are five steps starting with the river water reserve in a dam and ending with the flow of water during pumping at night.

Improved version:

The diagram details the five-stage process of electricity generation at a hydroelectric power station, beginning with the storage of river water in a dam and culminating in the nocturnal water pumping cycle.

Errors:  

- flow water generate electricity during a day

- which is used to generate electricity in the day time and at night it is used to pump water into high-level reservoir

Corrected version:

Initially, river water is directed to the dam where flowing water generates electricity during the day, moving in a downward direction. There are two reversible turbines which are used to generate electricity during the day and at night they are used to pump water into the high-level reservoir.

Improved version:

Initially, the dam harnesses the river's current to produce electricity throughout the day, with water descending through two reversible turbines that also function to elevate water into the high-level reservoir at night.

Errors:  

- which helps to generate electricity with water, after that generated electricity reserved in a power station before supply it on power lines and then national grids

Corrected version:

A generator helps to convert water flow into electricity, after which the generated electricity is stored in a power station before being supplied to power lines and then to the national grid.

Improved version:

The generator converts the kinetic energy of water into electrical energy, which is then stored at the power station prior to distribution through power lines to the national grid.

Errors:  

-  remain water pumped into low-level reservoir towards high-level reservoir with the help of turbines

Corrected version:

At night, the remaining water is pumped from the low-level reservoir to the high-level reservoir with the assistance of turbines. The flow of water during pumping is in an upward direction at night.

Improved version:

During the night, turbines facilitate the upward pumping of residual water from the lower reservoir back to the upper reservoir for the next day's energy generation.

Errors:  

- intake water produce electricity works only in a day time only at night it is closed, and only pumped water process into high-level reservoir continues whole night

Corrected version:

The process of using intake water to produce electricity operates only during the daytime; at night, it is halted, and only the process of pumping water into the high-level reservoir continues throughout the night.

Improved version:

Electricity production using water intake is exclusive to daylight hours, ceasing at night when the focus shifts to replenishing the high-level reservoir through continuous pumping.