What is a Reservoir

Question:-What is a Reservoir?

An artificial reservoir formed in the river valley by water-retaining structures to regulate its flow and further use in the economy.

With undoubted advantages, reservoirs can cause flooding, swamping and other negative consequences.
Now in the world there are more than 30 thousand reservoirs with a total total volume of about 6 thousand km 3 .
At the same time, the useful volume is estimated at almost 3.5 thousand km 3 , which is close to 10% of the average annual flow of all rivers in the world.

  • The total surface area of ​​the world’s reservoirs is 600-620 thousand km2 .
  • There are about 1200 reservoirs in Russia.
  • Their total volume is over 900 km 3, and useful – about 450 km 3 .
  • The area of ​​their water surface exceeds 100 thousand km 2 , including excluding dammed lakes – 60 thousand km 2 .
  • The largest reservoir in Russia in terms of volume is the Bratsk reservoir on the river. Angara.

According to the nature of flow regulation, reservoirs are distinguished:

  1. perennial,
  2. seasonal,
  3. monthly,
  4. weekly and daily regulation.

The filling of the reservoir and its drawdown are always carried out to certain levels.

The highest design level of the reservoir (upstream of the dam), which is maintained under normal operating conditions for a long time, is called the normal backwater level.

The minimum reservoir level to which it can be drawn under normal operation is called the dead volume level.

The volume of water between these 2 levels is called useful volume, since only it can be disposed of to solve various economic problems.

The volume of water below the dead volume level is called dead volume and is not intended to be used under normal operating conditions.

The reservoir is an absorber of nutrients and pollutants due to the processes of their decomposition and sedimentation.

Reservoirs perform the following major economic functions:

  • along with hydroelectric power plants – important suppliers of electricity;
  • water supply;
  • maintaining the depths required for river transport;
  • water recreation, fishing.

Equalization reservoir prevents sharp fluctuations in water level when the operating mode of the HPP changes.