1. Normal Pool Level.

  • This is the maximum level of water in the reservoir to which the water will rise during ordinary operating conditions.
  • This level corresponds either to the crest level of the spillway or top level of the spillway gates.
  • This level is also know maximum conservation level.

2. Minimum Pool Level.

  • The lowest elevation of water which has to be maintained in the reservoir under normal operating conditions is called minimum pool level.
  • The elevation is guided either by the lowest outlet in the dam or by minimum head required for efficient functioning of turbines.

3. Maximum Pool Level.

  • During floods water starts flowing over the spillways.
  • But discharge over spill-ways increases with further rise in reservoir level.
  • The maximum level attained by water during worst design flood is know the maximum pool level.
  • This level of water is essentially above the Normal pool level.