Spillway – || Purpose || Types || Spillway Gates


A spillway is the outlet portion of the dam, over which surplus discharge flow from the reservoir to the downstream. Hence, a spillway is known as surplusing work.

Spillway - || Purpose || Types || Spillway Gates

Purpose of Spillway

  • It resists water pressure at the mid reservoir level.
  • It can be able to control excessive flood water.
  • It can be able to save free-board and crest of the dam.
  • It’s shape and size so constructed that it should be able to resist excessive water pressure.
  • It should be able to protect the downstream side portion of the dam water-fall into the downstream.

Types of Spillway

  1. Waste weir type
  2. Ogee type
  3. Chute Spillway
  4. Straight drop type
  5. Siphon type
  6. Conduit type
  7. Shaft type
  8. Crest type

Spillway Gates

At the top of the spillway control gate is constructed that is called spillway gate.

Spillway - || Purpose || Types || Spillway Gates

It may be different type

  • Dropping shutters or permanent flash-boards.
  • Stop logs and needles.
  • Verticle lift-gate or rectangular gate.
  • Redial or triangular gate.
  • Drum gate

Read More:

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