• A structure whose main purpose is to supply water to the off taking canal is know as head works.
  • When the off taking canal is to supply water for irrigation purpose, its headworks is call irrigation head works.
  • Irrigation headworks may be divid into two categories.

1. Diversion headworks or simply head works.

2. Storage headwork.

1. Diversion head works.

  • The purpose of this head work is to divert river water into the off taking canal.
  • It is located across the river near the point of the take-off of the canal.

A diversion headwork performs the following functions:

  • It regulates the flow in the off-taking canal.
  • Silt entrance into the canal is controlled.
  • It raises the level of water in the river.
  • This causes diversion of the river water into the off taking canal, under gravity flow.
  • By raising the level of water in the river with the help of diversion work.
  • Consequently raising the off-take level of the canal, more area may be brought into the command of the propose canal system.
  • The level of water in the rivers remains fluctuating due to changing flow.
  • Diversion works reduce such fluctuations in river water level.
  • Although the purpose of diversion head work is not to store water but still some water definitely gets store.
  • This stored water can be use to augment the short supplies of the river.
  • This type of augmentation is possible for few days only, because stored water is not much in amount.

2. Storage head works.

  • Storage works the works which store surplus water when available in the river.
  • This store water is use to supplement the available flow when flow in the river falls short of the deman.
  • Storage head work comprises the construction of dams across the river.
  • Various aspects of storage of water have already been discusse in chapter on Reservoir Planning Construction Aspects.
  • Various types of days also have been discusse in earlier chapters.
  • In this chapter, only diversion headwork will be dealt with.