Clasication of Irrigation projects

Classification

Irrigation projects, are classified into two Main categories. They are

1.     Diversion works

2.     Storage works

Diversion Works

The purpose of a diversion work is mainly to raise the water level and divert the river flows into canals to feed the ayacut. A diversion work consists of an anicut or a weir across the stream or river, by which the water level could be raised to divert it into canals on either side of the river or stream.

There is no question of any storage here.

The main component works in this case are:

1.     A weir or Anicut across the river or stream in question

2.     Head sluices or Head Regulators at either end to feed the canals on either side.

3.     Scour sluices on either side to prevent silting of the approaches to the Heal Regulator.

A   detailed  design  of  a   River   weir   is  given   i

Storage Works

In big irrigation projects, where the river, the main source of water, has enough flows in the year and which go waste un-utilized, storage works are resorted to, to conserve the water by creating a reservoir, conserve the flows as far as possible without detriment to the riparian rights of the areas below the reservoir on the same river. These projects involving construction of huge reservoirs are also designed to serve as multipurpose projects. A multipurpose project means that it should serve the following useful purposes:

1.     Flood control

2.     Irrigation.

3.     Power generation.

4.     Navigation.

5.     Improve fish culture, and

6.     Supply of drinking water.

A storage work, consists of the following components

1.     A dam across the river to create a reservoir of adequate capacity to irrigate the command area, with provision for letting down the surplus water down stream.

2.     Head Regulators on either side to feed the main canals.

3.     Main canals and distributory system to feed the commanded area.