Agriculture is the backbone of national growth, and the water is the main requirement to farmlands for cultivation.

Agriculture land

Not all farmlands in the country will reside near water sources like rivers. Eventually, every farm needs water to grow the crops. Many different types of irrigation systems have been formed and used for cultivation. 

The canal irrigation system is the traditional irrigation method, which is very helpful for agricultural work at less cost.

What is meant by canal irrigation?

The water transported by gravity from the river, reservoir, and tank by the canal to the farmlands is called canal irrigation method.

The canals seem to trapezoidal shape constructed by reinforced concrete, brick masonry, and stone masonry. 

Canal irrigation

How do irrigation canals work?

The canals are designed in proper width and depth to carry sufficient water flow to the crop fields. The water will be distributed for cultivation in the right manner from the source point.

Suitable valves can control the flow of water from the source to the crop fields. Once the water reaches the right destination, the water will be pumped on the crops field either manually or mechanically. The agricultural land will be slightly formed in the slope for the natural flow of water.

Distribution System for Canal Irrigation System

The water transported from the source point will split into different channels to carry the water in all required areas.

Distribution System for Canal Irrigation System

The components of the canal irrigation system have been mentioned below.

  • Main Canal
  • Branch Canal
  • Main distribution
  • Minor distribution
  • Water Supply

It is more like the electricity distribution to your house from the powerhouse. The canals’ width and depth will be determined by the amount needed to be carried to the farmlands.

The main canal will get a significant amount of stream from the river. So the depth and width of the channel will be high. After that, the central canal will distribute the flow to the branch line according to the sub-branch and the distributor line and to the minor lines. At last to the crop fields

Canal alignment

When designing the canal route, the following things will be considered.

  • The canal route should cover all farmlands to serve the water.
  • The straight canal route will help maintain the proper velocity of water flow, and it helps to reduce the head loss of water.
  • The shorter length of the canal, which covers all cultivation land, will reduce construction costs and cross drainage work.
  • The shorter and straight canal route will reduce the water loss happening due to seepage, evaporation.
  • The canal route’s design should not be passed through the forest land, villages, towns, and others because it creates unnecessary problems and delays in construction works.
  • The canal route passing through the rock area should be avoided.
  • More curves in the canal must be avoided because it reduces the velocity of water flow.
  • The earth cutting and filling should be balanced to reduce the construction cost.
  • The water is flowing by gravitational force, so the canal line should be designed accordingly.

Advantages of Canal Irrigation

  • A proper irrigation system will help farmers in the lack of rain season for cultivation.
  • It helps expedite the cultivation work and speed up the economy.
  • It helps to increase the groundwater level.
  • Canals also help to produce electricity and supply drinking water.
  • Less maintenance cost.

Disadvantages of Canal Irrigation

  • The main disadvantage is identifying the right route else, which may lead to increased construction costs.
  • The continuous flow of water may lead to form the mosquitos, worms, etc.,
  • Improper design or intake source point will induce the water scarcity in other locations.
  • Regular maintenance is required.

Happy Learning 🙂


Bala is a Planning Engineer & he is the author and editor of Civil Planets.

1 Comment

  1. Dhananjaya BK Reply

    Hi Sateesh Sir,
    Very nice article. One of my friend has land adjacent to water canal. Is land good for cultivation? Do you see land will be wet due to water canal?

    We share lights on this please.

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