What is an inundation canal?
Inundation or flood irrigation is a type of irrigation in which the excess water during a flood from a river is diverted using a canal. This method is only possible only during flood season and the canals which are used for this irrigation are called Inundation Canals.
These have been used in India traditionally for water harvesting and also can help to control the floodwaters firm by spreading and transporting them. The irrigation was mainly performed by cuts in banks of channels and was closed when the floods were over.
The water supply in the inundation main canal depends on the water level in the river as there are no head works across the river. The water will be available only for a period on the main canal when the water level in the river is above the bed level of the inundation main canal at its off-take point from the river.
Also read: Sprinkler irrigation System – Its Working, Types, Advantages & Disadvantages
The inundation canals will only be introduced to an area only under the following situations:-
- Only if the level of water in the canal remains high and fairly constant for a long time
- Kharif crops can be irrigated when there is an early flood in the river
- When the river has a late last flood at the end of the rainy season so that Rabi crops can be irrigated
- When the area to be irrigated is nearby of the canal system so that a large area is not submerged in case there is the worst flood in the river
- The Soil must be sufficient self-stabilizing power so that the bed and banks of the canal remain stable
Advantages of inundation canal
Pros of a inundation canal:
- Since there is no headwork for inundation canals the cost of construction is very low
- The water carries silt and fine sand into the canal due to which the inundation canal system has good manorial qualities
- Water supply in the canal is intermittent and hence there is less trouble of waterlogging and other bad effects of irrigation
Disadvantages of inundation canal
Here are some cons of a inundation canal:
- The canal is liable to be washed off as there are no headwork protecting the canal
- The water supply available is not reliable as the water stored in the canal is mainly available during floods
- Duty achieved by inundation canal water is low as compared to other
- It’s constantly under silt trouble
- The size of canals will have to be larger dimensions to admit the full requirement of water within a limited time factor
What is a perennial canal?
Perennial irrigation is a constant and continuous water supply that is assured to the crops following the requirements of the crop throughout the crop period. In this irrigation system, water is supplied through storage canal headwork and a canal distribution system, and this type of canal is called a perennial canal. Perennial canals are also called permanent canals.
This type of canal takes water from Ice-fed perennial rivers. Various types of permanent hydraulic structures are constructed in this type of canal for water. In this type of canal, water is available throughout the year as the water is stored in a dam. So it is a reliable source of water. These canals are good when irrigating a large area of land.
Advantages of the perennial canal
Here are a few pros of a perennial canal:
- Water is provided throughout the year because it is stored in dams and barrages
- Drought situations can be avoided
- Continuous availability of water helps in the economic growth of farmers
- Irrigation through this type of canals is Cheap in the long run
Disadvantages of the perennial canal
Here are a few cons of a perennial canal:
- High cost of construction
- Maintenance Is required regularly as it consists of different structures
- Can cause waterlogging which can make soil unfertile
- Stationary water can also cause many diseases due to mosquitoes and insects
Differentiate between inundation canals and perennial canal
Here are the major difference between inundation canals and perennial canal:
| Inundation Canals | Perennial Canals |
| Not reliable as the supply of water is not available throughout the year | Reliable since the supply of water is available throughout the year |
| Water supply is uncertain | Water supply is certain |
| Taken out from the river without the construction of dams or headwork | Taken out from the river only after the construction of Dams or headwork |
| Can Irrigate only low lying areas of land | Can irrigate all types of land |
| Taken from large rivers | Taken from Ice-fed perennial rivers |
| Cheap Cost of construction and Maintenance | The cost of construction and maintenance is high |
| Not useful during dry months | Provides water through all seasons |
| Mainly used to prevent flooding | Mainly used for irrigation of largely cultivated lands |
Also Read: Rainwater Harvesting SystemÂ
Question and Answers Related to Inundation Canal
Canal taken off from ice-fed perennial rivers are known as?
Perennial Canals are the canals that take off from ice-fed perennial rivers. These canals run throughout the year providing water.
The perennial canal is widely practiced in?
In India perennial canals are widely used in the northern plains in states like Uttar Pradesh, Punjab, Haryana, Rajasthan. These are practiced mainly in areas where the rivers are available with water throughout the year.
Shah Nahr perennial canal was constructed by?
Shah Nahr canal was built during the reign of Shah Jahan by Ali Mardan Khan later was modified by Mulla Alaul Mulk. Shah Nahr Canal is a perennial canal that started functioning in the year 1849 AD. This canal is drawn from the Ravi river.
Why Inundation canals are converted into perennial canals?
Inundation canals become dry during the summer season so these are unreliable because water will not be available throughout the year so the inundation canals are converted into perennial canals for more reliability.
Inundation canal is the canal classified based on
Inundation canals are classified based on the supply source. This type of canal which water is available only during the flood periods.
Another name for inundation canal irrigation is?
Inundation canals are also called flood canals because they utilize the water from the river when it is flooded.
Inundation canals are mainly drawn from?
The water in inundation canals are mainly taken from large rivers having a huge capacity and mostly during the time of the flood.
Rainwater harvesting through inundation canals is common in?
In Karnataka, they utilize rainwater harvesting through inundation canals are common.
Inundation canal serve during which season?
Inundation canals serve during the rainy season when there is excess water in the river and that causes flooding.
Name of Indian inundation canal
Some of the Inundation canals found in India are Sirhind Canal, Indira Gandhi Canal, etc. These canals are mainly found in states like Uttar Pradesh, Punjab, Haryana, Rajasthan.
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