Impact of Indira Gandhi Canal

Topic: Regional Planning and Sustainable Development in India · NCERT: Class 12, Ch 6 "Planning and Sustainable Development in Indian Context"

Meaning

The impact of the Indira Gandhi Canal means the good and bad changes that canal water brought to the dry Thar Desert in western Rajasthan.

• Good changes: afforestation and new pastures made the land green. Wind erosion went down. More land was farmed, and more crops were grown on the same land each year. Farmers moved from dryland crops to irrigated cash crops.
• Bad changes: too much water and seepage from the canals led to waterlogging and soil salinity.

The canal is the textbook Indian example of how irrigation in a desert can work against itself. It is why NCERT lists seven measures for sustainable development in the canal's command area.

Explanation

Setting: why the desert reacts the way it does

• The Indira Gandhi Nahar Pariyojana (IGNP) takes water from the Harike barrage (Hari-ka-Pattan) in Punjab. A 204 km feeder canal carries this water to Rajasthan [4].
• The canal flows through the Thar Desert, which has desert soils. These soils are not fertile and hold very little water.
• A UNDP soil study (1971-74) found that the soil could hold at most 1.13% available moisture [4].

• The same study found about 40% porosity (open space between sand grains) and good to very good permeability (water passes through easily) [4].

• Result: canal water sinks through this sand quickly. This one fact explains both the benefits and the damage.

• Size of the command:
• Stage-II has a culturable command area (CCA) of 13.16 lakh ha under the Revised Project Estimates of January 1993. CCA is the land under a canal that can actually be farmed [3].
• Flow irrigation (water reaches the fields by gravity) covers 8.73 lakh ha. Lift irrigation (water is pumped up to higher land) covers 4.43 lakh ha [3].
• Bikaner district alone has an IGNP command of 5,91,000 ha: 1,79,000 ha in Stage-I and 4,12,000 ha in Stage-II (data as on March 2017) [4].

Positive impacts

• The land turned green and the soil stays moist for longer.

• The Command Area Development (CAD) programme planted trees and developed pastures. CAD is a programme of on-farm works that brings canal water from the outlet to each field and manages it well.

• Wind erosion and canal siltation fell.

• Trees and grass hold the loose sand in place.
• Less sand blows into the canals.

• So the canals fill up with silt more slowly.

• Farming expanded.

• The cultivated area grew.

• Cropping intensity rose. Cropping intensity is the number of crops grown on the same land in one year.

• The crops changed from dryland crops to irrigated crops:

Before the canal (rain-fed, can survive drought)	After the canal (irrigated, grown for sale)
Gram	Wheat
Bajra (pearl millet)	Cotton
Jowar (sorghum)	Groundnut
—	Rice

• Crop and livestock output rose sharply, because water and fodder were now available.

Negative impacts: waterlogging and soil salinity

• Waterlogging: the water table rises into the root zone, the top layer of soil where plant roots grow. Roots get no air, and the crops die.
• How waterlogging forms:
• Farmers use too much water, and water also seeps out of the canals.
• The water sinks until it reaches a hard layer it cannot pass through.
• A perched water body forms. This is water trapped above that hard layer.

• When the IGNP canal was filled for the first time, large areas along the main canal soon became waterlogged. Water came up to the surface at 127 locations and covered 900 ha [7].

• Soil salinity: salts build up in the topsoil, and plants can no longer take in water.

• How salinity follows waterlogging:
• The water table rises slowly over the years.
• In the hot, dry climate, water near the surface evaporates fast.
• The dissolved salts stay behind in the topsoil.

• CGWB links rising groundwater and heavy evaporation in semi-arid regions to salinity in canal command areas [5].

• Water that was created but not used: in IGNP Stage-II, only 29-46% of the irrigation potential created during 1997-2002 was actually used [3]. There were three reasons:

• pumping stations in the lift area were not finished;
• watercourses (small channels from the outlet to the fields) were not finished, because the IGNP and CAD departments did not work together (status as of March 2003);

• land was not allotted to settlers [3].

• Long-run verdict: both problems damage farming over time. Scholars doubted from the start that the project was ecologically sustainable. Four decades of experience have proved them right.

Responses: the seven measures for sustainable development

• NCERT gives seven measures. Five of them (i-v) aim at ecological balance.

#	Measure	What it means on the ground
i	Strict water management	Protective irrigation in Stage-I: water is given only to save crops from drought. Extensive irrigation in Stage-II: water is spread thinly over a large area of crops and pasture
ii	No water-intensive crops	Crops that need a lot of water, such as rice, are avoided. Plantation crops such as citrus are grown instead
iii	CAD works	Watercourses are lined, land is levelled and warabandi (sharing water by rotation) is followed. This cuts the water lost on the way to the field (conveyance loss)
iv	Reclaiming waterlogged and saline land	Surface and sub-surface drains remove the extra water, and the land is farmed again
v	Eco-development	Afforestation, shelterbelts (rows of trees that slow the wind) and pasture, especially in the fragile, sandy Stage-II area
vi	Social sustainability	Money and institutional support for poor land allottees, so they can actually farm the land they were given
vii	Economic diversification	Work beyond farming and animal husbandry, by linking basic villages, agro-service centres and market centres

• Eco-development is called the most crucial factor.
• Biodrainage shows eco-development fixing waterlogging. Biodrainage means planting trees that draw up a lot of water and release it through their leaves (transpiration), which lowers the water table.
• On a 1.5 km stretch of the IGNP main canal (km 290-291.8), about 47,210 trees were planted. The main species were Eucalyptus camaldulensis, Acacia nilotica, Prosopis cineraria (khejri) and Dalbergia sissoo (shisham) [7].
• The flooded area fell from 25 ha (1988) to 2 ha (1993), and there was no flooding by 1994 [7].
• The groundwater level fell by about 15 m over 1991-1997. The effect reached more than 500 m beyond the edge of the plantation [7].

Where it occurs

• The canal: it starts at the Harike barrage in Punjab, below the meeting point of the Satluj and Beas rivers. It runs through western Rajasthan, in the Thar Desert [4].
• Waterlogging: large areas along the IGNP main canal, with surface water at 127 locations covering 900 ha [7].
• Biodrainage site: km 290-291.8 of the IGNP main canal [7].
• Bikaner district: it has a large IGNP command, yet it is Over-Exploited for groundwater away from the canal. Its stage of groundwater development (groundwater taken out as a share of groundwater available) is about 170% (data as on March 2017) [4].

• CGWB proposes micro-irrigation over 3,408 sq km and a change of crops on 2,257 ha [4].

• Inland salinity in groundwater is common in the dry and semi-dry parts of Rajasthan, Haryana, Punjab and Gujarat, among other states [5].

• Similar problems in other canal commands: waterlogging in Punjab-Haryana, and salinity in the Tungabhadra command (Karnataka) and the Chambal command (Rajasthan-Madhya Pradesh).
• Central support: CADWM (Command Area Development and Water Management) has been part of PMKSY – Har Khet Ko Pani since 2015-16 [6]. It works through Participatory Irrigation Management (PIM), where farmers help run the system, for example through Pani Panchayats (farmers' water committees) [2].

Don't confuse with

• Waterlogging vs soil salinity: in waterlogging, the water table rises into the root zone and roots get no air. In salinity, the water evaporates and leaves salts in the topsoil. In the IGNP, waterlogging comes first and salinity follows.
• Protective irrigation vs extensive irrigation: protective irrigation is used in Stage-I and gives water only to save crops from drought. Extensive irrigation is used in Stage-II and spreads water thinly over crops and pasture. MCQ options often swap the two.
• Eco-development vs CAD works: CAD works are engineering on the farm (lined watercourses, levelling, warabandi). Eco-development means trees, shelterbelts and pasture. NCERT names eco-development as the most crucial factor.
• Waterlogging in canal belts vs over-exploitation in Bikaner: in the canal belts there is too much water. Away from the canal, Bikaner takes out more groundwater than is refilled (about 170%) [4]. The same region faces both problems at once.

Prelims Hooks

• Crop shift after the IGNP: gram, bajra, jowar → wheat, cotton, groundnut, rice.
• Stage-I → protective irrigation. Stage-II → extensive irrigation (crops and pasture).
• Of the seven sustainability measures, five aim at ecological balance. The most crucial factor is eco-development, not CAD works and not crop choice.
• Recommended crops: plantation crops such as citrus. Water-intensive crops such as rice should be avoided.
• Warabandi = canal water shared by rotation, for a fixed time on a fixed day, in proportion to landholding size.
• Biodrainage on the IGNP: eucalyptus, acacia, khejri and shisham plantations lowered the water table by about 15 m over 1991-1997 [7].

Mains Points

• Irrigation in drylands can work against itself (GS-I/III):
• Sandy, porous soil with only 1.13% water-holding capacity, plus too much water, leads to seepage, a rising water table, waterlogging and then salinity [4][5].

• Weak coordination between the canal and CAD departments meant only 29-46% of Stage-II irrigation potential was used in 1997-2002 [3].

• A single fix does not work. The answer has to combine three kinds of measures:

• ecological: afforestation, shelterbelts, pasture and biodrainage;
• engineering: lined watercourses, surface and sub-surface drains and land levelling;

• institutional: warabandi, PIM and Pani Panchayats, supported by CADWM under PMKSY [2][6][7].

• Social and economic sustainability, and lessons for other canal commands:

• Support for poor allottees, and links between villages, agro-service centres and market centres, spread income beyond farming. This lowers pressure on fragile land.
• Punjab-Haryana, Tungabhadra and Chambal can use drip and sprinkler irrigation, crop planning and drainage.
• All of them should manage canal water and groundwater together, because canal belts are waterlogged while nearby areas are over-exploited [4].

Related concepts

• Sustainability measures in Indira Gandhi Canal command
• Warabandi

Read more

• Impacts of the Indira Gandhi Canal and measures for sustainable development