Impacts of the Indira Gandhi Canal and measures for sustainable development

Detail

Setting: where the canal is and what it irrigates

• 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 runs through western Rajasthan, which is part of the Thar Desert. Its soils are desert soils. They 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 the soil had about 40% porosity (open space between grains) and good to very good permeability (water passes through it easily) [4].

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

• Bikaner district alone has an IGNP command of 5,91,000 ha (NAQUIM report, data as on March 2017). Of this, Stage-I has 1,79,000 ha and Stage-II has 4,12,000 ha [4].

• Stage-II has a culturable command area (CCA) of 13.16 lakh ha under the Revised Project Estimates of January 1993. CCA means the land in a canal's command that can actually be farmed [3].
• Flow irrigation (water reaches fields by gravity) covers 8.73 lakh ha [3].
• Lift irrigation (water is pumped up to higher land) covers 4.43 lakh ha [3].
• The estimated cost was ₹3,398.87 crore [3].

Positive impacts

• Soil stays moist for longer. The Command Area Development (CAD) programme planted trees and developed pastures, and this greened the land. 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, drought-hardy)	After the canal (irrigated, commercial)
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 means the water table rises into the root zone, the top layer of soil where plant roots grow. Roots cannot get air, and crops die.
• Soil salinity means salts build up in the topsoil. Plants then cannot take in water.
• How waterlogging forms (cause → process → result):
• Farmers use too much water, and water seeps out of canals.
• The water sinks down until it reaches a hard layer that it cannot pass through.
• A perched water body forms. This is water trapped above that hard layer.

• In the IGNP, the canal was filled for the first time, and soon after large areas along the main canal became waterlogged. Surface water appeared at 127 locations and covered 900 ha [7].

• How salinity follows (cause → process → result):

• The water table rises slowly over the years.
• In the hot, dry climate, the water near the surface evaporates fast.
• The dissolved salts stay behind in the topsoil.
• CGWB links rising groundwater levels and heavy evaporation in semi-arid regions to salinity problems in canal command areas [5].

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

• Long-run result: both problems harm farming in the long run. Scholars had doubted from the start that the project was ecologically sustainable. Four decades of experience have proved them right.

• Poor use of the water that was created: in IGNP Stage-II, only 29-46% of the irrigation potential created during 1997-2002 was actually used [3]. The reasons were:
• 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].

The seven measures for sustainable development

• There are seven measures, and five of them aim at ecological balance (measures i-v).

#	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 not grown. Plantation crops such as citrus are grown instead
iii	CAD works	Watercourses are lined, land is developed and levelled, and warabandi is followed. This cuts the water lost on the way to the field (conveyance loss)
iv	Reclaim waterlogged and saline land	Excess water is drained away and the land is brought back into farming
v	Eco-development	Afforestation (planting trees), 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 given to them
vii	Economic diversification	Work beyond farming and animal husbandry, by linking basic villages, agro-service centres and market centres

• NCERT MCQ trap: eco-development is named the most crucial factor for sustainable development in the IGNP command.

How the measures work in practice

• Reclaiming land (measure iv):
• Surface drains and sub-surface drains (pipes laid underground) collect the extra canal water.
• Link drains carry this water to a permanent out-fall point [2].

• Field drains remove extra water from farm plots and so prevent waterlogging [2].

• Biodrainage (measures iv and v together):

• Biodrainage means planting trees that take up a lot of water and release it into the air through their leaves (transpiration). This 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 [7].
• The main species were Eucalyptus camaldulensis, Acacia nilotica, Prosopis cineraria (khejri) and Dalbergia sissoo (shisham) [7].
• Results: the flooded area fell from 25 ha (1988) to 2 ha (1993). By 1994 there was no flooding [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].

• This shows how eco-development also fixes waterlogging.

• Central scheme support for CAD:

• CADWM stands for Command Area Development and Water Management.
• Since 2015-16, CADWM has been part of the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) – Har Khet Ko Pani [6].
• Its components include field channels, field drains, enforcement of warabandi, land levelling, realigning field boundaries and suitable cropping patterns [6].
• It works through Participatory Irrigation Management (PIM), which means farmers take part in running the irrigation system, for example through Pani Panchayats (farmers' water committees) [2].
• Cost norms in the Ministry of Water Resources interim guidelines (September 2015): field channels ₹35,000/ha, reclamation of waterlogged areas ₹20,000/ha and micro-irrigation ₹50,000/ha [2].

Warabandi

• Warabandi shares canal water by rotation.
• Every farmer under one outlet gets water for a fixed time on a fixed day.

• The time each farmer gets is in proportion to the size of their land.

• Why it matters:

• Equity: farmers at the tail end (the far end of the canal) get their fair share.

• Less waste: farmers do not over-irrigate, so less water goes to waterlogging.

• Where it is used: mainly in the canal commands of north-west India, including Punjab, Haryana and Rajasthan.

Lessons from other canal commands (beyond NCERT)

• Other large canal commands have the same problems: waterlogging in Punjab-Haryana, and salinity in the Tungabhadra command (Karnataka) and the Chambal command (Rajasthan-Madhya Pradesh).
• Common remedies:
• sub-surface drainage;
• drip and sprinkler irrigation, which give water only near the roots or as a fine spray;

• crop planning, which means growing crops that need less water.

• Groundwater in Bikaner today:

• Away from the canal, Bikaner district takes out much more groundwater than is refilled. Its stage of groundwater development (groundwater taken out as a share of groundwater available) is about 170%. This puts it in the Over-Exploited category (data as on March 2017) [4].

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

• The paradox: one region suffers two opposite water problems at the same time. Canal belts have too much water (waterlogging), while areas outside them run short of groundwater.

Prelims Hooks

• The Indira Gandhi Canal starts at the Harike barrage in Punjab, below the meeting point of the Satluj and Beas rivers. A 204 km feeder canal carries its water [4].
• Crop shift: gram, bajra, jowar → wheat, cotton, groundnut, rice.
• Protective irrigation → Stage-I. Extensive irrigation (crops and pasture) → Stage-II. This pairing is often swapped in MCQ options.
• Of the seven sustainability measures, five aim at ecological balance. The most crucial factor is eco-development, not CAD works and not crop choice.
• The recommended crop type is plantation crops such as citrus. Water-intensive crops are to be avoided.
• Warabandi = water shared by rotation, for a fixed time on a fixed day, in proportion to landholding size.
• Waterlogging = water table reaches the root zone. Salinity = salts left behind when water evaporates. Both are negative effects of the IGNP.
• CADWM has been part of PMKSY – Har Khet Ko Pani since 2015-16 [6].
• Biodrainage on the IGNP: eucalyptus and acacia 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 and too much water cause seepage and a rising water table. This leads to waterlogging and then salinity.

• In IGNP Stage-II, only 29-46% of the irrigation potential was used during 1997-2002. This shows weak coordination between the canal and CAD departments [3].

• A single fix does not work. The solution has to combine:

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

• institutional measures: warabandi, PIM and Pani Panchayats [2][7].

• Social and economic sustainability:

• Poor allottees need money and institutional support.
• Linking basic villages, agro-service centres and market centres spreads income beyond farming.

• This lowers the pressure on fragile land.

• Lessons for other commands: Punjab-Haryana, Tungabhadra and Chambal face the same problems. They can apply drip and sprinkler irrigation, crop planning and drainage. They should also manage canal water and groundwater together, because some parts are waterlogged while nearby areas are over-exploited [4][5].