Case study: the Indira Gandhi Canal (Nahar) project and its command area

Detail

1. What the canal is

• The Indira Gandhi Canal (Indira Gandhi Nahar) was earlier called the Rajasthan Canal. It is one of the largest canal systems in India.
• Britannica calls it the longest canal in India. It gives the canal's length as about 650 km (400 miles) [2].
• Key dates:
• 1948: the engineer Kanwar Sain first came up with the idea.

• 31 March 1958: work on the project began.

• Why it matters for regional planning:

• The Thar is a dry region with little rain and frequent drought.
• Canal water was meant to turn the desert into farmland.
• It was also meant to bring drinking water and settle people in the area.
• This makes it a classic target-area project: a plan made for one problem region instead of for the whole country.

2. Source of water and route

• Head (starting point): the Harike barrage in Punjab, where the Satluj (Sutlej) and the Beas rivers meet.
• A barrage is a low wall across a river with gates. It raises the water level so water can be sent into canals. It stores very little water, unlike a dam.

• From Harike, water flows south-west into the Indira Gandhi Canal. It irrigates about 6.07 lakh ha (1.5 million acres) of desert in western Rajasthan [3].

• Feeder:

• The Rajasthan Feeder is a canal that carries water only to the Indira Gandhi Nahar Project [4].
• Both the Rajasthan Feeder and the Sirhind Feeder leave the river just upstream of the Harike headworks.

• Both run through Punjab before they enter Rajasthan [4].

• Where the water is stored: in reservoirs upstream, at Pong Dam (on the Beas) and Bhakra Dam (on the Satluj). Water is shared among Punjab, Haryana and Rajasthan through inter-state agreements.

• Route:
• The canal runs parallel to the India–Pakistan border, about 40 km away on average.
• It passes through the Thar Desert (Marusthali). "Marusthali" means "land of the dead", the driest western part of Rajasthan.

3. Command area: the key terms

• Command area: all the land that a canal can supply with water by gravity or by pumping.
• Culturable command area (CCA): the part of the command area that can actually be farmed. It leaves out land that cannot be farmed, such as villages, roads, rocky ground and the tops of moving dunes.
• Planned figures:

Item	Planned figure
Total length of the system (main canal + branches + distributaries)	9,060 km
CCA	19.63 lakh ha
Irrigated by flow (gravity)	about 70%
Irrigated by lift (pumping)	about 30%

4. The two stages

	Stage-I	Stage-II
Districts	Ganganagar, Hanumangarh, northern Bikaner	Bikaner, Jaisalmer, Barmer, Jodhpur, Nagaur, Churu
Land	Gently undulating (low rolling ground, easy to level)	Shifting sand dunes; summer temperatures up to 50°C
CCA	5.53 lakh ha	14.10 lakh ha
Irrigation began	Early 1960s	Mid-1980s

• Stage-II is much bigger, but it is harder to farm. Why?
• Moving dunes bury canal channels and fields.
• Very high heat means a lot of water is lost to evaporation.

• More of the land lies higher than the canal, so lift (pumping) is needed.

• Note that Bikaner appears in both stages. The north of the district is in Stage-I and the rest is in Stage-II.

5. Flow irrigation and lift irrigation

• Flow irrigation: water moves downhill by gravity from the canal into the fields. No pumping is needed.
• Lift irrigation: water is pumped up so it can reach land that is higher than the canal, against the natural slope.
• Step 1: the fields lie above the canal, so gravity cannot carry water to them.
• Step 2: pumping stations lift the water into a raised channel.

• Step 3: from that channel, water flows down onto the higher fields.

• Map rule (Figs. 6.4–6.5), a frequent exam point:

• All lift canals start on the left bank of the main canal.
• All channels on the right bank are flow channels.
• The reason: the land on the left bank rises above the canal, while the land on the right bank slopes down from it.

6. Uses beyond irrigation

• Drinking water: seven districts of western Rajasthan depend fully on the project for drinking water. These include the cities of Jodhpur, Bikaner and Jaisalmer [4].
• Power: the canal supplies water to power plants at Suratgarh and Ramgarh [4].

7. Problems: seepage and waterlogging

• How waterlogging happens:
• Water leaks (seeps) out of unlined or damaged canals into the soil.
• The water table (the level of water under the ground) rises.
• The soil becomes waterlogged (soaked, with no air for roots), and crops fail.

• In strong summer heat, the water evaporates and leaves salt on the surface. Salty soil cannot grow crops [2].

• Example in Punjab, along the feeder canals:

• Damaged lining in the Rajasthan and Sirhind Feeders caused heavy seepage. The canals carried less water, and nearby farms became waterlogged [5].
• September 2018: the Union Cabinet approved ₹825 crore of central help to reline both feeders as twin projects [5]. The funding was approved on 26.09.2018 [4].
• The Rajasthan Feeder was relined from RD 179000 to RD 496000 (RD, or reduced distance, is the distance marked along a canal). The work was planned over 2018-19 to 2022-23 [5].

• Expected result: waterlogging reduced on 84,800 ha in Muktsar, Faridkot and Ferozpur districts of south-west Punjab [5].

• Also to know: the Punjab–Rajasthan dispute over sharing water, and the wider canal-lining debate, are covered under water resources of India.

Prelims Hooks

• The Indira Gandhi Canal starts at the Harike barrage, Punjab, where the Satluj and Beas meet. It does not start at Bhakra or Pong, which are storage dams upstream.
• Earlier name: Rajasthan Canal. Idea by Kanwar Sain (1948). Work began on 31 March 1958.
• It runs parallel to the Pakistan border, about 40 km away on average, through the Marusthali (Thar).
• CCA 19.63 lakh ha in total: Stage-I 5.53 lakh ha, Stage-II 14.10 lakh ha. Stage-II is the larger one.
• Stage-I districts: Ganganagar, Hanumangarh, northern Bikaner. Jaisalmer, Barmer, Jodhpur, Nagaur and Churu are Stage-II only.
• Trap: all lift canals start on the left bank and all right-bank channels are flow channels. The reverse statement is wrong.
• About 70% of the CCA was planned for flow irrigation and 30% for lift irrigation.
• The Rajasthan Feeder carries water only to the Indira Gandhi Nahar Project. It leaves the river upstream of Harike [4].
• 2018: ₹825 crore was approved to reline the Sirhind and Rajasthan Feeders, to fight waterlogging in Muktsar, Faridkot and Ferozpur (Punjab) [5].

Mains Points

• A target-area planning model (GS-I/III):
• One large project tried to deal with drought, a low population and unused desert land, all at once.
• In Stage-I it moved the Ganganagar–Hanumangarh belt from herding animals to farming crops.

• Today it is also the main drinking-water supply for western Rajasthan [4].

• Unequal stages:

• Stage-I (gentle land, irrigation since the 1960s) has done well.
• Stage-II (dunes, up to 50°C, more pumping, irrigation only since the mid-1980s) costs more for each hectare, and more water is lost to evaporation.

• This shows that the shape of the land and the climate limit how fast a region can develop.

• Environmental cost:

• Seepage → rising water table → waterlogging and salty soil. This happens both in the command area and along the feeders in Punjab [2][5].

• Fixes: lining canals, better drainage, wiser use of water, and switching to crops that need less water.

• Inter-state and security angle:

• The canal depends on water from Bhakra and Pong that is shared between states, so Punjab–Rajasthan disputes directly affect it.
• Settling people and farming along the border also strengthens the western frontier.