Irrigation: Systems, Problems and Water-Use Efficiency

Why irrigation matters

Rainfall dependence: India's rainfall is seasonal (about 75% falls in the four monsoon months), uneven across regions and variable from year to year. Irrigation stabilises production, allows multiple cropping, and makes high-yielding varieties possible.

Coverage: about 55% of India's net sown area is irrigated (Land Use Statistics, 2022–23). The rest, about 45%, is rainfed. Rainfed areas grow most of India's pulses, oilseeds, millets and cotton, and are home to many poor farmers.

Irrigation potential: the ultimate irrigation potential is estimated at about 140 million hectares. A persistent gap remains between potential created and potential utilised, because of incomplete canals, poor maintenance and lack of field channels.

Sources of irrigation

Groundwater (tube-wells and wells): the largest source, irrigating about 60–65% of the net irrigated area. Its growth followed the Green Revolution, cheap pumps and free or flat-rate electricity.

• Leading states: Punjab, Haryana, UP, Rajasthan and Gujarat.

Canals: about 24–26%. They are important in the Indus–Ganga plains and the deltas of the south.

• Major projects: the Indira Gandhi Canal (Rajasthan), Bhakra–Nangal, Sardar Sarovar (Narmada), Nagarjuna Sagar, and the Kaleshwaram lift irrigation project (Telangana).

Tanks: about 2–3%, mostly in peninsular India (Tamil Nadu, Karnataka, Telangana). Tanks are traditional systems that have declined through encroachment and siltation.

Others: small sources such as lift irrigation and springs.

Classification of projects (by culturable command area):

• major: above 10,000 ha;
• medium: 2,000–10,000 ha;
• minor: below 2,000 ha.

Groundwater crisis

Scale: India is the world's largest user of groundwater, extracting more than the US and China combined. The CGWB Dynamic Ground Water Resources assessment 2024 found:

• the stage of extraction is about 60% nationally;
• about 11% of assessment units are over-exploited, with extraction above 100% of annual recharge;
• they are concentrated in Punjab, Haryana, Rajasthan, Delhi and parts of Tamil Nadu.

The national stage of extraction has improved slightly since 2017 because of recharge structures, but hotspots remain severe.

Causes:

• free electricity for farm pumps;
• water-intensive crops;
• the absence of regulation: under the easement doctrine (Indian Easements Act 1882), groundwater belongs to the landowner;
• low recharge.

Quality problems: arsenic in the Ganga–Brahmaputra plains (West Bengal, Bihar), fluoride in Rajasthan, Telangana and Karnataka, uranium traces in Punjab, and nitrate pollution.

Regulation:

• the Central Ground Water Authority (under the Environment Protection Act) issues NOCs for industrial use;
• the Model Groundwater Bill (2011/2017) proposed treating groundwater as a common pool resource under public trust, but few states have adopted it;
• Atal Bhujal Yojana (2019, World Bank-supported) promotes community-led groundwater management through water security plans in about 8,200 water-stressed gram panchayats in seven states.

Policy programmes

Pradhan Mantri Krishi Sinchayee Yojana (PMKSY, 2015): "Har Khet Ko Pani" and "More Crop per Drop". Its components:

1. the Accelerated Irrigation Benefit Programme (AIBP), which completes major and medium projects; 99 priority projects were identified in 2016;
2. Har Khet Ko Pani: command area development and minor irrigation;
3. Per Drop More Crop: micro-irrigation, with subsidies of 55% for small and marginal farmers and 45% for others;
4. the watershed development component.

Micro-irrigation:

• Drip and sprinkler systems save 30–50% of water and raise yields.
• Coverage is about 15 million ha, concentrated in Rajasthan, Maharashtra, Andhra Pradesh, Karnataka and Gujarat.
• The Micro Irrigation Fund (NABARD, 2018) supports it.
• Its potential is estimated at about 70 million ha.

Solar pumps: PM-KUSUM (2019) installs standalone solar pumps and solarises grid-connected pumps, letting farmers sell surplus power. This cuts diesel use and subsidies, but cheap power could also encourage over-pumping unless it is metered.

Other initiatives:

• the National Water Mission (one of the NAPCC missions), whose target is a 20% increase in water-use efficiency;
• Jal Shakti Abhiyan;
• Mission Amrit Sarovar (2022);
• the proposed National Water Framework Bill (2016).

Interlinking of rivers

The National Perspective Plan (1980) identified 30 links:

• 16 peninsular;
• 14 Himalayan.

The National Water Development Agency (NWDA) prepares the feasibility reports.

Ken–Betwa link: the first to be implemented (cabinet approval 2021; foundation stone December 2024). It will irrigate about 10 lakh ha in Bundelkhand (MP and UP). It will submerge part of Panna Tiger Reserve, which has drawn concerns.

Debate on interlinking:

• For: it moves surplus water to deficit basins, controls floods, irrigates more land and produces hydropower.
• Against:
• huge costs;
• the ecological impact on rivers, deltas and forests;
• displacement;
• inter-state disputes;
• the uncertain "surplus" in a changing climate;
• the impact on river ecology and sediment flows.

Analysis: from irrigation to water management

The Mihir Shah Committee (2016) argued that India must shift from building dams and canals to participatory management of demand. Its recommendations:

• a unified National Water Commission;
• participatory irrigation management through water users' associations;
• recognising groundwater and surface water as one system;
• crop diversification away from water-hungry crops.

Pricing: rational pricing of water and power, with direct benefit transfer of subsidies, could curb waste without hurting farmers. Punjab's "Paani Bachao Paise Kamao" pilot paid farmers for saving power.

Common prelims traps

• Groundwater is the largest source of irrigation, not canals.
• Ken–Betwa is a peninsular link, not Himalayan.
• Major irrigation projects have a CCA above 10,000 ha.
• Atal Bhujal Yojana is about groundwater, not rivers.

Practice: Mains question

*"India's irrigation challenge is no longer about creating more potential, but about using water efficiently." Discuss. (250 words)*

Traditional water harvesting systems

India has a rich heritage of local water harvesting adapted to its varied environments:

• Khadin and kunds/tankas (Rajasthan): runoff farming and underground cisterns;
• Johads (Rajasthan): small earthen check dams. Rajendra Singh (the "Waterman of India") revived them in Alwar, bringing the Arvari river back to life;
• Bawdis/stepwells (Gujarat, Rajasthan);
• Kuhls (Himachal): gravity-fed channels from glacial streams;
• Zabo (Nagaland): combined forest, water and paddy and livestock system;
• Bamboo drip irrigation (Meghalaya);
• Eri (Tamil Nadu tanks), Kere (Karnataka) and Surangam (Kerala).

Lessons: these systems were community-managed, decentralised and adapted to local ecology. Their decline came with state-run canals and private tube-wells. Reviving them under MGNREGA water conservation works and Amrit Sarovar can recharge aquifers cheaply.

Quick self-test

1. *Why is canal irrigation less efficient than drip irrigation?* Seepage and evaporation losses in open channels, and flooding of fields.
2. *What is the difference between irrigation potential created and utilised?* Created is the capacity built; utilised is the area actually irrigated.
3. *How do free electricity and groundwater depletion connect?* Zero marginal cost encourages over-pumping and water-intensive crops.

Key terms

• Culturable command area (CCA): the area that a canal system can irrigate, excluding uncultivable land.
• Water-use efficiency: crop output per unit of water applied.
• Aquifer recharge: water added to groundwater from rain, rivers and recharge structures.
• Conjunctive use: planned combined use of surface water and groundwater, so that canals recharge aquifers and wells use them.