Chapter 4 — Water Resources

About 71% of the earth's surface is covered with water, but freshwater constitutes only about 3% of the total water, and only a very small proportion of that is effectively available for human use.

The total utilisable water resource in India is only 1,122 cubic km. Of the 1,869 cubic km available from surface water and replenishable groundwater, only about 60% can be put to beneficial use.

The Ganga, Brahmaputra, and Barak river basins account for 60% of India's total surface water resources, even though they cover only about one-third of the country — because precipitation is relatively high in their catchment areas.

Total replenishable groundwater is about 432 cubic km. Utilisation is highest in Punjab, Haryana, Rajasthan, and Tamil Nadu. States like Chhattisgarh, Odisha, and Kerala utilise only a small proportion of their groundwater potential.

Agriculture accounts for 89% of surface water utilisation and 92% of groundwater utilisation. The industrial sector uses only 2% of surface water and 5% of groundwater, while the domestic sector uses 9% of surface water.

Over-withdrawal has caused declining groundwater tables and increased fluoride concentration in groundwater in Rajasthan and Maharashtra. It has also led to increased arsenic concentration in parts of West Bengal and Bihar. Intensive irrigation in Punjab and Haryana is also increasing soil salinity.

PMKSY was launched by the Central Government in 2015-16 with the vision of ensuring access to protective irrigation for all agricultural farms. Its key goals include 'Har khet ko pani' (water to every field) and 'Per drop more crop' (improving on-farm water use efficiency).

The Yamuna between Delhi and Etawah is the most polluted river in India. Other severely polluted rivers include the Sabarmati at Ahmedabad, the Gomti at Lucknow, the Kali, the Adyar, the Cooum (entire stretches), the Vaigai at Madurai, the Musi at Hyderabad, and the Ganga at Kanpur and Varanasi.

Watershed management refers to efficient conservation of surface and groundwater by preventing runoff and recharging groundwater through percolation tanks, recharge wells, and judicious use of natural and human resources within a watershed. The success of watershed development largely depends on community participation; the Haryali project, for example, is executed by Gram Panchayats with people's participation.

Rainwater harvesting captures and stores rainwater for use and to recharge groundwater aquifers. Benefits include increased water availability, checking declining groundwater tables, improving groundwater quality by diluting contaminants like fluoride and nitrates, preventing soil erosion and flooding, and arresting saltwater intrusion in coastal areas. In Rajasthan, structures called Kund or Tanka (covered underground tanks) are used, while Tamil Nadu has made rainwater harvesting structures compulsory in all new buildings.

Key features include: a call for a national water framework law; treating water as an economic good after meeting drinking water, sanitation, food security, and ecosystem needs; adapting water resource structures to climate change; developing water footprints and water auditing; reducing urban-rural disparity in water supply; and managing water resources with community participation.

Atal Bhujal Yojana (Atal Jal) is being implemented in 8,220 water-stressed Gram Panchayats across 229 administrative blocks/talukas in 80 districts of seven states — Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, and Uttar Pradesh — which account for about 37% of all water-stressed blocks in India. Its key aim is to shift community behaviour from consumption to conservation.

Launched in 2015-16, Jal Kranti Abhiyan aims to ensure water security through per capita water availability. It proposes selecting one water-stressed village in each of the 672 districts to create a 'Jal Gram', identifying model command areas of about 1,000 hectares in different parts of the country, reducing groundwater pollution, constructing arsenic-free wells in selected areas, and creating mass awareness through social media, radio, TV, and school competitions.

Ralegan Siddhi, a village in Ahmadnagar district, Maharashtra, transformed from poverty in 1975 through community-led watershed development. Voluntary labour, a ban on open grazing and water-intensive crops like sugarcane, cultivation of low water-requirement crops (pulses, oilseeds), a percolation tank repair, and community institutions like Tarun Mandal and Nyay Panchayats revived the village. It shows that community participation and voluntary effort are central to successful watershed development.

Yes — the full PDF of Class 12 Geography 'India: People and Economy' Chapter 4 Water Resources is free to read and download on CBSEPrepMaster, with no sign-up required.