Natural Resources Geography Notes for UPSC IAS Prelims

Water Resources

Surface Water Resources in India

Surface water refers to water available in rivers, lakes, reservoirs, ponds, wetlands and streams. In India, rivers are principal source of surface water but its availability is highly uneven across space and time.

Surface Water Resources Potential

India receives about 3880-4000 BCM (Billion Cubic Meters) of annual precipitation. The total utilizable surface water potential is 690 BCM.

Distribution of Surface Water

Sectoral Use of Surface Water

• Around 85-90% of total water use has been estimated to be associated with agriculture.
• Domestic sector is second largest consumer.
• Industry is third.

Major Problems of Surface Water

• Spatial and Temporal Variability
  • About 75% of annual rainfall occurs during southwest monsoon.
  • Eastern India is flood prone and the western India like Rajasthan and parts of Deccan are drought prone.
• Inadequate storage
  • Large quantity of monsoon water drains into sea in-vain. The paradoxical thing is 52% of Indian agriculture is not only rain dependent but also lacks irrigation facilities.
• River Pollution
  • Untreated municipal sewage
  • Industrial affluence
  • Agricultural runoff
  • Plastic and solid waste
• Siltation of reservoirs
• Interstate river disputes like Mhadei River dispute between Karnataka and Goa, etc.
• Overexploitation and inefficient irrigation.

Government Initiatives

• Jal Shakti Abhiyan - Catch the Rain

  • It focuses on rainwater harvesting.
  • Renovation of traditional water bodies.
  • Watershed development
  • Water conservation
  • Community participation

  The 2025 campaign emphasized on "Jal Sanchay Jan Bhagidari" and included restoration, geotagging and desilting of waterbodies.

• Mission Amrit Sarovar

  • Creation / rejuvenation of waterbodies to increase local water storage and groundwater recharge.
  • Nearly 69,000 Amrit Sarovar has been constructed / rejuvenated according to January 2026 governments update to PIB.

• PMKSY

• National Water Mission

  • It focuses on
    • Integrated water resource management
    • Conservation of water
    • Reducing wastages
    • 20% improvement in water use efficiency
    • Basin level planning
    • Climate change assessment

• AMRUT 2.0

  • It is about urban water management through
    • Waterbody rejuvenation
    • Rainwater harvesting
    • Recycling and reuse of treated wastewater
    • Universal water supply
    • Sewerage management

• Namami Gange

  • It empathized upon
    • Sewage treatment
    • Industrial pollution control
    • River surface cleaning
    • Ecological restoration
    • Maintaining river flow

• Interlinking of rivers

  • Under this 30 links have been identified out of which 16 are in Peninsular India and 14 are in Himalayan components.

Groundwater Resources

Groundwater is the water restored beneath the earth surface in aquafers, recharged mainly through rainfall infiltration, seepage from rivers, lakes, canals and irrigation. It is India's largest source of irrigation water and important source of drinking water. Groundwater is second largest source of freshwater on the planet only after glaciers.

Present Status of Groundwater Resources

According to Dynamic Groundwater Resources Assessment 2025,

• Annual groundwater recharge is 448.52 BCM
• Annual extractable groundwater resource is 407.75 BCM
• Annual groundwater extraction is 247.22 BCM
• Stage of groundwater extraction is 60.63%

Distribution of Groundwater Resources

It is maximum in Indus - Ganga - Brahmaputra alluvial plain i.e. from Punjab to Assam. Causes are

• High rainfall
• Thick alluvial deposits
• High infiltration capacity
• Extensive aquafers

Low groundwater potential have mainly two parts

• Western Rajasthan and Northern Gujrat mainly due to low rainfall and high evaporation.
• Peninsular India i.e. Karnataka, Telangana, Maharashtra, Tamil Naidu, Andhra mainly due to low rainfall and poor infiltration of surface water.

The maximum use groundwater is done in irrigation i.e. 215 BCM (87%) followed by domestic 28 BCM (11%) and finally industry 4 BCM (2%).

Major Problems

• Groundwater depletion especially in North Western India, Karnataka (Bengaluru and Chennai) and Tamil Naidu
• Water intensive cropping pattern i.e. rice wheat combination.
• Falling water table
• Groundwater quality
  • Major problem include
    • arsenic in parts of Bihar, West Bengal, Uttar Pradesh and Assam
    • Fluoride in Rajasthan, Gujrat, Telangana, Andhra and Karnataka
    • Chromium in Uttar Pradesh
  • Nitrate in agriculture and sewage contamination.
  • Presence of heavy metals in groundwater in some industrial regions
• Increasing Urbanization
  • It restrict seepage or infiltration of surface water but causes intensive use of groundwater for domestic and industrial purposes.
• Groundwater is invisible

Government Initiatives

• Atal Bhujal Yojana
• Jal Shakti Abhiyan
• Mission Amrit Sarovar
• PMKSY
• NAQUIM (National Aquafer Mapping and Management Program)
  • It is to map aquafers, understand quality and quantity of water and prepare aquafer management plan.

Water Scarcity and Water Crisis

The Central Water Commission (CWC) uses the internationally recognized Falkenmark Indicator for water availability and water scarcity i.e.

• Availability of water more than 1700 cubic meter per person per year - Adequate
• Availability of water less than 1700 cubic meter per person per year - Water stress
• Availability of water less than 1000 cubic meter per person per year - Wate Scarcity

Scarcity is primarily a quantitative concept.

Water crisis is the situation when people, agriculture, industries or ecosystem can not reliably obtain adequate quantities + quality + accessibility of water because of factors such as depletion, pollution, poor infrastructure, drought, unequal distribution and weak governance.

Why is India facing Water Crisis?

• Population Pressure
  • CWC data show the dramatic decline in India's per capita water availability.
  • By CWC projection for 2031 it would be 1367 cubic meter per person per annum.

• Highly Uneven Spatial Distribution
  • As per CWC 2025 Basin estimates only Ganga, Brahmaputra, Godavari basins are comfortable rest Krishan, Kaveri, Sabarmati, Pinar are water scarers basins
• Agriculture is the biggest pressure mainly due to rice wheat combo.
• Over exploitation of groundwater.

Water Resources are Both Asset and Source of Conflict

South Asia posses substantial water resources through major river system such as Indus, Ganga and Brahmaputra however, their transboundary nature make water both economic asset and a potential source of conflict.

Water as Asset

• Supports agriculture
• Food security
• Hydropower e.g. Nepal and Bhutan
• Sustain industries and urban population
• Navigation
• Ecosystem support

Source of Conflict

• India-Pakistan dispute over Indus water Sharing
  • Agreement was signed between the two in 1960s. India has claimed that it won't be sharing Indus water with Pakistan anymore given to their hostile behaviour like terrorism.
• India-Bangladesh over Ganga water Sharing, Teesta water sharing and Barak water sharing
• India-Nepal differences over Mahakali water
• India-China, no open dispute till date as such but Brahmaputra water is the potential dispute region

Way Forward

• Strengthening river basin institutions
• Realtime date sharing
• Benefit sharing
• Joint watershed management
• Support to climate resilient water diplomacy