From UPSC perspective, the following things are important :
Prelims level : Groundwater in India
Mains level : Read the attached story
Groundwater extraction in India saw an 18-year decline, according to an assessment by the Central Ground Water Board (CGWB).
What is Groundwater?
- Groundwater is the water found underground in the cracks and spaces in soil, sand and rock.
- It is stored in and moves slowly through geologic formations of soil, sand and rocks called aquifers.
- Aquifers are typically made up of gravel, sand, sandstone, or fractured rock, like limestone.
- Water can move through these materials because they have large connected spaces that make them permeable.
- Aquifers, hand-dug wells, and artesian wells are different types of sources of groundwater.
Declining trend of groundwater extraction
- The total annual groundwater recharge for the entire country is 437.6 billion cubic metres (bcm) in 2022.
- However the extraction for entire country is only 239.16 bcm, according to the 2022 CGWB report.
- By comparison, an assessment in 2020 found that the annual groundwater recharge was 436 bcm and extraction 245 bcm.
- The 2022 assessment suggests that groundwater extraction is the lowest since 2004, when it was 231 bcm.
Implications of the CGWB report
- A detailed analysis of the assessment indicates increase in ground water recharge.
- This is mainly attributed to:
- Increase in recharge from canal seepage,
- Return flow of irrigation water and
- Recharges from water bodies/tanks & water conservation structures.
Significance of groundwater
- Groundwater supplies drinking water to a sizeable population in India and almost 99% of the rural population.
- It helps grow our food. 64% of groundwater is used for irrigation to grow crops.
- It is an important component in many industrial processes.
- It is a source of recharge for lakes, rivers, and wetlands.
Why discuss this?
- Depletion: People face serious water shortages because groundwater is used faster than it is naturally replenished.
- Contamination: In other areas groundwater is polluted by human activities.
Reasons for Depletion
- Increased demand for water for domestic, industrial and agricultural needs and limited surface water resources lead to the over-exploitation of groundwater resources.
- Limited storage facilities owing to the hard rock terrain, along with the added disadvantage of lack of rainfall, especially in central Indian states.
- Green Revolution enabled water-intensive crops to be grown in drought-prone/ water deficit regions, leading to over-extraction of groundwater.
- Frequent pumping of water from the ground without waiting for its replenishment leads to quick depletion.
- Subsidies on electricity and high MSP for water-intensive crops is also leading reasons for depletion.
- Inadequate regulation of groundwater laws encourages the exhaustion of groundwater resources without any penalty.
- Deforestation, unscientific methods of agriculture, chemical effluents from industries, and lack of sanitation also lead to pollution of groundwater, making it unusable.
- Natural causes include uneven rainfall and climate change that are hindering the process of groundwater recharge.
Impact of groundwater depletion
- Lowering of the water table: Groundwater depletion may lower the water table leading to difficulty in extracting groundwater for usage.
- Reduction of water in streams and lakes: A substantial amount of the water flowing in rivers comes from seepage of groundwater into the streambed. Depletion of groundwater levels may reduce water flow in such streams.
- Subsidence of land: Groundwater often provides support to the soil. When this balance is altered by taking out the water, the soil collapses, compacts, and drops leading to subsidence of land.
- Increased cost for water extraction: As the depleting groundwater levels lower the water table, the user has to delve deep to extract water. This will increase the cost of water extraction.
Regulation of Groundwater in India
(1) Central Ground Water Authority (CGWA)
- It has the mandate of regulating ground water development and management in the country.
- It is constituted under the Environment (Protection) Act of 1986.
- CGWA issues advisories, public notices and grant No Objection Certificates (NOC) for ground water withdrawal.
(2) National Aquifer Mapping and Management Programme (NAQUIM)
- The NAQUIM is an initiative of the Ministry of Jal Shakti for mapping and managing the entire aquifer systems in the country.
- It maintains the Hydrological Map of India.
(3) Atal Bhujal Yojana
- It is a Central Sector Scheme, for sustainable management of groundwater resources with community participation in water-stressed blocks.
- Routine survey: There should be regular assessment of groundwater levels to ensure that adequate data is available for formulating policies and devising new techniques.
- Assessment of land use pattern: Studies should be carried out to assess land use and the proportion of agricultural land falling under overt-exploited units.
- Changes in farming methods: To improve the water table in those areas where it is being overused, on-farm water management techniques and improved irrigation methods should be adopted.
- Reforms in power supply subsidies: The agricultural power-pricing structure needs to be revamped as the flat rate of electricity adversely affects the use of groundwater.
- Monitoring extraction: There should be a policy in place to monitor the excessive exploitation of groundwater resources to ensure long-term sustainability.