WATER WOES:ON THE STATE OF INDIA'S GROUND WATER

9th January, 2025

This article is based on the Editorial "Water woes: On the state of India’s groundwater" that appeared in The Hindu.

Context

An annual assessment by the Central Ground Water Board (CGWB) on the state of groundwater and its quality has raised several concerns. The most pressing issue is the increase in the number of districts with excessive nitrate levels in groundwater.

All about Nitrate contamination in groundwater

How nitrate contamination has increased

The number of districts with excessive nitrate levels has risen from 359 in 2017 to 440 in 2023. This means over half of India's 779 districts have nitrate levels exceeding the safe limit of 45 mg/L.

After analysing 15,239 groundwater samples around 19.8% were found to have nitrate levels above safe limits, which has not significantly changed since 2017 (21.6%).

Regions with highest nitrate contamination

Regions in central and southern India are witnessing a rise in nitrate contamination, which is a concerning development.

Rajasthan, Karnataka and Tamil Nadu reported the highest nitrate contamination levels, with 49%, 48%, and 37% of samples exceeding the permissible nitrate limit.

Concerns associated with excessive nitrate content

Two major concerns are raised with excessive nitrate content:

  • Health Concern: Nitrate contamination leads to methemoglobinemia--- a condition where red blood cells cannot carry oxygen causing 'Blue Baby Syndrome' in infants.
  • Environmental Concern: High nitrate levels contribute to algal blooms in lakes and ponds, which can harm aquatic ecosystems.

Impact of geology on nitrate contamination

Rajasthan, Madhya Pradesh and Gujarat face perennial nitrate contamination due to geological factors. These levels have remained fairly constant since 2017.

Correlation between intensive agriculture and nitrate contamination

Several studies have shown that intensive agriculture practices are linked to higher nitrate levels in groundwater, contributing significantly to the contamination.

Other chemical contaminants affecting groundwater quality

Apart from nitrates, fluoride and uranium are significant chemical contaminants. Fluoride concentrations exceeding permissible limits are a major concern in Rajasthan, Haryana, Karnataka, Andhra Pradesh and Telangana.

States with over-exploited groundwater blocks—where extraction exceeds replenishment—are more likely to have excessive chemical contaminants.

Status of groundwater extraction in India

The degree of groundwater extraction in India is 60.4%, which has remained relatively constant since 2009. About 73% of the blocks analyzed are in the 'safe' zone. This means they are sufficiently replenished to compensate for water extraction.

Need for action in response to these findings

While the CGWB has established a robust system to monitor groundwater health, there is a lack of action at the state level. Greater awareness programs and leadership involvement are essential to address the crisis effectively.

Central Ground Water Board (CGWB)

Central Ground Water Board (CGWB), a subordinate office of the Ministry of Water Resources, Government of India, is the National Apex Agency entrusted with the responsibilities of providing scientific inputs for management, exploration, monitoring, assessment, augmentation and regulation of groundwater resources of the country. Central Ground Water Board was established in 1970 by renaming the Exploratory Tube Wells Organization under the Ministry of Agriculture, Government of India. It was merged with the Ground Water Wing of the Geological Survey of India during 1972. Central Ground Water Board has its headquarters at BHUJAL BHAWAN. Major activities being taken up by Central Ground Water Board include macro/micro-level ground water management studies, exploratory drilling programme, monitoring of ground water levels.

Groundwater Recharge and Extraction in 2024

In 2024, total annual groundwater recharge increased by 15 BCM (Billion Cubic Meters). And extraction decreased by 3 BCM. These are in comparison to 2017 assessment. This is a significant progress in groundwater management. And it demonstartes a positive shift in water availability and usage.

India’s Groundwater Resources

The Central Ground Water Board (CGWB) in collaboration with State Groundwater Departments, provides annual reports on groundwater resources. The 'National Compilation on Dynamic Ground Water Resources of India, 2024' report is a vital tool for shaping water management policies. It provides a comprehensive, state-wise analysis that helps policymakers and stakeholders devise strategies for sustainable groundwater management.

Key Highlights from the 2024 Groundwater Report

  • Total Annual Groundwater Recharge: 446.90 BCM.
  • Extractable Groundwater Resource: 406.19 BCM.
  • Annual Groundwater Extraction: 245.64 BCM.
  • Recharge Increase: In 2024, recharge from tanks, ponds, and water control systems (WCS) increased by 0.39 BCM compared to 2023.
  • Recharge from Tanks, Ponds & WCS: Increased by 11.36 BCM from 13.98 BCM in 2017 to 25.34 BCM in 2024.
  • Assessment Units under Safe Category: Increased from 62.6% in 2017 to 73.4% in 2024.
  • Over Exploited Assessment Units: Decreased from 17.24% in 2017 to 11.13% in 2024.

Importance of Clean Groundwater for Future Generations

Groundwater quality is essential for public health and agricultural productivity. Key contaminants such as Arsenic, Fluoride, Chloride, Uranium, and Nitrate are prevalent in many regions and can pose long-term health risks. Elevated Electrical Conductivity (EC) is another indicator of potential contamination from agricultural runoff, industrial discharge, or saline intrusion.

Groundwater Quality and Contamination

The Annual Groundwater Quality Report for 2024 analyzed over 15,200 groundwater samples from monitoring locations and 4,982 trend stations across the country. The findings underscore the importance of maintaining both the quantity and quality of groundwater for long-term water security.

  • 81% of groundwater samples were deemed suitable for irrigation.
  • 100% of groundwater samples from the North-Eastern States were rated as "excellent" for irrigation, highlighting optimal conditions for agriculture in the region.

Groundwater Assessment and Management Initiatives

The positive results are driven by various government initiatives:

  • Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS): This scheme supports water conservation and harvesting structures thereby boosting rural water security.
  • 15th Finance Commission Grants: This provides funding for rainwater harvesting and other water conservation activities.
  • Jal Shakti Abhiyan (JSA): Launched in 2019 and now in its 5th phase ("Catch the Rain 2024"), focusing on rainwater harvesting and water conservation across rural and urban districts.
  • Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0: IIt basically promotes groundwater recharge through aquifer management plans and rainwater harvesting.
  • Atal Bhujal Yojana (2020): Targets water-stressed Gram Panchayats across 7 states for effective groundwater management.
  • Pradhan Mantri Krishi Sinchai Yojana (PMKSY): Expands irrigation coverage and improves water use efficiency.
  • Mission Amrit Sarovar (2022): Aims to create or rejuvenate 75 Amrit Sarovars in every district for water harvesting.
  • National Aquifer Mapping (NAQUIM): Completed mapping for over 25 lakh sq. km, supporting recharge and conservation plans.
  • Master Plan for Artificial Recharge to Groundwater (2020): Aimed at creating 1.42 crore rainwater harvesting and recharge structures to harness 185 BCM of rainfall.

National Water Policy and Awareness Campaigns

The National Water Policy (2012) advocates rainwater harvesting and water conservation. The National Water Awards, launched in 2018, recognize contributions to water management and raise public awareness about water conservation practices.

Reviving Groundwater for a Sustainable Future

India's coordinated efforts and initiatives have led to substantial improvements in groundwater recharge, quality and management. With continued innovation and commitment these efforts ensure a sustainable, water-secure future for generations to come.

“We must adopt the mantra of ‘Reduce, Reuse, Recharge, and Recycle’ to secure the nation’s water future”

~Prime Minister Shri Narendra Modi

SOURCE: 

THE HINDU

PIB