Context:
In August 2023, India, heavily dependent on monsoon rains, faced an exceptional challenge with a severe rainfall deficit. This deficit has led to a significant drop in water levels in the country’s vital reservoirs, sparking concerns about water supply for households, industries, and power generation. Historically, August is a month of substantial reservoir water storage increase, but 2023 witnessed the driest August in over a century. Instead of the anticipated 255 mm of rainfall, India received only about 162 mm, resulting in a substantial 36% rainfall deficiency.
Relevance:
GS I: Geography
Dimensions of the Article:
- India’s Reservoir Water Levels – August 2023
- Consequences of Water Scarcity in India’s Reservoirs
- Causes for Rainfall Deficit in India
India’s Reservoir Water Levels – August 2023:
- Live Storage: As of August 31, 2023, the Central Water Commission (CWC) reported that the live storage in 150 reservoirs was 113.417 billion cubic meters (BCM), which represented 63% of their total live storage capacity.
- Comparison to 2022: This storage level was approximately 23% lower than the storage during the same period in 2022.
- Comparison to 10-Year Average: It was also around 10% lower than the average storage of the last 10 years.
- Regional Variations: The water levels in these reservoirs varied across different regions and river basins in India.
- Southern Region: The southern region, which experienced a rainfall deficiency of 60% in August, had the lowest storage level at 49% of its combined capacity.
- Eastern Region: In contrast, the eastern region, which received normal rainfall, had the highest storage level at 82% of its combined capacity.
Basins with Deficient Water Levels:
- Highly Deficient Basins:
- Pennar basin in Karnataka and Andhra Pradesh.
- Mahanadi basin in Chhattisgarh and Odisha.
- Deficient Basins:
- Subarnarekha, Brahmani, and Vaitarni basins in Jharkhand, West Bengal, and Odisha.
- Kaveri basin in Karnataka and Tamil Nadu.
- Mahi basin in western India.
- Krishna basin in Maharashtra, Karnataka, and Telangana.
Overall Trend:
- Water storage in the reservoirs across the eastern, western, central, and southern regions (except the northern region) was lower compared to the previous year (2022).
Consequences of Water Scarcity in India’s Reservoirs:
Impact on Agriculture:
- Reduced water availability in the reservoirs can adversely affect crop production, especially during the rabi (winter) season.
- Farmers’ incomes may be at risk due to diminished irrigation water.
Energy Generation Challenges:
- The reservoirs play a crucial role in supplying water for hydropower generation, which accounts for over 12% of India’s total electricity production.
- Dry conditions in August led to increased power demand, primarily for irrigation, resulting in record-high power generation.
- To meet the demand, additional electricity production from coal-fired power plants may be required due to the declining water levels in the reservoirs.
Ecological Impact:
- Reservoirs also support biodiversity and provide ecosystem services like flood control, groundwater recharge, fisheries, and recreational activities.
- Lower water levels can disrupt these functions and lead to ecological damage, impacting both natural habitats and human activities.
Year-Round Water Supply Threatened:
- India relies heavily on annual rainfall, primarily during the southwest monsoon season.
- The declining water storage in reservoirs threatens year-round water supply for households, posing challenges to daily life and water security.
Causes for Rainfall Deficit in India:
El Niño:
- Definition: El Niño is a climatic phenomenon characterized by the rise in sea surface temperatures in the central and eastern Pacific Ocean, causing disruptions in global weather patterns.
- Impact on India: El Niño typically leads to reduced rainfall in India during the monsoon season.
- Current Status: According to the India Meteorological Department (IMD), El Niño was present during August 2023 and was expected to persist until September.
- Future Outlook: While the IMD forecasts that rainfall in September may not be more than 10% deficient, the growing strength of El Niño in the equatorial Pacific Ocean poses a significant risk to India’s water resources.
Indian Ocean Dipole (IOD):
- Definition: The Indian Ocean Dipole (IOD) is a climate pattern marked by differences in sea surface temperatures between two regions in the Indian Ocean – a western pole in the Arabian Sea and an eastern pole in the eastern Indian Ocean south of Indonesia.
- Impact on Climate: IOD significantly influences the climate in countries surrounding the Indian Ocean Basin and plays a vital role in rainfall variability in the region.
- Current Status: While the IMD expected the IOD to become favorable for monsoon rainfall, it did not have a substantial impact on the monsoon this year.
-Source: The Hindu
