El nino triggers rainfall deficit in ap reservoirs
Source:the-print ↗
Why It Matters
This article is highly relevant for APPSC Group 1 Prelims (Geography and Economy) as it practically illustrates the regional impact of El Nino on monsoons. It also covers critical state-specific geography and water infrastructure, such as the Krishna and Godavari river basins, and the significance of interlinking projects like Polavaram and Pattiseema, which are frequent subjects in APPSC examinations.
Summary
Andhra Pradesh Chief Minister N. Chandrababu Naidu has highlighted the severe impact of the El Nino phenomenon on the state's climate, leading to a projected 35.8% rainfall deficit. The erratic monsoon has drastically reduced inflows into critical Krishna basin reservoirs like Srisailam and Nagarjuna Sagar. To mitigate the crisis, the state is relying on the Pattiseema project to divert surplus water from the Godavari basin to the Krishna delta. The government has initiated contingency plans for drinking water and agriculture, while emphasizing the urgent need to complete the Polavaram national project to ensure long-term regional water security.
Key Points
- El Nino has triggered a severe rainfall deficit in Andhra Pradesh, with only 557 mm of rainfall expected against a normal 867 mm between June and December.
- Major reservoirs in the Krishna basin, such as Srisailam and Nagarjuna Sagar, are experiencing extremely low inflows due to poor rainfall in upper riparian states like Maharashtra and Karnataka.
- The Godavari basin remains relatively unaffected, allowing the state to divert surplus Godavari waters to the Krishna delta via the Pattiseema lift irrigation project.
- The state government is prioritizing drinking water supply and has cautioned farmers outside the Godavari delta about potential irrigation shortages.
- Expediting the Polavaram national irrigation project is emphasized to secure long-term water supply for regions including Anakapalli and Vizag.
Important Terms
Polavaram Project
A national multi-purpose irrigation project on the Godavari River in Andhra Pradesh. It provides irrigation, generates 960 MW of hydroelectric power, supplies drinking water, and facilitates inter-basin water transfer.
UPSC context
Highly relevant for AP Economy and Geography, testing knowledge of AP irrigation infrastructure and national projects.
Pattiseema Lift Irrigation Project
India's first completed river-linking project, diverting surplus floodwater from the Godavari River to the water-deficit Krishna Delta via the Polavaram Right Main Canal.
UPSC context
Critical for AP Geography and Economy, testing knowledge of inter-basin water transfers and drought mitigation strategies in AP.
El Nino
A climate phenomenon involving abnormal warming of surface waters in the central and eastern equatorial Pacific Ocean. It often weakens India's southwest monsoon, leading to rainfall deficits and droughts.
UPSC context
Essential for Geography and Disaster Management, testing understanding of global climate patterns and their impact on Indian monsoons.
Srisailam Dam
A major gravity dam and India's second-largest capacity hydroelectric project, built across the Krishna River in the Nallamala Hills on the Andhra Pradesh-Telangana border.
UPSC context
Key AP Geography and Economy topic, testing knowledge of major reservoirs, hydropower generation, and inter-state river basins.
Nagarjuna Sagar Dam
A massive masonry dam on the Krishna River between Andhra Pradesh and Telangana. It forms Asia's second-largest man-made lake and provides critical irrigation and hydroelectric power.
UPSC context
Important for AP Geography and Economy, testing knowledge of major river valley projects and state water resources management.
Prelims Trap
"Pattiseema diverts surplus water from the Krishna river to the Godavari basin."
Aspirants often confuse the direction of inter-basin transfers. Godavari has the surplus; Krishna faces the deficit. Pattiseema lifts Godavari water INTO Krishna, not the reverse.
Static Concepts Connected
What are the key characteristics of the Pattiseema Lift Irrigation Project?
- First River Interlinking: It is the first completed river-linking project in India, connecting the Godavari and Krishna rivers in record time to address regional drought.
- Location and Mechanism: It lifts water from the Godavari at Pattiseema village (Eluru district) and pumps it into the Polavaram Right Main Canal to reach the Krishna river.
- Strategic Purpose: It stabilizes the Krishna delta ayacut, saving standing crops, and helps divert Krishna water from Srisailam to the drought-prone Rayalaseema region.
How does the El Nino phenomenon suppress the Indian Summer Monsoon?
- Pacific Warming: It involves the abnormal warming of surface waters in the central and eastern equatorial Pacific Ocean.
- Walker Cell Shift: This warming shifts the Walker Circulation, creating high pressure over the western Pacific and Indian Ocean, which weakens the monsoon winds carrying moisture to India.
- Local Impact: It severely reduces rainfall in lower-riparian and rain-shadow regions, lowering reservoir inflows for dams like Srisailam and Nagarjuna Sagar.
Cross-Topic Patterns
El Nino + Inter-State Water Disputes
Climate anomalies like El Nino exacerbate lower-riparian vulnerabilities, intensifying legal and political friction between AP, Telangana, Karnataka, and Maharashtra over the Krishna Water Disputes Tribunal (KWDT) allocations.
Polavaram + AP Reorganisation Act
Polavaram's National Project status (under the AP Reorganisation Act, 2014) shifts the funding burden to the Centre, making it a cornerstone for AP's climate-resilient water and agricultural security strategy.
Expect multi-statement questions linking El Nino's local monsoon impact to Godavari-Krishna river interlinking (Pattiseema) projects.
Linked PYQs · 4
Linked PYQs · 4
- 2019APPSC_PRELIMSGS1
El-Nino is a complex weather system that appears once every three to seven years. Consider the following statements in this regard : A. The appearance of warm currents off the Coast of Peru in the Eastern Pacific. B. The word El-Nino means 'Christ Child' because the current appears around Christmas in December. C. El-Nino was one of the reasons for the deficit rainfall in India (2014). Which of the statements given above is/are correct ?
- 2023APPSC_PRELIMSGS1
Polavaram Project is a
- 2008APPSC_PRELIMSGS1
Across which river in Andhra Pradesh is Srisailam hydro-electric power plant built?
- 2024APPSC_PRELIMSGS1
Within India, Ganga river basin has the largest catchment area. After that, following is the correct sequence in the decreasing order:
