India’s Water Resources And Their Distribution

India’s water resources are critical for its sustainability, yet their availability and utilization vary across regions.

A recent study by the Central Water Commission (CWC) highlights key findings on the country’s average annual water availability, emphasizing its significance for effective management and addressing water scarcity challenges.

India’s Water Availability (1985-2023)

The Central Water Commission (CWC) released a study titled ‘Assessment of Water Resources of India 2024’, estimating that India’s average yearly water availability from 1985 to 2023 was approximately 2,115.95 billion cubic meters (BCM).

This figure highlights the country’s total water potential over the years.

Basis Of The CWC’s Estimate

The CWC calculated this figure using data on precipitation, evapotranspiration, land use, land cover, and soil characteristics. It assessed the average yearly water runoff across India’s river basins, excluding three western tributaries of the Indus (Indus, Jhelum, and Chenab).

Water Distribution Across Regions

Water availability varies significantly across different river basins in India. According to the report:

Top three basins: Brahmaputra (592.32 BCM), Ganga (581.75 BCM), and Godavari (129.17 BCM).
Bottom three basins: Sabarmati (9.87 BCM), Pennar (10.42 BCM), and Mahi (13.03 BCM).

Water Availability by Basin

Basin	Water Availability (BCM)
Barak & Others	93.65
Brahmani-Baitarani	31.27
Brahmaputra	592.32
Cauvery	26.53
Eastern Flowing Rivers Between Mahanadi & Pennar	23.33
Eastern Flowing Rivers Between Pennar & Kanyakumari	27.06
Ganga	581.75
Godavari	129.17
Indus (Eastern)	47.30
Krishna	86.32
Mahanadi	72.82
Mahi	13.03
Minor Rivers draining into Myanmar & Bangladesh	31.86
Narmada	49.45
Pennar	10.42
Sabarmati	9.87
Subarnarekha	14.48
Tapi	20.98
Western Flowing Rivers from Tadri to Kanyakumari	116.47
Western Flowing Rivers from Tapi to Tadri	110.44
Western Flowing Rivers of Kutch & Saurashtra including Luni	26.95
Total	2115.95

Comparisons With Previous Assessments

The latest estimate of 2,115.95 BCM is higher than the 1,999.2 BCM figure from 2019. Earlier assessments, dating back to 1901-03, placed water availability below 2,000 BCM, with the earliest figure being 1,443.2 BCM.

The increase in the latest estimate is due to improved methodologies.

Why Are the New Figures Higher?

The updated calculations include contributions from Bhutan to the Brahmaputra basin and a complete inclusion of Nepal’s contribution to the Ganga basin.

These factors were either partially considered or excluded in previous assessments.

Additionally, all transboundary water entering India in the Brahmaputra, Ganga, and eastern rivers of the Indus basin have been accounted for.

Importance Of Water Availability Assessments

These studies are crucial for managing water resources sustainably. With growing challenges like urbanization, industrialization, and climate change, accurate assessments help guide water management policies.

They are also essential for calculating per capita water availability—a key measure of water scarcity.

Measuring Water Scarcity

The Falkenmark Indicator categorizes water availability as:

Water stress: Below 1,700 cubic meters per person annually.
Water scarcity: Below 1,000 cubic meters per person annually.
Absolute scarcity: Below 500 cubic meters per person annually.

Based on the 2019 study, India’s annual per capita water availability was 1,486 cubic meters in 2021. With the updated estimate for 2024, this figure rises to 1,513 cubic meters. However, it remains below the 1,700 cubic meter threshold, placing India under “water stress.”

Usable vs. Total Water Availability

Not all water resources are usable. In 2019, out of the 1,999.2 BCM of water resources, only 690 BCM of surface water was deemed utilizable. Smaller basins generally have a higher proportion of utilizable water. However, larger basins like the Brahmaputra have a lower proportion due to geographic and hydrological constraints.

By understanding these factors, India can work towards better utilization and management of its water resources.

About the Central Water Commission (CWC)

The Central Water Commission (CWC) was established in 1945 and initially named the Central Waterways, Irrigation, and Navigation Commission (CWINC) based on the recommendation of Dr. B. R. Ambedkar.

The organization operates under the Ministry of Jal Shakti, specifically within the Department of Water Resources, River Development, and Ganga Rejuvenation. It serves as a statutory advisory body focusing on the development and management of water resources across the country.

Headquarters and Leadership

CWC is headquartered in New Delhi. The Chairman of the commission holds the position of Ex-Officio Secretary to the Government of India, ensuring close coordination with government authorities.

Key Responsibilities

The commission plays a vital role in managing India’s water resources. Its main responsibilities include:

Controlling, conserving, and efficiently using water resources.
Maintaining the National Register of Large Dams (NRLD).
Conducting hydrological surveys and studies.

While CWC oversees surface water management, the Central Groundwater Board (CGWB) handles the country’s groundwater resources.

Organizational Structure

CWC has three main operational wings:

Designs and Research (D&R) Wing: Focuses on technical designs and research for water resource projects.
River Management (RM) Wing: Deals with flood management, river training, and related activities.
Water Planning and Projects (WP&P) Wing: Manages water resource planning and project development.

Previous Year Question

PYQ: [2020]

Consider the following statements:

36% of India’s districts are classified as “overexploited” or “critical” by the Central Ground Water Authority (CGWA).
CGWA was formed under the Environment (Protection) Act.
India has the largest area under groundwater irrigation in the world.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(c) 2 only

(d) 1 and 3 only