The reservoir Gobind Sagar is on the river

1. The Indus River System: Tributaries and Drainage (basic)

The Indus River System is one of the world's largest drainage basins, acting as the lifeblood for millions across Tibet, India, and Pakistan. Known as the Singi Khambab (Lion's Mouth) in Tibet, the Indus originates near the Mansarovar Lake at an altitude of 4,164 m. It is a classic example of an antecedent river—a river that existed before the Himalayan mountains were uplifted and maintained its course by cutting deep, spectacular gorges through the rising landscape. The deepest of these, a massive synclinal gorge near Gilgit, plunges to a staggering depth of 5,200 m Geography of India, Majid Husain, p.9.

As the river traverses the rugged terrain of Ladakh and Baltistan, it receives a series of high-altitude Himalayan tributaries. On its right bank, rivers like the Shyok and Nubra (which originate from the Siachen Glacier) and the Shigar (draining the slopes of Mt. K2) join the Indus INDIA PHYSICAL ENVIRONMENT, NCERT Class XI, p.20. After emerging from the hills near Attock, it is joined by several western tributaries such as the Kabul, Khurram, and Gomal rivers.

Perhaps most significant for India’s agricultural and energy needs are the left-bank tributaries, often referred to as the Panjnad (Five Rivers): the Jhelum, Chenab, Ravi, Beas, and Satluj. Among these, the Satluj stands out due to its unique origin. Like the Indus, it is an antecedent river that rises from Rakas Tal (Raksas Tal) in Tibet, where it is known as Langchen Khambab. It enters India through the Shipki La pass and carves through the Zaskar and Dhauladhar ranges before feeding into the iconic Bhakra-Nangal project Geography of India, Majid Husain, p.10.

Feature	Right-Bank Tributaries	Left-Bank Tributaries
Key Rivers	Shyok, Gilgit, Kabul, Gomal, Nubra	Jhelum, Chenab, Ravi, Beas, Satluj
Characteristics	Mostly glacier-fed, high-altitude, rugged terrain	Form the fertile plains of Punjab; vital for irrigation

Sources: Geography of India (Majid Husain, 9th ed.), The Drainage System of India, p.9-10; INDIA PHYSICAL ENVIRONMENT (NCERT Class XI, 2025 ed.), Drainage System, p.20-21

2. Multipurpose River Valley Projects in India (basic)

In the early years of independent India, Prime Minister Jawaharlal Nehru famously described Multipurpose River Valley Projects as the "Temples of Modern India." These are massive engineering undertakings that involve constructing dams across major rivers to achieve several developmental goals simultaneously. Instead of just focusing on one outcome, these projects are designed to provide irrigation for agriculture, generate hydroelectric power, control devastating floods, and even support inland navigation and pisciculture (fish farming).

A flagship example of such a project is the Bhakra-Nangal Project. Built across the Sutlej River, it features the Bhakra Dam, which is one of the highest concrete gravity dams in the world. The massive reservoir created by this dam is known as Gobind Sagar, named in honor of Guru Gobind Singh, the tenth Sikh Guru Geography of India, Majid Husain, Chapter 8, p.20. This reservoir, located in Himachal Pradesh, is vital for providing water and electricity to the states of Punjab, Haryana, and Rajasthan. It is important to distinguish this from the Gobind Ballabh Pant Sagar, which is located on the Rihand river in Uttar Pradesh Geography of India, Majid Husain, Chapter 8, p.22.

India’s diverse geography means these projects are spread across various river systems to address regional needs. For instance, the Damodar Valley Corporation (DVC) was the first multipurpose project of independent India, modeled after the Tennessee Valley Authority (TVA) in the USA to manage the Damodar river in Jharkhand and West Bengal Indian Economy, Nitin Singhania, Irrigation in India, p.367. Similarly, the Chambal Project serves Rajasthan and Madhya Pradesh, while the Gandak and Kosi projects involve international cooperation with Nepal to manage transboundary waters.

Project Name	River System	Primary Beneficiary States
Bhakra-Nangal	Sutlej	Punjab, Haryana, Rajasthan
Damodar Valley (DVC)	Damodar	Jharkhand, West Bengal
Mahi Project	Mahi	Madhya Pradesh, Gujarat
Mayurakshi	Mayurakshi (Hugli tributary)	West Bengal, Jharkhand

Sources: Geography of India, Energy Resources, p.20; Geography of India, Energy Resources, p.22; Indian Economy, Irrigation in India, p.367

3. Hydrology of the Sutlej River (intermediate)

The Sutlej River (or Satluj) is a classic example of a trans-Himalayan antecedent river. This means the river existed before the Himalayas were even formed; as the mountains rose, the river was powerful enough to erode its bed at the same rate, cutting deep, spectacular gorges through the Zaskar, Greater Himalayan, and Dhauladhar ranges Geography of India, Majid Husain (9th ed.), The Drainage System of India, p.10. It originates at an altitude of approximately 4,555–4,600 meters from the Rakas Tal (Rakshas Tal) near Lake Mansarovar in Tibet, where it is known by the local name Langchen Khambab India Physical Environment, Geography Class XI (NCERT 2025 ed.), Drainage System, p.21.

The river's entry into India is a critical geographical marker. It flows roughly parallel to the Indus for about 400 km in Tibet before entering Himachal Pradesh through the Shipki La pass Geography of India, Majid Husain (9th ed.), Physiography, p.22. As it descends, it passes through the narrow gorge at Bhakra, where the iconic Bhakra Dam was constructed. This engineering marvel created the massive Gobind Sagar reservoir, which stretches nearly 90 km and serves as the lifeline for the Bhakra-Nangal multipurpose project, powering and irrigating the states of Punjab, Haryana, and Rajasthan Geography of India, Majid Husain (9th ed.), Energy Resources, p.20.

Hydrologically, the Sutlej has shown significant historical dynamism. Interestingly, the river once had a more easterly course and flowed independently into the Arabian Sea during the early Christian Era Geography of India, Majid Husain (9th ed.), The Drainage System of India, p.24. Today, it is the easternmost tributary of the Indus system in India. In the Punjab plains, it is joined by the Beas River at Harike, a confluence that marks one of the most important wetland sites in North India and the headworks for the Indira Gandhi Canal India Physical Environment, Geography Class XI (NCERT 2025 ed.), Drainage System, p.21.

Feature	Sutlej River Details
Tibetan Name	Langchen Khambab
Source	Rakas Tal (near Mansarovar)
Entry Point to India	Shipki La Pass
Major Reservoir	Gobind Sagar

Sources: Geography of India, Majid Husain (9th ed.), The Drainage System of India, p.10; India Physical Environment, Geography Class XI (NCERT 2025 ed.), Drainage System, p.21; Geography of India, Majid Husain (9th ed.), Physiography, p.22; Geography of India, Majid Husain (9th ed.), The Drainage System of India, p.24; Geography of India, Majid Husain (9th ed.), Energy Resources, p.20

4. Inter-State Water Sharing and Treaties (intermediate)

In the federal structure of India, water is primarily a State subject, but because rivers flow across state and international boundaries, their management requires a sophisticated legal and diplomatic framework. When we look at major river projects, understanding who gets the water is just as important as how the dam is built. This is governed by two main layers: International Treaties for trans-boundary rivers and Constitutional Provisions for inter-state disputes.

At the international level, the most significant framework is the Indus Waters Treaty (1960). Brokered by the World Bank (then the IBRD), this treaty resolved a fierce argument between India and Pakistan regarding the Indus basin NCERT Class XII, Contemporary World Politics, p.39. The treaty partitioned the six rivers of the Indus system into two groups:

Category	Rivers	Rights/Allocation
Eastern Rivers	Ravi, Beas, and Sutlej	India has exclusive rights for unrestricted use Majid Husain, Geography of India, p.39.
Western Rivers	Indus, Jhelum, and Chenab	Allocated to Pakistan, though India can use them for limited non-consumptive purposes (like run-of-the-river power).

Domestically, the governance of water sharing is anchored in Article 262 of the Indian Constitution. This unique article gives Parliament the power to adjudicate disputes relating to inter-state rivers and, crucially, allows Parliament to exclude the jurisdiction of the Supreme Court and other courts in these matters M. Laxmikanth, Indian Polity, p.167. Under this authority, two landmark laws were passed in 1956:

• The River Boards Act (1956): Aimed at the regulation and development of inter-state rivers through advisory boards.
• The Inter-State River Water Disputes Act (1956): Provides for the setup of ad hoc Water Disputes Tribunals whose decisions are final and binding D.D. Basu, Introduction to the Constitution of India, p.407.

A practical example of these principles in action is the Bhakra-Nangal Project on the Sutlej River. Since the Sutlej is one of the 'Eastern Rivers' granted to India by the 1960 Treaty, India was able to construct the massive Bhakra Dam, forming the Gobind Sagar reservoir. This project doesn't just serve one state; it is a collaborative multipurpose venture that provides irrigation and power to Punjab, Haryana, and Rajasthan, demonstrating how a treaty-protected resource is shared internally to drive regional development.

Sources: Geography of India (Majid Husain), The Drainage System of India, p.39; Contemporary World Politics (NCERT Class XII), Contemporary South Asia, p.39; Indian Polity (M. Laxmikanth), Inter-State Relations, p.167; Introduction to the Constitution of India (D.D. Basu), Inter-State Relations, p.407

5. Hydroelectric Power and Dam Classification (intermediate)

In our journey through Indian river projects, it is essential to understand why we build dams in the first place. Jawaharlal Nehru famously called these structures the 'temples of modern India' because they were designed to integrate agricultural growth with rapid industrialization NCERT, Contemporary India II, p.56. At the heart of this vision is Hydroelectric Power (HEP)—a renewable, clean, and cheap source of energy. India’s tryst with HEP began as early as 1879 in Darjeeling, though we have still only developed a fraction of our total potential Majid Hussain, Environment and Ecology, p.52.

Dams are not a "one-size-fits-all" structure; they are classified based on their height or structural design. For instance, according to height, they are categorized as low, medium, or high dams NCERT, Contemporary India II, p.56. Structurally, one of the most significant types is the straightway gravity dam, which uses its massive weight to resist the horizontal force of water. The iconic Bhakra Dam on the Sutlej River is one of the highest concrete gravity dams in the world, standing 226 meters tall Majid Husain, Geography of India, p.20. Its massive reservoir is known as Gobind Sagar, named after Guru Gobind Singh.

Modern projects are usually multipurpose, meaning they aren't just for electricity. As seen in the Bhakra-Nangal or Damodar Valley projects, they serve a variety of needs simultaneously:

Function	Description
Irrigation	Supplying water to dry regions like Rajasthan through canals.
Flood Control	Creating a 'flood cushion' to manage monsoon runoff.
Pisciculture	Developing fisheries within the large reservoirs.
Silt Management	Reducing the load of sediment that can choke river beds downstream.

However, these projects face challenges. For example, siltation can reduce the storage capacity of reservoirs over time, which paradoxically increases flood risks in lower catchment areas Majid Husain, Geography of India, p.21. Furthermore, power generation must often be balanced with flood control needs; during the monsoon, dams must be kept partially empty to absorb sudden surges, which can limit their power output during those months Majid Husain, Geography of India, p.67.

Sources: NCERT, Contemporary India II, Water Resources, p.56; Majid Husain, Geography of India, Energy Resources, p.20; Majid Husain, Geography of India, Energy Resources, p.21; Majid Hussain, Environment and Ecology, Environmental Degradation and Management, p.52; Majid Husain, Geography of India, Regional Development and Planning, p.67

6. Distinguishing Similarly Named Reservoirs (exam-level)

In the study of Indian geography, nomenclature can often be a student's greatest pitfall. A classic example is the confusion between two of India's most significant man-made lakes: Gobind Sagar and Gobind Ballabh Pant Sagar. While they share a similar name, they are located in entirely different river basins and serve different geographical regions.

Gobind Sagar is located in the Bilaspur and Una districts of Himachal Pradesh. It was created by the construction of the Bhakra Dam across the Sutlej River, which is part of the Indus river system. This reservoir is a cornerstone of the Bhakra-Nangal multipurpose project, providing irrigation and power to Punjab, Haryana, and Rajasthan. It is named in honor of Guru Gobind Singh, the tenth Sikh Guru. Given the Bhakra Dam's status as one of the highest concrete gravity dams in the world, this reservoir is massive, stretching nearly 90 km in length Majid Husain, Geography of India, Chapter 8, p. 20.

In contrast, Gobind Ballabh Pant Sagar is situated in the Sonbhadra district of Uttar Pradesh. It is formed by the Rihand Dam on the Rihand River, which is a major tributary of the Son River (a southern tributary of the Ganga) NCERT, India Physical Environment, Chapter 3, p. 25. Named after the first Chief Minister of Uttar Pradesh, this reservoir is often cited as the largest man-made lake in India by volume. It is primarily used for hydroelectric power generation and serves the industrial and agricultural needs of the Rihand valley Majid Husain, Geography of India, Chapter 8, p. 22.

Feature	Gobind Sagar	Gobind Ballabh Pant Sagar
River	Sutlej	Rihand (Tributary of Son)
State	Himachal Pradesh	Uttar Pradesh
Associated Dam	Bhakra Dam	Rihand Dam
Named After	Guru Gobind Singh	Govind Ballabh Pant (Statesman)

Sources: Geography of India (Majid Husain), Chapter 8: Energy Resources, p.20, 22; India Physical Environment (NCERT), Chapter 3: Drainage System, p.25

7. The Bhakra-Nangal Project and Gobind Sagar (exam-level)

The Bhakra-Nangal Project stands as a landmark of post-independence Indian engineering, often hailed by Jawaharlal Nehru as one of the "temples of modern India." Located in the Bilaspur and Una districts of Himachal Pradesh, the project is built across the Satluj River, which enters India from Tibet through the Shipki La pass Geography of India, Majid Husain, p.22. The project is a joint venture primarily serving the states of Punjab, Haryana, and Rajasthan. It consists of two major dams: the Bhakra Dam and the Nangal Dam, which work in tandem to manage the river's flow for irrigation and power generation Geography of India, Majid Husain, p.20-21.

The Bhakra Dam is the crown jewel of this system. It is one of the highest concrete gravity dams in the world, standing at 226 meters high and 518 meters long Geography of India, Majid Husain, p.20. Its massive reservoir is known as Gobind Sagar, named in honor of the tenth Sikh Guru, Guru Gobind Singh. This reservoir extends for approximately 90 km and is crucial not only for water storage but also for pisciculture (fish farming) and tourism. Approximately 13 km downstream from Bhakra lies the Nangal Dam, which acts as a secondary barrage to regulate water release and channel it into the Bhakra canal system Geography of India, Majid Husain, p.21.

Feature	Bhakra Dam	Nangal Dam
Primary Role	Storage & Gravity Power	Regulation & Canal Supply
Reservoir	Gobind Sagar	Small balancing reservoir
Structure	Concrete Gravity Dam	Barrage/Regulator

Beyond electricity and irrigation, the project serves as a comprehensive multipurpose scheme. It provides vital flood control in the Satluj basin, prevents soil erosion through controlled water release, and supports wildlife preservation and navigation in the region Geography of India, Majid Husain, p.20. It is important to distinguish Gobind Sagar on the Satluj from the Gobind Ballabh Pant Sagar, which is located on the Rihand River in Uttar Pradesh; students often confuse the two due to the similarity in names.

Sources: Geography of India, Majid Husain, Energy Resources, p.20; Geography of India, Majid Husain, Energy Resources, p.21; Geography of India, Majid Husain, Physiography, p.22

8. Solving the Original PYQ (exam-level)

This question integrates your foundational knowledge of North Indian River Systems and Multi-purpose River Valley Projects. Having mastered the course of the Sutlej River from its origin near Lake Rakshastal to its entry into India, you can now see its practical application. The key building block here is the Bhakra-Nangal Project, which is a centerpiece of India's post-independence infrastructure. Recall that large-scale gravity dams necessarily create extensive impoundments; in the case of the Bhakra Dam, that impoundment is the specific reservoir in question.

To arrive at the correct answer, (A) Sutlej, you must link the geographic location of Bilaspur, Himachal Pradesh, with the specific engineering feat of the Bhakra Dam. The reservoir, named in honor of Guru Gobind Singh, serves as the primary water storage for the high-yield agricultural belts of Punjab, Haryana, and Rajasthan. As your coach, I recommend visualizing the map of Himachal Pradesh where the Sutlej is 'tamed' by this massive concrete structure, forming a water body nearly 90 km long.

UPSC frequently uses "naming traps" to test the precision of your memory. The most common pitfall here is confusing Gobind Sagar with Gobind Ballabh Pant Sagar. While the former is on the Sutlej, the latter is located on the Rihand River (Option C), which is a tributary of the Son River (Option B) in the Uttar Pradesh-Madhya Pradesh border region. Similarly, the Narmada River (Option D) is home to the Indira Sagar and Sardar Sarovar reservoirs, which belong to an entirely different drainage basin. Distinguishing between these similarly named reservoirs is a critical skill for the Prelims, as highlighted in Geography of India, Majid Husain.