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A Comprehensive Overview of India’s Drainage System

indian drainage system, drainage system

Do you know from where rivers originate, flow, and then end? Well, rivers emerge from sources like glaciers, lakes and springs and eventually end in oceans or seas. However, to complete their fascinating journey, they follow well-defined channels, and this network of channels is known as a drainage system. In this blog, we will help you learn everything about India’s drainage system, exploring the major rivers of India, its tributaries and how these waterways shape our nation's landscape.

Different drainage systems in India

India is blessed with many rivers, each with its own unique story, significance, characteristics, and drainage systems. From the sacred Ganga in the north to the Dakshin Ganga or Ganga of the south, Godavari and many more. Our rivers are not just water bodies; they hold a special place in our hearts. They influence our culture, economy, ecology and many things. So, let us dive deep into two major drainage systems: the Himalayan and Peninsular Drainage systems, which form the foundation of our country’s extensive waterway network.

Himalayan drainage system

Rivers that emerge from the mystic and beautiful Himalayas fall under the Himalayan drainage system. The major rivers of the Himalayan drainage system are Indus, Ganga and Brahmaputra. These rivers receive water from the melting of snow and precipitation, therefore, they are called perennial rivers. (Perennial rivers are those rivers that keep flowing throughout the year). These rivers travel from the mountains to the plain through the giant gorges of the Himalayas and form V-shaped valleys, waterfalls, floodplains, and oxbow lakes. The course that Himalayan rivers take in the mountains is complicated, but if you think that it takes a straightforward path in the plains, you are not right. Himalayan rivers shift and meander in plains, and one of the best examples of this is “River Koshi” or “Sorrow of Bihar”, which is known for changing its course frequently and causing floods and devastation across the state of Bihar.

Himalayan River System

Although the Himalayan drainage system consists of several rivers system, some of its major river systems are:

The Indus river system

Most of us don’t know that one of the oldest civilizations in the world, “The Indus Valley Civilisation” or “Harappan Civilisation” is named after the Indus River system as it flourished across its fertile banks. In the Sanskrit language, the Indus River is known as “Sindu”, however, the Greek language refers to it as “Sinthos”.

The Indus River system is the longest on the Indian subcontinent and has a drainage area of about 11 lakhs, 65 thousand square kilometres, out of which most of the area is in Pakistan. Here is a brief introduction to the Indus River and its tributaries (Jhelum, Chenab, Satluj, Ravi, and Beas).

Indus river

The Indus River originates near Lake Mansarovar in Mount Kailash (known as the Abode of Lord Shiva), which is in Tibet, China. The river then flows northwestwards and enters the Union territory of Ladakh from Demchok, where several tributaries that originated from the Himalayas join it. After travelling through the Indian territory, the Indus enters Pakistan through the region of Baltistan and Gilgit and finally drains into the Arabian Sea. Below are five major tributaries of the Indus River.


Chenab is a significant tributary of the Indus River that forms when the Chandra and Bhaga rivers combine near Keylong in Himachal Pradesh (HP). Because of this, Chenab is also known as Chandrabhaga. It is also the largest tributary of the Indus River (about 1180 km) and, after flowing through Himachal Pradesh and Jammu and Kashmir, joins the Indus River.


Jhelum emerges from Verinag Spring at the foot of the Pir Panjal range in the Kashmir valley. Jhelum flows through Srinagar and then enters Wular Lake before going to Pakistain through a narrow gorge and joining the Chenab River in Pakistain at Jhang. It is a tributary of the Chenab River and has a length of 725 kilometres.


Beas originates from Beas Kund in Rohtang Pass, which is in the Indian state of Himachal Pradesh. The river flows through the Kullu Valley, passes through the Mandi district, and then enters the Kangra Valley. Near the village Talwara of Hoshiarpur district, beas enters Punjab. It then flows through the Kapurthala and Hoshiarpur districts of Punjab and joins the Satluj River at Harike Pattan.


Satluj begins on the southern slopes of Mount Kailash, which is not far from the Rakshas Tal and Mansarovar lakes. The river flows through Kinnaur, Shimla, Kullu, Solan, Mandi and several other districts of Himachal Pradesh. Near Bhakra, Satluj enters Punjab, where the Bhakra Nangal Dam- The world’s heaviest gravity dam was built. It is the longest tributary of the Indus River, with a total length of about 1450 km.


Another tributary of the Indus River system is Ravi, which is also known as Iravati. It originates from Rohtang Pass near the Chamba district of Himachal Pradesh. After crossing Chamba, it turns southwest, forming a deep valley in the Dhauladhar mountain. It enters the Punjab near Madhopur, which is a town close to Pathankot. It joins Chenab after entering Pakistan and then drains into the Arabian Sea.

Indus Water Treaty

After learning about the rivers that constitute the Indus River system, a question that may have come into your mind- How is water from these rivers distributed between India and Pakistan? The solution lies in the Indus Water Treaty.

The Indus Water Treaty agreement was signed by the first prime minister of India, Jawaharlal Nehru, and Pakistan’s president Ayub Khan on the recommendation of the UN. According to the treaty, India can unrestrictedly use the water from three eastern rivers- Ravi, Beas and Satluj. On the other hand, Pakistan has full control over the use of water from three western rivers- Indus, Jhelum and Chenab.

The treaty gave India 30% of the water from the Indus River system, and the rest 70% was given to Pakistan. Despite getting the entire right to use the three eastern rivers, a lot of water from the Ravi river kept flowing to the Pakistan unutilized. However, to curb this, the government of India took various steps, from completing the Shahpurkandi Project, which was long-stalled because of the dispute between Jammu and Kashmir and Punjab, to the UJH multipurpose project and many more.

The Ganga river system

The Ganga River and its tributaries constitute the Ganga River system, which approximately covers an area of 1,086,000 square kilometres. The rivers in the Ganga system flow through several states, which include Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, West Bengal and many more.

Also Read, Schedules of Indian Constitution

Ganga River and its tributaries

Ganga is one of the most important rivers in India, both in terms of its cultural significance (as it is a sacred river) and its impact on the lives of millions of people who use it for irrigation and as a water resource. Ganga has a total length of about 2525 km and flows through both India and Bangladesh.

Bhagirathi is the headstream or source stream of Ganga which emerges from Guamakh at the base of Gangotri and Khatling glaciers in the Uttarakhand. It is named after the name of King Bhagirath, who observed a strict penance to bring the pious river Ganga down to earth from the heavens. He wanted to purify the ashes of his ancestors in the sacred river Ganga to give them salvation.

Bhagirathi becomes Ganga when it joins the river Alaknanda at Devprayag. The union of these rivers is considered very auspicious, and thousands of people dip in the holy water of Ganga and perform several rituals to get blessings from the Goddess Ganga at Devprayag. After Devprayag, Ganga enters the town of Rishikesh, which is another important pilgrimage of Hindus. It enters the plains through Haridwar and then flows through states such as Uttar Pradesh, Bihar, Jharkhand and West Bengal.

On entering West Bengal, it is divided into two rivers, Padma and Hooghly. Hooghly River flows through many districts of West Bengal and finally drains into the Bay of Bengal. On the other hand, Padma enters Bangladesh and merges with the Jamuna River, which is a distributary of the Brahmaputra River and eventually joins the Meghna River and drains into the Bay of Bengal. The meeting of these three rivers- Padma, Jamuna and Megha lead to the formation of one of the largest delta systems in the world, known as the Sunderban Delta. The delta is the home of Bengal tigers and has numerous flora and fauna.

Ganga River has many right-bank and left-bank tributaries such as Yamuna, Ghaghara, Gandak, Kosi, Damodar, Son and several others. All these tributaries feed the Ganga River and therefore support the fertile land of northern India. Here, we will discuss the three major tributaries of the Ganga.


Yamuna is the largest tributary of the Ganga (1376 km) which originates from the Yamunotri glacier in Uttarakhand. Just like Ganga, the Yamuna river is highly revered in Hinduism and worshipped as the Goddess Yamuna. It merges with Ganga at Triveni Sangam in Prayagraj, where a Hindu festival called Kumbh Mela is celebrated every 12 years. The river flows through Haryana, Uttarakhand, and Delhi and meets with many tributaries along the way.


Kosi is another vital tributary of the Ganga, which originates from the glaciers of the Himalayan region in Nepal and Tibet. After flowing through Nepal, it enters the Bihar near Kursela in the Katihar district, where it joins the Ganga River. As we have mentioned above. Koshi often changes its course, resulting in the loss of thousands of lives and extensive property damage as well. However, governments are making efforts to control the devastation it causes by constructing embankments. Also note that despite its destructive nature, it also provides water for irrigation to the people of Bihar.


Damodar is a crucial tributary (Not direct) of Ganga which arises from the Chota Nagpur plateau in Jharkhand. Before entering West Bengal, it joins the distributary of the river Ganga and flows through Jharkhand. Damodar River has a total length of about 592 kilometres.

The Brahmaputra River System

After Ganga, the Brahmaputra river system has the largest draining potential. It provides our northeastern states fertile lands that support their agricultural activities and help grow their economy. The rivers that constitute the Brahmaputra river system flow through China, Bangladesh and India’s northeastern states.

Brahmaputra and its tributaries

The Brahmaputra is the lifeline of the northeastern states of India as it plays a vital role in supporting the region's economy (If we keep the flooding to one side). Mansarovar Lake region, near Mount Kailash (Tibet), is the source of the Brahmaputra River. It carves beautiful gorges in the Himalayan region before entering Arunachal Pradesh.

At Arunachal Pradesh, numerous tributaries join the Brahmaputra River, which helps the river gain its momentum and volume. However, when the Brahmaputra enters Assam, it slows down, which leads to the formation of floodplains. These floodplains are some of the most fertile lands in India, so they support a lot of agricultural activities.

After flowing through Assam, the Brahmaputra River crosses the India and Bangladesh boundary at Dubri, leaving India and entering Bangladesh, where it joins the Ganga River to form the Sunderban Delta, which we have discussed above. The average width of the Brahmaputra River is 5.46 kilometres, and it flows in the region which receives heavy rainfall,  leading to floods in Assam. The regions where the Brahmaputra flows (Arunachal Pradesh, Assam, Meghalaya, Nagaland, West Bengal and Sikkim) are the greenest part of India, which constitutes about 56% of India’s forest cover.

The Brahmaputra receives many tributaries such as Lhase He, Nyang Qu, Subansiri and many more. Some of its tributaries originate from India and some from other nations, such as China. For example, Subansiri, Kameng, Manas, and Dibang are its Indian tributaries, whereas Tsangpo, Dihang, Sankosh and Teesta are tributaries of other nations. The geography curriculum of the best schools in Nalagarh will give you deeper insights into these tributaries, helping you get a better understanding of the Brahmaputra River and its tributaries.

Peninsular Drainage system

The peninsular drainage system is another vital drainage system in India. And you might be surprised to know that it is older than the Himalayas. Almost all peninsular rivers flow from east to west, except Narmada and Tapi, which flow from west to east. Peninsular rivers get water from rainfall due to which their discharge is less during summer. However, they follow a shallower course as compared to their Himalayan counterparts. The peninsular rivers such as The Mahanadi, The Godavari and The Krishna flow eastwards and drain into the Bay of Bengal. Let's explore more about the Peninsular rivers of India.

The Godavari

The Godavari, or “Dakshin Ganga” is the largest peninsular river, which begins its journey from the western ghats in Nashik, Maharashtra. The total length of the river is approx 1465 km, and it drains into the Bay of Bengal. Some tributaries of the Godavari River are Pruna, Wardha, Wainganga, Penganga, Parhita and many more.

The Krishna

The Krishna is one of the longest rivers in India, about 1290 kilometres. Starting from the western ghats near the town of Mahabaleshwar, it flows to the east and then takes a southeastern direction to past Sangli (A town in Maharashtra) to enter the Karnataka state. It flows through central Karnataka and then enters into Telangana. After Telangana, it enters Andhra Pradesh and Vijayawada and finally drains into the Bay of Bengal.

The Mahanadi river

The Mahandi River emerges from the hills of Chhattisgarh and drains into the Bay of Bengal. With a total length of 851km, it is the third largest peninsular river after Godavari and Krishna. After the Senoth River joins it in Chattisgarh, it turns east and enters the Odisha state. It is the largest river in Odisha and supports the economy of Odisha and adjacent states where its basin is located.

The Kaveri

The Kaveri River originates from the Brahmagiri range of western ghats, Kadagu district, Karnataka. From there, it moves towards the state of Tamil Nadu and then breaks down into several distributaries, which make a wide delta called the Garden of Southern India and finally empty into the Bay of Bengal. Also, note that Kaveri is a very sacred river, and many temples are built across its banks.  

The Narmada

The source of the Narmada River is Narmada Kund, which is located in the Amarkantak hills of Madhya Pradesh, where it moves towards the west in a rift valley. Some other peninsular rivers that flow through Rift Valley are the Damodar River and Tapti River. Narmada is the largest river in Madhya Pradesh and flows through Gujarat and Madhya Pradesh. During its journey towards the sea, it forms many picturesque locations such as Marble Rocks near Jabalpur and Dhuandhar Falls.

The Tapti

The Tapti River flows parallel to the Narmada River in a rift valley and emerges from the Multai reserve forest in Madhya Pradesh. The river is 724 km long and flows through Gujarat, Madhya Pradesh and Maharashtra. Tapti is named after the Goddess Tapti, who is the daughter of the sun god- Surya.

The bottom line

India’s drainage system is such a vast and complex topic that even a 5000-word article cannot do justice to it. We have tried our level best to provide you with in-depth insights and essential information about this subject. Our aim is to help you understand the major drainage systems of India, so you can appreciate their role in our cultural heritage, ecology and economy.