Bangladesh: the longest border and shared rivers

Detail

A newborn neighbour

• Bangladesh was once East Pakistan. It became a free country in 1971, after a war between India and Pakistan.
• Its people speak Bangla (Bengali). People in West Bengal speak the same language, so language and culture link the two sides.
• The India-Bangladesh land border is longer than India's border with China. That makes it India's longest land border.
• On the map (Fig. 2.7), Bangladesh is surrounded by India on three sides (west, north and east). Only its south side opens onto the Bay of Bengal, and a short south-eastern stretch touches Myanmar.

Length of the border, state by state

• Total length: 4,096.7 km [4].
• Five Indian states touch Bangladesh [4]:

State	Border length	Rank
West Bengal	2,216.7 km	1
Tripura	856 km	2
Meghalaya	443 km	3
Mizoram	318 km	4
Assam	263 km	5

• West Bengal has more than half of the whole border. Assam has the shortest stretch.
• Tripura is almost an island of India inside Bangladesh: Bangladesh lies on its north, west and south.

Why this border is hard to guard

• Rivers cross the border many times. A river can shift its course after a flood, so a border line drawn along it can end up on dry land or in mid-stream.
• Chars: sandy islands in a river. They form from silt (fine soil carried by water) and can wash away again within a few years. People farm and live on them, but they are hard to mark and patrol.
• Crowded plains: villages, farms and homes sit right up to the border line. Some houses sit on the border itself.
• Result: fencing is slow and in some places cannot be built at all. This makes smuggling (cattle, drugs, fake currency) and illegal migration live problems.
• Fencing status (2025): 3,232.218 km is fenced. 864.482 km is still open, and 174.514 km of that is "non-feasible": the land is river or marsh, so a fence cannot stand there [4].
• In West Bengal, 1,647.696 km of 2,216.7 km is fenced. Of the 569.004 km gap, 112.780 km cannot be fenced at all [4].

Enclaves and the Land Boundary Agreement (LBA)

• Enclave: a piece of one country that lies fully inside another country. People living there were cut off from their own government: no schools, no police, no proper ID papers.
• Adverse possession: land that legally belongs to one country but is held and farmed by people of the other country.
• How the problem was solved, step by step:
• 1974: the Indira-Mujib Land Boundary Agreement (signed by Indira Gandhi and Sheikh Mujibur Rahman) was signed. It was never fully carried out.
• 2011: a Protocol (an add-on agreement) settled the details that were still open.
• 2015: the Constitution (100th Amendment) Act, 2015 gave Parliament's approval. A constitutional amendment was needed because giving away Indian land changes India's territory.

• 31 July 2015 (midnight): the enclaves were exchanged.

• What was exchanged [2][3]:

	Number	Area	Where
Indian enclaves inside Bangladesh	111	17,160.63 acres	Panchagarh, Lalmonirhat, Kurigram and Nilphamari districts (Bangladesh)
Bangladeshi enclaves inside India	51	7,110.02 acres	All in Cooch Behar district, West Bengal

• India gave more enclave land but gained in adverse possessions. India received 2,777.038 acres and transferred 2,267.682 acres [2][3].
• A joint headcount (14-17 July 2011) found about 51,549 people in the enclaves: 37,334 in Indian enclaves and 14,215 in Bangladeshi enclaves [2].
• Residents chose their citizenship. They could stay where they lived and take that country's citizenship, or move across.
• About 6.1 km of undemarcated border (a stretch never marked on the ground) was fixed. This was in three sectors.
• Sea border: the Bay of Bengal maritime boundary between the two countries was settled by arbitration (a ruling by a neutral tribunal that both sides agree to accept) in 2014 (link india-location).

Shared (transboundary) rivers

• Transboundary river: a river that flows through, or along the border of, two or more countries. What one country does upstream (dams, canals) changes what reaches the country downstream.
• Bangladesh sits at the lower end of the Ganga-Brahmaputra-Meghna system. Most of its water comes from India. So water sharing is a very sensitive issue for Bangladesh.
• These rivers matter for farming, fishing, transport and daily life on both sides.
• India and Bangladesh share 54 rivers. Seven of these were picked as priority rivers for water-sharing frameworks [7].
• Joint Rivers Commission (JRC): a body set up in 1972 to manage the shared rivers together. Its 38th ministerial meeting was held in New Delhi on 25 August 2022 [7].

River (name in Bangladesh)	Where it comes from and goes	Key deal or project
Ganga (Padma)	Rises at Gangotri (Uttarakhand); flows through the plains; crosses into Bangladesh below Farakka (West Bengal); joins the Jamuna, then the Meghna; reaches the Bay of Bengal	Farakka barrage (1975); Ganga Waters Treaty (1996)
Brahmaputra (Jamuna)	Rises in Tibet (as the Tsangpo); flows through Arunachal Pradesh and Assam; enters Bangladesh near Dhubri (Assam)	No water-sharing treaty
Teesta	Rises in the Sikkim Himalaya; flows through Sikkim and north West Bengal; joins the Jamuna in Bangladesh	Water-sharing deal still not signed
Barak (Surma-Kushiyara)	Rises in the Manipur hills; flows through Cachar (Assam); splits into the Surma and Kushiyara at the border; they meet again in Bangladesh to form the Meghna	Kushiyara interim MoU (2022)
Feni	Rises in the Tripura hills; forms the border in south Tripura; flows into the Bay of Bengal	Maitri Setu (2021); Feni water MoU (2019)

Ganga: Farakka barrage and the 1996 Treaty

• Farakka barrage (1975) is in Murshidabad district, West Bengal.
• Cause: silt was choking Kolkata port on the Hooghly.
• Process: the barrage pushes part of the Ganga's water into the Bhagirathi-Hooghly through a feeder canal.

• Result: more water flushes silt out of the Hooghly. But less water reaches Bangladesh in the dry months, which caused a long dispute.

• Ganga Waters Treaty: signed on 12 December 1996, for 30 years [5].

• Water is shared at Farakka, the last control structure on the Ganga in India [5].
• Sharing covers the lean season (1 January to 31 May), counted in 10-day periods, using a formula in the Treaty [5].
• The treaty runs out in December 2026, so talks on renewing it are now a key issue (verify current).

Teesta, Kushiyara and Feni

• Teesta: Bangladesh wants more of its water in the dry season. A deal was ready in 2011 but has not been signed, mainly because West Bengal objected. The Teesta irrigates north Bengal too, so both sides need it in the dry months.
• Kushiyara: an interim MoU was signed on 6 September 2022. India and Bangladesh may each draw up to 153 cusecs in the dry season (1 November to 31 May) [6]. (Cusec: one cubic foot of water flowing past a point each second.) This was the first water-sharing deal since 1996.
• Feni: under a 2019 MoU, India may draw 1.82 cusecs for drinking water for Sabroom town in Tripura [7].
• Maitri Setu ("Friendship Bridge") over the Feni opened in March 2021. It is 1.9 km long and joins Sabroom (Tripura) with Ramgarh (Bangladesh) [8].
• It gives Tripura a short road link to Chittagong port. This helps the landlocked North-East.

The Sundarbans

• Where: the Ganga-Brahmaputra delta on the Bay of Bengal. It is shared by West Bengal (India) and Bangladesh (Fig. 2.8).
• Mangrove: trees and shrubs that grow in salty, muddy water along tropical coasts. Their roots stick up out of the mud to breathe.
• World's largest mangrove forest [9]. It covers about 10,000 sq km [9]. It runs about 260 km along the coast and goes about 80 km inland [11].
• Share: about 60% lies in Bangladesh and the rest in India [9]. (NCERT: "about two-thirds" in Bangladesh in Class 7, Ch 2; "about half" in Class 7, Ch 1.)
• UNESCO World Heritage Site: the Bangladesh part ("The Sundarbans") was listed in 1997 [9]. The Indian part is listed separately as Sundarbans National Park (1987) [10].
• Royal Bengal tiger: the forest holds one of the world's largest tiger groups. These tigers swim long distances and eat fish, crabs and water monitor lizards [9].
• Cyclone shield:
• Thick roots slow down storm waves and the surge of seawater.
• Less water and wind reach the villages behind the forest.

• So the forest saves lives during cyclones (for example, Amphan in 2020).

• Threat: rising sea level.

• Warmer seas expand and ice melts, so the sea rises.
• Salt water moves further inland, and low islands sink under water.
• Mangroves and tiger habitat shrink.

Prelims Hooks

• India-Bangladesh border = 4,096.7 km, India's longest land border, longer than the India-China border.
• State order by border length with Bangladesh: West Bengal (2,216.7) > Tripura (856) > Meghalaya (443) > Mizoram (318) > Assam (263). Trap: Assam has the shortest stretch, not Mizoram.
• Constitution (100th Amendment) Act, 2015 → LBA. Enclaves exchanged on 31 July 2015: 111 Indian (in Bangladesh) for 51 Bangladeshi (in India). All 51 were in Cooch Behar.
• Farakka barrage (1975) is in Murshidabad, West Bengal. It diverts water into the Bhagirathi-Hooghly.
• Ganga Waters Treaty: 12 December 1996, 30 years. Water shared at Farakka in the lean season (1 January–31 May).
• River names in Bangladesh: Ganga = Padma; Brahmaputra = Jamuna; Barak splits into Surma + Kushiyara → Meghna.
• Kushiyara MoU (2022): up to 153 cusecs each. Teesta: no treaty signed.
• Maitri Setu (2021) over the Feni: Sabroom (Tripura) – Ramgarh (Bangladesh).
• Joint Rivers Commission: set up in 1972. India and Bangladesh share 54 rivers.
• Sundarbans: world's largest mangrove forest. About 60% is in Bangladesh. UNESCO listed the Indian part in 1987 and the Bangladesh part in 1997.

Mains Points

• The land and rivers make border management hard (GS-I/GS-III):
• Shifting rivers, chars and crowded plains mean the border cannot be fully fenced (864 km open; 174.5 km cannot be fenced).
• This leads to smuggling and illegal migration.

• What can help: "smart" fencing with sensors, river patrols by boat, and border haats (border markets) for legal trade.

• The LBA (2015) shows how a border dispute can be settled peacefully:

• Swapping 162 enclaves ended the stateless life of about 51,000 people.
• Settling adverse possessions and the 6.1 km gap made the border easy to mark.

• The 2014 sea-boundary ruling also opened the Bay of Bengal for fishing and oil and gas exploration.

• Water sharing (GS-I resources):

• Bangladesh is the lowest country on the Ganga-Brahmaputra-Meghna system, so changes upstream (Farakka, Teesta canals) hit its farms and fisheries.
• The pending Teesta deal and the 2026 renewal of the Ganga Treaty make this a central issue in the relationship.

• River-basin management through the JRC can help on floods, river navigation and silt.

• The Sundarbans (GS-III environment/disaster):

• It shields the coast from cyclones and holds tigers that live in mangroves.
• Rising seas, salt water moving inland and less fresh water reaching the delta all threaten it.
• It needs joint protection by India and Bangladesh, as one shared landscape.