Eastern Coastal Plains of India
Geography › India: Plains, Plateau, Coasts and Islands · Topic 14.6
The Eastern Coastal Plain stretches from the Subarnarekha river on the West Bengal-Odisha border to Kanyakumari, with an average width of about 120 km, much broader than the west coast. It is built by the deltas of the Mahanadi, Godavari, Krishna and Kaveri and is divided into the Utkal, Andhra and Tamil Nadu plains, also called the Northern Circars and the Carnatic.
5 min read · UPSC Prelims · Geography · India: Plains, Plateau, Coasts and Islands
At a Glance
- Width About 120 km on average
- Extent Subarnarekha to Kanyakumari
- Deltas Mahanadi, Godavari, Krishna, Kaveri
- Lagoons Chilika, Pulicat, Kolleru
- Hazard Cyclones from the Bay of Bengal
- Exam link UPSC Prelims, Geography: India: Plains, Plateau, Coasts and Islands
Where Does It Fit?
This is the sixth topic of the macro on India’s plains, plateau, coasts and islands. The previous topic described the narrow western plain, and this one covers the broad eastern plain with its deltas. The next topic begins the island groups with the Andaman and Nicobar Islands. Previous topic: Western Coastal Plains of India. Next topic: Andaman and Nicobar Islands.
What Are the Divisions of the Eastern Coastal Plain?
In short: the east coast is wide, delta-rich and low, and it faces the cyclones of the Bay of Bengal.
| Division | Extent | Features |
|---|---|---|
| Utkal Plain | Coastal Odisha, from the Subarnarekha to south of Chilika | The Mahanadi delta; Chilika Lake, the largest brackish water lagoon in the country, whose area varies from about 780 sq km in winter to about 1,144 sq km in the monsoon, and which is about 64 km long; low hills to the south of the lake |
| Andhra Plain | South of the Utkal plain up to Pulicat Lake; the Northern Circars between the Mahanadi and Krishna | The Godavari and Krishna deltas have merged into one physiographic unit and have advanced by about 35 km, leaving Kolleru Lake, once a lagoon, far inland; a straight coast with few harbours except Visakhapatnam and Machilipatnam |
| Tamil Nadu Plain | From Pulicat Lake to Kanyakumari, about 675 km, average width about 100 km; the Carnatic between the Krishna and Kaveri | The Kaveri delta, 130 km wide, is the granary of South India; Pulicat Lake is barred by the Sriharikota sand spit, the site of the ISRO launch centre |
Between the Mahanadi and the Krishna the region is called the Northern Circars, and between the Krishna and the Kaveri, the Carnatic. Tamil Nadu and part of Andhra Pradesh together are also known as the Coromandel Coast or the Payan Ghat, as in Coastline of India – Emergence and Submergence.
How Do the Eastern and Western Plains Compare?
| Feature | Eastern Coastal Plain | Western Coastal Plain |
|---|---|---|
| Width | Broad, about 120 km on average | Narrow, about 65 km on average |
| Rivers | Long, east-flowing rivers that form big deltas | Short, steep rivers that form estuaries |
| Coast type | Mostly emergent, smooth, with lagoons | Submerged in the north and emergent in the south |
| Rainfall | Moderate; the Tamil Nadu coast gets most rain from the retreating monsoon in October to December | Heavy, from the southwest monsoon |
| Harbours | Few natural harbours; Visakhapatnam is the best | More natural harbours, such as Mumbai |
| Hazard | Frequent cyclones and storm surges | Floods, landslides and erosion |
The deltas of the Mahanadi, Godavari, Krishna and Kaveri are the rice bowls of the east, irrigated by canal systems, and they continue to grow into the sea, as in Peninsular Drainage and East-Flowing Rivers. The Krishna-Godavari basin holds India’s largest offshore natural gas fields, and the coast has ports at Paradip, Visakhapatnam, Chennai, Ennore, Tuticorin and Haldia. Fishing, salt pans, mangroves such as Bhitarkanika, and prawn farming are other uses.
Why Is the Eastern Plain Vulnerable?
- Cyclones: the Bay of Bengal produces about four times more storms than the Arabian Sea, and most of them hit Odisha, Andhra Pradesh or Tamil Nadu, as in Path, Intensity Scale and Breeding Grounds of Tropical Cyclones. Fani in 2019 and Montha in October 2025, which made landfall between Machilipatnam and Kakinada, are examples.
- Delta subsidence and erosion: dams upstream trap sediment, so deltas receive less silt, while groundwater pumping and sea-level rise lower them relative to the sea; shoreline retreat is visible in parts of Odisha, Andhra Pradesh and Tamil Nadu.
- Salinity: sea water intrusion damages farmland and wells in the lower deltas.
- Lagoon degradation: siltation, pollution and encroachment affect Chilika, Pulicat and Kolleru, though Chilika has been restored through a new channel to the sea and is a Ramsar site with a rich population of migratory birds and Irrawaddy dolphins.
As an analytical point, the east coast shows how the same features, wide plains and big deltas, bring both prosperity and risk. Odisha’s cyclone preparedness since 1999, as in Naming, Warning and Effects of Tropical Cyclones, has made it a model, but deltas need long-term protection through mangrove belts, sediment management and climate-proof infrastructure, as the coast is among the most densely settled and agriculturally productive regions in India.
Why Is This Topic Important?
- Facts Divisions and lagoons asked
- Comparison East versus west plains
- Hazard Cyclones and deltas
What Came Next?
The next topic begins the study of India’s islands with the Andaman and Nicobar Islands. Next topic: Andaman and Nicobar Islands.
Key People and Terms
- Northern Circars Mahanadi to Krishna coast
- Carnatic Krishna to Kaveri coast
- Coromandel Tamil Nadu coast
- Lagoon Shallow water body behind a bar
- Delta Fan of sediment at a river mouth
- Payan Ghat Lowland below the Ghats
Exam Corner
Points to Remember
- Average width is about 120 km.
- Chilika is the largest brackish lagoon.
- Sriharikota bars Pulicat Lake.
- The Kaveri delta is the granary of the south.
- Northern Circars: Mahanadi to Krishna.
Do Not Confuse With
- Northern Circars and Carnatic North versus south of the Krishna
- Chilika and Pulicat Odisha versus Tamil Nadu-Andhra border
- Utkal and Andhra plains Odisha versus Andhra
Memory Hook
Utkal, Circars, Carnatic: Mahanadi, Godavari, Krishna, Kaveri build the rice bowls, and cyclones test them.
Mains Angle
Questions compare the two coasts and ask about vulnerability. These points add depth.
- Origin Deltaic deposition
- Economy Rice and gas
- Risk Cyclones and subsidence
A Question You May Face
An original practice question, not a past paper question.
“Compare the Eastern and Western Coastal Plains of India and discuss the vulnerability of the eastern plain.”
How to Answer
- Divisions Utkal, Andhra, Tamil Nadu.
- Compare Width, rivers, coast.
- Risk Cyclone and subsidence.
- Response Preparedness and mangroves.
GS Relevance
Frequently Asked Questions
What are the divisions of the Eastern Coastal Plain?
The Eastern Coastal Plain is divided into the Utkal plain of Odisha, the Andhra plain including the Northern Circars, and the Tamil Nadu plain, also called the Carnatic and Coromandel. It stretches from the Subarnarekha river to Kanyakumari and has an average width of 120 kilometres.
Which are the Northern Circars and the Carnatic?
The Northern Circars are the coastal districts between the Mahanadi and the Krishna rivers, in Odisha and Andhra Pradesh. The Carnatic is the coastal plain between the Krishna and the Kaveri, in southern Andhra Pradesh and Tamil Nadu. Both are parts of the eastern coastal plain.
Why is the Eastern Coastal Plain wider than the Western Coastal Plain?
The east-flowing rivers are long and bring large amounts of sediment, which build big deltas on a broad plain. The Eastern Ghats are lower and farther from the sea, while the Western Ghats rise sharply close to the coast, and so the plain on the west remains narrow.
What is Chilika Lake?
Chilika Lake in Odisha is a brackish water lagoon, the largest in India, separated from the Bay of Bengal by a sand bar. Its area changes from about 780 square kilometres in winter to over 1,100 in the monsoon, and it is a Ramsar site for migratory birds and Irrawaddy dolphins.
Why is the Eastern Coastal Plain prone to cyclones?
The Bay of Bengal has warm water, which makes it a breeding ground for tropical cyclones that move west and northwest, striking Odisha, Andhra Pradesh and Tamil Nadu. The flat deltas and shallow, funnel-shaped coast make storm surges more destructive, which is why there are mass evacuations.
PYQ Practice — Statement Analysis
1 The Cauvery delta is known as the granary of South India.
It has fertile soil and large-scale irrigation.
2 The Eastern Coastal Plain is narrower than the Western Coastal Plain.
It is broader, about 120 km on average.
3 Pulicat Lake is separated from the sea by the Sriharikota spit.
The ISRO launch site is located there.
4 Chilika is a freshwater lake.
It is a brackish water lagoon.
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