Geography
Drainage System of India
Lakes of India: Types, Major Lakes and Ramsar Wetlands
Lakes of India for CGPSC: tectonic, glacial, lagoon, crater, saline and man-made lakes, superlatives, Ramsar wetlands and Chhattisgarh's Kopra reservoir.
Prerequisites
- Himalayan Rivers: the Jhelum and Wular, centripetal drainage into Loktak, and oxbow lakes in the plains
- Peninsular Rivers: the deltas behind which Chilika, Pulicat and Kolleru lie
- Biodiversity and Conservation: why wetlands are protected
The Hook: Chhattisgarh Gets Its First Ramsar Site
Connect
In 2025, the Kopra reservoir (कोपरा जलाशय) in Bilaspur district became Chhattisgarh’s first Ramsar site, a wetland of international importance. It is a man-made reservoir fed by rain and seasonal streams, yet it qualified because of the birds and the village life it supports.
That raises the bigger question: how are India’s lakes formed, which ones are the “largest” and “longest” that examiners love, and why are wetlands protected?
Why it matters: Prelims asks lake–state pairs, “largest/longest” superlatives, lake origin types (Lonar, Sambhar, Wular) and Ramsar facts. Mains GS-III links lakes to water security, urban flooding and wetland conservation.
Types of Lakes by Origin
A lake (झील) is a body of standing water in a depression. Indian lakes are usually classified by how the depression formed:
| Type | How it forms | Indian examples |
|---|---|---|
| Tectonic (विवर्तनिक) | Earth movements create a basin | Wular (J&K) is usually described as tectonic in origin |
| Glacial (हिमनदीय) | Glaciers scoop out hollows or moraines dam valleys | Many high Himalayan lakes, e.g. Gurudongmar and Tsomgo (Sikkim), Roopkund (Uttarakhand) |
| Lagoon / backwater (लैगून) | Sandbars or spits cut off part of the sea | Chilika (Odisha), Pulicat (AP–Tamil Nadu), Vembanad, Ashtamudi (Kerala) |
| Oxbow (गोखुर झील) | A meander is cut off from the river | Common in the Ganga and Brahmaputra plains |
| Crater (क्रेटर) | Meteorite impact or volcanic crater | Lonar (Buldhana, Maharashtra), a meteorite impact crater in basalt |
| Inland saline / playa | Inland drainage in a dry region; evaporation leaves salt | Sambhar, Didwana, Pachpadra (Rajasthan) |
| Fluvial / floodplain wetlands | Low areas between deltas or in floodplains | Kolleru (between the Godavari and Krishna deltas), Deepor Beel (Assam) |
| Man-made (कृत्रिम) | Reservoirs behind dams and old tanks | Govind Ballabh Pant Sagar (Rihand), Bhojtal (Upper Lake, Bhopal), Hussain Sagar (Hyderabad), Chhattisgarh’s Kopra reservoir |
Major Lakes of India
| Lake | State / UT | Key facts |
|---|---|---|
| Wular (वुलर) | Jammu & Kashmir | Usually called India’s largest freshwater lake; the Jhelum flows through it |
| Dal (डल) | Jammu & Kashmir | Srinagar; houseboats, shikaras and floating gardens |
| Pangong Tso | Ladakh (and Tibet) | Long, narrow, brackish high-altitude lake; the larger part lies in Tibet; on the Line of Actual Control |
| Tso Moriri | Ladakh | High-altitude lake; Ramsar site |
| Loktak (लोकटक) | Manipur | Largest freshwater lake in north-east India; floating vegetation mats called phumdis; Keibul Lamjao National Park, the world’s only floating national park, home of the sangai (brow-antlered deer); centripetal drainage |
| Chilika (चिल्का) | Odisha | India’s largest coastal lagoon (brackish); Irrawaddy dolphins; Nalabana bird sanctuary; one of India’s first two Ramsar sites (1981) |
| Pulicat (पुलिकट) | Andhra Pradesh–Tamil Nadu | Second-largest brackish lagoon in India; the Sriharikota barrier island (ISRO launch centre) separates it from the Bay of Bengal |
| Kolleru (कोलेरू) | Andhra Pradesh | Large shallow freshwater lake between the Godavari and Krishna deltas; Ramsar site |
| Vembanad (वेम्बनाड) | Kerala | Longest lake in India; part of the Kerala backwaters; Kochi port lies at its outlet; boat races on its Punnamada stretch near Alappuzha |
| Sambhar (सांभर) | Rajasthan | India’s largest inland saline lake; salt production; flamingos; Ramsar site |
| Lonar (लोनार) | Maharashtra | Meteorite impact crater lake in basalt; saline and alkaline; Ramsar site (2020) |
| Nainital, Bhimtal | Uttarakhand | Kumaon hill lakes |
| Bhojtal (Upper Lake) | Madhya Pradesh | Bhopal; attributed to Raja Bhoj of the Paramara dynasty; Ramsar site |
| Hussain Sagar | Telangana | Man-made lake in Hyderabad |
| Govind Ballabh Pant Sagar | Uttar Pradesh | Reservoir of the Rihand dam (Sonbhadra), on a river that rises in Chhattisgarh |
Superlatives as usually stated in exams
- Largest freshwater lake: Wular (J&K)
- Largest freshwater lake in the north-east: Loktak (Manipur)
- Largest coastal / brackish lagoon: Chilika (Odisha)
- Largest inland saline lake: Sambhar (Rajasthan)
- Longest lake: Vembanad (Kerala)
- Crater lake in basalt: Lonar (Maharashtra)
Lake areas change with the season, so these rankings are the standard textbook answers rather than precise measured comparisons.
Wetlands and the Ramsar Convention (रामसर अभिसमय)
| Fact | Detail |
|---|---|
| Convention | Convention on Wetlands, signed at Ramsar, Iran, in 1971; World Wetlands Day is 2 February |
| India | Party since 1982; Chilika and Keoladeo (Rajasthan) were designated in 1981, India’s first two sites |
| Number of Indian sites | 100 in June 2026, about 101 by August 2026 (two added before World Wetlands Day 2026). The number has grown fast since 2020 and keeps changing; check the latest figure before the exam |
| Most sites | Tamil Nadu (as of 2026) |
| Chhattisgarh | Kopra reservoir, Bilaspur district: the state’s first Ramsar site (2025) |
| Montreux Record | Register of Ramsar sites under threat. Keoladeo and Loktak are on it; Chilika was placed on it in 1993 and removed in 2002 after restoration |
| Indian law | Wetlands (Conservation and Management) Rules, 2017, under the Environment (Protection) Act, 1986 |
Why lakes and wetlands matter (Mains)
- Flood control: wetlands absorb peak flows; encroached lakes worsen urban flooding (Bengaluru, Chennai, Hyderabad).
- Groundwater recharge and drinking water for cities.
- Biodiversity: migratory birds (Chilika, Keoladeo), endemic species (sangai at Loktak).
- Livelihoods: fishing (Chilika, Kolleru, Loktak), salt (Sambhar), tourism (Dal, Vembanad).
- Climate: wetlands store carbon and moderate local temperatures.
- Threats: encroachment, sewage and eutrophication, invasive weeds (water hyacinth), siltation, aquaculture conversion (Kolleru), hydropower projects (Loktak’s Ithai barrage).
Chhattisgarh angle: Most of Chhattisgarh’s large water bodies are reservoirs (Gangrel, Minimata Hasdeo Bango, Kopra) and traditional village tanks (तालाब), which Raipur and Ratanpur are known for. Their protection is a practical Mains point on water security. See Forests, Wildlife, National Parks and Sanctuaries and Environment and Ecology.
Memory Tricks
Lake superlatives: 'Wise Cats Sleep Very Long'
Wular (largest freshwater), Chilika (largest lagoon), Sambhar (largest saline), Vembanad (longest), Loktak (largest in the north-east, floating park).
Pulicat = Pad for rockets
Pulicat lies behind the barrier island of Sriharikota, ISRO’s launch pad, on the Andhra Pradesh–Tamil Nadu coast north of Chennai.
Don’t Confuse
| This | vs | That |
|---|---|---|
| Chilika: brackish lagoon, Odisha | Kolleru: freshwater lake, Andhra Pradesh | |
| Loktak: phumdis, Keibul Lamjao | Dal: houseboats, Srinagar | |
| Sambhar: inland saline lake (Rajasthan) | Pangong Tso: high-altitude brackish lake (Ladakh) | |
| Lonar: meteorite crater lake | Wular: tectonic lake on the Jhelum | |
| Vembanad: longest lake | Wular: largest freshwater lake | |
| Ramsar Convention: 1971, Iran | India’s accession: 1982; first sites 1981 |
Common Mistakes
Trap 1: Chilika is a freshwater lake
Chilika is a brackish-water lagoon: sea water mixes with river water from distributaries of the Mahanadi delta.
Trap 2: Lonar is volcanic
Lonar lies in the basalt of the Deccan Traps, which were formed by volcanic eruptions, but the crater itself was made by a meteorite impact.
Trap 3: quoting an old Ramsar count
The number of Indian Ramsar sites has changed almost every few months since 2020. Always attach a date (“100 in June 2026, about 101 by August 2026”) and check before the exam.
Trap 4: Chhattisgarh has no Ramsar site
Older books say so, but Kopra reservoir (Bilaspur) was designated in 2025.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- The floating vegetation mats of Loktak lake are called ________.
- India’s largest inland saline lake is ________ in ________.
- Chhattisgarh’s first Ramsar site is ________ in ________ district.
Answers
- Phumdis
- Sambhar; Rajasthan
- Kopra reservoir; Bilaspur
Level 2: Prelims MCQs
Q1. Consider the following statements:
- Lonar lake in Maharashtra was formed by a meteorite impact.
- Pulicat lake is separated from the Bay of Bengal by the island of Sriharikota.
- Kolleru lake is a brackish-water lagoon in Odisha.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
(b) 1 and 2 only. Lonar is a meteorite impact crater in basalt. Sriharikota is the barrier island between Pulicat and the sea. Kolleru is a freshwater lake in Andhra Pradesh, between the Godavari and Krishna deltas; the brackish lagoon in Odisha is Chilika.
Q2. Match List-I (Lake) with List-II (State/UT):
| List-I | List-II |
|---|---|
| A. Vembanad | 1. Manipur |
| B. Loktak | 2. Kerala |
| C. Wular | 3. Rajasthan |
| D. Sambhar | 4. Jammu and Kashmir |
- (a) A-2, B-4, C-1, D-3
- (b) A-1, B-2, C-4, D-3
- (c) A-2, B-1, C-4, D-3
- (d) A-3, B-1, C-4, D-2
Answer and explanation
(c) A-2, B-1, C-4, D-3. Vembanad is in Kerala, Loktak in Manipur, Wular in Jammu and Kashmir, Sambhar in Rajasthan.
Q3. Keibul Lamjao, the only floating national park in the world, is located on which lake?
- (a) Dal
- (b) Loktak
- (c) Chilika
- (d) Deepor Beel
Answer and explanation
(b) Loktak, Manipur. The park rests on phumdis and protects the endangered sangai (brow-antlered deer).
Q4. Which one of the following Indian wetlands was removed from the Montreux Record after successful restoration?
- (a) Keoladeo
- (b) Loktak
- (c) Chilika
- (d) Sambhar
Answer and explanation
(c) Chilika. It was placed on the Montreux Record in 1993 and removed in 2002 after the reopening of a sea mouth improved salinity and fish catch. Keoladeo and Loktak remain on the record.
Q5. The Kopra reservoir, declared a Ramsar site in 2025, is located in which district of Chhattisgarh?
- (a) Bilaspur
- (b) Dhamtari
- (c) Korba
- (d) Raigarh
Answer and explanation
(a) Bilaspur. Kopra reservoir became Chhattisgarh’s first Ramsar site in 2025. Dhamtari has the Gangrel dam and Korba the Minimata (Hasdeo Bango) dam, but neither is a Ramsar site.
Level 3: Mains Answer Writing
Q1. Classify the lakes of India by origin, with one example of each. (60 words)
Model answer outline
- Tectonic: Wular (J&K).
- Glacial: Himalayan lakes such as Gurudongmar (Sikkim).
- Lagoon: Chilika, Pulicat, Vembanad.
- Oxbow: cut-off meanders in the Ganga plain.
- Crater: Lonar (meteorite impact).
- Inland saline: Sambhar (Rajasthan).
- Man-made: Govind Ballabh Pant Sagar, Bhojtal, Kopra reservoir (Chhattisgarh).
Q2. “Wetlands are the kidneys of the landscape.” Examine the importance of wetlands in India and the challenges to their conservation. (150–200 words)
Model answer outline
- Intro: Wetlands filter water and regulate flows. India is a party to the Ramsar Convention (1971) and crossed 100 Ramsar sites in June 2026 (about 101 by August 2026).
- Importance: flood buffering, groundwater recharge, biodiversity and bird habitat (Chilika, Keoladeo), livelihoods (fisheries, salt), carbon storage.
- Challenges: urban encroachment, sewage and eutrophication, invasive species, siltation, aquaculture conversion (Kolleru), altered hydrology from barrages (Loktak).
- Measures: Wetlands Rules 2017; integrated management plans; the restoration of Chilika as a success story; community participation.
- Chhattisgarh angle: Kopra reservoir (first Ramsar site, 2025) and the state’s tradition of village tanks; reviving tanks helps drought-proof the plains.
- Conclusion: Treat wetlands as water infrastructure, not wasteland.
Quick Revision Table
| Fact | Detail |
|---|---|
| Largest freshwater lake | Wular (J&K), on the Jhelum, tectonic |
| Largest in the north-east | Loktak (Manipur); phumdis; Keibul Lamjao; sangai |
| Largest coastal lagoon | Chilika (Odisha); Ramsar 1981; off the Montreux Record in 2002 |
| Second brackish lagoon | Pulicat (AP–TN); Sriharikota |
| Longest lake | Vembanad (Kerala) |
| Largest inland saline lake | Sambhar (Rajasthan) |
| Meteorite crater lake | Lonar (Maharashtra); Ramsar 2020 |
| Freshwater lake between deltas | Kolleru (AP) |
| High-altitude lakes | Pangong Tso (brackish), Tso Moriri (Ladakh) |
| Ramsar Convention | 1971, Ramsar (Iran); World Wetlands Day 2 February |
| Indian Ramsar sites | 100 reached in June 2026 (about 101 by August 2026); Tamil Nadu has the most |
| Chhattisgarh | Kopra reservoir, Bilaspur: first Ramsar site (2025) |
Key Takeaways
Key Takeaways
- Learn lakes by origin: tectonic (Wular), glacial, lagoon (Chilika, Pulicat), oxbow, crater (Lonar), saline (Sambhar), man-made.
- Superlatives: Wular largest freshwater, Chilika largest lagoon, Sambhar largest saline, Vembanad longest.
- Loktak has the phumdis and Keibul Lamjao, the floating national park.
- Ramsar counts change: 100 in June 2026, about 101 by August 2026; always date the figure.
- Kopra reservoir (Bilaspur) became Chhattisgarh’s first Ramsar site in 2025.
What’s Next
- Inter-linking of Rivers: reservoirs and canals at a national scale
- Environment and Ecology: wetlands as ecosystems
- Biodiversity and Conservation: protected areas and international conventions
- Forests, Wildlife, National Parks and Sanctuaries: Chhattisgarh’s protected areas
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