In this guide
Every winter, thousands of migratory birds — ducks, geese, waders — arrive at Kanwar Jheel (also called Kabartal) in Begusarai district, after flying from Central Asia and Siberia. The lake, fed by the Burhi Gandak's floodwaters, is one of the largest freshwater oxbow wetlands in Asia. In 2020, it became Bihar's first Ramsar site — a wetland of international importance. It is only the most famous of Bihar's many wetlands.
Types of wetlands in Bihar
| Type | Description | Examples / regions |
|---|---|---|
| Chaur | Saucer-shaped depressions that hold water for much of the year | North Bihar — Darbhanga, Madhubani, Samastipur, Begusarai, Purnia |
| Maun | Oxbow lakes formed when rivers change course | Along the Gandak, Burhi Gandak and Kosi |
| Tal | Low-lying land on the Ganga's south bank, flooded seasonally | Mokama, Barahiya |
| Reservoirs and dams | Human-made | Nagi and Nakti (Jamui) |
| River floodplains | Seasonal wetlands along rivers | Throughout north Bihar |
Ramsar sites of Bihar
| Site | District | Year | Notes |
|---|---|---|---|
| Kanwar Jheel (Kabartal) | Begusarai | 2020 | Bihar's first Ramsar site; oxbow wetland |
| Nagi Dam Bird Sanctuary | Jamui | 2024 | Reservoir wetland |
| Nakti Dam Bird Sanctuary | Jamui | 2024 | Reservoir wetland |
| Gokul Jalashay | Buxar | 2025 | Oxbow wetland on the Ganga floodplain |
| Udaipur Jheel | West Champaran | 2025 | Oxbow lake near Valmiki |
Why wetlands matter
| Value | Explanation |
|---|---|
| Biodiversity | Habitat for resident and migratory birds, fish, turtles, aquatic plants |
| Flood buffering | Absorb and store floodwater, reducing flood peaks |
| Groundwater recharge | Replenish aquifers |
| Livelihoods | Fisheries, makhana cultivation, water chestnut (singhara), fodder, reeds |
| Water quality | Filter sediments and pollutants |
| Culture | Chhath and other festivals on water bodies |
| Carbon storage | Wetland soils store carbon |
Wetlands and makhana
Makhana (fox nut, Euryale ferox) grows in shallow, stagnant water bodies — ponds, chaurs and wetlands — especially in Mithila and the Kosi–Seemanchal region. Bihar produces the vast majority of India's makhana, and Mithila makhana has a GI tag. Makhana cultivation is labour-intensive (harvesting involves diving into ponds), and it supports many families, especially from the Mallah (fishing) community.
The government has promoted makhana through research (the National Research Centre for Makhana at Darbhanga), processing and marketing — and a national Makhana Board was announced in the 2025–26 Union Budget. See our guide on makhana, litchi and GI products.
Threats to wetlands
| Threat | Explanation |
|---|---|
| Drainage and conversion | Wetlands drained for agriculture and housing |
| Encroachment | Settlement around lakes |
| Siltation | Sediment from floods fills wetlands |
| Pollution | Fertiliser and pesticide runoff; sewage |
| Invasive species | Water hyacinth |
| Disruption of hydrology | Embankments cut wetlands off from river floodwaters that used to replenish them |
| Poaching | Of migratory birds |
| Ownership disputes | Unclear rights over land and water in chaurs |
Kanwar Jheel itself has shrunk over the decades due to drainage, siltation and agricultural encroachment.
Conservation
- The Wetlands (Conservation and Management) Rules, 2017 require states to set up State Wetland Authorities — Bihar has one.
- The Jal-Jeevan-Hariyali Abhiyan includes renovation of water bodies.
- Amrit Dharohar (a Union initiative, 2023) promotes the conservation of Ramsar sites through community participation and eco-tourism.
- Integrated management plans for Ramsar sites.
- Community-based fisheries and makhana cultivation can give local people a stake in conservation.
Practice
Prelims-style:
- Which was Bihar's first Ramsar site, and in which district is it?
- What is a chaur?
- What is a maun?
- Where is the National Research Centre for Makhana?
- Under which rules are State Wetland Authorities set up?
Mains-style:
- "Wetlands are north Bihar's natural flood defence." Discuss.
- Examine the threats to Kanwar Jheel and suggest measures for its conservation.
A note on dates and numbers. Exam patterns, vacancies and schedules change from year to year. Always confirm the current details in the latest notification on the Bihar Public Service Commission website .
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