Kanwar Lake – Bihar’s Neglected Wetland Gem

Kanwar Lake

Bihar’s only wetland of international importance, Kanwar Lake, is facing neglect despite being designated a Ramsar site in August 2020. According to recent news reports (Oct, 2023), the water levels in the lake are significantly low this year due to deficit rainfall. Local communities like fisherfolk that are dependent on the lake are bearing the brunt, with declining fish catch affecting their livelihoods.

Kanwar Lake is also an important stopover for migratory birds along the Central Asian flyway, but threats like hunting prevail. There is limited implementation seen on the ground despite policies and meetings for conserving the lake. Environmentalists have warned that if timely action is not taken, the threats of urbanization, agriculture and reduced water inflow could destroy Kanwar Lake.

Kanwar LakeDetails
Location and FormationGandak-Kosi interfan, North Bihar plainsResult of Gandak river meanderingEncircled by Burhi Gandak river basin
Hydrological RegimesInfluenced by rainfall, river flows, groundwater rechargeHigh siltation causing reduced depth/capacity
Biodiversity Values50+ fish species, endangered migratory waterbirdsChanging aquatic vegetation
Threats and ChallengesDisrupted hydrology, poaching, land encroachmentSiltation and pollutionInadequate conservation plan execution
Conservation EffortsDesignated Ramsar Site in 2020

Geography and Hydrology

Location and Formation

  • Part of Gandak-Kosi interfan area in North Bihar plains
  • Formed due to meandering of Gandak river
  • Surrounded by Burhi Gandak river basin

Kanwar Lake is located in the Gandak-Kosi interfan area in the North Bihar plains. It is a residual oxbow lake formed due to the constant meandering and shifting of the Gandak river over centuries. The lake is surrounded by the basin of the Burhi Gandak river on all sides. The Burhi Gandak flows around the lake before meeting the Ganga river downstream.

Catchment and Hydrological Regimes

  • Rainfall, river overbank flows, groundwater recharge
  • Water quality, sedimentation patterns

The hydrological regimes of Kanwar Lake are defined by its location within the Burhi Gandak river basin. The lake receives water from rainfall during the monsoons, overbank flows from the Burhi Gandak during peak monsoons, and groundwater recharge. Water quality monitoring indicates the lake to be alkaline, with high nutrient levels. Sedimentation patterns show high siltation, reducing the depth and water holding capacity of the lake.

Kanwar Lake Location Map

Kanwar Lake Map

Significance

  • Asia’s largest freshwater oxbow lake in Begusarai district, Bihar
  • Only Ramsar site in Bihar, designated in August 2020
  • Important stopover for migratory birds on Central Asian Flyway
  • Valuable site for fish biodiversity with over 50 species

Kanwar Lake, also known as Kabartal Jheel, is located in Begusarai district of Bihar. It is Asia’s largest freshwater oxbow lake formed due to the meandering of Gandak river, which is a major tributary of Ganga. The lake was designated as a Ramsar site in August 2020, making it the only wetland in Bihar to be recognized under the Ramsar Convention for wetlands of international importance.

The lake serves as an important stopover for migratory birds along the Central Asian Flyway, providing a place for 58 migratory waterbird species to rest and refuel during their annual migrations. It is thus a critical site for conservation of avian diversity. Besides migratory birds, Kanwar Lake is also a valuable habitat for native fish biodiversity, with over 50 fish species documented from the site. The biodiversity value of this floodplain wetland ecosystem adds to its ecological significance.

Threatened species

  • 5 critically endangered species inhabit the site

Kanwar Lake is home to 5 critically endangered species as per the IUCN Red List of Threatened Species. Three of these are vulture species – the red-headed vulture, white-rumped vulture and Indian vulture. All three species have suffered severe declines in their populations across the Indian subcontinent and are classified as Critically Endangered.

The other two critically endangered species found in Kanwar Lake are migratory waterbirds – the sociable lapwing and Baer’s pochard. The sociable lapwing is a migratory wader that breeds in central Asia and winters in the Indian subcontinent. Only a few hundred individuals of the sociable lapwing are estimated to remain globally. The Baer’s pochard is a diving duck that migrates from eastern Russia to South and Southeast Asia for wintering. It has undergone extremely rapid population declines and only a few thousand individuals survive in the wild. Protection of sites like Kanwar Lake is therefore critical for conservation of these threatened species.

Biodiversity Values

Flora

  • Marsh vegetation, aquatic plants
  • Changes over time

Kanwar Lake supports extensive marshes and aquatic vegetation like reeds, sedges, water chestnut and lotus. The composition of aquatic plants has changed over time due to changing hydrological regimes and sedimentation. Several native species have declined while invasive species have spread.

Fauna

  • Fish diversity – over 50 species
  • Waterbirds – migratory birds, threatened species
  • Other wildlife

Kanwar Lake is an important habitat for fish, recording over 50 species. The lake serves as an important stopover site for migratory waterbirds along the Central Asian Flyway. Over 50 migratory species use the lake seasonally. Several threatened waterbirds like the Sociable Lapwing, Baer’s Pochard and three vulture species inhabit the site. Other wildlife found in the lake includes turtles, otters, jackals, mongooses and snakes.

Kanvar Lake Bird Sanctuary
Kanvar Lake Bird Sanctuary

Threats and Challenges

  • Drainage, water abstraction
  • Hunting of migratory birds
  • Encroachment, land use changes
  • Siltation, pollution

Major threats to Kanwar Lake include disruption of hydrological regimes due to drainage and abstraction of water upstream, poaching and hunting of birds, encroachment for agriculture reducing the area of the lake, and heavy siltation due to soil erosion in the catchment. Lack of conservation focus, poor implementation of management plans and continued neglect remain key challenges.

Efforts for Conservation

  • Declared as Ramsar site in 2020
  • Proposals for restoration
  • Challenges in implementation

Kanwar Lake was declared as a Ramsar Site in 2020 given its biodiversity values and ecosystem services. Proposals for desilting, restoring hydrological connectivity and regulating agriculture have been made but implementation remains weak. Coordinated efforts between communities, government agencies and conservation groups are needed to ensure the site’s ecological integrity.

Final Thoughts

In conclusion, Kanwar Lake is a unique floodplain wetland of immense ecological significance but faces severe conservation challenges. Urgent action is needed to manage catchment land use, restore hydrology, regulate resource use and involve local communities before the lake degrades irreversibly. The need of the hour is focused implementation of conservation plans.

FAQ

Which river is Kanwar Lake on?

Kanwar Lake is located on the Gandak River. It is a residual oxbow lake formed due to the constant meandering and shifting of the Gandak river over centuries.

Which is Asia’s largest freshwater oxbow lake?

Kanwar Lake is the largest oxbow lake in India. It is located in the Gandak-Kosi interfan area in the North Bihar plains. The lake was formed due to the meandering of the Gandak River.

Share This Article
UCN Team
UCN Team

UCN Team: Combining expertise in UPSC Exams and Tech to deliver high-resolution, insightful content for aspiring civil servants

Leave a Reply

Your email address will not be published. Required fields are marked *