Dipor Bil: Assam’s Only Ramsar Wetland with Rich Biodiversity

Introduction

Dipor Bil, also spelled Deepor Beel, is a unique freshwater lake located southwest of Guwahati, Assam. Recognized as the only Ramsar site in the state, this wetland is an ecological hotspot, known for its rich Biodiversity, including rare and endangered bird species. It plays a crucial role in maintaining the environmental balance of the region while also supporting the livelihood of local communities.

A Significant Wetland in Assam

Dipor Bil covers an area of approximately 40 square kilometers, with 4.14 square kilometers designated as a Bird Sanctuary by the Assam government in 1989. It was officially recognized as a Ramsar site in 2002 due to its wetland biodiversity and ecological importance. The wetland functions as a natural drainage system for Guwahati, collecting water from Basistha and Kalmini rivers before draining into the Brahmaputra River through the Khonajan channel.

Home to Rare and Endangered Bird Species

One of the most remarkable features of Dipor Bil is its avian diversity. With around 220 bird species recorded, including 70 migratory species, this wetland is a paradise for ornithologists and nature enthusiasts. Several endangered birds listed in the IUCN Red Data List are found here, such as:

• Spot-billed Pelican (Pelecanus philippensis)
• Greater Adjutant Stork (Leptoptilos dubius)
• Lesser Adjutant Stork (Leptoptilos javanicus)
• Baer’s Pochard (Aythya baeri)
• White-bellied Sea Eagle (Haliaeetus leucogaster)

Siberian Cranes and other migratory birds from Central Asia, China, and Russia visit Dipor Bil during the winter, making it a seasonal hub for diverse avifauna.

A Lifeline for Local Communities

Beyond its ecological importance, Dipor Bil is a vital resource for nearby villages, supporting around 1,200 families. The wetland provides freshwater fish, which is a primary source of protein and income for the local communities. However, overfishing and pollution threaten the wetland’s sustainability, raising concerns about conservation efforts.

The Name and Historical Significance

The name Dipor Bil is believed to have originated from the Sanskrit word ‘Dipa,’ meaning elephant, as wild elephants were once commonly seen in the area. Historically, this wetland served as a docking site during the Ahom and Mughal periods, and it was also linked to the conflicts between these two ruling powers. The site remains an integral part of Assam’s history and cultural heritage.

Climate and Seasonal Changes

Dipor Bil experiences significant seasonal variations in water levels. During peak monsoon, the depth of the beel reaches around four meters, while in the dry season, it reduces to about one meter. The area receives an annual rainfall of approximately 2,500-3,500 mm, with humidity levels varying from 50.5% in winter to 82.5% in summer. The average temperature ranges between 10°C in winter and 32°C in summer.

Flora and Fauna Beyond Birds

While Dipor Bil is famous for its birds, it also harbors diverse aquatic and terrestrial species. The wetland is home to:

• 20 amphibian species
• 12 lizard species
• 18 snake species
• 6 turtle and tortoise species
• A high concentration of indigenous freshwater fish

Aquatic vegetation covers the beel during different seasons, supporting a dynamic ecosystem. Common plants found here include Water Hyacinth (Eichhornia crassipes), Water Lettuce (Pistia stratiotes), Duckweed (Lemna minor), and Red Water Lily (Nymphaea rubra). The surrounding forests consist of tree species such as Teak (Tectona grandis), Banyan (Ficus bengalensis), and Silk Cotton Tree (Bombax malabaricum).

Conservation Challenges

Despite its ecological and cultural importance, Dipor Bil faces multiple threats, including:

• Encroachment and land-use changes
• Industrial and urban pollution
• Unregulated fishing practices
• Loss of aquatic vegetation due to invasive species

Conservation efforts are crucial to preserving this wetland for future generations. Organizations and local authorities have been working to implement sustainable practices and promote awareness about its importance.

Best Time to Experience Dipor Bil

The ideal time to visit Dipor Bil is between October and March, when migratory birds arrive, and the wetland is at its most vibrant. The cooler weather and the presence of thousands of birds make this period perfect for birdwatching and nature observation.

Conclusion

Dipor Bil is more than just a wetland; it is a vital ecological and cultural treasure of Assam. Recognized for its avian diversity, historical relevance, and role in supporting local livelihoods, it remains one of the most significant natural sites in India. With proper conservation efforts, this Ramsar site can continue to thrive as an essential component of Assam’s rich biodiversity.

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