The Udhwa Lake Bird Sanctuary (ULBS) is located at 24° 57’51” N to 25°1’14”N Latitude and 87°47’40”E to 87°49’27”E Longitude in the Rajmahal Subdivision of Sahebganj district of Jharkhand. The largest natural Gangetic floodplain wetland of Jharkhand was declared a sanctuary in 1991 under the Wildlife Protection Act (1972). The sanctuary comprises of two connected complex wetlands namely the Barhel lake (area of 410 ha) and the Pataura lake (area of 155 ha). The Udhwa lake a natural wetland is situated in the a luvial plains of River Ganga and is surrounded by several hi locks of Rajmahal hi ls. The Udhwa Nala connects the wetland to the Ganges near the Farakka Barrage and it forms the main source of water to the wetland sanctuary. Additionaly, several channels originate from the Rajmahal hi locks and drain into the Berhale lake. The ULBS has a wide variety of habitats each supporting diverse flora and fauna. The Lake is rich in algae (over 41 species) and has 29 species of documented macrophyte that include six species of free floating, 17 species of rooted floating vegetation, seven species of submerged vegetation and six emergent vegetation. Among the vegetation the grass Cyperus tagetum (localy caled petali ) is widespread in the wetland and is localy used for livestock feeding. The fauna comprises of 146 species of birds, over 45 species of fish, mammals including fishing cat and Otter. The ULBS wetland was the only sanctuary in the state of Jharkhand at the time of its separation from Bihar. The wetland provides habitats for over 146 birds that comprise of 80 species of water and water dependent birds. Further 79 species are resident while 39 are migrant and 28 species are resident migrants. The wetland has around 14 species categorized as threatened as per the IUCN Red list. These include the Asian Wooly-necked Stork, Lesser Adjutant Stork, Common Pochard etc. Considering the diversity and abundance of birds in the wetland ULBS is also designated as Important Bird and Biodiversity Area (IBA) during 2016. The wetland complex forms an important landscape in the Central Asian fly way with the large number of birds that visit the wetland during the winters. Thus, owing to the uniqueness of the wetland landscape located in the Lower Gangetic plains associated with biodiversity, ecosystem services and climate co-benefits (both tangible and non-tangible) makes the protection, management and conservation a priority for the Udhwa lake.

A wetland should be considered internationally important if it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.

A wetland should be considered internationally important if it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.

A wetland should be considered internationally important if it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.

A wetland should be considered internationally important if it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.

A wetland should be considered internationally important if it regularly supports 20,000 or more waterbirds.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of waterbird.

A wetland should be considered internationally important if it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages, species interactions and/or populations that are representative of wetland benefits and/or values and thereby contributes to global biological diversity.

A wetland should be considered internationally important if it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of wetland-dependent nonavian animal species.