|Most recent IBA monitoring assessment|
|Year of assessment||Threat score (pressure)||Condition score (state)||Action score (response)|
|2003||high||not assessed||not assessed|
|For more information about IBA monitoring please click here|
The Asan Barrage, near village Dhalipur 38 km from Dehra Dun, is located at the confluence of the Yamuna hydel canal (from Dak Pathar which was built in the mid 1970s) and river Asan (a small rainfed tributary of the Yamuna). It is under the control of the Irrigation Department and has an area of 250 ha. When the water level is low, it provides good habitat for waterfowl. The dominant aquatic vegetation comprises of Potamogeton pectinatus, Typha elephantina and Ceratophyllum demersum. The southern side of the barrage is surrounded by agricultural fields. Further south, there is mixed forest typical of the Siwalik hills, consisting chiefly of Shorea robusta, Anogeissus latifolia, Lannea coromandelica, Dalbergia sissoo and Bombax ceiba. Some parts of the reservoir are covered by weeds Eichhornia crassipes and Ipomea fistulosa (Kumar and Porwal 1998).
AVIFAUNA: This IBA has a 30-year old nesting site of the Vulnerable Pallas’s Fishing Eagle Haliaeetus leucoryphus. During winter, it is not unusual to count up to 5,000 waterfowl, with high species diversity, as Asan Barrage has both shallow and deep water and the River Yamuna flows close by. Brahminy Duck Tadorna ferruginea, Mallard Anas platyrhynchos, Red-crested Pochard Rhodonessa rufina, Common Pochard Aythya ferina, Tufted Pochard A. fuligula, Wigeon Anas penelope, Northern Shoveller A. clypeata and Common Teal A. crecca are commonly seen. It is one of the best sites for large congregations of Brahminy Ducks (Kumar and Porwal 1998) and other birds (Gandhi and Singh 1995a, b and Singh 2000). On 12 February, 2003, more than 2,000 were seen (Arun P. Singh pers. comm. 2003). The 1% threshold for this species is 500 (Wetlands International 2002) so the population in this IBA exceeds the threshold four times, thus this site also qualifies A4i criteria. Raptors recorded in this IBA include the Osprey Pandion haliaetus, Marsh Harrier Circus aeruginosus, Steppe Eagle Aquila nipalensis, Oriental Honey Buzzard Pernis ptilorhynchus and Changeable Hawk Eagle Spizaetus cirrhatus. Being located towards the northwest and serving as a halt for Trans-Himalayan migratory birds, the Asan Barrage receives waterfowl migrants which are rare elsewhere. These include the Black-necked Grebe Podiceps nigricollis and Great Crested Grebe P. cristatus. Other rare records include Common Shelduck Tadorna tadorna, Black-necked Stork Ephippiorhynchus asiaticus, and Black-bellied Tern Sterna acuticauda. Altogether, more than 150 species have been recorded in this IBA, including many globally threatened and Near Threatened ones.
OTHER KEY FAUNA: Except for Common Otter Lutra lutra, there is no mammal of conservation concern. The Fishing Cat Prionailurus viverrina could be present but there are no confirmed record.
Key contributors: Arun P. Kumar, Dhananjai Mohan and S. S. Gandhi.
BirdLife International (2022) Important Bird Areas factsheet: Asan Barrage. Downloaded from http://www.birdlife.org on 18/01/2022.