ca. 4 sq km area, located 40 km west of Dehradun, in the west
of Dehradun valley on Dehradun-Paonta road. The barrage is
287.5 m long, the river bed being 389.4 m above sea level,
with minimum and maximum water levels respectively at 402.4 m
and 403.3 m. The Asan reservoir exists throughout the year and
is fed from the river Asan and the discharge channel of Yamuna
through Dhalipur powerhouse. Although the water level is
controlled, it often goes down, and swampy islands in the
middle become visible, attracting a variety of marsh-loving
birds like Egrets, Herons and Lapwings, etc.
Vegetation and Flora in Assan Barrage
The aquatic vegetation of the reservoir consists of Eichhornia
crassips, Potamogeton pectinatus, Typha elephantina, and
Ceratophyllum demersum. The surrounding bushes include
Xanthium strumarium, Eclipta prostrata, Ipomoea sp., Mimosa
pudica, Achyranthus aspera, Polygonum glabrum, P. lanigerum,
Aeschynomene sp., Ageratum conyzoides, phyllanthus sp.,
Monochoria hastata, Mosla dianthera, and Lantana camara. On
the southern side, agricultural fields surround the barrage.
Further south there is mixed forest in Siwaliks comprising
principally Shorea robusta, Anogeissus Latifolia, Lannea
coromandelica, Dalbergia sissoo, and Bombax ceiba.
Birds in the Assan Barrage Bird Sanctuary
The Asan reservoir attracts 53 species of water birds out of
which 19 are winter migrants from Eurasia. During winter
months 90% of the water birds population comprises of 11
migratory species, namely Brahminy Duck, Pintail, Red Crested
Pochard, Gadwall, Common Pochard, Mallard, Coot, Wigeon,
Common Teal, Tufted Duck, and Shoveller.
How to reach Assan Barrage Bird Sanctuary
The peripheral road has become a preferred
route from Himachal, Punjab, Haryana and Chandigarh.