The
Asan Barrage, popularly known as Dhalipur lake, was created in the year
1967 as a result of the construction of Asan barrage at the confluence
of the river Yamuna & Asan through Dhalipur power house. Asan
Barrage is famous for bird watching.
The
Asan reservoir attracts 53 species of water birds of which 19 are winter
migrants from Eurasia. During winter months 90% of the waterbird
population comprises the following 11 migratory species, namely Brahminy
Duck, Pintail, Red Crested Pochard, Gadwall, Common Pochard, Mallard,
Coot, Wigeon, Common Teal, Tufted Duck, and Shoveller.
- Topography
The Asan Reservoir is a small man-made
wetland of ca. 4 sq km area, located 40 km west of Dehradun, in the
west of Dehradun valley on Dehradun-Paonta road. Geographically it
is situated between latitude 30o 24'-30o 28' N and longitude 77o
40'-77o 44' E, near the confluence of the rivers Asan and Yamuna.
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 asl.
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 & Flora
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.
- Birding Season
Arrival & Departure October
November December March-end Or Early April, Sometimes April- end
