An Inland wetland of Man-made origin located in the Dry Zone of the North-Western province. The Tabbowa reservoir is a medium sized, shallow water, ancient storage reservoir, constructed by damming the Nanneri Oya, a major tributary of the Mi Oya, for irrigation. The tank and its environs are included within the Karuwalagaswewa Sanctuary, due to its importance as a habitat for elephants and water birds. Aquatic vegetation consists of phytoplankton and rooted and unrooted macrophytes. The peripheral areas of the wetland, including its immediate catchment area comprises mainly of tropical dry/mixed evergreen forest, scrubland and grassland savannah communities. The dominant phytoplankton is the blue green algae, Myxophyceae, while the zooplankton community is dominated by small-sized rotifers. 65 macrophytes have been identified from the wetland and its environs. Grasses such as Cynodon dactylon and sedges dominate the submerged vegetation and the drawdown areas. Unrooted vegetation consists of Naja marina and Lippa nodiflora. On either side of the major inlet of the Nanneri Oya, Carex filicine is the dominant species while there is also a strand of trees and shrubs consisting of species such as Acacia nilotica. Nymphoides indicum and Amaranthus sp. can be found in flooded pools in the drawdown area around the reservoir. Tall trees and shrubs such as Terminalia arjuna, Nauclea orientallis, Barringtonia ceylanica, Syzygium makull, Vitex leucoxylon and Caesalphia bonduce occupy the periphery of the reservoir. About 65 species of plants have been recorded. Economically valuable timber species around the reservoir include Diospyros ebenum, Tectona grandis, Terminalia arjuna, Azadirachta indica, and Manilkara hexandra. A mixture of grasses and sedges thrive on the reservoir's border. The abundance of gastropods, bivalves and chironomid larve in the shallow areas might explain high waterfowl diversity in the wetland. 16 fish, 57 bird, 13 reptile and 12 mammal species have been recorded. Freshwater fish are dominated by exotics such as Oreochromis spp., and Labeo rohita. Among the freshwater fish, Clarias brachysoma is endemic. Aquatic reptiles include Crocodylus palustris and serpents such as Xenochrophis asperrimus (endemic) and Gerarda prevostianus. The tank is ideal feeding habitat for large nesting water birds. The reservoir functions as an important source of water for large mammals such as Elephas maximus, while locally declining mammals such as Lutra lutra and Prionailurus viverrinus have also been recorded in this area. There are considerable traces of ancient settlements in the vicinity, which go back to the commencement of the Vijayan dynasty, 543 BC.

Tabbowa Reservoir Related references