The Site consists of irrigation tanks interconnected by a network of canals built a few centuries ago and fed by the rivers originating from the Western Ghats mountain range. Otherwise it only receives water only through seasonal monsoon rainfall. This wetland is the largest reserve for breeding resident and migratory waterbirds in South India. It is an Important Bird and Biodiversity Area (IBA) on the Central Asian Flyway. Notable waterbird species include Indian pond heron (Ardeola grayii), Eurasian wigeon (Anas penelope), spot-billed pelican (Pelecanus philippensis), oriental darter (Anhinga melanogaster) and Northern pintail (Anas acuta). The wetland supports rich social and cultural heritage as well as the agriculture which is the major source of local people’s livelihoods. It also acts as a buffer against flooding during periods of extreme rainfall. It was declared a Bird Sanctuary in 1994; however some significant threats still affect the wetland including encroachments, household sewage and urban wastewater, the growth of shrimp farms, and other human activities.