river in southern Kerala state, southwestern India. Periyar is also the name given to a lake in the river's course. The river, 140 miles (225 km) long, rises in the Western Ghats range near the border with Tamil Nadu state and flows north to Periyar Lake near Kottayam. The lake, 12 square miles (31 square km) in area, is an artificial reservoir created by damming the river. It lies at an elevation of about 2,800 feet (850 metres), is ringed by mountain peaks, and is surrounded by a wildlife sanctuary. A tunnel carries water from the lake eastward through the mountains to the Vaigai River in Tamil Nadu, where it is used for irrigation. From the lake the Periyar River flows in a generally northwest direction through the mountains and onto the coastal plain, past Alwaye, emptying into the Arabian Sea at Parur. Further development of the river during the late 20th century included construction of a hydroelectric project and another irrigation dam.