Lake Bato is a freshwater lake and the 7th largest in the Philippines. It is located in the town of Bato, approximately 9 kilometres southwest of Iriga City, Camarines Sur Province, southeastern Luzon, Philippines. It has extensive marshes and swamp forests. The lake drains into a tributary of the Bicol River which enters the sea near Naga City. Average depth i…Lake Bato is a freshwater lake and the 7th largest in the Philippines. It is located in the town of Bato, approximately 9 kilometres southwest of Iriga City, Camarines Sur Province, southeastern Luzon, Philippines. It has extensive marshes and swamp forests. The lake drains into a tributary of the Bicol River which enters the sea near Naga City. Average depth is 8 metres, and the bottom is muddy clay. The pH value is 6.1, the average dissolved oxygen 10 p.p.m., and the total hardness 2.4.