Laguna de Bay - Geography

Geography

The middle part of Laguna de Bay between Mount Sembrano and Talim Island, is the Laguna Caldera believed to have been formed by two major volcanic eruptions, around 1 million and 27,000-29,000 years ago. Remnants of its volcanic history are shown by the presence of a maar at the southern end of Talim Island and a solfataric field in Jala Jala.

Laguna de Bay is a large shallow freshwater body in the heart of Luzon Island with an aggregate area of about 911 km2 (352 sq mi) and a shoreline of 220 km (140 mi). It is considered to be the third largest inland body of water in Southeast Asia after Tonle Sap in Cambodia and Lake Toba in Sumatra, Indonesia. Laguna de Bay is bordered by the province of Laguna in the east, west and southwest, the province of Rizal in the north to northeast, and Metropolitan Manila in the northwest. The lake has an average depth of 2.8 metres (9 ft 2 in) and its excess water is discharged through the Pasig River.

The lake is fed by 45,000 km2 (17,000 sq mi) of catchment areas and its 21 major tributaries. Among these are the Pagsanjan River which is the source of 35% of the Lake's water, the Santa Cruz River which is the source of 15% of the Lake's water, the Balanak River, the Marikina River, the Mangangate River, the Tunasan River, the San Pedro River, the Cabuyao River, the San Cristobal River, the San Juan River, the Bay, Calo and Maitem rivers in Bay, the Molawin, Dampalit and Pele rivers in Los Baños, the Pangil River, the Tanay River, the Morong River, the Siniloan River and the Sapang Baho River.