LAGUNA DE BAY
"Laguna de Bay", properly translated, means "The Lake of [the town of] Bay", with the last word pronounced as "Bä'ï." It was named after Bay, a town in Laguna province which once served as the provincial capital.
Alternate spellings of the town's name include "Bae", "Ba-i", and in early colonial times, "Bayi", or "Vahi". The name of the lake is thus sometimes also spelled "Laguna de Bae" or "Laguna de Ba-i", particularly by locals. The town's name is believed to mean "settlement" (bahayan), and is related to the Tagalog words for "house" (bahay), "shore" (baybayin), and "boundary" (baybay), among others.
Confusion about the name would later arise upon the introduction of the English language during the American occupation of the Philippines, because the word "bay" in English refers to a body of water. However, the word "Bay" in Laguna de Bay has always referred to the town.
Another common misconception arises from the word Laguna, which is the Spanish word for lagoon. This body of water, however, is not a mere lagoon but a true lake.
The alternate name "Laguna Lake" is also a misnomer of sorts, translating as "Lagoon Lake." In this case, however, the word "Laguna" refers to the Province of Laguna, and the name asserts the body of water as "the lake of the Province of Laguna."
In the pre-Hispanic era, the lake was known as "Puliran Kasumuran" (Laguna Copperplate Inscription. 900 AD), and later by "Pulilan" (Vocabulario de Lengua Tagala.1613. Pila, Laguna).
The middle part of Laguna de Bay between Mt. 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 square kilometres (352 sq mi) and a shoreline of 220 kilometres (140 mi). It is considered to be the third largest inland body of water in Southeast Asia. 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 southern and eastern portions of Metro Manila occupy a huge portion of its watershed. 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 square kilometres (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 Sta. 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 river, Dampalit, and Pele river, Pele rivers in Los Baños, the Pangil River, the Tanay River, the Morong River, the Siniloan River, and the Sapang Baho River.