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Laguna de Bay: The Largest Lake in the Philippines

lakeLaguna de Bay
countryPhilippines
surface area898 km2
maximum depth20 m
average depth3 m
lake typeTectonic
length48 km
width41 km
catchment area3,158 km2
altitude2 m
volume3 km3
inflows21 tributaries
outflowsPasig River
islandsTalim, Calamba, Cielito Lindo, Malahi, Bonga
shore length319 km
mixing typePolymictic
settlementsMetropolitan Manila, Laguna, Rizal
residence time207 days
frozenNever freezes
trophic stateEutrophic
originVolcanic
average discharge141 m3 / sec.

Laguna de Bay Information and Facts

Laguna de Bay is the largest lake in the Philippines and the third largest inland body of water in South-East Asia, after Toule Sap of Cambodia and Lake Toba of Sumatra.

Geography and Hydrology

The lake is located 50 kilometers east of Manila, between the provinces Laguna (to the South) and Rizal (to the North). It is bordered by Laguna Province on the east, west and southwest, Rizal Province on the north and northeast and Metropolitan Manila on the northwest.

The lake is shaped like a “W” with two distinct peninsulas on the north. The middle lake lobe between the two fills the large volcanic Laguna Caldera, formed by two volcanic eruptions sometimes between 1 million and 27 000 years ago. There are a total of nine islands on the lake of which the largest is Talim Island, which is part of the division between the West and Center Bay. The island is under the jurisdiction of Cardona and Binangonan. The remnants of the region’s volcanic history appear at the southern end of Talim Island in the form of maar, and in Jaja Jala on a solfataric field.

Laguna de Bay is one of the primary freshwater sources in the Philippines. It has 21 tributaries in total of which the largest is the Pagsanjar River, which brings in 35% of its water. Other important rivers are the Balanak, Marikina, Mangangate, Tunasan and San Pedro. Despite its many tributaries, the lake only has one main outflow, the Pasig River, which drains into Manila Bay.

Because of the low altitude it is situated on, the surrounding low-lying plains often get inundated during the heavy rainy season. During the dry seasons, because of the lower lake levels the water often flows back into the lake from the rivers, changing its salinity. This occurrence is fairly regular and is considered by fishermen a yearly necessary cleansing process that contributes to the diversity of the lake.

The lakeshore is relatively unbalanced, since the eastern bay is less populated whilst the western part is heavily developed. A total of 12 cities, 49 municipalities and numerous villages lie close to the lake with a population of over 6 million.

Importance of Laguna de Bay

The lake is used for many purposes. It represents a major transportation route between the towns and cities lying on its shores. It has been used as a navigation lane for passenger boats since the Spanish era. It is also an important source of water for the Kalayaan Pumped Storage Hydroelectric Project in Kalayaan, province of Laguna. The lake is also a significant fishery, and represents one of the stopping points for many migratory birds. Laguna de Bay is also a prime spot for recreation and is extremely important for local agriculture, since they use it for irrigation.

The lake itself is substantial in the development of the Laguna de Bay Region, therefore its water quality has been carefully monitored. Although it is dealt with more caution than any other lakes in the country, it is still affected by the pressures of local development which include the growth of population, rapid industrialization and resources allocation.

Environmental Issues

The quick development of the area has become a real stress factor for Laguna de Bay. Its waters are used for irrigating large crops of rice paddy and sugarcane fields, coconut plantations, vegetables and fruit. Furthermore, the lake is used as cooling water for local industrial plants, and these plants insert great quantities of chemicals back into the water.

In 1966 the Laguna Lake Development Authority formed, which is an agency focusing on flourishing the lake area in a sustainable manner, aiming not only to develop but also to protect its ecosystem. They confirmed through government data that over 60% of the 8.4 million inhabitants of the lake area dump their solid and liquid waste into either the lake or its many tributaries. 40% of this waste is made up of agricultural elements, 30% is domestic and the remaining 30% industrial waste.

The many chemicals contribute to a rapid algal growth in the lake, which takes oxygen from native fish, eventually killing them, and causing a decline in fish productivity. Local native fish are the Manila catfish, the freshwater eel, goby, Indonesian bard and the common carp. The massive amount of chemicals also contributes to the fall of the phytoplankton community.

There are numerous plans to implement a waste water charge system. This would provide factories enough money to invest in pollution control technology to reflect the damage they’ve cost and the rehabilitation it would need to mend the situation.

For now, an environmental user fee system was installed. The companies which have an unusually high concentration of pollutants are to pay a significant fee depending on the volume of the discharged waste.

Origins of its Name

The lake’s name means “lake of the town of Bay”, referring to the lakeshore town Bay, the former provincial capital of Laguna Province. Alternate spellings are “Bae”, “Ba-I”, “Bayi” and “Vahi”. The lake’s name is sometimes spelled as Laguna de Bae or Laguna de Ba-I by locals. The town’s name originates from the Tagalog word “bahayan” meaning “settlement” and is related to the words “bahay” (house), “baybayin” (shore) and “baybay” (boundary).

During the introduction of the English language in the time of the American occupation, the lake’s name elicited confusion, when the English word “bay” was being mistakenly used for the town, leading to somewhat of a mispronunciation.

The Spanish word “laguna” doesn’t only refer to lagoons, but also to freshwater lakes. The lake’s alternate name “Laguna lake” cites the Province of Laguna, lying south of the lake. During the pre-Hispanic era the lake was known as “Puliran Kasumuran”.

Tourism and Recreation

The lake’s shores have been inhabited for thousands of years, according to the Angono petroglyphs in the lakeshore towns of Binangonan Rizal. There are local guided tours that lead up to the painted caves where one can admire age-old depictions of humans and animals. Plenty of churches were constructed during the Spanish rule, which offer great sights to architecture-fans. One of these spectacular churches is the Nagcaran church and underground cemetery.

Mount Makiling National Park is located south of the lake. It is a dormant volcano, where tourists can go cycling, camping, mountain biking and bird watching. The Mount Makiling Forest Reserve has a total of 2048 plant species, many of which are exotic flowers. The “Mud Springs”, a hot spring where volcanic heat and sulfuric acid break down the rocks into bubbling mud, is also located in the park, together with Makiling Botanical Gardens and the National Art Center. There are numerous modest hotels around Laguna de Bay, but the Manila area is home to a wider accommodation offer, ranging from guesthouses to luxury hotels.

Laguna de Bay Fish Species

Bighead carp
Perch
Carp
Tilapia
Catfish