In the Philippines, there are 421 principal rivers — rivers with a catchment area larger than 40 square kilometers.
Do you know any of them?
Have you been to one before?
Is there a river near where you live?
Rivers are amazing places. They are a source of water for humans, a home to many other creatures, and they can even be a watery “road” that people can use to get from one place to another. If you live near a clean, healthy river — or even if you’ve just been able to visit and bathe in and play in one — you’re very lucky!
Unfortunately, not all our rivers are clean or healthy, and if we don’t take care of them, there might soon be none. That’s why it’s important for us to get to know our rivers, to appreciate them, to learn their importance, and to find out how we can protect them.
Among the 421 major rivers in the Philippines, perhaps the most well-known is the Pasig River.
At only 25 km long, it is far from the longest river in the Philippines, nor is it particularly beautiful. However, the Pasig River is among the most well-known rivers in the Philippines because it flows through the capital city of Manila, as well as many other major cities in the Metro Manila area, and some very famous landmarks can be found along its banks such as Malacañang Palace and Intramuros.
The source of the Pasig River is Laguna de Bay, the largest lake in the Philippines. From there, it passes between Taguig and Taytay, Rizal; then it goes through the city of Pasig, from where it gets its name; then it flows between Mandaluyong, Makati, and Manila; and finally empties into Manila Bay.
Did you know that — contrary to what most of us know about the water in rivers flowing towards the sea — the water in the Pasig River sometimes flows backwards? During some parts of the year, the water actually flows from Manila Bay to Laguna de Bay. That happens during high tide in the dry season, when the water level in Laguna de Bay is low, and the tide in Manila Bay is high. Since water always flows from a higher level to a lower level, the flow of the Pasig River is temporarily reversed. However, when low tide sets in, or when the country goes into its wet season and the water level in Laguna de Bay becomes high again, the flow of the Pasig River goes back to its original direction towards Manila Bay.
Another interesting thing about the Pasig River is that it actually has an island in the middle of it. The island is called the Isla de Convalecencia and it is the home of the Hospicio de San Jose, which takes care of orphans, the elderly, and other abandoned people.
The Pasig River, unfortunately, is also known for one other thing: pollution. Various groups have tried to act on the problem of pollution in the Pasig River but it still hasn’t been completely solved. And not only is the river itself polluted — because of the garbage and sewage dumped into it by both factories and humans — it has also been identified by a study published just this April 2021 as the no. 1 river in the world that contributes the most to ocean plastic pollution. That’s not the kind of no. 1 ranking we want to be known for. And think about it: the Pasig River wasn’t always polluted or polluting. There was a time when it was clean and healthy and full of living things. But because of the mindless abuse of humans, it is now biologically dead and a major contributor to world pollution.
But for all its huge impact, the Pasig River is not even anywhere near the longest river in the Philippines.
Do you know which river is the longest river in the Philippines?
Do you think it would be in Luzon, Visayas, or Mindanao?
Unsurprisingly, the longest river in the Philippines is in the largest island in the Philippines. That island is, of course, Luzon, and that river is the Cagayan River.
Also known as the Rio Grande de Cagayan, the Cagayan River is 505 km long. It starts at the Caraballo Mountains in the center of Luzon, and it passes through four provinces — Nueva Vizcaya, Quirino, Isabela and Cagayan — before emptying into the Babuyan Channel, at its river mouth in the town of Aparri, in the province of Cagayan.
Along its way, the Cagayan River passes through one of the few remaining primary forests in the Philippines, where a lot of endangered and endemic species live, such as the Philippine eagle, the Luzon bleeding heart pigeon, and the lobed river mullet (ludong). The river also supports a fertile valley where crops such as rice, corn, coconuts, and bananas are grown. Finally, it traverses four Philippine provinces, which are home to approximately 2 million people, including indigenous tribes and farmers. In short, the Cagayan River is an important part of the ecosystem in northeast Luzon.
The second longest river in the Philippines is found in — you guessed it! — the second largest island in the Philippines. The Rio Grande de Mindanao, also known as the Mindanao River, is 373 km long. Its headwaters are in the town of Impasug-ong, in the province of Bukidnon, part of the Central Mindanao Highlands. From Impasug-ong, it flows south across the Bukidnon Plateau, goes down to the Cotabato plains, veers west, and finally empties into Illana Bay (also known as Iranun Bay) at its river mouth in Cotabato City.
The third longest river in the Philippines is also in Mindanao: the Agusan River, which is 349 km long. Its headwaters are in Mount Tagubud (also called Mount Pandadagsaan or White Peak) in the province of Davao de Oro. From there, it flows north, through the Agusan River Valley, and finally empties into Butuan Bay at its river mouth in Butuan City.
Part of the drainage basin of the Agusan River is the Agusan Marsh. It is a vast wetland biome, home to peat swamp forests, thousands of migratory birds, crocodiles, fresh water turtles, carp, catfish, and of course, humans, particularly the Manobo tribe. The swamp forests of the marsh contain nearly 15% of the fresh water resources of the whole country. That’s why the Agusan Marsh is considered one of the most ecologically significant wetlands in the Philippines. It’s been designated by the government as a wildlife sanctuary; unfortunately, it is still being threatened by upstream pollution, climate change, and habitat destruction.
The other rivers that make up the top 20 longest rivers in the Philippines are the following: Pulangi River, Pampanga River, Agno River, Ilagan River, Magat River, Abra River, Abulog River, Chico River, Angat River, Panay River Davao River, Amburayan River, Tarlac River, Bicol River, Cagayan de Oro River, Marikina River, and Bued River.
Name of River
Nueva Vizcaya to Cagayan (Luzon)
Rio Grande de Mindanao
Bukidnon to Cotabato (Mindanao)
Davao de Oro to Butuan (Mindanao)
Sierra Madre to Manila Bay (Luzon)
Benguet to Pangasinan (Luzon)
Nueva Vizcaya (Luzon)
Benguet, Abra, Ilocos Sur (Luzon)
Apayao, Cagayan (Luzon)
Mountain Province, Kalinga, Cagayan (Luzon)
Capiz, Iloilo (Visayas)
Bukidnon to Davao City (Mindanao)
Benguet, Ilocos Sur, La Union (Luzon)
Camarines Sur (Luzon)
Cagayan de Oro River
Bukidnon, Misamis Oriental (Luzon)
Rizal Province to Pasig (Luzon)
Benguet to Pangasinan (Luzon)
Only one of the rivers in the top 20 longest rivers in the Philippines is in the Visayas — probably because the Visayas is made up of islands that are much smaller than either Luzon or Mindanao.
But one river in Central Visayas that you might have heard of, despite its relatively short length, is the Loboc River in Bohol. Its source is in the municipality of Carmen and it flows into the Bohol Sea, at its mouth in the town of Loay. The Loboc River is a major tourist destination, and the activities that it offers include river cruising, birding, firefly watching, and even stand-up paddleboarding.
The Bojo River in Aloguinsan, Cebu is another river in the Visayas that is known as an ecotourism destination.
In Mindanao, the Cagayan de Oro River is known for whitewater rafting.
And a river that is a favorite among tourists — although some might say it’s more of a tourist trap — is the Hinatuan Enchanted River in Surigao del Sur.
Finally, a river you should definitely be aware and proud of is the Puerto Princesa Underground River. This river is part of the Puerto Princesa Subterranean River National Park, which has been recognized as a World Heritage Site by UNESCO and as a Ramsar wetland of international importance.
Among the things that make this river special is its underground location — it winds through a cave underground for over 8 km then empties directly into the West Philippine Sea. The national park of which the river is a part has a full mountain-to-sea ecosystem, including a limestone karst landscape and eight intact forest formations: forest on ultramafic soil, forest on limestone soil, montane forest, freshwater swamp forest, lowland evergreen tropical rainforest, riverine forest, beach forest, and mangrove forest. And it is home to around 800 plant species and 233 animal species, including critically endangered animals such as the hawksbill turtle and the Philippine cockatoo; endangered animals such as the green sea turtle and the Nordmann’s greenshank; and endemic bird species such as the Tabon scrub fowl and Palawan peacock pheasant.
All over the Philippines, there are some amazing rivers and river ecosystems.
But if we want them to last — if we want these rivers to still be there for coming generations of Filipinos — we need to protect them. We need to make sure that our human activities do not destroy the delicate balance of life in river ecosystems so that our rivers — in the Philippines and in the world — will always be a source of life and nourishment, not trash and death.
This is a very quick worksheet that will just see if you remember where the longest and most well-known rivers in the Philippines are located.
How many rivers are in the Philippines?
There are 421 principal rivers — rivers with a catchment area larger than 40 square kilometers — in the Philippines.
What are the major rivers in the Philippines?
The three longest rivers in the Philippines are the Cagayan River, the Rio Grande de Mindanao, and the Agusan River. Other ecologically or economically important rivers include the Pasic River, the Loboc River, and the Puerto Princesa Underground River.
What is the biggest river in the Philippines?
In terms of drainage basins, the Cagayan River is the largest river in the Philippines. It is also the longest.