The Davao River is the third largest river catchment on the Island of Mindanao and is the 10th longest river in the Philippines. It drains an area of over 1700 km² with a river length of 160 km. Davao River curves its way in Davao Region particularly in the province of Bukidnon.
River discharge measurements taken from 1984 to 1990 indicated an average river flow of approximately 78 cubic meters per second for the period. Davao River is also the main source of drinking water in Davao City.
9. Chico River (174.67 km)
The Chico River is a river system in the island of Luzon, encompassing the regions of Cordillera and Cagayan Valley. It is the longest tributary of the Cagayan River.
The most extensive river in the Cordillera region, it covers the provinces of Mountain Province, Kalinga and Cagayan. It is referred to as a “river of life” for the Kalinga people who live on its banks, and is well known among development workers because of the Chico River Dam Project, an electric power generation project which local residents resisted for three decades before it was finally shelved in the 1980s – a landmark case study concerning ancestral domain issues in the Philippines.
8. Abulog River (175 km)
The Abulog or Abulug is the 9th largest river system in the Philippines in terms of watershed size, and eight longest rivers. It has an estimated drainage area of 3,372 square kilometres (1,302 sq mi) and a length of 175 kilometres (109 mi) from its source in the mountains of Apayao in the Cordillera Administrative Region. More than 90% of the drainage area of the river is located in Apayao province while the remaining, including the mouth of the river, is in Cagayan province.
7. Abra River (178 km)
The Abra River is the sixth-largest river system in the Philippines in terms of watershed size, and seventh-longest. It has an estimated drainage area of 5,125 square kilometres and a length of 178 kilometres from its source in the vicinity of Mount Data in the Benguet province.
The river originates in the southern section of Mount Data. It descends westward to Cervantes, Ilocos Sur, and flows into Abra province. At a point near the municipality of Dolores, it is joined by the Tineg River, which originates in the uplands of Abra.
6. Agno River (206 km)
Agno River or Pangasinan River is a river on the island of Luzon in the Philippines. Traversing the provinces of Benguet and Pangasinan, it is one of the largest river systems in the country with a drainage area of 5,952 km².
It originates in the Cordillera Mountains and empties into the South China Sea via the Lingayen Gulf. The river is 206 km long. Roughly 2 million people live in the Agno River Valley and it comprises one of Philippines’ larger population clusters.
The river is dammed by three hydroelectric power plants; the Ambuklao Dam in Bokod, the Binga Dam in Itogon, and the San Roque Dam in San Manuel.
The Agno is the largest Philippine river in terms of water discharge, draining around 6.6 cubic kilometres of freshwater into Lingayen Gulf, or almost 70% of the total freshwater input into the gulf.
5. Pampanga River (260 km)
Pampanga River is the second largest river on the island of Luzon in the Philippines (next to Cagayan River) and the country’s fourth longest river. It is in the Central Luzon region and traverses the provinces of Pampanga, Bulacan, and Nueva Ecija.
Its headwaters are at the Sierra Madre and runs south and southwesterly course for about 260 kilometres until it drains into Manila Bay.
At the higher sections of the basin, dams — especially the Pantabangan Dam in Pantabangan, Nueva Ecija — provide irrigation for farms in the province of Nueva Ecija.
At the lower sections of the basin, where the Pampanga delta lies, the Pampanga River system divides into small branches, crisscrossed with fishponds to form a network of sluggish, tidal flats and canals, which eventually find their way to Manila Bay.
4. Pulangi River (320 km)
The Pulangi River also spelt Pulangui, is the longest river in Bukidnon. It is one of the major tributaries of the Rio Grande de Mindanao, an extensive river system in Mindanao, Philippines. It has a length of 320 kilometres and traverses through the majority of the cities and municipalities of Bukidnon from its source in Barangay Kalabugao, Impasugong, Bukidnon.
Pulangi has one reservoir type power plant, the Pulangi IV Hydroelectric Plant and watershed. The Pulangi IV Hydroelectric Plant has a capacity of 255 megawatts and provides for 25% of Mindanao’s power needs. The reservoir and dam is also the main water source for the province of Bukidnon, both for drinking water and for irrigation through the National Irrigation Administration (NIA).
The Pulangi IV Hydroelectric Plant watershed (also known as the Upper Pulangi Watershed) is the second-largest watershed in the Philippines, covering an area of around 1.8 million hectares. It has ten catchments and covers the cities and municipalities of Impasugong, Cabanglasan, San Fernando, Lantapan, Maramag, Quezon, Valencia City, and Malaybalay City.
3. Rio Grande de Mindanao (320 km)
The Rio Grande de Mindanao, also known as the Mindanao River is the third-longest and second largest river system in the Philippines, located on the southern island of Mindanao. It has a drainage area of 23,169 km2 (8,946 sq mi), draining the majority of the central and eastern portion of the island. With a total length of approximately 320 km (200 mi). It is an important transportation artery on the island, used mainly in transporting agricultural products and, formerly, timber.
Its headwaters are in the mountains of Impasugong, Bukidnon, south of Gingoog City in Misamis Oriental, where it is called the Pulangi River. Joining the Kabacan River, it becomes the Mindanao River. Flowing out of the mountains, it forms the centre of a broad, fertile plain in the south-central portion of the island. Before its mouth in the Illana Bay, it splits into two parallel sections, the Cotabato and Tamontaka, separated by a 180 meters (590 ft) hill.
Population centres along the river include Cotabato City, Datu Piang, and Midsayap.
2. Agusan River (350 km)
Agusan River is located in the north-eastern part of Mindanao island, draining the majority of the Caraga Region and some parts of Compostela Valley province. It is the country’s third-largest river basin (after Cagayan River and Rio Grande de Mindanao) with a total drainage area of 11,937 square kilometres (4,609 sq mi) and an estimated length of 350 kilometres (220 mi) from its origin, making it the second-longest river in the Philippines after Cagayan River.
One of the prominent features in the Agusan River basin is the presence of the Agusan Marsh covering a total area of 19,197 hectares. The marsh serves a flood retention basin for the Agusan River, cutting the high discharge of water causing flash floods in the lower reaches of the river. Aside from that, the marsh harbours unique and pristine habitats like the sago and peat swamps forest and is home to endangered and endemic flora and fauna.
1. Cagayan River (350 km)
The Cagayan River, also known as the Rio Grande de Cagayan, is the longest river in the Philippines and the largest river by discharge volume of water (followed by Rio Grande de Mindanao). It has a total length of approximately 350 kilometres (220 mi) and a drainage basin covering 27,753 square kilometres (10,715 sq mi). It is located in the Cagayan Valley region in the northeastern part of Luzon Island and traverses the provinces of Nueva Vizcaya, Quirino, Isabela and Cagayan.
The river’s headwaters are at the Caraballo Mountains of the Central Luzon at an elevation of approximately 1,524 meters (5,000 ft). The river flows north for some 350 kilometres (220 mi) to its mouth at the Babuyan Channel near the town of Aparri, Cagayan. The river drops rapidly to 91 meters (299 ft) above sea level some 227 kilometres (141 mi) from the river mouth. Its principal tributaries are the Pinacanauan, Chico, Siffu, Mallig, Magat and Ilagan Rivers.
The river traverses four provinces: Nueva Vizcaya, Quirino, Isabela and Cagayan. These provinces have an approximate population of two million people, mostly farmers and indigenous tribesmen.