The Agusan River is third longest river in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, located in the north-eastern part of

Mindanao Mindanao ( ) ( Jawi: مينداناو) is the second-largest island in the Philippines, after Luzon, and seventh-most populous island in the world. Located in the southern region of the archipelago, the island is part of an island group of t ...

island, draining majority of the Caraga region and some parts of Davao de Oro. It is the country's third largest river (after the Cagayan River and Rio Grande de Mindanao) with a total drainage area of and an estimated length of from its origin.

Geography

The

headwaters The headwaters of a river or stream is the farthest place in that river or stream from its estuary or downstream confluence with another river, as measured along the course of the river. It is also known as a river's source. Definition Th ...

of the river are found in the mountains of Davao de Oro, near its border with Davao Oriental and east of

Tagum Tagum, officially the City of Tagum ( ceb, Dakbayan sa Tagum; fil, Lungsod ng Tagum), is a 1st class Cities of the Philippines#Legal classification, component city and capital of the Davao del Norte, Philippines. According to the 2020 census, it ...

. It flows through the wide Agusan River valley which measures from south to north and varies from in width. Plains of Mindanao It finally drains into the Butuan Bay at its mouth in Butuan. One of the prominent features in the Agusan River basin is the presence of the Agusan Marsh covering a total area of . The

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

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 harbors unique and pristine habitats like the sago and peat swamps forest and is a home to endangered and endemic flora and fauna. As a consequence, it was designated a

wildlife sanctuary A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

by then-President Fidel V. Ramos in 1996.

Watershed

The Agusan River basin is divided into three sub-basins on the basis of topographic features: the upper Agusan River basin, the middle Agusan River basin, and the lower Agusan River basin. The upper Agusan River basin is the section from its

in the mountains of Davao de Oro to Santa Josefa, Agusan del Sur to Veruela, Agusan del Sur, the middle Agusan River basin is the section of the river from

Santa Josefa Santa Josefa, officially the Municipality of Santa Josefa ( ceb, Lungsod sa Santa Josefa; tgl, Bayan ng Santa Josefa), is a 3rd class municipality in the province of Agusan del Sur, Philippines. According to the 2020 census, it has a population ...

to Amparo,

Agusan del Sur Agusan del Sur, officially the Province of Agusan del Sur ( ceb, Habagatang Agusan; Butuanon: ''Probinsya hong Agusan del Sur''; tl, Timog Agusan), is a province in Caraga region, Mindanao, Philippines. Its capital is the municipality of ...

while the lower Agusan River basin is from Amparo to its mouth at Butuan.

References

External links

{{Principal Rivers of the Philippines Rivers of the Philippines Landforms of Agusan del Norte Landforms of Agusan del Sur Landforms of Davao de Oro Butuan

Geography

Watershed

See also

References

External links