Rio Grande de Pampanga

Pampanga River
Rio Grande de Pampanga
Pampanga River with Mount Arayat in the background
Country	Philippines
Region	Central Luzon
City	Cabanatuan, Palayan
Source
- location	Sierra Madre, Central Luzon
Mouth	Manila Bay
- location	Hagonoy, Bulacan, Central Luzon
- elevation	0 m (0 ft)
- coordinates	14°46′N 120°39′E / 14.767°N 120.650°E / 14.767; 120.650Coordinates: 14°46′N 120°39′E / 14.767°N 120.650°E / 14.767; 120.650
Length	260 km (162 mi)
Basin	9,759 km2 (3,768 sq mi)
Drainage area of Pampanga River

Pampanga River (also known as Rio Grande de Pampanga - Great River of Pampanga) is the second largest river in the island of Luzon, next to Cagayan River and the third largest but most important river in the Philippines. It is also the fourth longest river in the Philippines next to Agusan River and Mindanao River. It is located in the Central Luzon region and traverses the provinces of Pampanga, Bulacan, and Nueva Ecija.

Its headwaters are located at the Sierra Madre and runs a south and southwesterly course for about 260 kilometers until it drains into Manila Bay.

The river's basin covers an area of 10,540 km², including the allied basin of Guagua River. The basin is drained through the Pampanga River and via the Labangan Channel into the Manila Bay.

Its main tributaries are Peñaranda and the Coronel-Santor Rivers on the eastern side of the basin and the Rio Chico River from the northwest side. The Angat River joins the Pampanga River at Calumpit, Bulacan via the Bagbag River. Mount Arayat (elevation: 1,026) stands in the middle of the basin. Southeast of Mount Arayat and the Pampanga River is the Candaba Swamp, covering an area of some 250 km². absorbing most of the flood flows from the western slopes of a portion of the Sierra Madre and the overflowing of the Pampanga River via the Cabiao Floodway. This area is submerged during the rainy season but is relatively dry during summer.

The basin experiences, on an average, at least one flooding in a year. The dry season generally occurs from December to May, and wet the rest of the year. The wettest months are from July to September.The Pampanga River Basin could handle between 100-130mm of 24 Hour Rainfall.

Extensive flooding occurred at the Pampanga River Basin in July 1962, May 1966, May 1976, October 1993, August 2003, August 2004, Late September–October 2009, and August 2012. The flooding the occurred in September 2011 associated with Pedring (Typhoon Nesat (2011)) nearly swallowed the Province of Pampanga and Southern parts of Bulacan