Marikina River

The Marikina River has a number of tributaries in the form of creeks and rivers, and at least one former river-section in Marikina's Barangay Tumana from which the original flow of the river has been diverted. These tributaries drain four municipalities and one city in the province of Rizal, and three cities in the Philippines' National Capital Region.[5]

The biggest of these tributaries are upstream in the more mountainous areas of Rodriguez. This includes the Tayabasan River and Montalban River, the Boso Boso River, and the Wawa River, which meets the Marikina River just upstream of Wawa Dam. Further downstream from the dam, but still in the town of Rodriguez are the Puray River (which flows near Avilon Zoo) and Manga River.[5]

Until this point the river follows a more or less east–west direction until San Jose, Rodriguez, where it takes a sharp north–south turn towards the municipality of San Mateo, where the Ampid River forms the boundary between Barangays Maly and Ampid. At this point across the river in Quezon City, Calamiong Creek drains Barangay Bagong Silang.[6] Further downstream the Nangka River and its own tributary in the Sapang Labo Creek mark the boundary between San Mateo and Marikina.[5][7]

Somewhere north of Brgy. Tumana in Marikina marks a point at which an American Colonial Era levee shifted the flow of Marikina River west, away from the population center of Sitio Bayanbayanan (now known as Concepcion Uno), where erosion had been a problem. The construction of a levee left behind a remnant waterway now known as Patay na Ilog (literally "Dead River", referring to the former path of the river) where the original path of the river once traversed, which rejoins the Marikina River just south of Tumana Bridge. The dredging for this American era levee left behind a large stone outcropping just below water level where the Marikina's children would play, back when the water was still clean, such that this part of the river is still called luksong kabayo.[8]

The name of Barangay Tumana refers to the Tagalog word for a wide level land just above water level. The area was considered ideal for vegetable farming due to the rich riversoil, and the annual inundation of the area by the Marikina River during the rainy season, which prevented crawling insect pests from staying permanently. This area was eventually also used for riversoil quarrying and saw an influx of informal settlers which turned it into a residential area, eventually becoming a separate barangay from Concepcion, with Patay na Ilog forming part of the boundary.[5][8]

Further south on the Quezon City side Barangay Pansol is drained by Pansol Creek, with headwaters reaching as far up to just behind the University of the Philippines Integrated School campus. Even further south in Barangay Malanday, Marikina, the Lamuan-Bulelak creek also empties into the Marikina River, although its precise mouth area has been blurred by the construction of residential buildings.

In Marikina, numerous other creeks flow nearby the Marikina River but are not directly connected. These include the Bankaan Creek in Barangay Parang, the Concepcion Creek in Barangay Concepcion Dos, and the Usiw Creek in Barangay Santa Elena. Instead, these waterways are linked in a complex network with the Balanti, Halang, and Muntingdilao Creeks and the Sapang Baho River, eventually emptying into the Manggahan Floodway and Laguna de Bay.

On September 26, 2009, at about 6:00 pm PST, Typhoon Ondoy hit Metro Manila and dumped one month's rainfall in less than 24 hours, causing the Marikina River system, including the Manggahan Floodway, to burst its banks rapidly. Along with flooding along other river systems, 80 percent of the National Capital Region became flooded. Also flooded were 25 nearby provinces. In Metro Manila alone, 20 feet (6.1 m) of dirty water forced people to evacuate their homes. By September 30 at least 450,000 inhabitants had been displaced, with at last 380,000 forced into makeshift shelters; 246 people were reported dead. It is believed that blocked pipes, a poorly maintained sewerage system, and uncollected domestic waste were major factors in the speed with which the flood waters engulfed the surrounding area. This prompted President Gloria Macapagal Arroyo to declare a State of National Calamity and set up a task force to rescue the inhabitants. However, the government was forced to admit that resources were in short supply and called for global assistance. Thereafter, efforts have been made to make the drainage system better for the whole city by fixing the sewers together with the new trademarked "Red Sidewalks".

This is the worst storm that Metro Manila has experienced since 1967.

On June 24, 2011, heavy rains of Severe Tropical Storm Meari affected Luzon including Metro Manila. The water level in the Marikina River reached its critical level, flooding beside its riverbanks, just near along the river. However, the water level did not reach its higher banks, into the streets and communities. No casualties were reported but the mud and debris from the river was left by overflowed riverbanks.

On September 27, 2011, Typhoon Pedring dumped heavy rains like Ondoy over Luzon including Metro Manila and nearby provinces. Marikina's water level reached a higher level than June 24, 2011, reaching 20.1 metres (66 ft) by 5 pm. The flood submerged houses in several barangays of Marikina and San Mateo. SM City Marikina Basement Parking submerged in muddy water. No deaths were recorded in Marikina, but in San Mateo, there is one. The day after, the Marikina River returned in critical level. On September 29, 2011, 5 am, water subsided in the banks of the river and the residents started to clean. At 6 am, water reached 15.2 metres (50 ft).

Although located hundreds of kilometers away from the Philippines, the southerly flow from Typhoon Haikui in early August 2012 enhanced the southwest monsoon across much of Luzon.[13] As a result, widespread heavy rains impacted regions still recovering from deadly floods triggered by Typhoon Saola less than a week earlier.[14] During a 22‑hour span from August 6–7, 687 mm (27.0 in) of rain fell in parts of Metro Manila, leading local media to compare the event to Typhoon Ketsana in 2009, which killed 464 in the city.[15] Some of the most severe flooding took place along the Marikina River, which swelled to near-record levels. During the afternoon of August 7, the river reached a height of 20.6 m (68 ft), well beyond the flood level of 16 m (52 ft) and about 3 m (9.8 ft) below the record level set during Typhoon Ketsana. About 70 percent of Metro Manila was affected by flooding.[16] Some areas were submerged in up to 3 m (9.8 ft).[17] Due to the expanding floods, officials in the city evacuated more than 23,000 residents from flood-prone areas and relocated them to shelters set up across the area.[16] According to a reporter from the British Broadcasting Corporation, many residents were reluctant to leave their belongings behind, and some traveled back through flood waters to retrieve their belongings. Officials feared the flooding could worsen as the La Mesa Dam continued to overflow at the time.[18] At least nine people were killed and four others were injured in a landslide in Quezon City.[19] More than fifty people died on this day.[20]

This was the worst rain in non-direct typhoon or tropical storm on record that Metro Manila has experienced since 2009, surpassing the accumulated amount of rain brought by Typhoon Ketsana.

The Marikina River surpassed the water levels reached by Typhoon Ketsana in 2009, which brought massive rainfall and caused severe flooding. As of 11:00 PHT the river's water level had risen to 22 metres (72 ft), submerging most parts of the city in flood waters, according to the Marikina Public Information Office.[21]

Panorama of Marikina River Park