VALENZUELA: RIVER FLOODING
“Philippines gets more than its share of disasters,” according to Hilary Whiteman of CNN news, as the country is located on a “path of destruction…The Philippines sits on the western rim of the Pacific Ocean, the most active area for tropical cyclones because of the vast expanse of deep, warm ocean water. The country comprises more than 7,000 islands, leaving plenty of exposed coast at the mercy of wind and rain… An average of eight or nine tropical cyclones make landfall in the Philippines each year… (In 2013) Super Typhoon Haiyan made landfall south of the capital… where it severely devastated the city of Tacloban, and then struck the Central Visayas. “
Valenzuela, FLOOD PRONE CITY
Valenzuela is located north of Manila. It is bounded in the north by Meycauayan and Caloocan (NE), Quezon City in the east, Manila in the south and Malabon and Navotas in the west. Valenzuela City have access to Manila Bay via the Malabon wetlands.
The document “Valenzuela Livable City” begins with the case of Typhoon Yolanda hitting the Philippines in Tacloban. This is done since “Valenzuela City was cited almost at similar state as Tacloban. The City is facing land subsidence and multi-faction. It is below sea level and practically also along the coastal area.”
According to Valenzuela City Pre-Feasibility Study on the Integrated Flood Risk Management:
- The City of Valenzuela is located in an area which is susceptible to frequent typhoons and intense tropical storms. The topographic characteristics show that about 25% of the City is below sea level making natural drainage very difficult. The combination of the above factors exposes Valenzuela City to frequent and severe flooding as the existing systems can no longer cope, in addition to the impacts due to climate change.”
- Besides the localised drainage problems, Valenzuela experiences heavy flooding when earth dikes along Meycauayan River… and along Santolan River under the jurisdiction of other cities, are breached. Tidal flooding is also known to occur in some of the downstream areas of the City.
- The frequent severe floods do impact significantly on the socioeconomic fabric of the City. It is therefore important to reduce the City’s vulnerability to floods and to improve drainage in the flood-prone areas in Valenzuela City with the end result of improving the quality of life of affected residents and enhancing economic growth of the City.
Rivers – Interior Drainage
- There are several large drainage channels that drain Valenzuela City and discharge mostly towards the northwest to the Meycauayan River. The Polo, Coloong, Lingahan, and Longos Rivers are the most important of these drainage channels. The Polo River also drains a small area to the Tullahan River. These channels discharge at the lowest end via sluice gates and pumping plants. They are unable to drain by gravity when the two principal rivers are high.
- Interior drainage is a real problem for various reasons, but mostly because (i) there is insufficient pumping capacity on the major drainage channels, (ii) secondary drains are too small and water must travel long distances to join the main drainage channels, (iii) culverts are blocked with rubbish and situation, (iv) tertiary drains along the sides of the roads are also blocked with rubbish and silt, and (v) depressed areas”
Internal Drainage Improvements
- “The Pre-Feasibility Study suggests concentrating on seven of the most severe problem areas in the city… The seven includes an enlarged 3.8 km concrete drainage channel and three box culverts through the Central Business District from Marulas, Karuhatan, and Maysan to a large creek that discharges through a new Viente Reales pumping facility and into the Tullahan River…”
The research aims at exploring:
- creative and alternative solutions to create a flooding resilient community
- urban design and urban planning to endow the community with resiliency in light of a natural disaster like typhoon. The idea revolves around discovering how urban design and planning can mitigate the effects of a natural disaster within a vulnerable community through the built environment’s ordnance.
- the morphology and the program of the built environment to support the resiliency of the community’s inhabitants and their livelihoods in light of the typhoon occurrence. The aim is to discover how architecture can bolster the inhabitants of a vulnerable community through the built environment’s form and function.
- the processes, materials, and systems involved in creating the built environment to amplify a community’s resiliency in light of the typhoon occurrence. The aim is to discover how innovative building technologies and methodologies can enhance the essential facilities and infrastructure for a vulnerable community through the built environment’s construction.
- the social and technical policies needed to maintain a community’s resiliency in light of a natural disaster. The aim is to discover how prescient and innovative planning guidelines and building codes can sustain a vulnerable community’s physical and social longevity through the built environment’s regulation.