Eliminate floods!

I was not planning to write a column on the country’s tragedy regarding floods and the havoc it is creating in people’s lives. After all, so many newspaper articles and media hours are being devoted to this tragedy. However, the continuous economic disaster that is being wrought by floods has ignited my personal anger I therefore have decided to write at least one column on flooding, if only as a personal release of emotions.

I will still try to make my column as commonsensical as possible and bereft of emotions.

It is clear that flooding is one of the most serious and recurring problems in the Philippines. This has been magnified by the corruption that diverted billions if not trillions of pesos into the pockets of unscrupulous politicians and contractors.

Pampanga, Bulacan and Nueva Ecija and surrounding provinces are connected by rivers and waterways that form one large hydrological system. When excessive rainfall occurs, water from upstream areas eventually move towards the lower Pampanga River Basin and Manila Bay. When the rivers, floodways and drainage systems cannot accommodate the increase in the volume of water, communities become flooded.

However, the problem is much more complicated than simply saying, “There was too much rain.” Heavy rainfall may be the immediate trigger but the severity of flooding is influenced by the capacity of rivers, high tides, sedimentation, land development, drainage, infrastructure, watershed management and, the most critical, the availability of flood control facilities.

Flood control projects can reduce flooding but they cannot completely solve a problem that exists across an entire river basin. Unless those flood control projects are planned and connected as one comprehensive system.

When there is no comprehensive flood control system, several factors turn heavy rainfall into massive flooding.

The first is limited river capacity. Rivers have a maximum amount of water they can carry. When water exceeds that capacity, the river overflows.

The second is sedimentation. Over time, soil and other materials accumulate in river channels. The river becomes shallower and therefore carries less water, thereby increasing the possibility of overflowing.

The third is urbanization. Roads, buildings, warehouses, subdivisions and concrete surfaces prevent rainwater from naturally infiltrating into the soil. Instead, the increase in water leads to surface runoff.

The fourth is loss of natural flood storage area. Wetlands, swamps, agricultural lands and open areas naturally absorb or temporarily store excess water. When these areas are reduced or obstructed, more water reaches rivers more rapidly and leads to the overflow of the rivers.

The fifth is high tide and downstream conditions. Even if water is flowing towards Manila Bay, it cannot leave the river basin efficiently when the Manila Bay area is already extremely high with water.

The sixth is climate change and increasingly extreme rainfall events. Infrastructure designed along historical rainfall patterns may not be sufficient when extreme rainfall becomes more intense.

Therefore, massive flooding is usually the result of several problems occurring simultaneously. Even if the government builds dikes, pumps and other flood control infrastructure, the flooding will continue.

For example, a flood wall may protect one location while increasing risk somewhere else if the broader drainage system is not improved.

However, the permanent solutions which require coordinating different projects are already well known. Unfortunately, the funding for these projects have been lost through corruption. For those who are truly interested, the permanent solutions requiring several layers.

First: Build the Pampanga River Floodway. This proposed 59-kilometer floodway could provide an additional route for excess water to reach Manila Bay. This is one of the most important long-term approaches because it addresses the capacity problem at the river basin level. The plan for this project is sitting at the DPWH.

Second: Protect San Antonio Swamp and other natural storage areas. Natural wetlands should not simply be viewed as vacant land. They are part of the flood management system. San Antonio Swamp, for example, is incorporated in the proposed floodway concept as a retarding pond or storage area.

Third: Improve rivers. Rivers need regular assessment for sedimentation, erosion and obstructions. But dredging must also be scientifically planned. Simply removing soil from a river without considering upstream sediment sources and downstream effects may provide only temporary benefits.

Fourth: Improve urban drainage. Cities and municipalities need drainage systems for present and future rainfall conditions. New subdivisions, industrial areas and commercial developments should also provide adequate storm water management.

Fifth: Protect watersheds. Flood control begins far upstream. If forests and watersheds are degraded, more water runs rapidly towards downstream communities. Reforestation, watershed protection and sustainable land use planning should therefore be treated as flood control measures.

Sixth: Make infrastructure flood-resilient. Major highways should be designed with sufficient elevation, drainage and water crossing structure. The objective should be to keep critical transportation routes operational even during severe weather conditions.

The Philippine government must therefore have a holistic approach to flood control. It must combine engineering and public works with watershed protection, wetlands conservation, responsible urban development, better drainage, early warning systems, flood resilient roads and effective disaster preparedness.

This government and future governments must stop relying on disaster relief and ayuda. I am personally tired of the term that the Filipino is “resilient.” The Filipino deserves a government that will strive for, as its final objective, flood elimination.

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