Urban planning and the Metro Manila Floods

Typhoon Ondoy dumped a record rainfall over the Philippine capital of Manila causing flooding beyond anything in memory, even for a city fairly used to high water.

A lot of President Gloria Macapagal-Arroyo's enemies have been blaming her for the severity of the disaster, but this isn't really fair. Indeed, whatever failings the Macapagal government may have, it actually has done more than its predecessors in a number of key areas.

Probably highest on this list of accomplishments is cleaning out the Pasig River, and at least attempting to move back the shantytowns on its banks at least 3 meters from the water. There have also been pumping stations built to deal with waters that flood these areas.


Massive scale of flood

However, it would have been difficult to prepare for a disaster of this magnitude. Even developed countries like the United States have difficulties when record natural disasters of any type strike. The Hurricane Katrina example is just one of many. So, rather than spend time laying blame, it might be a better idea to look ahead and plan for such occurrences in the future. And given the forecasts of global warming and rising sea levels, we should expect serious events to become more normal than they were before.

The natural inclination is to build higher and stronger dikes and levees to keep the water within the banks of rivers, creeks, canals, etc.

However, there are problems to this unnatural solution. As we can see from what happened in New Orleans in the United States, water barriers are not really the ideal solution.

Flood plains like New Orleans and Manila depend on sediment deposits from flooding to replenish the soil. When the floodwaters are blocked, the deposits stop but the loss of earth continues due to drainage, wind, and other factors. This loss of earth causes the city to actually sink lower and lower as in the case of New Orleans.


Ecological solutions for flooding

Here are a few things that have been done or have been suggested to manage flooding in areas like Manila that is ecologically sustainable.

• Reduce drainage by building more tree and green cover, and by building green roofs and architectures. Trees and plants hold water and they also help create ecosystems. The fallen fruit, leaves, twigs, and the dead insects, lizards and other varmints that live in these ecosystems decompose and become part of the soil. Pavement contributes nothing and does not completely stop rain from draining off soil. Promote urban gardening in abandoned lots and encourage the use of compost bins.
  
• Do not let squatters rebuild their lost or destroyed homes near the rivers, creeks, estuaries, etc. The government needs to use some of its foreign reserves to build subsidized housing for these shantytown dwellers. Keep as much area as possible near the river banks clear from buildings.
• Create a system that can charge the ground with composted, treated sewage instead of letting it run into the Manila Bay.
• Create a high tech solution that can pump some of the silty flood water in an orderly way into parks, golf courses, even private lawns. Maybe a separate type of watering system can be created.
• The government must enforce prohibitions on illegal activities on waterways that impede the natural flow of water. At the same time, it must provide those who depended on such illegal livelihoods with alternative methods of earning a living.

The government should implement these measures not only in Manila but in other urban areas of the country. No excuses about not having any money. If they need more money, then they should raise more money. That's their responsibility.