Floods, like other disasters, make headline news but recede just as quickly from the public's attention - unless you happen to be a victim. But Houston's flooding, though geographically more remote, seems to strike closer to home than the far more frequent and more fatal floods in Bangladesh, India, Nepal, China and even our Asean neighbours because Houston, in the US state of Texas, is a wealthy, First World global metropolis, an important port and petrochemical hub, a top medical centre and home to many Fortune 500 multinational companies. It is also flat and low lying.
So can what happened to Houston also happen to Singapore?
Mother Nature has been kind to Singapore. Although we often bemoan our lack of natural resources, we actually have a very rich biodiversity. We are also free of natural disasters like tsunamis, hurricanes, typhoons, volcanic eruptions and earthquakes.
Singapore has also been extremely fortunate to have a far-sighted government which has made good urban planning and water management a priority from the start.
Most of the damage to Houston was from water and not strong winds. Houston's floods appear to be largely a result of poor urban planning and unregulated building. This article, however, is not intended to be a paean of self-congratulation but a sober look at what lessons Singapore can learn.
Although we do not rank high among cities at risk of flooding, unlike Shanghai, Bangkok or New York, we are not risk-free as climate change has resulted in increasingly frequent and more severe episodes of extreme weather and rising sea levels.
If Singapore were to suffer serious flooding, the social, economic and political consequences would be far more serious than Houston's. First, because of land scarcity, much of our key infrastructure is on low-lying coastal land or even underground. Second, our hard-earned reputation as a First World city that attracts global talent and investments (and is even exporting our urban planning and building model overseas), will be seriously damaged.
But most devastating of all is the question of where we could go. People from Shanghai, Bangkok or Houston and Florida can relocate inland either temporarily or even permanently, as has happened in New Orleans. This already traumatic social dislocation would, in our case, take on a national dimension and we might become environmental refugees like the citizens of Kiribati and Tuvalu.
So here are three lessons we should remember.
1 Don't overbuild
We should never underestimate the ability of the human species to think short term, both regarding our past and future. The deadliest hurricane in American history was one that hit Galveston in 1900, effectively wiping it out. It seems to have also been wiped out of Houston's memory, which is surprising because many of the refugees moved inland and settled in Houston, then a one-horse town which then grew to become the fourth-largest city in the US. Such rapid growth in slightly more than a century might seem a success story but "what made Houston so vulnerable to flooding was rampant, unregulated growth", economist Paul Krugman wrote in the New York Times on Sept 7. Singapore's growth as a city has also been phenomenal but matched by strict regulation and long-term urban planning and water management.
But we too have had our episodes of excessive complacency like the series of flash floods from 2010-2013 after 35 years of being flood-free. The first was initially dismissed as a one-in-a-hundred year freak event till the second flood less than two weeks later. That prompted the setting up of a commission to investigate the causes and to recommend corrective measures to our outdated drainage system.
Flooding can also be caused by roads, paved areas, carparks and other impermeable surfaces. While government planners have generally been vigilant about preserving sufficient porous land cover such as parks and nature reserves, it is obvious that these are gradually being eroded by built surfaces, Bukit Brown and Bidadari being two recent examples of green spaces being replaced by roads and housing developments.
Land use planners and developers should not only replace the equivalent area of permeable surfaces but should increase it to cater for more extreme weather conditions. This simple precautionary measure would save the state and taxpayers a fortune in downstream flood-control infrastructure and damage.
En bloc sales and the high price of land lead private developers to maximise their built-up space to the extent that any recently built private condominium is likely to have far less open space than Housing Board blocks. All this increases our risk of flooding and adds to its potential severity.
Building is essential but we should distinguish between necessity and vanity projects and build with humility, not hubris.
2 Avoid overpopulation
The larger and wealthier a city, the more complex, diverse and potentially conflicting its needs and demands. Predicting and juggling the intricate interactions between people and their environment goes far beyond simple arithmetic.
In the aftermath of the Fukushima tragedy in Japan, it seems highly irresponsible to the point of insanity to have sited a nuclear reactor in a tsunami-prone area, however well protected by sea walls and levees. But a crowded country needs energy, and nuclear reactors are usually sited in the least-populated part which typically is that way for a reason, in this case, tsunamis.
Singapore's planners have a Herculean task fitting our multifarious requirements on such a small island with no real hinterland. Our international airport, financial district, petrochemical and other major industries, many reservoirs and waste-disposal facilities are sited on low-lying, reclaimed land. We have little choice. But do we want to narrow our options further? People, unlike buildings, cannot be abandoned in an emergency.
The Government's 2010 White Paper on population projected for an artificial population growth to 6.9 million based largely on economic growth, the desired labour force and the changing dependency ratio of an ageing population. Factoring in social cohesion accurately turned out to be more challenging, but our ecological carrying capacity seems to have been missed out completely - except for a brief mention on green recreational spaces. Worryingly, in the subsequent furious debate, some well-respected planners said that we could actually comfortably grow to a population of 11 million or 12 million.
The more our population grows, the more ecologically vulnerable we make ourselves; and the faster we grow, the less time we have to correct our mistakes. How would we know we have reached or even exceeded the tipping point if we don't have time for checks and balances?
3 Developing EQ (Ecological Quotient)
Like much of the developed, urbanised world, Singaporeans generally have a narrow anthropocentric view of nature which we regard as recreational or ornamental rather than providing essential ecosystem services. We fail to realise that nature is often not the problem but the solution.
After the tragic Asian tsunami in 2004, it was found that coastal villages with intact mangroves and coral were relatively unscathed but those nearby that had destroyed these natural barriers were severely damaged.
But most coastal cities like Miami, New Orleans and Singapore have removed these natural barriers in the course of development. Singapore has projects to regenerate our mangroves and corals but it will take a long time to do so.
Massive engineering projects like sea walls and pumps may afford temporary protection but are hugely expensive to build and maintain and when they fail, as happened in Fukushima and New Orleans, they can do so disastrously.
The Dutch, past masters of flood control (60 per cent of Holland is below sea level) depend heavily on technology and man-made barriers but they also integrate nature-based solutions and adaptations to flooding, following Francis Bacon's dictum that nature to be commanded must be obeyed. Wetlands and floodplains provide additional layers of protection to sea-level rises and storm surges and, if required, a well-managed, controlled retreat. Their safety margins are gargantuan; equivalent to a once-in-10,000-year flood for the most populous areas - something that engineering alone could not achieve.
They have been advising us on water and flood control but other than different geographical conditions, the Dutch have a nationwide awareness of their risks and an inclusive stakeholder approach to solutions whereas we Singaporeans leave the problem to the Government.
Our leaders are always reminding us of our many social and economic vulnerabilities and how every Singaporean must play a part. The same should go for our environmental fragility. If we could have the same checks and balances for our environmental resources as for our fiscal reserves and social fabric, we would be far more sustainable.
Don't forget that past perfor- mance is not a reliable predictor of the future in environmental as much as economic crises. The once-in-a-hundred-year flood is as likely statistically to happen tomorrow as in a hundred years.
• The writer, an environmentalist and former Nominated MP, is the immediate past president of Nature Society (Singapore).
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