Tackle floods? Create more space for water

The Dutch have moved away from building storm surge barriers to having 'water plazas'
Lin Yangchen Straits Times 20 Feb 16;
When you tell people about the rise of sea levels and flooding wrought by climate change and extreme weather, the first thought of some people may be to find ways to keep the water out.

But civil engineers and landscape architects are beginning to realise that water need not always be the enemy. While it threatens to inundate coastal cities, it is vital to everyday life at the same time.

"Water can sometimes be our friend," argued Ms Tracy Metz, director of the Amsterdam-based John Adams Institute, a non-profit foundation that promotes cultural exchanges between the United States and the Netherlands, in a lecture on Thursday at the Ministry of National Development (MND).

Ms Metz was explaining to the audience of academic, industry and government representatives how the Dutch have moved from a focus on getting rid of water to one on redesigning cities to create more space for water.

For example, the Dutch started by building enormous storm surge barriers to protect their cities. However, the barriers disrupted the tidal flows that supported marine life.

Now, "water plazas" are being constructed instead in places like Rotterdam, most of which lies below sea level.

These plazas, being lower than the surrounding area, act as temporary reservoirs that prevent flooding in heavy storms. During dry periods, the water drains away, allowing people to use the plaza for their activities.

"It makes it possible for the water to come and go without creating any serious damage," said Ms Metz.

The lecture, which had a question and answer session, was organised by the Centre for Liveable Cities, which was set up by MND and the Ministry of the Environment and Water Resources.

Professor Kees Christiaanse, programme leader at the Future Cities Laboratory, a joint programme between Singapore's National Research Foundation and ETH Zurich, cited other flood-alleviation measures used in some cities, such as collecting water on roofs and making pavements out of porous material.

"If you add up all these interventions, then you can get quite a lot of effect," he added.

It was generally agreed that in order to realise these visions of making a city more resilient to floods, a change of mindset is needed.

Ms Metz noted the challenge of garnering public support for designing parts of a city to flood on purpose. "We're not used to places changing character.

"Children are by far the best investment in outreach that we could possibly do," she said.

PUB chief sustainability officer Tan Nguan Sen, who moderated the Q&A session, said: "Children are brought up with the mindset that they should avoid getting wet in water. So it's really an uphill task to educate the younger generation to actually embrace water."