In the summer of 2011 I happened upon something that changed my view of society and the course of my professional life. I had been working as a landscape architect before drifting into environmental education and eventually eco-tourism. While visiting Zürich to attend a conference hosted by the International Federation of Landscape Architects, I stepped outside to get some fresh air.

On my wanderings up and down the city’s streets, I heard laughter, then a sound that seemed at odds with my surroundings: a splash. I followed the noise down an unassuming lane that opened up to reveal a body of water with people playing games, doing lengths, enjoying the weather and cooling off.

How sensible the scene suddenly appeared. But, also, how sadly unusual. Why doesn’t this happen beyond the beaches in my home country of Australia? Or elsewhere for that matter? I felt a sudden, overwhelming urge to join the revellers in the water – to celebrate the existence of such a wholesome pastime.

Within weeks, I visited Copenhagen and some other choice cities in the Nordics, which revealed just how behind the curve the rest of us were with our water use. What’s more, swimmable water is within reach for far more cities than make proper use of it – as long as the sites are accessible, not too polluted and swimming hasn’t been criminalised by an overbearing city government. Such barriers, it seems to me, are often the result of a lack of planning rather than any malice. Waterways in many cities are the product of a long-defunct post-industrial legacy rather than proactive policy. The careful reversal of this is the basis of the Swimmable Cities initiative.

Inspired by that hot Swiss summer, it has grown into a global movement that co-ordinates grass-roots initiatives, rallies supporters and petitions local governments in 72 cities and towns across 27 countries, all to advocate for more and better access to swimmable spaces and cleaner water within our cities. Venice is a city more intimately connected to water than most. That means, like many places with potential, it must renegotiate its contracts – some legal, some social.

Different nations have drastically different tolerances for risk. In some cities, pleasure crafts and freight liners drift within 100 metres of open swimming spaces with little more than a couple of marker beacons to separate the streams. What might outrage or frighten a water-weary Londoner or a dip-averse New Yorker might be water off a duck’s back to Oslo folk or the drip-drying Dane.

The way to find success in making any city swimmable is to mould the available spaces to the expectations and needs of the people who use them. It’s often a matter of realignment; there’s no one-size-fits-all approach. It’s about dipping in a toe to find out what will maximise public enjoyment without disrupting industry – and, of course, being prepared to change course if something isn’t working.

It’s amazing how a topic as whimsical as larking around in the water can become a serious, interdisciplinary one (as it happens, such knowledge-sharing between disciplines is the theme of this year’s Venice Biennale). In our case, we borrow from anthropology, politics, law and design. But above all, it’s culture. The good news is that the complications and co-ordination are well worth the effort if it leads people back to the water. In Venice, there are stories of clearer water and the proliferation of wildlife in Venetian canals – a phenomenon that occurred largely due to the slowdown of human industrial activity. Sometimes, perhaps, doing nothing is the remedy.

I’m biased, of course. I would love to see more initiatives making waves. For events such as the Venice Biennale, which are hubs that celebrate local design, contextualise it and set a global precedent, I see the waters around us as an opportunity, not a barrier. Why shouldn’t art be displayed on floating pavilions or architecture woven into open-air swimming structures? It’s a slow process and one that won’t necessarily turn the tides immediately – but perhaps it might be enough to stop a too-warm wanderer in their tracks and help them consider diving into the debate.