Of Engineers and Gutters

In a recent article, Sydney Morning Herald columnist Elizabeth Farelly laments the damage caused to trees in the urban environment by 'perfect' non-leaky guttering. Her argument is that evil 'un-civil' engineers, in designing gutters that are leak proof (and root proof) are responsible for thirsty trees struggling to survive, therefore not providing shade, therefore increasing global-warming, while rainwater rattles off wasted into the harbour.

In her highly enjoyable opinion pieces, Ms Farelly often uses exaggerated imagery and colourful language to emphasise a heartfelt opinion on urban design, and this article was no exception. In blaming engineers for this problem with inflammatory language equating them to terrorists, she predictably caused a storm of protest, and may well have laid the groundwork for the formation of a new corollary to the famous Godwins's Law* - we'll call it Farelly's Law - that automatically renders any argument invalid when the object of the author's scorn is labelled as, or compared to, a terrorist.

Of course, engineers aren't actually to blame for this particular problem. Engineers, for better or worse, are given problems and asked to build solutions. If they have designed gutters that don't leak, it's because they were asked by the council or road's authority to design gutters that don't leak. Indeed, it's a common lament of the engineer that they are not engaged earlier in the process to be part of the problem definition phase, rather than receiving half-baked requirements, then copping it for the resultant solution not making everyone happy. Not that I'm speaking from experience or anything ...

The fallacy of her argument is exposed by the counter-example in the same article - praising the (yet to be built I believe) gutter solution in Sydney's Green Square that makes clever re-use of storm water. Clearly, however, these gutters were also designed by engineers - albeit as a response to a more environmentally sensitive statement of the problem to be solved.

Approved Guttering

Apart from the unjustified engineer slandering, the author makes a valid point about the waste of rainwater in our cities, and the sadly missed opportunity for more thoughtful solutions. The problem, I would suggest is far greater than just thirsty trees - the waste of storm water in dry Australian cities is a problem crying out for creative engineering solutions - if only someone would ask !

One place that has a creative guttering system is the Argentinean town of Mendoza, which I visited in January. Lying in a desert at the foothill of the Andes, Mendoza takes advantage of an ancient Incan irrigation system with a series of linked open gutters running through the city.

Non leaky gutters ...

...that still let trees drink

You can see that Mendozan trees don't go thirsty. As the run-off comes from melted ice in the Andes, the result is a city permanently cooled in summer by a giant open air cooling system, that also maintains very healthy trees - so much so it's hard to believe you're in a desert.

Leafy Mendozan Streets

One downside to this solution can be gleaned from the gutters' nickname - Gringo traps, in reference to unwary (and possibly inebriated - the areas around Mendoza, also irrigated by melted Andean ice, produce 70% of Argentina's excellent wine) foreign tourists falling into the gutters. For this reason it's hard to see this particular design ever being adopted in an Australian society increasingly being dominated by litigious American style lawyers - who deserve to be the true villains in this story, rather than those poor (and definitely not terrorist) engineers :)

*PS There's an interesting article by the epnonymous Mr Godwin to mark the 18th 'birthday' of his famous law. The law initially stated (indeed still states) that as a discussion (in usenet - a proto-online-forum) goes on and on, the probability of someone mentioning Hitler or the Nazis approaches 1 (i.e. 100%). These days most people assume the law refers to the far better known corrollary, which states that the first person to resort to such parallels in a discussion automatically loses the argument.