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Comment by x775 | Hacker News Reader

> Maple trees need to consume around 50 litres of water per day. Since street trees can’t get much of this from rainwater, which falls on concrete and drains into the city’s sewers, Poirier says the most likely explanation is that it is coming from Montreal’s leaky pipes, which lose 500 million litres of water per day.

I feel like this is burying the lede.

What can be done to reduce leakage?

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  >Since street trees can’t get much of this from rainwater, which falls on concrete and drains into the city’s sewers, Poirier says the most likely explanation is ...

  I feel like this is burying the lede. What can be done to reduce leakage?

Seems like a better question is, why didn't we design our urban and suburban hydrology to water those trees, instead of shunting rain to an already overburdened storm system?

This is hardly a pipe dream. Village Homes demonstrated the concept[0] over five decades ago.

[0] https://www.youtube.com/watch?v=zZ7RmsJOlgc&t=980s

Because it’s cheaper not to do it.

I see this response a lot, as if it's insightful or useful, but it really isn't. There are good times to save money and bad times to save money, and it's almost never the sole point of consideration. There are lots and lots of things we could spend more money on. Is that the goal?

Any cost to a city that doesn’t have immediate utility to the people governing the city has to fight an uphill battle against everything else. And a in a lot of cases all available money is already allocated. In such an environment people generally don’t choose to make long term investments. Cheaper is easier to sell politically. And if large projects like a subway get greenlit it’s usually for an unrealistically low budget and the project ends up costing 2 or 3 times more because it’s easier to raise taxes based on sunk cost than careful planning.

Thanks - that's a hell of a lot better than the original comment. I disagree, though. Officials are elected based on projects they want to undertake. Nobody is saying "I'm beating the national average cost of building a bridge by 17%!!" in their campaigns, they're saying they're gonna build a bridge. And it'll be damn impressive. A legacy, even. Might put my own name on it.

Citation needed. Curbs are expensive. Sewer pipes are expensive (for the last 60 years, Montreal has separated rainwater and wastewater sewers in all new construction).

Montreal likely doesn’t do it because it would lower the density of buildings.

Sewer systems are bankrupting municipalities worldwide. Either the city fails to grow (and can't afford to fix the pipes), or the city grows (and can't afford to shut down traffic to fix the pipes).

Far from being unaffordable, fixing our broken urban water management is the only affordable option.

> What can be done to reduce leakage?

Do we really want that? Thousands of people are being killed each year by heat strokes. Keeping those trees alive by its environmental services is much more valuable in terms of lives and also energy saved. Maples have soft big leaves but also reduce the asphalt temperature by 5-10 degrees. If required just plant a tree species that can live with less water.

While there are some interior pipe lining solutions, they are just kind of a short term bandaid that will cost more in the long run and has its own complications, the only real answer is to bury brand new pipe. And that can get expensive if a lot of stuff has been built on top and around it which is why most municipalities just live with even major leaks and kick the can down the road until it breaches the surface and starts flooding areas. It is probably cheaper to replace them sooner rather than later in the long run, but no politician cares about how well a city's finances will be decades after they are gone.

Hopefully the lede, lead would be an even bigger concern.

Montreal has plenty of lead pipes too. ;(

Hah, that was an unfortunate auto-correct. Fixed!

The lede rendering is optional:

>The spelling lede (/ˈliːd/, from Early Modern English) is also used in American English, originally to avoid confusion with the printing press type formerly made from the metal lead or the related typographical term "leading".

https://en.wikipedia.org/wiki/News_style#Lead

Why should anything be done to reduce leakage? They take water out of the St Lawrence and, as much isn't diverted by trees, it goes back in (cleaner then when it came out.)

Because trees will clog those pipes eventualay and then we must dig them up. Pipes that don't leak don't attract roots and so last longer

You have to dig them up to fix the leaks…

Yeah let's wilt all those pesky maple trees in Canada

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