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Trees on city streets cope with drought by drinking from leaky pipes

newscientist.com

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Re: Trees on city streets cope with drought by drinking from leaky pipes

#91

Post by vondur »

mschuster91 wrote: post #51
Spooky23 wrote: post #48

Earlier quoted context omitted.

That’s really high. There’s either a big problem in your city, or they are making generous estimates to justify asking for more capital. 10-15% is more typical. In my region, the street trees are usually getting sewer water. Residential service in older houses are usually clay pipes with lead solder that the tree infiltrates. It’s not a problem until the clay pops and roots clog it. It varies a lot by region and juri…

Here in Germany, we estimate sewer infrastructure to last anywhere from 50-100 years, and water mains around 50-ish years. After that, it needs replacement or, that's the modern thing but it's a one-trick pony, re-lining. The prudent thing would be to set aside and invest a tiny bit of money every year to fund a replacement, but unfortunately modern economic theory ("run lean") and manufactured income crises (aka, po…

In Los Angeles, they have basically given up on doing any preventive maintenance of the water/sewer lines. They just wait for something to break and replace it. We have areas with pipes over a 100 years old. Too expensive to dig up huge areas of the city to replace the lines all at once. This may also have something to do with the notoriously corrupt LA Dept. Of Water and power too. Other cities in LA County do periodically replace the lines, but it's still tremendously expensive.

Re: Trees on city streets cope with drought by drinking from leaky pipes

#92

Post by kurthr »

btbuildem wrote: post #42

The city where I live estimates that we lose somewhere between 25% and 30% of drinkable water to leaky infrastructure. We've had something close to a drought this summer -- unseasonally long periods without rain. You can see the young trees on the streets and trees in the middle of large parks suffer from it - wilted leaves and leaves dropping earlier than usual. BUT, large old trees seem to be thriving - full canopi…

Austin is close to 50% leakage. Now up to 110gal/day per connection in 2024.

https://www.kxan.com/investigations/city-of-austin-pipes-lea...

Re: Trees on city streets cope with drought by drinking from leaky pipes

#93

Post by throwaway290 »

x775 wrote: post #34

> 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?

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

Re: Trees on city streets cope with drought by drinking from leaky pipes

#94

Post by refactor_master »

estimator7292 wrote: post #80
bluGill wrote: post #72

Earlier quoted context omitted.

Smart is to have a crew that replaces a little every year. That way they build expertise in how to do it and there isn't a large expense all at once. You can likely get a discount with private plumbers because you want it done sometime and so they schedlue around other customers who want it now.

That doesn't track because the real cost to replacing underground infrastructure is not the digging, materials, or labor. We avoid such maintenance as long as possible because shutting down a road is usually very expensive in terms of second-order effects. Digging up a pipe and replacing it is actually pretty cheap and easy. Disrupting a main thoroughfare is incredibly expensive in terms of lost productivity, transpo…

This just sounds like a different way of saying "one more lane bro, trust me". Usually one doesn't "shut down" a road, but divert lanes, perform construction outside of peak hours (e.g. at night) etc.

Finally, some people may even consider the construction too much of a hassle and use the car less. Empirical studies suggest that "removing" a road does not cause productivity loss overall, since having the road in the first place induces a lot of "non-essential" demand.

Re: Trees on city streets cope with drought by drinking from leaky pipes

#95

Post by mschuster91 »

amluto wrote: post #89
gnabgib wrote: post #83

Earlier quoted context omitted.

Pipes have lifetimes of 2-10x roads... where's your data from? Roads[0]: Asphalt (18 years), Concrete (25 years) - requires good expansion gaps, good substrate, zero roadwork over its lifetime. Pipes[1]: HPDE (50-100 years), PVC (50-70 years), Reinforced Concrete (75-100 years) Vitrified Clay Pipes (Several centuries), Galvanised Steel (40-70 years) [0]: https://www.ayresassociates.com/the-long-and-short-of-it-lif...…

A city could replace pipes preventatively as part of road resurfacing when the pipes are sufficiently old.

Not that easy. A road resurface, that can be done in a few days worth of work, less if you hire enough machines and staff.

A pipe replacement? Sewer mains at least here in Germany tend to be anywhere from 2 to 8 meters below ground. That's a lot of soil to move. Freshwater mains is below freezing depth, so usually around 1-2 meters below ground. And above that is a ton of other wiring... electricity, phone, fiber, cable tv, gas and district heat/cooling just to name a few, so when you want to replace the sewer mains, it involves a lot of companies, plus the city authorities for coordination, permits, traffic re-routing (a bus route is bad enough - a tram line or a legit full size train line is a nightmare).

Outside of immediate emergency work from a burst pipe, replacement works take years to plan.

Re: Trees on city streets cope with drought by drinking from leaky pipes

#97

Post by close04 »

mlinhares wrote: post #50
Spooky23 wrote: post #48

Earlier quoted context omitted.

That’s really high. There’s either a big problem in your city, or they are making generous estimates to justify asking for more capital. 10-15% is more typical. In my region, the street trees are usually getting sewer water. Residential service in older houses are usually clay pipes with lead solder that the tree infiltrates. It’s not a problem until the clay pops and roots clog it. It varies a lot by region and juri…

TIL clay pipes are a thing but it does make a lot of sense there would be.

These are probably the longest lasting option we have right now, and is far more eco-friendly than the closest alternatives, plastics or concrete.

Re: Trees on city streets cope with drought by drinking from leaky pipes

#98

Post by gblargg »

SoftTalker wrote: post #79
npstr wrote: post #38

Earlier quoted context omitted.

Why can't they bill for it? It's not like they are losing money on it, it's simply getting priced into the billable services they provide. Utilities are usually monopolistic, so there is little incentive for them to fix this.

They do, but rates are regulated, they can’t just tack on this month’s pipe replacement expenses. They have to make a guess, propose a rate increase, and get it approved by the relevant regulator or government authority.

So they cut corners in other ways?

Re: Trees on city streets cope with drought by drinking from leaky pipes

#99

Post by Cthulhu_ »

dmbche wrote: post #59
Spooky23 wrote: post #48

Earlier quoted context omitted.

That’s really high. There’s either a big problem in your city, or they are making generous estimates to justify asking for more capital. 10-15% is more typical. In my region, the street trees are usually getting sewer water. Residential service in older houses are usually clay pipes with lead solder that the tree infiltrates. It’s not a problem until the clay pops and roots clog it. It varies a lot by region and juri…

My city loses about 30% of the water going through it's pipes, including leaking wastewater directly into rainwater drains ( left untreated). I believe some of the plumbing was wood pipes in select very busy parts of the city until somewhat recently, as it was a nightmare to replace.

> as it was a nightmare to replace.

I suspect this is the problem with all aging infrastructure; 100 years ago or more, water, sewage and electricity was deployed everywhere, but then they just kept building and rerouting and now the systems have become unmaintainable.

I wonder if this has improved in any way since then in newly constructed areas / cities. I'm thinking a service tunnel underneath roads with all the pipes and lines clearly marked and installed in a highly accessible fashion. Said service tunnel can also be used for daring heists and escapes and the like.

Re: Trees on city streets cope with drought by drinking from leaky pipes

#100

Post by dhosek »

Not really mentioned, but I suspect that at least part of the time, the leaky pipes are caused by the trees. I used to own a house in southern California with a sprinkler system and a couple Chinese elms. Trying to track down why some sprinkler heads weren’t sprinkling, I discovered that the trees had sent roots into some of the (PVC) piping, going as far as six feet of the pipe. I ended up digging up and replacing a lot of piping on that project, although I wouldn’t be surprised if the Chinese elms (which are nasty nasty trees that I will hate until I die) didn’t pull the same stunt on subsequent owners of the house.
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