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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

#101

Post by teruakohatu »

aziaziazi wrote: post #54
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…

OP numbers aren’t only a city problem, IIRC [0] the numbers are close here in France. There’s a startup that try to tackle it : www.leakmited.com/en I applied there 3 month ago and they never responded. Can’t blame them but I’m a bit sad: it’s the dream impact-job. [0] 20% apparently https://www.eaufrance.fr/repere-rendement-des-reseaux-deau-p...

I wouldn’t be too sad. There are lots of companies offering ML leak detection. Most or many are using fibre optics and using them to detect changes in temperature or noise along the line. Sample the signal for period of time and run it through a model and you have leak detection.

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

#102

Post by topspin »

andix wrote: post #62

Not only trees in cities do that. A lot of clogged home sewers are caused by trees that wanted more to drink. Once the sewer line is fully blocked, they've arrived in paradise. Now there is a constant supply in the permanently filled sewer line.

I use to live on a property in a development. On my property were a pair of big willows. The trees were large and healthy, well over 50' tall. That was strange, because the region is high desert with little water, and I made no effort to irrigate them.

One morning in spring, after I'd been living there about 15 years, the neighborhood streets flooded. There were geysers of water shooting up from manholes. Turns out, the willows had been planted over an irrigation ditch[1]. The willows had driven their tap roots into the pipeline and plugged it about 10' underground. When the water authority opened gates miles upstream, the water pressure blew water up the manholes into the streets and a few yards.

Farmers are very motivated to get their water. They, and the ditch company, rapidly cleared the plug and removed the trees.

Before this happened I had no idea the irrigation system ran through the property. I knew about an easement, but I thought it was for sewage, because the developer used an iron manhole cover from the local municipal waste management operation when they covered the irrigation ditch: it literally had "Sewer" cast into the iron.

[1] Formerly an actual ditch, later made into a pipeline and covered over, but still technically a "ditch" for purposes of water management.

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

#103

Post by londons_explore »

Jenk wrote: post #37
londons_explore wrote: post #21

I wonder how much human health is impacted by these leaky pipes. I would like to see a city where pipes are guaranteed leak free, for example by making them double walled with high pressure air in the outer layer, and then seeing if disease levels in the city are lower.

That double wall thing is a red herring. The water system already protects against intrusion because the water itself exerts pressure on the pipes. Thus leaks are typically of the water getting out and not contamination of the water (most of the time, anyway.) Contamination rarely happens outside of the source of supply, and not somewhere along the pipeline.

And the sewage pipes...?

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

#104

Post by pjc50 »

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 whole thread reminds me of the Edinburgh tramworks; despite there having been 19th-century trams on the same street, the modern trams are heavier. So the tram building project turned into a saga of underground "technical debt": sewers had to be rebuilt to take higher weight overhead, which meant digging up everything buried in the road, all the pipes and wires, plus extra bits of archaeology. Hence massive cost overruns.

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

#105

Post by PeterStuer »

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…

It is not cheap nor easy. For many of those pipes, especially yhe waste water ones, there are no AS-BUILDs, and they are unmapped in a very real sense.

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

#107

Post by bluGill »

refactor_master wrote: post #94
estimator7292 wrote: post #80

Earlier quoted context omitted.

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…

That arguement is stupid. the world is not only about productivity. If people want to do something just because they enjoy it then they should. If the lack of a way means they do something else that is a loss. The whole point of Cities is all the options, if you want lack of options there are a lot of small towns - and even they have more options than you want to allow.

now it need not be by roads - a great transit system should enable moreeobtions. However the point is all the things you can do if you choose not a train or road to nowhere.

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

#108

Post by bluGill »

mschuster91 wrote: post #95
amluto wrote: post #89

Earlier quoted context omitted.

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, ca…

That it takes years to plan means you have time to work with the road people. We will have to dig this road up anyway don't resurface it. Often they know roads were built sub-modern standard and want to dig it up but it isn't ecconomical.

this needs to be done for all roads constantly sometimes the pipes are still good and you resurface, sometimes they will fail in a few years so may as well dig them up since we have to do the road now.

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

#109

Post by reactordev »

devnullbrain wrote: post #45
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…

Older, bigger plants have roots that go deeper and have access to more water. You can see the same effect in gardens, where new plants wilt sooner than established plants (and the care instructions advise frequent watering for the first couple of weeks).

Both are facts and both are true.

Big trees, with their deeper, longer roots - have access to more leaky infrastructure. Or are the cause of it.

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

#110

Post by Chris2048 »

topspin wrote: post #102
andix wrote: post #62

Not only trees in cities do that. A lot of clogged home sewers are caused by trees that wanted more to drink. Once the sewer line is fully blocked, they've arrived in paradise. Now there is a constant supply in the permanently filled sewer line.

I use to live on a property in a development. On my property were a pair of big willows. The trees were large and healthy, well over 50' tall. That was strange, because the region is high desert with little water, and I made no effort to irrigate them. One morning in spring, after I'd been living there about 15 years, the neighborhood streets flooded. There were geysers of water shooting up from manholes. Turns out,…

> They, and the ditch company, rapidly cleared the plug and removed the trees.

Did they need your permission to remove the trees?

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