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Peru is reviving a pre-Incan technology for water

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Re: Peru is reviving a pre-Incan technology for water

#21

Post by abdullahkhalids »

gus_massa wrote: post #11
abdullahkhalids wrote: post #4

Earlier quoted context omitted.

The linked paper > Infiltrated water is retained for an average of 45 d before resurfacing, confirming the system’s ability to contribute to dry-season flows. We estimate that upscaling the system to the source-water areas of the city of Lima can potentially delay 99 × 106 m3 yr−1 of streamflow and increase dry-season flows by 7.5% on average, which may provide a critical complement to conventional engineering soluti…

I can't see the paper, but there is some interesting technical details in the supplementary data https://static-content.springer.com/esm/art%3A10.1038%2Fs418... In page 15, table 2 they show that they put some Eosin https://en.wikipedia.org/wiki/Eosin upstream before the water entered the earth, and then they collected water from the springs downstream a few weeks later and measure how much Eosin was there, and used…

I didn't have time to read the paper, but here is the pdf http://mural.maynoothuniversity.ie/13800/1/SG_geog_potential...

Re: Peru is reviving a pre-Incan technology for water

#22

Post by JuettnerDistrib »

KaiserPro wrote: post #19

tldr: Diverting streams to go into different places increases the dwell time of the water by 45 days. when you have a rigid dry season, keeping the streams running for an extra 45 days is absolutely fucking huge. The clever part is that over the years the locals have managed to find the best place to divert water so it goes into springs that feed streams. its a similar idea to a Johad, https://en.wikipedia.org/wiki/J…

> In LA, everything is done to make sure the water yeets into the sea as quick as possible.

The infrastructure bill may change that [0]:

"Also, the money could fund stormwater capture and reuse projects, like the ones that filter rainwater into underground aquifers rather than let it flow into the ocean."

Anyone know how likely this actually is?

[0] https://laist.com/news/climate-environment/socal-could-get-b...

Re: Peru is reviving a pre-Incan technology for water

#23

Post by qubidt »

gus_massa wrote: post #11
abdullahkhalids wrote: post #4

Earlier quoted context omitted.

The linked paper > Infiltrated water is retained for an average of 45 d before resurfacing, confirming the system’s ability to contribute to dry-season flows. We estimate that upscaling the system to the source-water areas of the city of Lima can potentially delay 99 × 106 m3 yr−1 of streamflow and increase dry-season flows by 7.5% on average, which may provide a critical complement to conventional engineering soluti…

I can't see the paper, but there is some interesting technical details in the supplementary data https://static-content.springer.com/esm/art%3A10.1038%2Fs418... In page 15, table 2 they show that they put some Eosin https://en.wikipedia.org/wiki/Eosin upstream before the water entered the earth, and then they collected water from the springs downstream a few weeks later and measure how much Eosin was there, and used…

FYI: https://unpaywall.org/

Re: Peru is reviving a pre-Incan technology for water

#24

Post by droopyEyelids »

vanderZwan wrote: post #9

I can't speak for Peru specifically, but natural ecosystems play a huge role in absorbing and holding on to rain water, ensuring it doesn't all just flow back into the sea. This has been known for ages - I remember a friend who did environmental sciences telling me stories of cities in developing countries that cut all the nearby forests and as a side-effect also ruined their water supply. So with that in mind I'm a…

I saw an interesting farmer presentation on YouTube[1] the other day where he eventually starts talking about how cover crops have improved his land's ability to absorb and retain water. He even includes photos contrasting his neighbor's monoculture fields with his during rain storms.

https://www.youtube.com/watch?v=9yPjoh9YJMk

Re: Peru is reviving a pre-Incan technology for water

#25

Post by slownews45 »

What's interesting is water management historically was a huge area of research and work for cultures.

But if you look at a place like CA, despite supposed water shortages - there are very very few water projects to increase for example storage capacity. I'd be curious in last 10 years how much capacity has come online vs population growth. I mention supposed shortages because it's really a shortage of free or near free water.

We have passed a lot of bonds for water projects - with little to show for some reason. Not at all close to the details, but would be curious to know what is going on.

Re: Peru is reviving a pre-Incan technology for water

#26

Post by seltzered_ »

Okay, the article references "Potential contributions of pre-Inca infiltration infrastructure to Andean water security" (https://www.nature.com/articles/s41893-019-0307-1 , https://doi.org/10.1038/s41893-019-0307-1 )

The problem is it could just be used just to extract more water rather than be part of a broader reforestation effort & cultural change around it's relationship to water. Joe Brewer criticized this a couple years ago: https://twitter.com/cognitivepolicy/status/12125332029649264...

Re: Peru is reviving a pre-Incan technology for water

#27

Post by vidanay »

slownews45 wrote: post #25

What's interesting is water management historically was a huge area of research and work for cultures. But if you look at a place like CA, despite supposed water shortages - there are very very few water projects to increase for example storage capacity. I'd be curious in last 10 years how much capacity has come online vs population growth. I mention supposed shortages because it's really a shortage of free or near f…

I think this is derivative of humans inability to comprehend large numbers.

Do I have enough water for me and my family? Yes, I'm not thirsty and my crops look fine.

Do we have enough water for 10 billion people for the next 150 years? We have no clue.

Re: Peru is reviving a pre-Incan technology for water

#28

Post by slownews45 »

vidanay wrote: post #27
slownews45 wrote: post #25

What's interesting is water management historically was a huge area of research and work for cultures. But if you look at a place like CA, despite supposed water shortages - there are very very few water projects to increase for example storage capacity. I'd be curious in last 10 years how much capacity has come online vs population growth. I mention supposed shortages because it's really a shortage of free or near f…

I think this is derivative of humans inability to comprehend large numbers. Do I have enough water for me and my family? Yes, I'm not thirsty and my crops look fine. Do we have enough water for 10 billion people for the next 150 years? We have no clue.

What's funny though is that folks are paying $5 for a tiny water bottle in an airport. They are rationing URBAN water use (where water is relatively insanely expensive already).

Even in CA where we have droughts - the amount of water used in ag / industrial is measured in ACRE FEET. And the cost is in pennies to dollars per ACRE FOOT. The scale is just totally different than your bottle of water or glass of water. You go to a restaurant "due to water shortage we aren't serving water"??

We've had insane population growth here. Last damns were in like 71 and maybe 79? So it's been 40+ years with no new reservoirs?

https://www.mercurynews.com/wp-content/uploads/2016/08/20140...

You'd better be working on desalination or maybe a small tax on water for all users (could be TINY) or something because otherwise yeah, you are going to have serious water problems.

We've doubled population since 71. You can't do that without doing something around reservoirs, water use in ag / industrial or supply improvements.

Re: Peru is reviving a pre-Incan technology for water

#29

Post by hinkley »

themanmaran wrote: post #13

Very long winded. The actual technique is only described about 2/3s the way through. They're using canals to divert water into well draining soil. "They use water canals called amunas – a Quechua word meaning "to retain" – to divert wet-season flows from mountain streams and route them to natural infiltration basins." "Because the water moves more slowly underground as it travels through gravel and soil, it emerges d…

Ground storage of fresh water is a simple technique that people seem to resist. 'Controversial' is not the right word but in the permaculture community there is a definite divide between people who embrace it and those who resist. The interactions are... frustrating.

There's also a relationship between water, soil health and climate change. The rule of thumb is that an acre of land can store an additional 20k gallons of water by increasing the soil carbon by 1% (of overall fraction, not relative to previous carbon levels, so in most real world cases that may involve increasing carbon by 10-25%).

Re: Peru is reviving a pre-Incan technology for water

#30

Post by wolverine876 »

ralfn wrote: post #5
koheripbal wrote: post #3

TLDRV They divert the rainy season water to natural aquifers and hope it reappears down river in the dry season. The small scale of the effort currently makes me a little skeptical that it's achieving anything. Underground water is impossible to measure. What might be more effective and certainly more measurable would be to build a dam/reservoir.

Thank you so much. The article is just too polluted with pseudo intellectual nonsense, but water management is a very underappreciated discipline of engineering. Although it seems impossible to measure how much water is stored in the deep soil, it is often possible to notice if it runs out. We had that last summer in the Netherlands. I suppose knowing we reached zero, and knowing the influx (mm rain, and the flow of…

> The article is just too polluted with pseudo intellectual nonsense

Always an ironic comment!

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