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Peru is reviving a pre-Incan technology for water

bbc.com

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

#41

Post by wolverine876 »

The amunas are channels that slow the movement of water from mountain streams to farmers; "the diverted water spends between two weeks to eight months underground, with an average delay of 45 days".

As far as I can tell, they are used to retain water from the wet season into the dry season. How is that advantageous over using water storage at or near the endpoints? Perhaps ancient farmers didn't the ability to create underground storage, but how are amunas preferable now?

I imagine there's a good answer, but if it's in the article I overlooked it.

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

#42

Post by tharkun__ »

wolverine876 wrote: post #41

The amunas are channels that slow the movement of water from mountain streams to farmers; "the diverted water spends between two weeks to eight months underground, with an average delay of 45 days". As far as I can tell, they are used to retain water from the wet season into the dry season. How is that advantageous over using water storage at or near the endpoints? Perhaps ancient farmers didn't the ability to create…

Storing water in ponds has to deal with evaporation, algae growth etc. Also expensive to build.

Storing water in tanks means buying and maintaining something as well.

I think the point here is the "low tech, thousands of years old and it works" part. Underground water doesn't evaporate or grow nasty stuff. You do have to have the right terrain I suppose but where you do this sounds awesome. The ground will actually even help with filtering out many nasties.

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

#43

Post by tharkun__ »

kjkjadksj wrote: post #34
foxhop wrote: post #33

I'm not sure why it's only happening in Peru, we should be doing this work world wide. I have similar water capturing techniques at my house where I redirect road runoff into a gentle stream and allow it to infiltrate my landscape, watering Maple, Apple, Plums trees, hydrating the landscape to reduce effects of multi-month droughts: Reference: https://www.youtube.com/watch?v=lAQS4CN_4OY

Road runoff is usually pretty polluted in cities and some places have laws against capturing rainwater to protect downstream resources.

He doesn't say where he lives. While I agree with you that if he indeed lives in a place where the "road runoff" is nasty he should be careful, I really can't see why capturing rainwater should be banned. Of course "some places" is very vague so there might be good reasons but you'd have to provide much more context for me to believe that it's a good idea to prevent it.

If my house wasn't where it is, the ground on which it is built would absorb that water. Now I capture it and put it on my veggies or use it to flush the toilet which ends up going out to the septic drain field on the lwab and then it filters further down. I don't see any issues with that.

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

#45

Post by syntaxing »

colochef wrote: post #44

If you are into this, you have to check all the different systems found in Lo Tek. Can't recommend this enough. https://lampoonmagazine.com/lo-tek-sustainable-resilient-inf... https://longnow.org/seminars/02020/sep/15/design-radical-ind...

The first link is NSFW as a headsup

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

#46

Post by naravara »

hinkley wrote: post #29
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…

What arguments do people have for resisting it?

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

#47

Post by hinkley »

naravara wrote: post #46
hinkley wrote: post #29

Earlier quoted context omitted.

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…

What arguments do people have for resisting it?

Some people think 'store water' and immediately jump to cisterns, or above-ground storage tanks. You simply cannot store a useful amount of water above ground, and exposing it to light and air (and thus mosquitoes) is a whole other set of problems.

Some people do it anyway, others get very upset about what they see as wasted time and resources.

Storing water [this way] is fundamentally about reserving the right to be wrong about where water 'needs to be' on your property, and I think without a way to correct it they feel like their hands are tied. The person I know who is loudest against this strategy is also very philosophical about not fighting nature. If a tree is happy, great. If it's not happy, then it wasn't meant to be. Let it go, get over the sunk cost, and try something else. To his thinking, trying things is cheap, forcing things is expensive (and arrogant).

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

#48

Post by beambot »

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…

Too true. For example, compare the 2-meter long root ecosystem of prairie grass that holds water exceptionally well to that of wheat:

https://images.app.goo.gl/PHmVUNRwwBg8oUKv7

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

#49

Post by baxtr »

hinkley wrote: post #47
naravara wrote: post #46

Earlier quoted context omitted.

What arguments do people have for resisting it?

Some people think 'store water' and immediately jump to cisterns, or above-ground storage tanks. You simply cannot store a useful amount of water above ground, and exposing it to light and air (and thus mosquitoes) is a whole other set of problems. Some people do it anyway, others get very upset about what they see as wasted time and resources. Storing water [this way] is fundamentally about reserving the right to be…

What is the right way to do it then? Can share any resources on this topic? I think it's very interesting.

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

#50

Post by appleflaxen »

wolverine876 wrote: post #41

The amunas are channels that slow the movement of water from mountain streams to farmers; "the diverted water spends between two weeks to eight months underground, with an average delay of 45 days". As far as I can tell, they are used to retain water from the wet season into the dry season. How is that advantageous over using water storage at or near the endpoints? Perhaps ancient farmers didn't the ability to create…

It's a capacity issue. The bandwidth of the amunas is enormous compared to a reservoir.
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