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  • From: Lawrence London <lfljvenaura@gmail.com>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: [permaculture] Pre-Inca canals may solve Lima's water crisis - environment - 09 April 2015 - New Scientist
  • Date: Sun, 12 Apr 2015 11:58:19 -0400

Pre-Inca canals may solve Lima's water crisis - environment - 09 April 2015
- New Scientist
http://www.newscientist.com/article/dn27311-preinca-canals-may-solve-limas-water-crisis.html#.VSqSZZPqHIV
Pre-Inca canals may solve Lima's water crisis
12:30 09 April 2015 by *Fred Pearce*
<http://www.newscientist.com/search?rbauthors=Fred+Pearce>

A revival of pre-Inca water technology in the mountains of the Andes is set
to keep taps flowing in the drought-affected Peruvian capital, Lima.
Grouting ancient canals, it turns out, is a far cheaper solution to the
city's water crisis than building a new desalination plant.

Lima is one of the world's largest desert cities and relies for water on
rivers that flow out of the Andes. But those rivers diminish to a trickle
during a long dry season, leaving the population of almost 9 million with
intermittent water supplies.

Now the city's water utility company, Sedapal <http://www.sedapal.com.pe/>,
has decided to invest in conservation projects in the Andes to keep the
rivers flowing and taps running. And researchers have discovered that the
most cost-effective way is to revive a system of ancient stone canals,
known locally as *amunas*, that were built in the Andes by the Wari culture
between AD 500 and 1000, centuries before the rise of the Incas.
Forgotten paths

The canals captured water from rivers in the mountains during the rainy
season and took it to places where it could infiltrate rocks that fed
year-round springs further down the mountains, so maintaining river flow
during the dry season.

The *amunas* fell into disrepair long ago and had been largely forgotten.
In most places, their water now quickly returns to the rivers. But
hydrologists such as Bert De Bièvre of Condesan, a Lima-based
non-governmental organisation behind the project, say re-grouting the lined
stretches of the canals with cement would allow them to resume their
original purpose.

"The idea is to build a timelag into the hydrological system, delaying
water run-off for weeks or even months until it benefits water supply in
the dry season," De Bièvre says.

SEDEPAL has now decided to fund the plan by taking 1 per cent from its
water charges for the next five years. The costs are estimated to be $23
million.
Holding back the flood

Lima has water shortages for seven months of the year but during the other
five months, the Rimac, Chillon and Lurin rivers, which pass through Lima
on their way to the Pacific Ocean, regularly cause floods
<http://www.peruthisweek.com/news-lima-water-service-restricted-due-to-flooding-affecting-rimac-r-105658>
and landslips. Keeping floodwaters back for the dry season makes obvious
sense.

Research into the hydrology of individual canals is still in progress. "We
have been injecting ink into the canal water to see where it resurfaces,"
says De Bièvre. But he is confident that the project could revive 50
*amunas*, mostly in the Chillon catchment.

According to a study by De Bièvre and Gena Gammie, a water specialist at
Forest Trends, an NGO based in Washington DC that is backing the project, that
should be enough to increase water supplies <http://bit.ly/1E5H6gl> to Lima
by 26 million cubic metres, and reduce the city's current water deficit in
the dry season by as much as 60 per cent.

According to the study, other green investment initiatives that could keep
water on the mountainsides for longer include reviving forests, wetlands
and ancient agricultural terraces, and restricting livestock grazing on
upland pastures. But the study found that reviving *amunas* would be by far
the cheapest option, costing less than a hundredth as much as water from
the city's new desalination plant.

<>

http://www.newsweek.com/revival-ancient-pre-inca-canals-may-prevent-peru-droughts-321315
Peru Turns to Ancient Aquaducts to Prevent Droughts By Jack Moore
<http://www.newsweek.com/authors/jack-moore> 4/10/15 at 1:29 PM

One of the world’s driest cities is attempting to solve its water problems
by reviving its ancient network of waterways. The Peruvian capital, Lima,
is to restore pre-Inca aqueducts in the Andes mountains to service its
population during the seven-month dry season.

The project, as reported by *New Scientist
<http://www.newscientist.com/article/dn27311-preinca-canals-may-solve-limas-water-crisis.html#.VSfPnvnF9qI>*,
would see a series of disused stone canals, locally referred to as amunas,
re-grouted with cement to collect surplus rainwater in the rainy season to
be used for during the dry season when there is a substantial rainwater
deficit.

The canals are believed to have been constructed in 508 AD before the Incas
and their revival is set to cut the city’s water deficit by 25.9 cubic
meters of water, over half of the current 42 million cubic metre water
deficit.

The purpose of the amunas is to prevent the water flowing downhill quickly,
taking it sideways across the mountains and slowing its descent, allowing
for it to be preserved and used weeks later. This strategy will allow
Peruvians access to additional water during the dry season instead of it
being lost as surplus in the wet season.

Anna Thiel, communications manager at Forest Trends, a U.S.-based NGO
supporting the initiative, says that the restoration project will be much
cheaper than alternatives because the infrastructure is already in place.

“The structures are there already, these waterways are there,” she says.
“The infrastructure is existing, all it needs is some improvement to the
infrastructure. The other thing is the cost-effectiveness, it’s very
non-disruptive to the environment.”

“It will be pretty significant. They are going to have more water
available,” she adds. “It just means there is a much more steady supply of
water. It is not like other places where there is a deficit all year round.”
The canal restoration is to be overseen by Lima’s water company Sedapal and
is set to cost $23m (£15.7m) “for restoration of the waterways but also the
grasslands and the wetlands,” Thiel notes.

<>

>From Reddit, excellent commentary and useful links to related resources:
<>

"Interesting parallel in Cambodia - during the Khmer Rouge reign - the
Khmer Rouge generals, having killed off anyone with an education, set the
citizens on digging massive canals uphill across the country. The effort
killed millions of Cambodians. If they had kept any historians alive, they
would have known that Cambodia already had developed an ingenious
irrigation system that relied on the natural slow-sloping contours of the
land. This medieval system was so successful, they could harvest rice twice
in each season. Instead, the Khmer Rouge dug channels across the ancient
irrigation and plunged the country into a massive famine."

"What may be even more impactful is adopting the agricultural practices of
the pre-contact societies. Those systems were complex multicrop plots that
encouraged positive feedbacks. One example in the past was Three Sisters
Agriculture. Grow corn, beans, and squash together. The beans fix Nitrogen,
the squash lay roots, and the maize grows up to provide a structure, all
often together help retain soil moisture. Eat them together and you have a
perfect protein. Instead, we have monocropping of rice which is a big drain
on water supplies, requires other food to complete the protein, and is more
at risk to pests."

"platypocalypse 8 points 16 hours ago*

This is absolutely correct. Corn beans and squash were more of a North
American thing (*edit: nope they were South American too*); in Peru they
had things like quinoa, tomatoes, and potatoes, but your point is spot-on.
The best thing we can do is learn how people did so well in the Americas
before the European invasion, and apply that knowledge. Are you familiar
with permaculture?"

/r/permaculture <http://www.reddit.com/r/permaculture>

/r/selfsufficiency <http://www.reddit.com/r/selfsufficiency>

Ecovillages <http://en.wikipedia.org/wiki/Ecovillage>

Map of ecovillages <http://www.ic.org/directory/map/>

Another map <http://www.permacultureglobal.com/projects>

Yet another map <http://gen.ecovillage.org/en/projects/map>

Global Ecovillage Network <http://gen.ecovillage.org/>

GEN Africa <http://www.gen-africa.org/>, Americas
<http://genna.ecovillage.org/>, North America
<http://northamericanpermaculture.org/>, Latin America
<http://www.casacontinental.org/>, Europe <http://www.gen-europe.org/>,
Asia/Oceania <http://genoa.ecovillage.org/>

PBS/Nova documentary about how all Earth's systems are already in harmony
with one another <http://www.youtube.com/watch?v=38peWm76l-U>

Redesigning Civilization with Permaculture
<http://www.youtube.com/watch?v=_y_MleU8iNQ>

Ted Talk by Ron Finley: Food Deserts and Gangster Gardening
<http://www.ted.com/talks/ron_finley_a_guerilla_gardener_in_south_central_la.html>;
23 more excellent Ted talks
<http://www.reddit.com/r/Permaculture/comments/1eul92/24_great_ted_talks/>

In Thailand <https://www.youtube.com/watch?v=2cr10nOm0xU>

In Vermont <http://vimeo.com/63333459>

2,000 year old food forest in Morocco
<https://www.youtube.com/watch?v=hftgWcD-1Nw>

Sustainable mangrove harvesting in Mexico
<https://www.youtube.com/watch?v=DIAJ33yqdbQ>

Snoop Lion's community garden project <http://mindgardens.org/>

Bukowski quote <http://i.imgur.com/0NMbimL.png>

Earthships <http://en.wikipedia.org/wiki/Earthships>

An Earthship in Haiti <http://www.youtube.com/watch?v=h7jAkwhTq4c>

Earthbag building <http://en.wikipedia.org/wiki/Earthbag_construction>

More Earthbag building <http://www.earthbagbuilding.com/>

Food foresting <http://en.wikipedia.org/wiki/Food_forest>

Protecting local bee populations <http://www.reddit.com/r/beekeeping>

Textiles: Making Dog Hair Sweaters
<https://www.youtube.com/watch?v=6jHTfshTzpM>

Opportunities <http://www.wwoofinternational.org/how-it-works/>

Xeriscaping <http://www.calrecycle.ca.gov/organics/xeriscaping/>

US/Canada community gardens list <http://acga.localharvest.org/>

Jordan Valley: Greening the Desert
<http://permaculturenews.org/2013/11/19/rough-ready-real-november-2013-update-dead-sea-valley-permaculture-project-aka-greening-desert-sequel-site/>

Nomads United - ride horses across continents and help people grow food
<http://www.nomadsunited.com/>

Nomads United Facebook page <https://www.facebook.com/NomadsUnited?sk=wall>

"P. K. Bretting

1990 New Perspectives on the Origin and Evolution of New World Domesticated
Plants: Introduction. *Economic Botany* 44(3):1-2

*For example, isozymatic, genetic, and ethnobotanical data (Rick and Holle
1990) suggest that the Ceja de la Montaña, the eastern foothills of the
central Andes, does not represent the center of origin for the domesticated
tomato (Lycopersicon esculentum var. esculentum) but rather is a "contact
zone" where the relatively recently introduced weedy cherry tomato (L. e
var. cerasiforme) has hybridized with the domesticate in swidden fields.
Rather than a phylogenetic series of tomatoes in various stages of
transformation from wild through weedy to domesticate, these polymorphic
tomato populations therefore probably represent a "swarm" of weeds,
domesticates, and hybrids/introgressants between the latter two forms."*

Who would have though that ancient structures are non-intrusive to the
environment. I wonder how many more ancient structures are still around
that could be used to address areas affected by drought. Even copy their
techniques and apply them in other areas.

Maybe we could have asked the hundreds of indigenous Californian tribes if
they weren't all brutally massacred.

Did they have aquaducts?

No, but they were damn good at thriving in all parts of California.

http://en.wikipedia.org/wiki/Indigenous_peoples_of_California

"The great thing is that they stood unused for thousands of years without
being torn down. Now they are useful again".

"When I lived in Peru, back in the '70s, most small farming communities
maintained, and used, the pre-Inca irrigation ditches. Every spring, the
whole community would designate a day when all the men would weed and
re-rock the aquacias and, when done, drink beer and feast. The first sip of
beer was always poured for pacha mama (Mother Earth). The educated men
would laugh nervously, but they always did it, saying "Just for luck,"
sheepishly. During Inca times, doing upkeep on the irrigation system and
the roads was mandated for all citizens, so this "folkways" is at least 600
years old."




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