[HN Gopher] Pre-Inca Canal System Uses Hillsides as Sponges to S... ___________________________________________________________________ Pre-Inca Canal System Uses Hillsides as Sponges to Store Water Author : bryanrasmussen Score : 35 points Date : 2020-01-06 21:04 UTC (1 hours ago) (HTM) web link (eos.org) (TXT) w3m dump (eos.org) | vanderZwan wrote: | > _A team of hydrologists, engineers, and social scientists is | hoping to strengthen the water security of Lima and other | Peruvian cities through analysis of a 1,400-year-old nature-based | system developed by pre-Inca mountain communities. The technique | uses a canal system that diverts water from streams to small | ponds or spreads it over rocky hillslopes that act as natural | sponges. This slows the flow of water down the mountains, | preserving it into the dry season._ | | Isn't that exactly what swales in permaculture practices intend | to do as well? Did the permaculture community copy this from | indigenous techniques perhaps? | | > _Like most modern cities, Lima relies on gray infrastructure | like reservoirs and dams for water diversion and storage. Gray | infrastructure alone, however, has its drawbacks. It is often | expensive and challenging to implement. It also has a static | threshold, unable to adapt to shifting environmental conditions._ | | > _Natural (green) infrastructure can be much more dynamic and | cost-effective than gray infrastructure. Green infrastructure is | a broad category that can include planting native grasses to | prevent erosion and maintaining wetland health to hold and filter | water. Crucially, communities can use it in addition to the dams | and reservoirs already in place, amplifying their effectiveness | and providing a buffer when their threshold is exceeded._ | | This reminds me of a few articles I've seen in the last years | about a German city that is trying to be better at coping with | lots of rainfall by installing lots of green areas specifically | designed to hold a lot of water, while at the same time reducing | the heat island effect. | KaiserPro wrote: | The paper is far more illuminating: | https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/503994 | | This similar to some of the things I've heard about in central | india(I think) where they create half moon dams (less than | 2m(8ft) tall) that hold water back creating mini-lakes. | | This serves two purposes: one it slows down water, meaning that | flash flooding is reduced. Two is keeps water hanging around | longer, meaning it makes the area less arid. | | However it means more mosquitoes, so its not all good. ___________________________________________________________________ (page generated 2020-01-06 23:00 UTC)