Peru’s fertile past: learning lessons about water from pre-Incan societies. From the article:

The Andes Mountains are one of six places in the world where complex civilisations emerged, spurred by precipitation so seasonal it was a catalyst for hydrological innovations again and again. People cultivated deep knowledge of water and the underground, deploying strategies that still astonish – and which some still use.

Today, modern Peruvians are redeploying that ancient knowledge and protecting natural ecosystems such as high-altitude wetlands to help the country adapt to climate change. It’s one of the world’s first efforts to integrate nature into water management on a national scale….

Several years ago, desperate for water security, the country’s leaders did something radical: they passed a series of national laws requiring water utilities to invest a percentage of their customers’ bills in “natural infrastructure”. These funds … go to nature-based water interventions, such as restoring ancient human systems that work with nature, protecting high-altitude wetlands and forests, or introducing rotational grazing to protect grasslands. Before, it was considered a misuse of public funds if utilities invested in the watershed. Now it’s required….

The people who live here are comuneros: members of an agricultural collective. 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. The strategy, invented by an ancient people called the Huari (WAR-i), is still practiced here and in a few other Andean villages. Because the water moves more slowly underground as it travels through gravel and soil, it emerges downslope from springs months later, when the comuneros collect it to water their crops. Because much of their irrigation soaks into the ground and eventually makes its way back to the rivers that supply Lima, repairing abandoned amunas scattered throughout the highlands could extend water into the dry season for city dwellers too….

Built by carefully placing rocks together, it’s about two feet wide and a couple of feet deep and winds like a sinuous snake along the contour of the hills. It’s July, mid-dry season, and the amuna is nearly empty of water, having delivered its liquid riches to a rocky, bowl-shaped depression where it infiltrated into the ground. One comunera, Lucila Castillo Flores, a grandmother in a skirt and white-brimmed hat, likens what happens here to sowing water, using the verb sembrar: to plant. “If we plant the water, we can harvest the water,” Flores says. “But if we don’t plant the water, then we will have problems.”

For more on Erica Gies’s work, see here.

For a related post, see here.