Ancient Peruvian water system tackles modern problem

Restored ancient water recharge systems known as amunas. Image: Aquafondo

A Peruvian brewer is tapping into a 1,500-year-old water harvesting system in the capital of Lima in a bid to tackle water shortages.

Lima, the world's second-largest city, is located in a desert and only gets around 9mm of rainfall each year for a population of 11 million.

Back in 500 AD people living in the mountainous areas of Peru used a series of channels, known as amunas or mamanteos, to filter rainy-season runoff from the mountains, so people living in the lowlands could access water during periods of low-rainfall. Sadly over the millennia these ancient systems have fallen into ruin and can no longer be used to harvest the water Lima needs.

Aquafondo: The Water Fund for Lima & Callao was created in 2010 to protect the water supply through solutions based on nature and sustainable management. With climate change expected to cause a severe water shortage in the area within the next 10 to 15 years, the fund decided to approach Peruvian brewer Backus, which is owned by AB InBev, to see if it could help restore the ancient water systems back to working order.

"The restoration of the aquifers contributes directly to confronting the water crisis."

Mariella Sánchez, Aquafondo

“Aquafondo presented us with the opportunity to work together to restore amunas, an ancient water-harvesting system in the area,” said Maria Atuesta Vegalara, regional sustainability manager for AB InBev's Middle Americas Zone. “Aquafondo has been a great ally and partner in this mission because they have the technical knowledge to rehabilitate these amunas and strong relationships with the local community.”

To date, Backus has invested US$5 million to restore 32.5km of amunas across the region.

“The restoration of the aquifers contributes directly to confronting the water crisis,” said Mariella Sánchez, executive director of Aquafondo. “It will allow the lower part of the micro-basin to have greater water availability in the dry season, positively impacting the local livestock and farming.”

To restore the amunas, Aquafondo pairs technical expertise with the local communities’ ancestral knowledge of the terrain. From this, the organisation has also developed awareness workshops in places where there is not yet extensive knowledge about using the ancestral channels for water conservation.

Backus and Aquafondo face further challenges in Peru's tricky terrain and naturally variable climate. Navigating up the mountain is dangerous or even impossible in the rainy season, meaning rehabilitation is limited to the dry season, typically lasting from April through November.

So far, 15km has been restored, with a goal of restoring the entire 67km network of amunas by 2025. Although the effort is well on its way, Backus says it cannot be achieved alone.

In addition to Aquafondo and The Nature Conservancy, other corporations have been invited to join the project, which was recognised with a Lighthouse Award from the Brave Blue World Foundation.

Over the next three years more than 400 residents from San Pedro de Casta, Huachupampa, Huanza, San Juan de Iris and Carampoma will be trained in operating and maintaining the amunas as part of a partnership with the German Development Cooperation.

“By teaching residents how to restore the amunas themselves, this knowledge stays in the community and will benefit future generations,” added Vegalara. “When you think about sustainability, in the long run, the maintenance of the amunas by the communities is essential.”