One of the most remarkable things about the amunas is that the comuneros know which canal feeds which spring, meaning they understand the path water takes underground. Co-author Perez's interviews with local people documented this knowledge, which had been passed down through the generations.
Urbanites tend to discount the expertise of rural and Indigenous people, says Ochoa-Tocachi, but the researchers were able to verify their information as "very accurate" by adding tracers to amunas' flows and then using sensitive detectors to track those molecules' emergence in the spring-fed ponds. This finding "surprised us", says Ochoa-Tocachi. "It shows that we can use indigenous knowledge to complement modern science to provide solutions to current problems."