Restoring ancient water supplies in Peru

A community-based NbS project in the Peruvian Andes improved water provisioning whilst permitting grazing of livestock, and has sparked funding and interest in ecosystem-based water management in Peru. An ancient mamenteo canal was restored: a technology that predates the Incan Empire and diverts water from streams during the wet season, increasing infiltration in mountain slopes to increase water availability downslope during drier months. The canal was restored partially by preventing grazing along the banks; this allowed the banks to stabilise and increased water infiltration. The restored canal delayed water flow by 2 weeks to 8 months, and hence increased water availability during the dry season. This, in turn, increased the length of the growing season for farmers. In response, Lima’s water utility allocated US$1 million to community-based mamanteo canal restoration.

This was an Ecosystem Services for Poverty Alleviation (ESPA)-funded project.