Solutions Based on Nature to Face Water Stress: Lessons from the Past and Present

Nature-based solutions (NbS) to water scarcity, environmental degradation, climate change, and biodiversity losses are enjoying increasing implementation throughout the world. This manuscript reviews three case studies from Brazil, Panama, and Portugal that illustrate NbS and searches for commonalities that may assist their usefulness in new sites. The Tijuca Forest in Rio de Janeiro is a remarkable story of centuries of forest management and restoration that initially aimed at providing water security for the capital of the country during the XIX Century while it was still a monarchy. Today, it is recognized as a UNESCO World Heritage Site. The Panama Canal Watershed produces water for canal operations, electricity generation, and drinking water for half the country’s population. Traditional water mills and weirs near streams in the Alentejo Region, Portugal, have largely been abandoned due to the damming of the Guadiana River. Yet today, weirs are increasingly recognized for their important contribution to water provisioning in this dry region. All have a primary goal related to water provisioning, yet their ecosystem benefits are multiple. The cases offer important lessons for adaptation to climate change, cultural benefits from traditional human activities, and concerns about social equity.