Brazil faces a multi-dimensional water challenge. Severe water crises- such as floods and droughts- have hit a quarter of Brazil’s municipalities in the last year, including major cities such as Brasilia, São Paulo, Rio de Janeiro and Vitória. These same communities have also suffered from  threats to safety and water quality, as floods, landslides and insufficient wastewater treatmenthave endangered residents and polluted water sources with sediment and sewage.

As these trends have intensified, Brazil has also lost its first line of defense against these natural disasters: its forests.

Forests are a form of natural infrastructure that can ameliorate water challenges. Restoring forests is a nature-based solution that can  provide protection from flooding, increase water flows during dry periods and improve water quality by filtering out pollutants and preventing erosion.

The question is: Will Brazil scale up investment in its natural infrastructure, or continue to get hit by water crisis after water crisis?

Brazil’s Natural Infrastructure

Brazil has an inherent wealth of natural infrastructure. The Amazon Rainforest is a powerful regulator of cloud patterns, with transpiration from its trees feeding the “rivers of the sky” that determine when, where and how much rain will fall. The Atlantic Rainforest provides important water sources for Brazilian metropolitan regions that are home to more than 63 million people.

Yet deforestation in the Amazon and Atlantic Forests is once again on the rise – a mere 12 percent of the Atlantic Rainforest is left. When forests are slashed, trees are unable regulate water flow below ground and hold sediment in place. In the sky above, hydrologic cycles are disrupted.

At the same time, the Cerrado, Caatinga and Pampa biomes are losing more than 1 million hectares (2.5 million acres) of native vegetation per year, an area seven times the size of São Paulo city. These lowlands are home to thousands of endemic species and are the headwaters for the some of the most important Brazilian water sources, including the Amazon Basin and Guarani Aquifer, the largest in the world.

The resulting water crises, caused in part by these disruptions, have crippled the national and local economies, caused electricity blackouts and spurred protests.

Keep the Forests, Keep the Water

Brazil is starting to wake up to the importance of natural infrastructure, committing to restore 12 million hectares (nearly 30 million acres) of forest, increase agricultural production and eliminate illegal deforestation by 2030. But that may not be enough to prevent looming water crises.

There are additional opportunities to restore forest for water benefits in Brazil, especially in the watersheds surrounding major cities. Brazil’s cities, where much of the country’s population lives, have been hit hardest by recent water crises. But protecting the forested lands around them can provide economic and environmental benefits, in addition to providing livelihoods and recreation opportunities for thousands of Brazilians. 

Three cities may find that natural infrastructure is a key solution to stopping ongoing and future water crises:

  • Vitória – Can forests stop an ongoing crisis? One of Brazil’s main ports, the city has struggled with severe droughts and floods that filled streams with soil. The local water company wants to build a water storage reservoir to secure water supply during dry seasons, but the reservoir and entire water system is still vulnerable to sedimentation and variable water flows. Restoring the forested watershed that surrounds Vitória may address the root causes of sediment pollution and help regulate the timing and flows of water – making water treatment more affordable, and protecting the reservoir.

  • São Paulo- Can restoration prevent the next crisis? Brazil’s record droughts hit São Paulo hard. At the same time, sediment and pollution threaten the city’s water quality, raising water treatment costs. Rapid degradation of the Atlantic forests that supply Sao Paolo with its water is only worsening the situation. In addition to investing in traditional water treatment options, utilities may benefit by restoring the nearby Atlantic Forest to affordably filter water, reduce erosion, and improve flows.

  • Rio – What kinds of forests provide which benefits? There’s still a lot to learn about how Brazil’s many forest types impact water quality and quantity. A new water research station in the cloud forests, recently established in Rio, may finally answer some of the biggest questions related to this. The Nature Conservancy (TNC) and IAG-USP (Climatology Laboratory) are studying how much water cloud forests produce. The insights gained from this project can inform future restoration efforts, to ensure that trees are planted and prioritized to maximize their water benefits.

World Resources Institute, TNC and partners are studying these three cities, to determine the answers to the questions above. In particular, this research seeks to uncover the financial benefits – from increased water flows, to reduced water treatment cost – that can accrue from protecting and restoring forests.

Brazil’s abundant forests are an essential tool for water security: they can filter water, regulate water supply, and guarantee that atmospheric and terrestrial rivers flow. When utilized alongside built “grey” infrastructure like dams and treatment plants, they can bolster resilience and extend environmental benefits. But unless these natural systems are protected and restored, water crises will only continue. In order for forests to protect Brazil’s water, Brazil must protect its forests.