Brazil has lost 15% of its surface water since the early 1990s

New Mapbiomas platform details alarming declines in surface water in the Pantanal and Amazon

Brazil is drying up!

The country has lost 15 per cent of its surface water in the past 30 years, according to an alarming analysis published on the new Mapbiomas Water Platform. Overall, Brazil’s surface water plunged from 19.7 million hectares in 1991 to 16.6 million hectares in 2020. It’s a decline that’s been recorded across all biomes, with some particularly shocking findings:

* Take the Negro river. One of the largest tributaries of the Amazon and one of the world's ten largest rivers by average discharge - it has lost 22% of its surface water.

* Or the Pantanal, the world’s largest tropical wetland – the Brazilian section has lost 74% of its surface water

Some of the greatest losses are close to agricultural zones, which suggests that increased consumption and the construction of small farm dams that fragment the drainage network, are contributing to the loss of natural surface water in Brazil – along with deforestation and rising temperatures due to climate change.

“Changes in land use and coverage, construction of dams and hydroelectric plants, excessive use of water resources for the production of goods and services have altered the quality and availability of water in all Brazilian biomes,” said Carlos Souza, coordinator of the Water Working Group at the Mapbiomas project - a network of researchers, NGOS, universities and companies.

The loss of nearly three-quarters of the Brazilian Pantanal’s natural surface water is bound to have a major impact on river flows and water dynamics – and on all the people and over 4000 species that depend on them. Hydropower plants have certainly contributed to the losses and yet there are still dozens of other hydropower dams on the drawing board for this region – dams that will generate negligible amounts of power, while having significant social and environmental impacts.

Unsurprisingly, there seems to be a link between wildfires and the reduction in surface water in some areas. Such as in the municipality of Corumba in Mato Grosso do Sul, which boasts two unwanted records – it’s seen the most fires and lost the most surface water between 1985 and 2021.

“The fire and water cycles are interconnected. Less water makes the earth and the organic matter that settle on it more vulnerable to fire. More fire suppresses the vegetation, which plays a crucial role in perpetuating springs,” explained Tasso Azevedo, Coordinator of Mapbiomas.

Another example is the São Francisco River. One of the largest rivers in the country, it has lost 10% of its surface water over the past 15 years, which coincides with a period of agricultural expansion in Matopiba region. At its mouth, communities are already feeling the effects, with salt water intruding further up the river and inland.

And then there is the vast Cerrado savanna, which is critical for Brazil's agricultural production and home to incredible biodiversity. But its water system is being transformed. Natural surface water has fallen from 864,000 hectares to just 490,000 hectares. Much more surface water is now governed by hydropower, changing water flows and impacting people and nature.