South America: Water surpluses forecast for Buenos Aires Province; deficits central Brazil

26 April 2017

The Big Picture
Large pockets of exceptional water deficits are forecast for much of Brazil through December 2017, as seen in the 12-month map (below), along with deficits of varying intensity in Venezuela, Guyana, Suriname, French Guiana, Bolivia, and northern Chile.

Surpluses are forecast for Buenos Aires Province and La Pampa Province in Argentina, and San Martín Region in northern Peru.

Impacts
Torrential rainfall in southern Colombia triggered a massive mudslide in the city of Mocoa, killing over 300 people and leaving over 100 missing. Water and power services remained down a week after the avalanche that left neighborhoods and cars buried and several bridges destroyed. More than 1,100 soldiers and police officers were called to the area to help locate survivors, and workers rushed to bury identified bodies quickly to prevent disease outbreaks as survivors lines up for vaccinations.

Reconstruction costs due to flooding and landslides in Peru are estimated at over $6 billion, more than 3 percent of Peru's GDP. More than 200 bridges and between 2,000 and 7,000 kilometers of highway were destroyed or blocked. Agricultural and livestock losses total US$645 million, says the National Convention of Peruvian Agriculture (Conveagro), destroying 92,000 hectares of bananas, sugar cane, rice, and other crops primarily in the north. The Peruvian Council of Ministers has approved a US$42 million agricultural assistance program for growers to replace infrastructure, restore plantations, and compensate for crop loss.

As of the end of March the federal government of Brazil recognized a state of emergency in 872 cities across the nation due to prolonged drought. Stored water was down to 8.8 percent of reservoir capacity in Ceará state, and rationing programs were instituted in 198 cities in Paraíba this year. With lack of rainfall negatively impacting hydroelectric production, more expensive thermoelectric plants will be activated, bumping up electricity prices in April by R$3 (US$0.96) more for every 100 kilowatt-hours (kWh) consumed.

The USDA Foreign Agricultural Service reports that Chilean farmers planted 10.5 percent less acreage in wheat in anticipation of drought conditions; corn planted area also decreased.

Chile's Petorca Province has become a focus of water rights as local activists stand with small farm owners against avocado plantations accused of illegally siphoning river water. Both drought and the increase in water-intensive avocado production for the international market have made water shortage worse in recent years. Two major Danish supermarket chains - Aldi and Dansk Supermarket - have changed policies to avoid buying from plantations involved in the illegal extraction of water.

Forecast Breakdown
The 3-month maps (below) for the same 12-month period show the evolving conditions in greater detail.

Though the extent of water deficits in South America is expected to shrink April through June, severe to exceptional deficits are forecast in central and eastern states of Brazil including southern Pará, Tocantins, Mato Grosso, Goiás, Minas Gerais, São Paulo, as well as northeastern Amazonas in the north and Rondônia in the west. Many rivers in northeastern Brazil are visible on the map as paths of deficits including the São Francisco and the Tocantins.

Severe deficits are expected to emerge in the Caquetá River basin in southern Colombia during this period. Deficits in Bolivia are forecast to shrink overall but severe to exceptional deficits will persist along the border with Brazil. Likewise, the extent of exceptional deficits in Chile will shrink but exceptional deficits will persist in the north, in the south near the Gulf of Corcovado, and in southernmost Patagonia. Moderate to exceptional deficits are forecast in coastal Peru from Lima south.

Exceptional surpluses are forecast to continue to emerge and increase in extent in western Buenos Aires Province, Argentina into La Pampa Province, and also slightly southwest in Neuquén Province. Primarily moderate surpluses are forecast for eastern Paraguay and Rio Grande do Sul in southern Brazil.

From July through September much of the northern half of South America is forecast to experience deficits conditions. Exceptional deficits will persist across Brazil’s mid-section, moderate deficits will continue to emerge in the east, and the extent of deficits in northern regions will increase. Deficits ranging from moderate to extreme are expected to emerge in Colombia, Venezuela, Guyana, Suriname, and French Guiana. Deficits will continue to emerge in coastal Peru and northern Chile. Extreme to exceptional surpluses remain in the forecast for Argentina’s Buenos Aires, La Pampa, and Neuquén Provinces.

The forecast for the latter months – October through December – indicates near-normal conditions across Brazil’s mid-section but the persistence of deficits elsewhere in northern South America.

(It should be noted that forecast skill declines with longer lead times.)