Bahia relaxes irrigation rules amid climate crisis, drawing expert criticism

In early June, as Brazil's agricultural heartland gathered for one of the country's largest agribusiness conferences, Bahia's governor announced a decision that would reshape how water flows across the state's western frontier. Rui Costa, speaking at the Bahia Farm Show in Luís Eduardo Magalhães, said his government would soon publish new rules loosening restrictions on how much water farmers could extract from underground sources and how close together they could drill their wells. The move came as the region faces a deepening climate crisis—rainfall has declined 12 percent since 1980, and river flows are shrinking—yet the governor framed the relaxation as scientifically sound and necessary for agricultural growth.

The new regulations would cut the minimum distance between artesian wells from 2,500 meters to 1,000 meters, allowing denser drilling in areas where farmers currently cannot expand. Water extraction volumes would shift seasonally based on rainfall and river availability. The policy rests on a five-year study that cost R$5 million, funded by the farmers themselves and conducted by universities in Brazil and the United States. Some of the region's wells reach 300 meters deep and pump 500,000 liters per hour; others are shallower but still substantial. The changes could open 500,000 additional hectares to irrigation, according to the Bahia Agricultural and Irrigation Association, though that expansion depends partly on increased electricity supply.

Western Bahia is already a vast agricultural engine. The region currently cultivates 2.3 million hectares, with 200,000 under irrigation. This year alone, farmers expect to harvest 7.07 million tons of soybeans, 2.05 million tons of corn, and 1.3 million tons of cotton, plus smaller volumes of banana, watermelon, coffee, cocoa, wheat, beans, and sorghum—more than 10.7 million tons in total. Irrigated land allows three harvests annually, compared to one reliable crop on rain-fed fields. For farmers like Antônio Rodrigues Porto, a 77-year-old rancher with 2,000 head of cattle and eight existing wells, the relaxed rules promise relief. He wants to irrigate pasture during dry seasons, improving feed quality when rainfall fails. Celestino Zanella, a soybean and cotton producer on 7,000 hectares and one of the study's architects, said the new distance rules would end disputes between neighbors—currently, some farmers cannot drill because a well would be too close to an adjacent property.

The governor defended the decision with confidence. "We will establish new parameters based on these studies, making water use more flexible and expansive," Costa said. He argued that previous rules had been excessively restrictive, tying up the same volume of water in overly tight conditions. "It has been proven that some level of flexibility can be introduced without harming the environment or the region's water replenishment," he said. The agricultural association's president, Odacil Ranzi, echoed this, noting that the study showed water could be extracted for many years to come, with much of it returning through rainfall. The association is investing in reforestation and sustainable land management to keep water in the soil longer, allowing it to percolate down to the aquifer.

Yet the decision has drawn sharp criticism from environmental researchers. Valvey Dias Rigonato, a geographer at the Federal University of Western Bahia, called it "an announced disaster with the state's blessing." In his research area alone, he documented at least 500 families from eight communities already suffering serious water shortages, with whatever water remains often too poor quality for human or livestock use. He accused the state of prioritizing "environmental marketing and political messaging" over genuine environmental management. Marcos Heil Costa, an agrometeorologist with a doctorate in atmospheric sciences, warned that western Bahia and much of the Northeast and parts of Tocantins are experiencing rainfall declines tied to climate change, with further scarcity predicted. "Water use for irrigation requires great caution," he said. "When done rationally, irrigation can be excellent for climate-resilient agriculture, but the conditions here are not favorable."

The aquifer at the center of this debate, the Urucuia, stretches across 125,000 square kilometers spanning Maranhão, Piauí, Bahia, Minas Gerais, and Goiás. The region's other water sources are the Grande and Corrente rivers, tributaries of the São Francisco. Lineu Neiva Rodrigues, a researcher at Embrapa Cerrados, acknowledged that the aquifer can sustain extraction, but only if recharge areas around springs are protected—places where rainwater flows toward the aquifer to replenish it. The problem is that rainfall in western Bahia is wildly uneven, varying between 50 and 350 millimeters annually depending on location, and the trend is downward.

To address concerns, the agricultural association announced a new monitoring system called SIMA, launching in August, that will collect daily data on rainfall, soil moisture, irrigation water use, and aquifer levels, with public access by municipality. Farmers will also gain access to a carbon credit calculator for soybean cultivation. Whether these tools will prove sufficient to prevent overextraction in a region already stressed by climate change remains an open question. The governor's decision reflects a calculation that growth must continue, that science supports it, and that monitoring will manage the risks. His critics see a different equation: a region losing water to climate change, communities already without enough, and a government choosing to accelerate extraction anyway.