1626 Potosí flood

The 1626 Potosí flood was a major disaster in Charcas (present-day Bolivia) that led to estimates of 2,000^[1] or 4,000 human deaths.^[2] On March 15, 1626, the San Ildefonso Dam burst causing a flood in the city of Potosí that destroyed many silver ore-processing plants (ingenios) and led to massive economical losses and environmental damages. Some interpreted the catastrophe as a divine punishment for past episodes of violence such as the 1622–1625 War of the Vicuñas and Basques.^[3][4] There are reports that more than half of the ingenios were destroyed.^[5] As silver ore in Potosí was extracted in a process that required mercury by one estimate 19.3 tons of the element, at concentrations of 48 mg/l Hg, were washed away by the flood.^[1][6] Reconstruction after the flood went fast and ten years later, by 1636, there were more ingenios than before the flood.^[7] The flood is in hindsight seen by some historians as the beginning of a century-long period of decline of Potosí.^[7]