From Guarapiranga to Billings: Changes in São Paulo’s Urban Water Supply, 1940–60

By 1940, São Paulo had climbed to economic prominence as the industrial center of Brazil. Since the late nineteenth century, state officials and sanitation engineers worked to expand the collection and distribution of water, but by 1940 only fifty percent of urban dwellings were supplied by the metropolitan water systems. This paper looks at the process amplification and improvement of São Paulo’s water system that took place in the 1940s and 1950s, resulting in the expansion of the Santo Amaro (Guarapiranga) and Rio Grande (Billings) reservoirs. In particular it considers the shared attention that administrators and engineers gave to balancing hydroelectric and domestic needs. The decision made in these two decades had important and unforeseen consequences for the city’s water supply in the latter half of the twentieth century. This paper seeks to uncover the process by which administrators transformed the waterscapes of the growing metropolis of São Paulo (including reversing the River Pinheiros and rectifying the River Tietê) in order to balance these needs, while neglecting to account for supply shortages during dry periods. Additionally, it hopes to show how a major shift in São Paulo’s urban water management manifested among different social groups in the city as the city’s environmental managers attempted to fulfill the promise of modernity.