This article considers the impact of social inequities on technological diffusion in an impoverished region of Brazil. It examines the anti-revolutionary aims of infrastructural improvements (dams, road networks, and irrigation canals) that were intended to mitigate suffering during droughts while preempting radical social transformation in northeast Brazil’s semi-arid sertão. It argues that the political moderation of engineers, agronomists, and the public-works agencies they staffed during the early and mid-twentieth century, combined with the self-interested priorities of regional power brokers, produced a pattern of federal investment that reinforced northeast elites’ control over land and water resources and human labor in the sertão. Instead of reducing social inequities that made landless agricultural workers vulnerable to starvation during droughts, technological-development efforts exacerbated the economic and political distance between landowners and the landless poor. The article emphasizes the technological determinism that informed the work of northeast Brazil’s civil engineers in particular, a perspective they shared with their counterparts in the United States and elsewhere during this period. Brazilian agronomists and economists adopted more culturally and sociologically sophisticated analyses of sertão poverty, which led them to criticize the engineers’ development recommendations.