This article examines the origins of national electrification in Chile, situating its technocratic promoters within a broad trend – unfolding across Latin America – toward the ‘rational’ management and conservation of natural resources by the state. It surveys the early history of Chilean electrification (1890s–1940s) to show how conservationist thinking flowed through discussions and debates among engineers about the proper uses of the country's waters. These ideas eventually shaped the 1943 national electrification plan, which focused on hydropower. The article sheds new light on the history of Chile's technocracy, the relationship between perceptions of the environment and development planning, and the political and economic debates over national electrification. It also shows how the conservationist dilemma of using versus preserving natural resources operated within a utilitarian and highly technical framework for thinking about nature's bounty. The article thus contributes to recent historical scholarship on conservation and environmental technocrats in Latin America.

Hundreds of indigenous Mayo ejidatarios became members of the SICAE (Sociedad de Interés Colectivo Agrícola Ejidal) sugarcane cooperative in North-West Mexico in the 1930s, gaining control of irrigated lands and marginalising non-members, called ‘individualists’, by the 1940s. This article focuses on how indigenous individualists of Los Goros and El Teroque ejidos navigated the SICAE's control of water and attempts to annex their lands. Mayo individualists’ resistance to corrupt ejidal leadership and the SICAE cooperative allowed them to influence local water development decisions. These individualist Mayo experiences exemplify how hydraulic social mobilisation became an indigenous people's strategy of survival in mid-twentieth-century Mexico.