'Thirsty Sugar Lands': Environmental Impacts of Dams and Empire in Puerto Rico Since 1898

Abstract

The story of North American dam building is incomplete without the United States' Caribbean territories because the motivations and consequences of building dams there were different from on the mainland. Between 1910 and 1914, the Puerto Rican Irrigation Service built three large dams in the island's south-east to irrigate canefields owned by North American sugar companies. The water harnessed by the South Coast Irrigation Project (SCIP) doubled sugar yields in its district in the decades following the project's completion, generating huge profits for North American sugar interests. However, the sugar boom did not lead to sustained economic growth on the island and did little to increase the standard of living for many Puerto Rican fieldworkers and their families. The project also brought a bumper crop of unforeseen environmental consequences. North American engineers underestimated the vagaries of Puerto Rico's climate. Droughts and extended dry periods led to water shortages that continually menaced irrigation. Stormy weather created another unanticipated problem for the dams. Hurricanes and heavy rains in the mountains north of the sugar lands contributed to high erosion rates that accelerated sediment accumulation in the reservoirs and reduced their storage capacity. Together, drought and siltation threatened to render the dams obsolete. Hydroelectric turbines, installed as an incidental part of the project, provided affordable electricity that powered groundwater pumps to make up for surface water shortages. Groundwater saved the sugar boom, but sediments continued to build in reservoirs, an enduring legacy of US imperialism that is expensive to mitigate. The SCIP preserved socioeconomic and racial inequalities, but re-engineered the island's hydrosphere, turning the parched south-east into a giant canefield and its rivers into repositories for sediments.