The chapter reveals the envirotechnically complex and sociopolitically charged tasks that government técnicos encountered trying to make the reparto de tierras (land distribution) of 1936 compatible with the reparto de aguas (water distribution). Facing a series of difficult tradeoffs, they reengineered the Laguna’s irrigation system to rely on an unbuilt dam and—to their growing alarm—on groundwater pumping they long knew depleted and contaminated the aquifer. The chapter demonstrates how the incompatibility of the two repartos compromised the long-term sustainability of Cardenista agrarian reform even before sociopolitical factors, such as the endemic corruption of and implacable opposition to ejidos, severely weakened and then undermined the reform.