In the Maya lowlands ancient water management was multi-componential, diverse across space, and shifted over time. In the seasonally dry Puuc region of the northwestern Yucatan Peninsula, large reservoirs dominated water management during the Late Classic to Early Postclassic periods (a.d. 600–1250). Research reported here suggests that reservoirs were central components of Puuc urban settlements and that natural depressions—from which water reservoirs could be made in the Puuc terrain—were key settlement attractors in the region. In particular, new evidence of the pre-Hispanic construction of a berm of monumental proportions along the perimeter of a water reservoir at Xuch—a Late Classic to Early Postclassic Puuc Maya agro-urban settlement in Campeche, Mexico—stresses the political, economic, and symbolic importance of water and water reservoirs in pre-Hispanic Maya communities, previously demonstrated by colleagues working elsewhere in the Maya lowlands. This article discusses the “weight” of water reservoirs in Classic period Puuc Maya landscapes, adds to the literature on water management in other regions of the Maya lowlands, and explores aspects of economy, power, environment, and cosmology in water management systems of the dry regions of the northern Yucatan Peninsula.