In Mexico City, water engineers have pushed the aquifer beyond its limit. As a result of decades of unrelenting groundwater extraction, the sprawling city of 22 million is literally sinking under the weight of its own growth. The current construction boom threatens to increase the risk of flooding and curtail the already minimal water services that reach the poor on the periphery, who attempt to halt new construction and demand services by blocking roads and contractors' equipment. Yet engineers remain confident that their massive new aqueducts and tunnels will allow the city to grow indefinitely. This project attempts to explain this persistent confidence in engineering to overcome the problem of environmental limits. It explores how engineers produce and project this confidence not only through their discourse as previous critical studies of development would suggest, but through their material work of moving paper, water, and soil. Preliminary research suggests that engineering work displaces the costs of endless growth onto the poor on the periphery, distant watersheds, and the deep aquifer below – rendering environmental limits increasingly invisible. In attending to the material work of engineers, this project offers to ground discursive critiques of development in a firmly material foundation while providing crucial spatial specificity to previous ecological scholarship on the limits to growth. It also serves as a model of what I call an "anthropology of engineering," which combines the insights of the anthropology of science with the materialist focus of studies of infrastructure to understand the way engineers' designs shape – and are shaped by – increasingly limiting landscapes and obstinate residents.