The Neo-Assyrian empire offers a clear example of the key relationship between imperial power and water management. Irrigated landscapes under the direct impulse of the Assyrian state were important during its imperial heydays of the late 9th to 7th centuries BC. In the very heartland of the empire (the “Assur-Nineveh-Arbela Triangle” this imperialization of the landscape was the most dramatic, with large canals, aqueducts, and dams redirecting water flows toward the urban areas. Our hydraulic analysis of the canal network connecting Nineveh to its northeastern hinterlands explores how large-scale imperial investments generated imperialized landscapes that marked a substantial divergence from the preexisting conditions in terms of shape and sizes of canal infrastructure. One key question is whether Sennacherib’s hydraulic accomplishments provided meaningful changes to the agricultural economy of the region surrounding Nineveh, especially whether the canals allowed shifting the focus from extensive dry farming to intensive irrigation farming. Our hydraulic modelling shows that Assyrian water controllers and users would benefit from irrigation on the fields upstream of Nineveh. However, they would not benefit automatically from more control of flows in and from the system. Our results do not provide a single, definitive answer, given the uncertainty in data and the many options to model and understand the water systems, but especially for inflows below reference levels, the importance of controlled irrigation is evident. This suggests that irrigation will have been very likely to increase yields throughout the canal area.