Since the reopening of the mission in 2019, the water supply of Larsa has been a central focus of field investigations on this urban site of South Mesopotamia (Iraq). The first map of its hydraulic network can be established thanks to the cross-analysis of photogrammetric and geomagnetic images, to which is added the data of the geo-archaeological study and archaeological operations. In its final state, the intra-mural network had more than a hundred canals including several large ones such as the Grand canal, more than 22 m wide, basins of storage, the largest reserve in the northwest had a 26,000 m 2 , irrigation and drainage canals, but also a port area of 31,645 m 2 to the south. This approach made it possible to establish the connection with the canals works of the surrounding plain structuring the peri-urban network and to apprehend the major developments during the 2 nd millennium, between the