Recent research suggests that immigration and dispersal is a key driver of population dynamics of some native fish species in the southern Murray Darling Basin, with this process likely linked to patterns of hydrology. As such, a key objective of environmental watering across several rivers in the southern MDB includes flows to enhance migration or dispersal opportunities, to potentially assist population recovery. Here, we report on the findings of a joint Murray Darling Basin Authority/Victorian Environmental Flows Monitoring & Assessment Program project aimed at assessing the outcomes of coordinated environmental flow releases, spanning multiple jurisdictions and waterway managers, on facilitating movement of native fish into and throughout tributaries of the Murray River. Early findings suggest a positive response in both immigration of juvenile fish from the Murray River and dispersal throughout tributaries. Whilst continued monitoring of a range of flow conditions and long term population outcomes is required, we suggest appropriately designed and coordinated environmental flows, across river networks represent an important targeted management action to promote tributary fish population recovery.