The Gwydir Wetlands Complex in the Northern Murray-Darling Basin is a valuable environmental asset important for supporting local, regional and global populations of nomadic and migratory waterbirds. The wetlands are a target for management with environmental water under the Murray-Darling Basin Plan, and watering aims to support waterbird breeding events. Successful breeding requires sufficient food resources (energy) available over appropriate spatial and temporal scales. But how much energy can a watering event produce, and how is it spread in time and space? Using measures of organic carbon and biomass we quantified the energy available in invertebrate prey and its distribution in time and space to understand how a managed inundation event influenced resource availability for higher consumers. Patterns of succession in the wetland invertebrate community over time exerted a strong influence on energy availability with the highest prey energy density occurring in the later stages of inundation. Understanding the distribution of energy in time and space, coupled with improved understanding of energy requirements of target taxa, informs environmental water planning. This study highlights the importance of inundation duration in maximising energy availability from invertebrate prey.