The Hattah Lakes floodplain system in north-west Victoria, Australia, is a highly modified, climate-constrained wetland and one of the Murray-Darling Basin's 'Living Murray' icon sites. Over the past century, river regulation and water over-allocation have reduced overbank flooding, contributing to ecological decline. This paper reviews 50 years of adaptive management, focusing on environmental water delivery as the key mechanism for sustaining ecological function. Three management phases are identified: a passive conservation phase (1975-2000) with limited intervention and declining condition; an active intervention phase (2000-2013), involving environmental water recovery and temporary pumping; and a contemporary infrastructure-enabled phase (2013-present), characterised by permanent pumping, flow-control infrastructure, and adaptive, hypothesis-driven watering supported by monitoring. This progression reflects broader institutional reforms under programs such as The Living Murray and the Murray-Darling Basin Plan. Results show that infrastructure combined with targeted monitoring enables a shift from opportunistic watering to deliberate, learning-based flow design. However, climate change introduces increasing hydrological variability, reduced water availability, and heightened ecological risk. Adaptive management must therefore move beyond replicating historical flooding to designing functional flow regimes that maintain ecosystem resilience under drier conditions. The Hattah Lakes case highlights how policy, infrastructure, and long-term monitoring can build adaptive capacity in regulated floodplains.