To prevent flooding, the sandbar at the mouth of Nullaki (Wilson Inlet) in Western Australia is opened annually. The protocol dictates that opening should occur between June and early September when inlet water levels are above 0.7mAHD, and ideally between 0.9-1.0mAHD. Openings outside June to September are permitted only if levels exceed 1.0mAHD. Following this protocol, there were no openings in 2010, 2014, and 2019. In these years, seagrass degradation, vegetation loss, and other undesirable ecological changes were observed. With climate forecasts suggesting less frequent openings due to drier winters, the Department of Water and Environmental Regulation has developed a Decision Support Tool. The tool automatically inputs weather forecasts into a catchment model and inlet hydrodynamic model. The result is a seven-day forecast of catchment inflows, water temperature, salinity, water levels, and currents in the inlet and coast. This information is integrated into a risk matrix to guide sandbar management decisions, aiming to protect the inlet’s ecology in a drying climate. The hydrodynamic model operates in 3D mode for detailed analyses or 2D mode for swift decision-making. Here we showcase how monitoring, modelling, and can be integrated to meet multiple environmental objectives in estuary management.