The purpose of flood warning networks is to provide accurate information to emergency managers which underpin specific disaster management actions in response to extraordinary weather conditions. The primary objective is to reduce the exposure and flood risk to the community. However, the enduring socio-economic and political consequences caused by a false evacuation diminish the willingness of the population to evacuate in the future. In 2013 KBR delivered the Central Highlands Regional Council floodplain management plan. During this process accuracy issues were identified in the existing stream rating tables for some of the key river height gauges. The rating table is usually constructed from a number of observed gaugings based upon small flows, and then extrapolated for higher flows. The uncertainty of flow estimates increases for high stage discharges. From an emergency management perspective, it is the large episodic events that generally cause the significant risk to community. To this end, KBR prepared detailed, two-dimensional hydraulic models to generate rating curves at a number of gauge sites, better estimating high stage discharges. The paper focusses on the Craigmore Alert gauge which provides key inflow estimates to Fairbairn Dam, and crucially a lead time of approximately 24 hours to Emerald. The methodology was proposed in consultation with key stakeholders including hydrographers from DRNM, BOM, and SunWater. It includes a review of the gauging system, the value of a redundant high stage gauge and a second gauging station at Craigmore to better estimate the high flow rating. Through working with key agencies, the Craigmore improved rating curve has now been universally adopted, providing consistent information across all levels of government. The upgraded rating curve provides an increased accuracy to streamflow and will be used to provide decision makers with much needed flood warning information better preparing the community for the next flood.