Abstract

The storage and subsequent release of water is a key function of catchments and provides a buffer against meteorological and climate extremes. While catchment storage sits at the intersection of the main hydrological processes and largely controls them, it is difficult to quantify due to catchment heterogeneity and the paucity of hydrogeological data. We adopt a multi-method approach to estimate the dynamic and extended dynamic storages using hydrometric data in 75 catchments across the south east of Australia that span across the largest mountain range in the country. The results are compared to hydrological and physical characteristics to determine the main controls of catchment storage. Each of the methods produced a wide range of storage estimates for each catchment, but estimates from each of the methods were largely ranked consistently across the study catchments. Consistent and robust relationships between catchment characteristics and estimates of storage were difficult to establish, however the results suggest that streamflow is derived from slow storage release and long flow paths while a substantial portion of storage is reserved for evapotranspiration. This study highlights some limitations with the current methodology and reinforces the need to collect data that can validate storage estimates at the catchment scale.