The Australian Drinking Water Guidelines (ADWG) Framework for the Management of Drinking Water Quality (NHMRC, NRMMC 2011) promotes a structured and systematic preventative management approach to assure safety of drinking water at point of supply. Central to the ADWG Framework are 12 Elements considered good practice by which to manage drinking water supply from catchment to tap. Application of key ADWG Elements to the treatment and distribution components of a water supply system tends to be relatively straightforward, but less so to the source water catchments and raw water reservoirs components. This can lead to a breakdown in the integrated approach for managing water contamination risks across all stages of water supply. Accordingly, the leading aim of this study was to practically demonstrate how Element 2 (Assessment of the drinking water supply system) of the ADWG framework can be applied to a source water catchment to improve recognition and knowledge of water quality at this key juncture in the water supply system.