The main source of irrigation water in the intensely irrigated area of the Padthaway Proclaimed Wells Area is groundwater extracted from the underlying unconfined aquifer. Excess irrigation water, that is, water applied to the crops but not used, infiltrates back down into the aquifer, and is enriched in dissolved salts. Over time, continued repetition of this process has caused a significant deterioration in the quality of the underlying groundwater. The Padthaway Irrigation Area is one of the State's main viticultural districts, and continued groundwater degradation will have a severe impact on present levels of productivity. The local community, together with government departments involved in the groundwater sector, have collectively put forward a number of possible options to halt the present rate of salinity degradation. One of these options is to extract lower salinity groundwater from the adjacent Naracoorte Range, and use it to supply the main irrigation area. This report presents the results of a hydrogeological assessment to determine the viability of this option. Results of the assessment suggest that better quality groundwater is available in the Range, and the aquifer represents a good potential source for groundwater extraction. However, inherent properties related to the aquifer, such as the high proportion of fine sand produced from some pumped wells, and low well yields due to the spatial variability in hydraulic conductivity of the aquifer, make it difficult to accurately predict the suitability of this proposal on an individual well basis.