Reduced allocations of surface water for agriculture is now causing Australian irrigation farmers to augment their supplies by increasing groundwater use, including waste and/or drainage water. Water salinity as measured by its EC is generally used to assess water quality ignoring water chemistry pertinent to potential soil salinity and/or sodicity problems. Saline and/or sodic water were, therefore, evaluated for their impact on ESP, EC, pH, hydraulic conductivity, and dispersion index of five red brown earths (Red Chromosols), and a non-mulching grey clay soil (Vertosol). The results show an increase in soil EC, pH and exchangeable sodium percentage (ESP) with increased SAR, salinity, and residual sodium carbonate (RSC) of infiltrating water. An increase of about 5-15 ESP occurred when non-sodic red-brown earths (RBE) were infiltrated with 25-50 pore volumes of 0.62-3.5 dS/m EC and 3-10 SAR waters. Proportionate increase in their ESP was related to their clay content. Hydraulic conductivity (HC) showed dependence on the ESP after infiltrating water was replaced with deionised water. Relative decrease in HC due to increased ESP was 1.5-2.5 times greater in the non-mulching grey clay than RBE. However, higher dispersion in the latter indicates comparatively more structural stability of grey clay than that of RBE, probably due to their different clay mineralogy. Experimental results emphasise the need for reliable guidelines based on a range of water quality parameters rather than EC alone. Because sustainable use of suspect quality water supplies depends largely on complex relationships of soils, crops, ground water features, climatic variables in addition to irrigation and crop management practices.