This paper is concerned with site investigation practices that are used as part of the design of foundations for civil engineering infrastructure in Adelaide. The semi-arid conditions in Adelaide mean that the results of any soil testing need to be viewed within the context of soil moisture deficiency, and the soil parameters adopted for design need to take into account the critical moisture profile likely to be encountered over the service life of the structure. It is argued that guidelines should be developed based on the soil moisture conditions in order to ensure that realistic soil parameters are used in analyses and designs. The paper presents a procedure for selecting shear strength and compressibility design values. The variations in total soil suction profiles due to construction activities and over the service life of the foundation are highlighted.