Maximum groundwater level for urban development: Evaluation of different calculation methods in Western Australia

This paper closely evaluates three conventional methods of calculating the maximum groundwater level to be used for design purposes in Perth, Western Australia, in order to identify the shortcomings. The results of all of the methods are incorporated into ArcGIS in a study area in Perth for the interpretation of groundwater changes in calculated levels and to assess their reliability. The range of differences in results by application of the methods is presented at monitoring locations and other places over the study area. A comparison of the methods shows that, despite similar principles in calculation, the results are very different, thus creating uncertainty for decision making and risks for urban structures, people and the environment. The results vary as a consequence of different density and types of data used in each method, the inconsistent period of data selection, impact of anthropogenic activities and climate change, as well as the physical properties of the aquifer, such as slope. In areas of high groundwater levels and in major engineering projects, it is critical to more accurately calculate the maximum groundwater levels. Therefore, a combination of detailed data analysis in order to estimate maximum groundwater level accurately at monitoring locations at certain times is proposed, along with using a numerical simulation of physical processes to reduce and define uncertainty for planning. This can pave the way towards the development of a reliable method for the calculation of maximum groundwater levels