Approach to view groundwater level fluctuations on an aquifer to national scale

South Africa is known for droughts and their effect on groundwater. Water levels decrease, and some boreholes run dry during low recharge periods. Groundwater level fluctuations result from various factors, and the comparison of the levels can be a challenge if not well understood. The “Groundwater Level Status” approach was developed to simplify the analysis of groundwater level fluctuations. Groundwater levels of two boreholes within different hydrogeological settings can thus be compared with each other. The current groundwater level is given as the status, which is compared to the shallowest and deepest groundwater levels ever measured at the geosite. The “Status” can now be used to indicate the severity of the drought and thus be used as a possible groundwater restriction level indicator. The Sustainable Development Goal (SDG) 6.6.1 calculation on the groundwater level change is based on the groundwater level status approach. This paper presents the approach's details with a description of its use and limitations of the approach. The applicability to use the approach from a national to a local level will be showcased through practical examples of the recent droughts that have hit South Africa from 2010 to 2018. [Display omitted] •The GwLS methodology compares groundwater level data of any geosite/borehole with each other on the same scale.•The GwLS Averages can be plotted on a map, classed into ranges and severity profiles developed for decision-makers.•The methodology can be applied on an Aquifer Region or wellfield/local aquifer scale.•A Sustainable Development Goal indicator or a drought severity indicator are examples of applicability.