South Africa is known for droughts and its effect on groundwater. Water levels drop, and some boreholes run dry during low recharge periods. However, how different groundwater levels indicate a drought?
The department monitors the water levels of just over a 2000 geosites of which some monitored on a monthly, bi-monthly, quarterly and some bi-yearly base. The data is analysed from a national perspective to assess the groundwater level trends made. The analyses indicate the decline or rise in groundwater levels for the last ten years. The analysis was extended to provide a “Groundwater level Status” per each geosite. 2 boreholes with different geological settings, water levels, characters, etc. can be compared with each other for the first time. The current groundwater level is given as the status then the shallowest and deepest groundwater levels ever measured at the geosites are compared against the current groundwater level. The “Status” can now be used to indicate the severity of the drought and thus a possible groundwater restriction level indicator. SDG Goal 6.6.1 on the change of the groundwater level calculation is base on the groundwater level status methodology.
The paper will present a detail methodology description and limitations of the methodology. The applicability to use the methodology from a national to a municipal level will be showcase through practical examples of the recent drought.