Hydro-ecology

The maps below show various geohydrological data for South Africa . Click on the “plus” sign to expand each section

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Boreholes

The map below shows the location, province, farm name and unique ID of 79 374 boreholes within the District Municipalities of South Africa. Click here for an interactive map:

Source: National Groundwater Archive (NGA). All boreholes (comma seperated values dataset). Available from the NGA website.

Groundwater level

The map below shows the groundwater levels (meters below ground level) within the District Municipalities of South Africa.

From dataset custodian: The Groundwater Strategy (GS) is the outcome of a three-year consultative process, led by the Department of Water and Sanitation (DWS). It is designed to ensure that groundwater is recognised, utilized and protected as an integral part of South Africa’s water resource. The Strategy is divided into a series of themes or chapters, each of which has a number of recommended actions which address the challenges raised in the theme. The Strategy is designed as an input document to the National Water Resource Strategy (NWRS) 2nd edition. Click here for an interactive map:

Source: Department of Water and Sanitation. Groundwater Strategy [vector geospatial dataset] 2010. Available from the DWS website.

Groundwater quality

Groundwater contains dissolved “minerals” such as chloride, sodium, iron and others, in the same way as surface water. The natural dissolved mineral content of groundwater depends on a number of factors, including the aquifer material and the groundwater residence time. The map below indicates natural groundwater electrical conductivity (mS/m) within the District Municipalities of South Africa. In some cases, high levels of dissolved minerals cause groundwater to be brackish or even saline. In some (relatively rare) cases, naturally high levels of dissolved constituents like fluoride, arsenic or nitrate render groundwater unfit to drink, even though it may taste perfectly fresh.

From dataset custodian: The Groundwater Strategy (GS) is the outcome of a three-year consultative process, led by the Department of Water and Sanitation (DWS). It is designed to ensure that groundwater is recognised, utilized and protected as an integral part of South Africa’s water resource. The Strategy is divided into a series of themes or chapters, each of which has a number of recommended actions which address the challenges raised in the theme. The Strategy is designed as an input document to the National Water Resource Strategy (NWRS) 2nd edition. Click here for an interactive map:

Source: Department of Water and Sanitation. Groundwater Strategy [vector geospatial dataset] 2010. Available from the DWS website.

Groundwater vulnerability

The map below shows a groundwater vulnerability to contamination dateset produced using the DRASTIC method (which considers depth to groundwater, recharge, aquifer media, soil type, topography, impact of the vadose zone, and conductivity. This dataset can be used to give a broad indication of relative vulnerability to non-point source pollution.

From dataset custodian: Please note the GRA2 project was completed as part of a national planning requirement and the data must be used with this in mind. The quantification and mapping of groundwater is an inherently uncertain and low confidence task – thus an exact answer is never achievable. The data is not to be used for site specific information. The useful scale of the data is to the quaternary catchment level and should not be used in a more detailed scale than this. The GRA2 was a “best estimate” at the time of the project in 1995. The intention of the project was to develop a methodology and to release data sets thereby enabling continual improvement of the accuracy of the methodology and the data sets. The data is to be used bearing the above in mind. Click here for a larger map:

Source: Department of Water and Sanitation. Groundwater Vulnerability [raster geospatial dataset] 2005. Available from the SASDI website.

Groundwater harvest potential (lithology, rock type and safe abstraction)

The maps belows show the lithology, rock type and safe abstraction (m3/km2) of the groundwater harvest potential in South Africa. This is an appended coverage created from the following DWAF’s coverages: Saturated Interstices, Mean Annual Groundwater Recharge, Groundwater Quality, Annual Percentile Precipitation and Borehole Yield; used in the mapping of Groundwater Resources of South Africa 1995. The coverage is used to provide a preliminary national quantitative depiction of sustainable rates of groundwater potentially available for abstraction. Click here for an interactive map:

  

Source: Department of Water Affairs And Forestry (DWAF): Groundwater Harvest Potential [vector geospatial dataset] 2005. Available from the DWS website.

Average groundwater exploitation potential

The map below shows the Average of Groundwater Exploitation Potential for wet and dry conditions displayed in m3/km2/a using a 1x1km grid.

From dataset custodian: Please note the GRA2 project was completed as part of a national planning requirement and the data must be used with this in mind. The quantification and mapping of groundwater is an inherently uncertain and low confidence task – thus an exact answer is never achievable. The data is not to be used for site specific information. The useful scale of the data is to the quaternary catchment level and should not be used in a more detailed scale than this. The GRA2 was a “best estimate” at the time of the project in 1995. The intention of the project was to develop a methodology and to release data sets thereby enabling continual improvement of the accuracy of the methodology and the data sets. The data is to be used bearing the above in mind. Click here for a larger map:

Source: Department of Water and Sanitation. Average Groundwater Exploitation Potential [raster geospatial dataset] 2005. Available from the SASDI website.

Groundwater aquifer type and yield

The maps below shows the Amalgamation of 1:500 000 Hydrogeological Map series, giving a country-wide extent of aquifer type (groundwater classification) and expected borehole yield. Click here for an interactive map:

 

 

Source: Department of Water and Sanitation. Aquifer type and yield (Groundwater classification and borehole yield) [vector geospatial dataset] 2005. Available from the SASDI website.

Areas of large scale abstraction

The map below shows the large scale abstraction areas and sites of groundwater within the District Municipalities of South Africa. These sites are categorised as domestic, municipality, irrigation, industrial and mining.

From dataset custodian: The Groundwater Strategy (GS) is the outcome of a three-year consultative process, led by the Department of Water and Sanitation (DWS). It is designed to ensure that groundwater is recognised, utilized and protected as an integral part of South Africa’s water resource. The Strategy is divided into a series of themes or chapters, each of which has a number of recommended actions which address the challenges raised in the theme. The Strategy is designed as an input document to the National Water Resource Strategy (NWRS) 2nd edition. Click here for an interactive map:

Source: Department of Water and Sanitation. Groundwater Strategy [vector geospatial dataset] 2010. Available from the DWS website.