JG Afrika is helping Laingsburg Municipality optimise the use of groundwater resources in its jurisdiction.
The Sustainable Development Groundwater Project for Laingsburg Municipality is being undertaken on behalf of the Western Cape Department of Local Government (DLG).
“JG Afrika is part of a consortium of four consulting engineering firms that was appointed by the Western Cape DLG to help municipalities in the Great Karoo improve the management and use of their groundwater resources to help alleviate drought conditions. Our area of focus is Laingsburg Municipality, which has also been experiencing water shortages,” Regan Rose, an Executive Associate of JG Afrika, says.
Commencing in 2019, the project included monitoring the municipality’s existing groundwater resources. JG Afrika also assessed the municipality’s own groundwater monitoring strategy and proposed various solutions to overcome existing constraints, which are mainly logistical in nature. The municipality is gradually implementing them to improve its own groundwater resource monitoring capabilities. These interventions are expected to improve water service delivery to constituents, considering that monitoring is just as important as the maintenance and repair of borehole infrastructure for the sustainable use of groundwater resources. JG Afrika will continue the monitoring function until such time that the municipality is ready to assume these duties.
As a specialist in geohydrology, JG Afrika has helped to significantly bolster Laingsburg Municipality’s skills and experience in the field. For example, the firm’s geohydrologists have been able to share important insights with the municipality that they have gained since they commenced monitoring the groundwater resources. This includes overextraction in certain areas whereas ideally groundwater use needs to be spread over a larger area in the Great Karoo to ensure sustainable use.
Another component of the project entails finding and assessing other available groundwater resources within the jurisdiction to bolster existing supplies.
Notably, JG Afrika used state-of-the-art Danish technology to significantly improve the accuracy of its geohydrological investigations on this project. Known as a towed transient electromagnetic (tTEM) system, the technology enables the detailed investigation of the top 20m to 50m of the subsurface. While traditional technologies can image this zone, they are unable to create high-resolution full three-dimensional (3D) images over extremely large areas. The tTEM system can image a subsurface up to a depth of 70m at a high resolution both horizontally and vertically.
The team managed to achieve very good results using this technology. Two of the drilling sites that were presented to the municipality produced very high yields. Notably, one of them provided yields of up to 36 000l/hour
A total of 14 drilling sites were presented to Laingsburg Municipality for testing and 10 were drilled during the hard lockdown in 2020. They are sited on a farm that is located north-west of Laingsburg that is owned by the municipality. The two holes that were already located on this site will also be tested as part of the next phase of the project to determine if there is sufficient water to supply demand in Laingsburg.
This supply could be augmented from groundwater resources from an area located west of the existing site. While it still needs to be explored further by Rose and his team, the area already has infrastructure to support groundwater supply schemes.
As part of the project, JG Afrika will also develop a borehole management plan on behalf of Laingsburg Municipality.