Management strategies for the lower berg river aquifer system, Western Cape
| dc.contributor.advisor | Vermeulen, P. D. | |
| dc.contributor.author | Vermaak, Nicolette | |
| dc.date.accessioned | 2022-03-03T06:12:12Z | |
| dc.date.available | 2022-03-03T06:12:12Z | |
| dc.date.issued | 2021-02 | |
| dc.description.abstract | The development of the town of Saldanha is a coastal town in the semi-arid west coast of South Africa was constrained by lack of reliable water resources till the Berg River pipeline that was built in the 1940s to provide water to the military installations. This supply was later turned over to the town, and the area began to grow. Saldanha Bay is one of the few natural harbours in South Africa, and the export of steel in the late 1990s resulted in the development of the Langebaan Road wellfield. The groundwater potential of the coastal aquifer system in the area was discovered in the early 1970s when a number of artesian wells with good water quality were drilled. This led to the declaration of the Saldanha Subterranean Government Water Control Area, which was later expanded. Timmerman did further groundwater exploration in the area for the Department of Water Affairs. The work by Timmerman was very detailed, but some misconceptions about the system was built into the conceptual model, and later the model that was built. Timmerman divided the Lower Berg River aquifer system into four units – the Adamboerskraal, Langebaan Road, Elandsfontein and Grootwater aquifer units. The system consisted of a number of deeply incised palaeochannels into the bedrock that was filled with layers of different Cenozoic deposits. This work remained the foundation of the understanding of the Lower Berg River Aquifer System for many years. After the wellfield became operational in December 1999 discrepancies between the measurements and the Timmerman conceptual model were observed. The artificial recharge test carried out by the CSIR during the winter of 2008 and 2009 raised some more questions. The need to re-evaluate the conceptual model with the additional monitoring data was identified. The improved scientific understanding would be used to develop a management strategy for the management of the groundwater resources in an area. Analysis of the water level data and the groundwater chemistry were done. Time series graphs were plotted, and comparisons were done between data sets. The analysis of the data shows a clear link between the Adamboerskraal and the Langebaan Road aquifer unit, with the palaeochannel below the Berg River. The link between the Langebaan Road and Elandsfontein aquifer units was also established through the groundwater levels and the groundwater chemistry. This is possible through a break in the bedrock high – a palaeochannel connecting the two units – and the shale-granite contact. The link between the Elandsfontein and Grootwater aquifer unit could not be established conclusively. A conceptual model was constructed using the data that was available. The conceptual model included a regional understanding of the Berg River catchment area, with possible recharge from the mountains in Franschhoek through the Colenso Fault System. It also provides a clearer picture of the local situation in the study area. The deposits of Cenozoic layers are not uniform, with the clay layer pinching out at the edges of the palaeochannel, which at times brings the different aquifer layers in direct hydraulic contact. The system thus consists of different layers with unique. characteristics that are interlinked. The Lower Berg River Aquifer System should thus be treated as a complex integrated aquifer system. An action plan for the development of an adaptive management strategy framework was developed with the different components or principles that needed to be included. The site-specific adaptive conditions were taken into consideration and it is recommended that these items be included in the development of the management plan with relevant stakeholders for maximum impact. | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/11482 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Thesis (Ph.D. (Geohydrology))--University of the Free State, 2021 | en_ZA |
| dc.subject | Coastal aquifer | en_ZA |
| dc.subject | Lower Berg River Aquifer System | en_ZA |
| dc.subject | Adaptive management | en_ZA |
| dc.subject | Geohydrology | en_ZA |
| dc.title | Management strategies for the lower berg river aquifer system, Western Cape | en_ZA |
| dc.type | Thesis | en_ZA |