Review: Groundwater management and groundwater/surface-water interaction in the context of South African water policy

Abstract

Groundwater/surface-water interaction is receiving increasing focus in Africa due to its importance to ecologic systems and sustainability. In South Africa's 1998 National Water Act (NWA), water-use licenses, including groundwater, are granted only after defining the Reserve, the amount of water needed to supply basic human needs and preserve some ecological integrity. Accurate quantification of groundwater contributions to ecosystems for successful implementation of the NWA proves challenging; many of South Africa's aquifers are in heterogeneous and anisotropic fractured-rock settings. This paper reviews the current conceptualizations and investigative approaches regarding groundwater/surface-water interactions in the context of South African policies. Some selected pitfall experiences are emphasized. The most common approach in South Africa is estimation of average annual fluxes at the scale of fourth-order catchments (~500 km 2 ) with base flow separation techniques and then subtracting the groundwater discharge rate from the recharge rate. This approach might be a good start, but it ignores spatial and temporal variability, potentially missing local impacts associated with production-well placement. As South Africa's NWA has already been emulated in many countries including Zambia, Zimbabwe and Kenya, the successes and failures of the South African experience dealing with the groundwater/surface-water interaction will be analyzed to guide future policy directions.

Groundwater and Surface Water Interaction at the Regional-scale – A Review with Focus on Regional Integrated Models

“…the generalisation of data or model parameters obtained from distinct points or small spatial entities to larger areas (Diekkrüger et al 1999;Kleeberg et al 1999;Parajka et al 2005;Samaniego et al 2010). Few authors, however, deal explicitly with the scale dependency of GW-SW (CSIRO 2008;Dahl et al 2007;Kollet and Maxwell 2008;Levy and Xu 2012). Most works dealing with scale dependency are limited to spatial extents that are significantly smaller than regions within the meaning of this paper.…”

“…Dahl et al (2007) review different classification systems of GW-SW in a process-oriented manner and propose a new typology for these interactions, which can be used for a better comparison of different settings or sites. Levy and Xu (2012) review and compare methods to describe GW-SW at different scales and list exemplary applications in South Africa.…”

“…Overviews describing different coupling strategies are provided by Barthel et al (2008a), Ebel et al (2009), Furman (2008, Kollet and Maxwell (2006), Markstrom et al (2008), Levy and Xu (2012), Rossman and Zlotnik (2013), Sebben et al (2013), and Spanoudaki et al (2009).…”

“…Overviews of ready-made model packages for GW-SW (primarily addressing loosely coupled schemes) have been compiled by CDM (2001), Blum et al (2002), Levy and Xu (2012), Bobba (2012), Alaghmand et al (2013), and Sebben et al (2013). These overviews, however, do not directly address applicability or applications at the regional scale.…”

An Alternative Strategy for Mitigating the Effect of Rainfall Variability in Burkinabe Sahel

“…This issue requires a robust way to analyze water flow in the vadose zone located between groundwater and the bottom of RWHB. Yet, according to [19] groundwater is hydraulically connected to surface water by the vadose zone. However, the water flow study in unsaturated porous media is very difficult and a numerical approach [20] is the best alternative among methods that were developed to estimate groundwater recharge and reported by [21].…”