The Use of Reserve Determination in Assessing Groundwater Quantity
South Africa, Department of Water Affairs,
South Africa is a water-scarce country and the pressure on the water resources are increasing. South African National Water Act (Act 36 of 1998) provides a means by which water resources can be managed. The Act created a mechanism that allowed the South African Department of Water Affairs to review all water uses in an area. The Act makes provision for water required for basic human needs and the water required to maintain ecosystem functioning. In order to manage the available water resources in an efficient, effective and sustainable manner, the quantity of water being used, available and the Reserve need to be known. All water users who do not receive their water from a service provider, but are using water for irrigation, mining, industrial, and feedlots are required to register their water use. This registration sometimes requires a water use license. This applies to both surface and groundwater. Before the Act, the management of water was haphazard and not well coordinated. There was, therefore, a need to develop some tool with which water can be managed in sustainable manner. This study looks at a set of tools formulated in order to evaluate the groundwater quantity and quality when assessing for a water use license. The country was divided into quaternary and data from among other things, groundwater component of the reserve, the registered water uses, the maximum and minimum harvest potential, exploitation potential and recharge were collected. These data sets were computed for each quaternary, the volume of water available were estimated. The results show that these set of tools have helped in assessing groundwater quantity and quality in a particular area, thereby improving the management of groundwater in a more efficient and effective manner. Although these are estimates, the tool can be used to quantify up to more than 75 percent of the quantity of water available for use. The developed tool has demonstrated that it can be used to estimate the quantity of water available.