Solution Exercise 1
a) Groundwater is recharged from rain that falls on the surface of the earth, infiltrates through the soil and then into the pores, cracks and fissures of geologic formations until these interstices become saturated. This is natural recharge. Much rainfall runs off over the surface or evaporates back into the atmosphere, thus there are limits to the magnitude of natural recharge.
b) Artificial recharge is the practice of increasing the amount of water that enters an aquifer through human-controlled means. For example, groundwater can be artificially recharged by redirecting water across the land surface through canals, infiltration basins, or ponds from which water seeps into the subsurface; creating irrigation furrows to allow infiltration of excess irrigation water; using sprinkler systems to irrigate with surface water, some of which infiltrates beyond plant roots; or injecting water directly into the subsurface through wells.
c) The term ‘Artificial’ does not capture the process of humans enhancing natural recharge in a systematic manner. These deficiencies in the term “Artificial Recharge” have been overcome by the now generally accepted term “Managed Aquifer Recharge” (MAR).
d) The term “Aquifer Storage and Recovery” is mainly used in the United States and Australia. It describes well injection of surface water supplies such as potable water, reclaimed wastewater, harvested rainwater, stormwater, or river water into an aquifer for later recovery and use. This term explicitly describes that the managed aquifer recharge is a matter of placing water into aquifer storage and retrieving it for later use.
e) In South Africa a number of new small schemes, similar in local importance to the Kharkams case study, have been reported. Mr. Fanus Fourie of the Department of Water and Sanitation, a champion of MAR, calls them ‘nature-based solutions’ to emphasize the need for holistic management of locally available water resources for small towns and communities. The only natural resources these small communities have are water, soil and vegetation. Before expecting pipelines to come their way, these communities need to manage their local environment in an integrated and sustainable way. A further dimension is added in the community-driven, multiple use water services (MUS) approach – as a critically important alternative to urbanized models of water supply – i.e., water supply, livelihood and health addressed holistically and with community participation.