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Managing Internationally Shared Groundwater Resource In Southern Africa: The Case Of The Ratmotswa Aquifer Between Botswana And South Africa

Congress: 2015
Author(s): Yvan Altchenko, Karen Villholth
IWMI / French Ministry of Agriculture / Laboratoire METHIS - UPCM1, IWMI2

Keyword(s): Sub-theme 12: Transboundary river basins and shared aquifers,
Abstract Groundwater resources are heavily relied on in the SADC (Southern Africa Development Community) region, with an estimated 70% of the population dependent on groundwater as their sole source of water for drinking, domestic use, livestock and irrigation. However, with population growth, urbanization, climate change and need to combat growing food insecurity, demands for groundwater and more integrated solutions are set to increase in the future, especially in the arid and semi-arid areas where stress on available water resource are already limiting development. The present paper documents the current knowledge on the Ramotswa dolomite aquifer shared by Botswana and South Africa and presents early results of a USAID-supported project aimed at determining the role the aquifer can play in addressing multiple-level water insecurity, drought and flood proneness and livelihood insecurity. The aquifer is located in the upper part of the Limpopo basin and about 20 km south of the Botswanan capital Gaborone. The area is semi-arid, with a mean annual rainfall of 400 to 600 mm, but with precipitation dominated by strong seasonal and annual variability. High yielding wells can be found in the area of major linear karst and the aquifer was investigated for water supply to Gaborone in the early 1980's. Unfortunately, the successful promotion of pit latrines in the suburban areas of Gaborone occurred at the same time and human waste and wastewater polluted the shallow and largely uncovered and unprotected aquifer. The entire well field was abandoned in favor of water supply from surface water. During the last decade, however, water has quickly become a limiting factor for urban and economic development in the border region between South Africa and Botswana, especially around the Gaborone and Ramotswa urban conurbations. This situation is exacerbated with recurrent and escalating droughts in the area, further exposing the exigency of growing water demands and under-performing water management and disaster management systems. Hence, while water infrastructure so far has kept up with Gaborone urban growth on the Botswana side, through the Gaborone Dam and a couple of long-distance water transfer schemes from northern parts of the country as well as from South Africa, the situation is presently dire. Groundwater from the productive Ramotswa dolomite is currently re-investigated for emergency supply as pollution has been reduced through expanding coverage of wastewater treatment. The South African side relies heavily on groundwater for most uses, with irrigation schemes and urban centers presently using larger shares. There are currently plans for limited growth in the agricultural sector for emerging farmers as social inequalities are addressed. Also, the Ramotswa aquifer is part of the contiguous or non-contiguous dolomite aquifer systems in the North West Province, which receive considerable interest from local and national water planners because of rising water demands on the South African side, which includes the cities of Mafikeng, Zeerust and Lichtenburg. The USAID-supported project aims at developing scientifically informed and participatory strategies for how to solve some of the demographic, institutional, and climate-related water issues of the region, with a focus on what the internationally shared aquifer(s) can provide in terms of sustainable, equitable and socially acceptable solutions. If the resource is large and easily rechargeable, it may play a significant role in buffering variability in climate, through a combination of a significant source of new water in times of low availability and a significant source of storage in times of water surplus. The concept for the buffering capacity of the aquifer has to be based on a stringent perspective of long-term sustainability, through resource protection, managed aquifer recharge (MAR) and cross-border collaboration. Continuous, reflective and collaborative learning through the project will improve stakeholder and institutional capacities to manage water, both surface and underground, and ecosystem resources in the border region. The multi-disciplinary and nested (from local to transboundary) approach to understand the characteristics of the aquifer as well as the socio-economic constrains and needs of the (ground)water users will be used to facilitate knowledge exchange between the countries across the Limpopo basin and with other basins in SADC, and to develop reliable adaptation strategies to climate change in the region.
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