Four of the main rivers in the Limpopo River basin (Lephala, Mokolo, Matlabas, and Mogalakwena rivers) originate from the Waterberg. This area is also underlain by a major coalfield. The coalfield was first discovered in the 1920s, but at the time was considered to be too remote to justify development. With increasing energy demands in South Africa, driven by economic growth and an increasing population, the feasibility of developing this area for power generation is being reassessed. It is estimated that the area will provide enough coal to power up to 8 power stations for the next 150 to 200 years (CSIR 2009). However, this prospect could contribute to dramatic changes in the already stressed aquatic ecosystem of the Waterberg area (CSIR 2010).
Proposed Developments
The Medupi Power Station is the biggest coal-fired power plant ordered by Eskom for the past 80 years. Because the region is so water-stressed, it will operate with air-cooled condensers. Exxaro’s Grootegeluk coal mine, also at Lephalala, will be expanded to accommodate the increased demand for coal (CSIR 2010).
Atmospheric deposition from the proposed coal mines and the power stations is expected to greatly alter the present (and already stressed) ecosystem. In addition, new settlements to house employees and associated agriculture to feed employees and their families will contribute to further ecosystem degradation (CSIR 2009).
ACID MINE SEEPAGE FROM AN ABANDONED MINE INTO A TRIBUTARY OF THE OLIFANTS RIVER. SOURCE: CSIR 2010
Current State of the Aquatic Ecosystem Study
A CSIR study of the ecological status of rivers and wetlands in the Waterberg aims to minimise the potentially adverse consequences of new power stations and mining in the area. This will be the first study of its kind conducted prior to the establishment of large infrastructural developments such as the Medupi power plant, which is being built close to Lephalala (formerly Ellisras) (CSIR 2010).
The CSIR’s Waterberg study aims to develop a set of ecological indicators that provide an accurate estimate of the ecological status of the river and wetland ecosystems in the study area. These will then be used to detect existing processes of change in the aquatic ecosystems and to estimate the likely future direction and extent of changes that increased atmospheric deposition, water pollution and water transfers will cause (CSIR 2010).
The likely adverse consequences in the Waterberg may be minimised if managers and decision-makers base their decisions, plans and actions on a sound scientific understanding of the current ecological situation in the basin, as well as an understanding of the cause-effect relationships that link atmospheric deposition and land-use patterns to water quality changes and their ecological consequences (CSIR 2010).
DR. OBERHOLSTER SAMPLING FOR ALGAE UPSTREAM OF THE OLIFANTS RIVER. SOURCE: CSIR 2010
Interesting Findings to Date
During their investigations they discovered the rare colonial protozoa ophrydium versatile, never before recorded in Africa in the Lephalele River. This species indicates good water quality in this reach, as it requires high light penetration to persist and is sensitive to heavy metals. The CSIR team also confirmed DWA reports that a new fish species inhabits the waters of the Waterberg (yet to be classified) (CSIR 2009).
