The Sunday News
Vusumuzi Dube, Online News Editor
THE Bulawayo City Council has insisted that it cannot harvest water flowing under most of the southern parts of the city — Matshuemhophe Aquifer — despite the city now being forced to introduce water rationing.
Numerous academic studies — both local and regionally — have indicated that the groundwater potential of the aquifer can be used for improvement and development of the water resources of Bulawayo Metropolitan Province.
The aquifer covers most southern parts of the city which include suburbs such as Montrose, Ilanda, Hillside East, Hillside West, Hillside, Hillcrest, Malindela, Morningside, Greenhill, Barham Green, Barbourfields, Thorngrove, Mzilikazi, Tshabalala, Sizinda, Romney Park, North End, Paddornhurst, Suburbs, Khumalo, Bradfield and the Central Business District, among others. However, the local authority has insisted that it was not possible to harness water from the aquifer.
“Yes, there is an aquifer under the Central Business District known as the Matsheumhlope Aquifer, harnessing the water at commercial scale has numerous challenges as it would destabilise buildings in the Central Business District.
Boreholes are drilled at vertically (going straight down) and most of the aquifer points already have buildings on top of them. As such boreholes cannot be drilled at an angle,” said council’s corporate communications manager Mrs Nesisa Mpofu.
She said high-rise buildings in the city have de-watering pumps to maintain certain optimum levels. Mrs Mpofu, however, noted that the water pumped out was not economically viable to be harnessed.
According to a study by Rusinga and Taigbenu (2005) titled Groundwater Resource Evaluation of Urban Bulawayo Aquifer for the School of Civil and Environmental Engineering, University of the Witwatersrand, they describe the aquifer as being “marginally good”.
“The hydro-geological study of the urban Bulawayo aquifer, commonly referred to as the Matsheumhlope well-field, has been carried out with a view to providing a tool by which the Bulawayo City Council can manage the aquifer. The aquifer is a heterogeneous unconfined system of marginally good aquifer characteristics and holds great promise for the future development of the city whose growth has been considerably hampered by water insecurity,” reads part of the study.
Rusinga and Taigbenu further noted in their findings that the Matsheumhlope well-field was demarcated into three aquifers according to the abstraction rate per day, namely: the high yielding aquifer (yield of more than 120 cubic metres per day), medium yielding aquifer (20-120 cubic metres per day) and the low yielding aquifer (less than 20 cubic metres a per day).
According to a study carried out by the National University of Science and Technology (Nust) in Bulawayo published by Canadian Centre of Science and Education as part of the Journal of Geography and Geology in 2013, the institution noted that the water could be harnessed although with adherence to proper management policies.
“The study has managed to identify and delineate the nature, extent and spatial distribution of the components of the low yield aquifer in the Matsheumhlope well-field. This has invariably provided some preliminary data on the groundwater potential of the area that can be used for improvement and development of the water resources of Bulawayo Metropolitan.
“The correlation of geophysics and borehole logging have discovered the low yielding aquifer as a basement aquifer developed within the weathered and fractured crystalline, greenstone rocks of intrusive and metamorphic. Generally, the aquifer has shallow occurrence and fissure permeability of the bedrock aquifer,” reads part of the study findings.
The study also noted that if not properly managed when harnessing the aquifer there could be borehole failure because of the geomorphological occurrence (pertaining to geological structure), shallow existence of the permeable (penetrable) bedrock, poor sitting of wells and boreholes, and low groundwater storage capacity.
“The long dry spells experienced in the region (could) also contribute much to borehole failure. Considering the high demand for groundwater in the city due to erratic water supplies, borehole failure may worsen if proper management policies are not implemented.
Therefore, intensive geophysical methods, remote sensing and geological maps should be used in sitting boreholes to identify the weathered, saturated fracture zone and to map its extent and eliminate negative sites that have hard rock at shallow depth,” read part of the findings.
