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Bulawayo sits on perennial river

by Staff reporter
05 Jul 2020 at 11:06hrs | Views
IN a case depicting poverty amid plenty, part of the Bulawayo Central Business District (CBD) was built on top of an underground perennial river, despite the city experiencing a crippling water shortage.

At a time when some suburbs in the city are going for six days without water, companies that own buildings constructed above the "river" are now forced to install pumps to dewater the river to protect their structures from collapse.

However, the city council has maintained that it cannot harness the water to ease shortages as it might result in the collapse of part of the CBD. Bulawayo is relying on water that is pumped from supply dams in Matabeleland South and boreholes that are in Nyamandlovu in Matabeleland North, areas that are about 40 kilometres from the city.

Council is also on record as saying that at least 40 percent of the water it is drawing from these water sources is lost before reaching residents because of antiquated piping system. Responding to written questions from Sunday News, the Bulawayo City Council (BCC) senior public relations officer, Mrs Nesisa Mpofu, confirmed that there was water flowing under the CBD. She however, said harnessing water from the water body was not ideal as it could destabilise the buildings in the CBD.

"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 vertically and most of the aquifer points already have buildings on top of them. As such boreholes cannot be drilled at an angle," said Mrs Mpofu.

She said that owing to the aquifer, some buildings were now pumping out the water to the streets but insisted that this could not constitute wastage as it was not economically viable to harness the water.

"The high-rise buildings in the city have dewatering pumps to maintain a certain optimum level by pumping it out when it gets to certain levels. But the water pumped out is not economically viable to be harnessed," she said.

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 wellfield. 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.

Source - sundaynews