Chronicle Editor
Mashudu Netsianda, Senior Reporter
BULAWAYO City Council (BCC) is set to recommission three of its supply dams after the city’s six supply dams received 28 million cubic metres of inflows since the onset of the rainy season.
However, despite the significant inflows, the weekly 144-hour water shedding programme will continue to be implemented as the dam levels are still at 31 percent.
Bulawayo has a daily water consumption of 150 megalitres, but due to a decline in water levels at the city’s supply dams, BCC is supplying 120 megalitres per day.
Following the rains that are pounding the country, the bulk of the inflows went into Insiza Dam due to its catchment size. The city’s three supply dams which are set to be recommissioned are Umzingwane, Upper Ncema and Lower Ncema which now have a usable volume of 11 million cubic metres.
BCC decommissioned the three dams between last year and this year due to a sharp decline in water levels. The depleting water levels at the city’s dams resulted in the local authority imposing a weekly 144-hour water shedding programme, but persistent technical faults and pipe bursts have seen council failing to abide by the schedule.
According to the Zimbabwe National Water Authority (Zinwa), there has been significant inflows into the country’s dams raising hope not only for Bulawayo but other cities and towns that are also facing water shortages.
Speaking soon after a special full council meeting yesterday, Bulawayo Mayor Councillor Solomon Mguni told journalists that the city was now in the process of recommissioning Umzingwane, Upper Ncema and Lower Ncema to reduce the current water shedding period affecting the residents of Bulawayo.
“The City of Bulawayo’s supply dams have received 28 million cubic metres of inflows since the onset of the rain season, with the bulk of the inflows going into Insiza dam due to its catchment size. Council is aware of the considerable strain which is being faced by the residents of Bulawayo due to water shedding.
It is council’s hope that the recent inflows while still low will assist in alleviating the stress faced by the residents,” he said.
Clr Mguni said the recommissioning strategy of the city’s three supply dams is of high priority to Bulawayo with various efforts being made to ease the current water shedding.
He said under the Bulawayo Water and Sewerage Services Improvement Project (BWSSIP), six new flowserve pumps have been supplied and installed at the Ncema and Fernhill pump stations. The new pumps were a replacement of obsolete ones.
“As part of the recommissioning strategy for bringing back online the three decommissioned dams, the city had proposed that the raw water from Umzingwane, Insiza, and Inyankuni will be utilised to feed the new flowserve raw water pumps and pipeline while Upper and Lower Ncema will feed the Ncema Water Treatment Works for clear water pumping for the Tuli reservoir,” he said.
“It had been our wish as a city to have the flowserve pumps fully functional before the onset of the rain season so as to quickly ease the burden being faced by the residents. During the onsite testing, these past two weeks, a significant problem occurred which is affecting the timeline for the commissioning of the flowserve pumps.
Four of the six non-return valves (NRVs) have failed due to design and manufacturing defects. The NRVs have an important function to protect the pumps; in that when a pump is switched off or when there is a power outage, the NRVs prevent backflow from the water in the rising main.”
Clr Mguni said due to challenges that came up during the testing of the flowserve pumps the expected commissioning that had been scheduled to take place tomorrow has now been deferred until the teething problems have been ironed out.
He said the contractor has been given a deadline of January 15 to come up with a temporary option while working on a permanent solution.
Currently on average the Nyamandlovu Aquifer is delivering just over 9 megalitres of water per day down from the previous average of 12 to 13 megalitres per day which was realised through the test run of some of the Epping Forest boreholes.
“Residents are further advised that repairs on the second sulzer pump that was burnt due to an electrical fault in July 2020 at Fernhill Pump Station are now almost complete although there is an outstanding challenge emanating from the main transformer that feeds power to the affected pump.
“Council electricians are in the process of establishing the problem that is causing the second sulzer to trip,” said Clr Mguni.
“Council is also in the process of testing another transformer to supply the sulzer pump.
“Thereafter repairs based on the findings are projected to continue and be finalised by Wednesday (tomorrow).”
Clr Mguni said once the second sulzer comes online, the amount of raw water pumped through, is expected to increase from the current average of between 50 to 55 megalitres per day to almost 90 megalitres per day.
“Once the second sulzer is successfully brought online there will be enough capacity to bring the city from the current systematic shedding that is based on daily reservoir levels to the established 144-hour per week shedding programme.
“Further review of the shedding thereafter will be made as the decommissioned dams fill up and are recommissioned from further projected inflows expected from more rains,” he said.
BCC Director of Engineering Services Engineer Simela Dube said from Thursday onwards, they will be able to put into the system 90 megalitres of raw water through the sulzer pumps.
“From December 24 going forward there will be review in terms of what is existing in our dams assuming all things remain equal, that is we don’t have any interruptions in pumping,” he said. — @mashnets
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