THE government yesterday cancelled leave for all employees of the Energy ministry including those who were on Easter holidays to report to office as a matter of urgency to ensure that a crippling power supply challenge is solved.

Dr Doto Biteko, the deputy prime minister and Energy minister, issued this directive when visiting the Kidatu hydropower plant iin Morogoro Region, where a water level control system technical fault causes a massive power outage.

Kenneth Boymanda, spokesman at the Tanzania Electric Supply Co. Ltd (TANESCO) said that the fault occurred two hours after midnight, with outages felt towards 4am in most parts of the city of Dar es Salaam, through to Monday afternoon.

Most regions connected to the national grid experienced power cut for about ten hours, leaving shocked residents seeking an explanation, now that the supply shortage had already been ended.

The technical fault in the water level control system overpowered the control mechanism thus letting water into plant systems that work on oil, thus causing an automatic stoppage.

Failing to prevent the large flow of water entering the plant caused it to suddenly shut down in an automated plant protection mechanism, he stated.

Technicians were at work to reverse the situation, with considerable clean up needed in the disturbed hydropower plant area and rectification of the control mechanism.

One way was to open the control gets to let the water flow out to desired levels consonant with the control mechanism capacity, officials said in a range of interviews.

Affected regions like Dar es Salaam, Tanga, Unguja, Pemba and Coast had power supply reactivated later in the afternoon, he said, noting that power restoration was yet to be completed by the evening yesterday,  with expectations that outages would be ended within the day.

“The challenge occurs very rarely and that’s why it has brought a huge impact but the company is works on measures to permanently prevent the problem,” he stated.

The Zanzibar Electricity Corporation (ZECO) said in a statement that a power outage occurred in Unguja following a technical fault at the power transmission line tied to a power boosting station at Tegeta in Dar es Salaam.

TANESCO technicians have already fixed the water level control system by installing different control machines, while Dar es Salaam, Tanga and Zanzibar consumers were routed to get power through the Pangani and Ubungo II power plants.

At Kidatu, work to remove the water that entered power plant rooms is ongoing and once the work is done, power generation will be resumed, he added.