Lusaka – Zambia and Zimbabwe are under threat of power supply shortage, as water levels in the Kariba Dam continue to drop.
In the first week of this month, water levels in the 58-year-old man-made lake, which is the main source of water for hydro power production for Zimbabwe and Zambia dropped to 41 percent.
This, according to a report by the Zambezi River Authority (ZRA) which regulates the dam, resulted in the water dropping by 0.13m during the week ending 7 November and closing at 481.29 metres.
As a result, several stakeholders in the energy sector fear intermittent power outages, which have afflicted Zambia and its neighbour before and could have a negative impact economic growth.
ZRA, in its report, expressed doubt that the water levels in Lake Kariba would recover to maximum power generation capacity until 2020 due to various factors like continued delays to refurbish the plunge pool, which poses a real risk of the dam collapsing.
It has also sought to restrict water intake for power generation this year to only 30 billion cubic metres from the installed capacity of 65 billion cubic metres, a move expected to see a continued reduction in power generation by both national power utilities – Zambia Electricity Supply Corporation Limited (ZESCO) and Zimbabwe Electricity Supply Authority (ZESA).
The north bank hydro power plant that is operated by ZESCO has an installed capacity of 1,080 MW, while the south bank on the Zimbabwean side has capacity of 750MW, with plans to increase this to 1,050 by 2018.
Bob Mwangala, a hydrology technician with ZRA, has predicted that it would take at least three years of normal rains for the lake to fill up to capacity, the water needed to produce enough electricity.
He argued that water inflows into the lake had in the last three years drastically dropped owing to reduced rainfall in its catchment area in north-western and western provinces, adding:
“From the hydrological simulations that we have done, for the lake Kariba to reach its normal levels, it will take at least three consecutive years, given that the status quo, remains the same where we anticipate above average inflows,” Mwangala said.
Fears are that while funds have been mobilised in excess of $294 million to facelift the dam, ZRA, a bi-national company that manages the iconic dam on behalf of Zambia and Zimbabwe, the reshaping of the plunge pool and rehabilitation of the spillway could probably take up to five years or more.
Kariba Dam manager, Kozanai Gyrukumba, is cited in other reports as saying expansion of the plunge pool needs to be completed by the end of 2020 while rehabilitation of the spillway to contain the swelling of the same should be done by 2022.