The Zambezi River Authority (ZRA) on Saturday opened two of the six floodgates, Gate 3 and Gate 5 at Kariba Dam, raising fears of flooding in low-lying areas.
The opening of the gates is aimed at ejecting excess water that has been accumulating in recent weeks in the upper part of the Zambezi catchment area following heavy rains pounding Mozambique and Angola.
Hundreds of residents from both Zambia and Zimbabwe and tourists witnessed the event.
A large number of people from Mozambique, Zambia and Zimbabwe live downstream of the Zambezi Valley and would be swept away should excess water continue to be released from Kariba Dam.
Areas susceptible to flooding in Zimbabwe include Hurungwe, Muzarabani, Rushinga and Tsholotsho.
The valley experiences floods almost every year and at one time military aircraft from the region had to be deployed to rescue people who had been marooned.
ZRA director for water resources and environmental management Clement Mukosa said the development was aimed at easing pressure ahead of anticipated increased inflows between February and April.
“There has been a lot of rainfall between Victoria Falls and Zambezi, hence the need to ease the pressure”, said Mukosa.
“We will be monitoring the situation every day. We are doing this to safeguard the lifespan of the dam.
The two gates release at least 3 000 cubic metres of water per second.
Mukasa said extensive campaigns had been undertaken in both countries through the Civil Protection Unit (CPU) in Zimbabwe and the office of the Disaster Management Unit in Zambia, warning people of the impending opening of the gates.
“It’s only that at times people can be arrogant. Even when they are given a warning they sometimes decide not to take heed,” he said.
In November last year, the CPU dispatched teams to low-lying areas in the country to carry out awareness campaigns ahead of possible flooding this rainy season.
The teams comprised officials from the CPU, the Meteorological Services Department, Zinwa hydrologists, the police Sub-Aqua Unit, and non-governmental organisations in an initiative funded by the United Nations Development Programme.
ZRA director for projects and dump safety David Mandizvidza said enough warning had been given to people living downstream of the river.
“Even if it stops raining today (Saturday) it will take at least two to three weeks before we can close the gates again,” he said.
The authority warned the public and the communities living along the Zambezi River banks to take the notice seriously to avoid loss of life and property due to flooding that might occur after the gates were opened.
A team of Sadc weather experts who met in Harare in September predicted normal to above-normal rainfall across the region and requested that regional disaster management systems be activated to minimise loss of life and damage to property in the event of flooding.
Kariba Dam was built between 1956 and 1959.
When a spillway gate is fully open, the water jets out about 43 metres from the wall, landing in the plunge pool that acts as a shock absorber for the foundations of the wall and the surrounding river bank.