Agric, Environment & Innovations Editor
Just recently, the western Mozambican province of Tete suffered flooding, with at least 640 hectares of farm land swamped after Hidro-electrica de Cahora Bassa (HCB), the company that operates the Cahora Bassa Dam, opened a floodgate to relieve pressure on the dam.
All this led to increased water flow downstream the Zambezi River, affecting croplands and several islands in the Mutarara District in Tete.
Livelihoods have been affected and this should send signals to SADC countries that share the Zambezi River about the risk that might befall millions of smallholder farmers that live along the fourth longest river in Africa flowing into the Indian Ocean.
Livelihoods were disrupted and with increased risks of the salinisation of soils in farmlands in the Tete province.
Despite a drought that ravaged several countries in the region, there have been significant inflows into the Zambezi River, leading to pressure building up on the Cahora Bassa Dam.
Regional climate experts say the bulk of the SADC region is likely to experience above normal levels of rain in the 2020-2021 summer season and this could have profound implications on the livelihoods of millions of people along the Zambezi River.
Tete province on the border with Mozambique, Zimbabwe and Malawi faces the greatest risk of flooding in the current rainfall season.
It will be hardest hit in addition to the increasing frequency of other natural disasters such as lightning and cyclones.
“These floods are human inflicted,” said Bindura University of Science Education (BUSE) disaster risk and climate change expert Professor Desmond Manatsa. “Actually someone didn’t do his job properly.
“These are not natural floods neither from a broken dam wall nor from rainfall which is difficult to plan. The normal procedure is to give early warning so that downstream communities are not caught unawares. At least movable property and livestock can be rescued from the floods if adequate lead time is provided.”
Prof Manatsa said river authorities within the region need to coordinate more and plan ahead of the season which is likely to have more rains.
“They have already opened the floodgates from the rains from up north,” he said. “Monitoring of the dam levels is essential so that the gates will be opened when enough lead time is given to downstream communities.
“These are human-induced disasters where appropriate action could have saved life and property downstream. There is a need for greater cooperation between the Zambezi River Authority member states to help reduce loss of lives and livestock along this major river. Coordination is key, particularly this season when we expect above normal rains.” The flooding crisis that is expected to be severe along the Zambezi River will be compounded by people who refuse to evacuate at the height of floods into the camps on their own or other secure higher ground settings.
The region, therefore, needs to mobilise resources ahead of time and avoid knee-jerk reaction to the flooding crisis that might affect several countries in the region.
In 2001, Tete was among the provinces hardest-hit by flooding. More than 81 people died in the floods that affected more than 635 000 people.
Records show that the 128-metre-tall and 579-metre-long Lake Kariba Dam wall holds 181 billion cubic metres of water when full, more than three times the capacity of Cahora Bassa at around 52 billion cubic metres.
Closer discussion and cooperation between Zimbabwe, Zambia and Mozambique will be critical to manage the opening of the floodgates at Lake Kariba Dam wall to help reduce pressure on Cahora Bassa.
If little is done to coordinate the opening of sluice gates, chances are high that the opening of Cahora Bassa floodgates will inundate the low-lying Zambezi Delta on Mozambique’s coast on the Indian ocean.
Failure to plan, is planning to fail, so goes the old adage.
With closer coordination between the Zambezi River Authority and HCB, Lake Kariba could limit the flow into the Cahora Bassa Dam in Mozambique, something that may help spur power production at Kariba and reduce the flooding of the low-lying Zambezi Delta. It is also worth noting that it is not the low-lying Zambezi Delta that may face severe flooding alone should the region receive above normal rains.
Other rivers throughout much of the SADC region could reach above flood alert levels forcing thousands of people to be relocated higher ground as we have seen 2001, 2010 and other years when the region experienced above normal rains.
Nearly two years ago, tropical Cyclone Idai brought heavy rainfall and strong winds to Malawi, Mozambique and Zimbabwe between March 5 and 19, 2019, causing severe flooding which led to loss of lives, destruction of infrastructure, disruption of livelihoods and destruction of crops.
It is estimated that close to 780 000ha of cropland in the three countries was destroyed by the cyclone, with the bulk of this area in Mozambique.
Dams and wells were also damaged, and livestock washed away.
If torrential rains buffet the region, basins of the Zambezi, Save, Pungwe, Limpopo, Shire, Buzi and others could place millions of people living in such risky areas to be evacuated.
Risks of aggravating localised flooding are also a possibility for rivers and streams that feed into the major rivers in the region.
The region will also need a hovercraft to help attend to any emergencies that might arise due to excessive flooding.
In the past, the air forces of Zimbabwe, South Africa, Namibia and Zambia have proved to be useful in reaching out to the affected populations along the Zambezi, Save, Pungwe and Limpopo river basins.
At present, the threats are still remote, but based on weather forecasts that indicate that there will be above normal rains this season, planning and coordination will be critical.
There will be a need for authorities to educate the public and communities living along the region’s major rivers to take notices seriously to avoid loss of life and property due to flooding that might occur when floodgates are opened.
Radio communications remains important and also mainstreaming these with community communications systems.
As global warming intensifies, the Zambezi basin and other impoverished riverine communities in the region are increasingly at risk.
Flooding often leads to high levels of food insecurities.
Record numbers of people in the region who are already facing severe food insecurity because of a acute drought last season might require more food if crops fail due to flooding.
The inability to have adequate water, generate enough power and grow enough food has been worsened by climate change.
National meteorological and hydrological services within the region should closely monitor flood levels and update relevant institutions such as disaster risk management agencies at member states level to support preparedness and actions taken to protect lives and property.