News24

Dams waiting to burst

2001-03-02 14:22

Johannesburg û While Zambia may seem to be ignoring the plight of its neighbour Mozambique, it is, in reality, only trying to save its own people.

All indications are that ZambiaÆs Kariba dam and MozambiqueÆs Cahora Bassa dam are time bombs waiting to explode. If pressure on the dam walls and infrastructure is not released by opening the floodgates, a disaster of boundless proportions may result.

There are serious concerns about the regularity and thoroughness of maintenance of both dams' infrastructure and about the strength of the walls. Nobody knows the answers.

There are also fears that the Cahora Bassa dam wall may burst if water continues flowing into the dam at the current rate. To try and avoid such a disaster, four of the dam's eight floodgates have been opened.

While this may save the dam, it endangers the lives of thousands of Mozambicans living downstream of the dam.

International teams are evacuating nearly 200 000 people out of the path of the floodwater. About 80 000 people have already been taken to higher ground.

At least 7 500 m3/s are flowing through Cahora BassaÆs floodgates and nearly 11 000m/3s is still flowing into the dam.

The floodwater was expected to reach Tete, the first big town downstream of the dam on the Zambezi river by Thursday.

Tete has a population of about 100 000. Further downstream, a further estimated 105 000 people will also likely be in the way of the floodwaters.

Pana reports that Radio Mozambique on Wednesday reported sections of Tete were already flooded, but that most of the floodwaters had not reached the town by then. Higher lying areas of the town have already started forming islands.

Meanwhile more floodwater from Kariba is on its way to Cahora Bassa and will also be released through the floodgates.

The Times of Zambia has confirmed in a report that KaribaÆs safety is also under threat. Zambian Energy and Water Development Deputy Minister Celestino Chibamba apologised for releasing the water from Kariba into Mozambique.

"We sympathise with Mozambique but there is a danger that if the water is not released, the dam may be damaged which would result in an even greater disaster," he said.

Kariba, with its 171m high dam wall, has a capacity of 180 billion m3, the biggest in Africa. Cahora Bassa has a capacity of 52 billion m3 and a 171m high dam wall.

Chibamba said the water safety level for the Kariba dam is 484.15 m above sea level. The water level is currently at 484.80m. There is a real danger that the immense pressure of the water could cause the dam's infrastructure to collapse if the floodgates are not opened.

The Cahora Bassa hydroelectric plant was completed in the late 1960s but the planned provision of electricity to Mozambique and South African never got off the ground. During the freedom struggle and civil war in that country power masts and cables were often destroyed.

South Africa eventually refused to buy the electricity as it was too expensive.

It is not clear whether regular maintenance was carried out during the Mozambican civil war. The turbines have never been used to full capacity.

In 1978 all of the eight floodgates were opened and 13 000 m3/s was released, resulting in the worst floods ever downstream of the dam.

United Nations Mozambique bureau spokesperson Francis Christie told Pana it would be "disastrous" if more water was released. People below the dam are already living on borrowed time.

A statement from the UN bureau for co-ordinating humanitarian aid said the evacuation programme needed a five-day grace period, being the time taken by the floodwater to travel 500km from Cahora Bassa to the sea.

The Zambezi valley is shallow and water spreads fast over a huge area, which can hamper rescue efforts. A priority for rescue teams is to save people from the lowest lying areas in the valley and move them to camps and towns in higher lying areas.

Three camps have been erected, including Caia, Chemba and Mutarara. Caia has three centres and about 26 000 people have been registered there.

About 18 400 people in the immediate vicinity still need to be evacuated.

The Mozambican Institute for Disaster Control says the lives of at least 400 000 in the Zambezi region were disrupted during the earlier floods and that this figure could increase dramatically.

Flood danger warnings are broadcast regularly over the radio but many people probably did not hear them.

Some residents refuse to leave their homes for fear of their belongings being plundered and of not receiving government compensation. Many of them are still rebuilding their lives after last year's devastating floods.

In Malawi conditions are deteriorating quickly. On February 24 the government declared 13 of the countryÆs 27 districts disaster areas. Unconfirmed reports say that 200 000 people have been left homeless by recent heavy rains.

At least 62 families urgently need assistance.

Meanwhile the international community is preparing for a protracted aid campaign. Several control centres have been erected in bigger cities such as Beira.

A USAid spokesperson told Pana there was great concern about conditions in Mozambique but that at this stage, everything was still under control. American aid has arrived and money has been made available to hire South African helicopters and fixed wing aircraft.

Satellites will identify the worst affected areas.