Maputo — Despite lurid headlines in the Mozambican press about a foreign plot to destroy the Cahora Bassa dam, in reality the dam is working normally, and its management knows nothing about the alleged plot.

"This came as a complete surprise to us. At no time did the police tell us the dam was under threat", Paulo Muxanga, the chairperson of the dam operating company, HCB, told AIM on Wednesday. He had first heard about the supposed plot from the media.

Muxanga was reacting to a press conference given on Tuesday by the spokesman of the national police command, Pedro Cossa, who claimed that the police had arrested four foreigners who had been dumping an unspecified substance in the Cahora Bassa lake in an attempt to sabotage the dam. The four were a German military architect, a Portuguese hotelier, a Botswanan aircraft pilot, and a South African whom (so the police claim) calls himself a prophet.

The objective, according to Cossa, was to corrode the concrete and steel structure of the dam. He said the four had dropped 170 units of the mysterious corrosive substance in the lake and were in possession of a further 500 kilos.

Muxanga told AIM he had no idea what substance the police had seized, and since HCB does not have a forensic laboratory it is unable to analyse the substance.

But HCB does have laboratories that analyse the quality of the lake water on a daily basis. Muxanga told AIM there has been no change whatever in the quality of the water at the dam wall. "It's the same quality now as it was thirty years ago", he said. (The quality of the lake water is important, not only for HCB, but also for the thriving fishing industry on the lake, and for the people of the dam town of Songo, who draw their drinking water from the lake).

Muxanga also said there were no signs of damage to the dam or its power station which are "operating absolutely normally".

Muxanga said the Tete police have now told HCB that the four suspects were staying at a tourist lodge, about five kilometres upstream from the dam. They then took a pleasure boat up the lake towards the Zambian and Zimbabwean borders. They were arrested at Zumbo, which is about 300 kilometres west of the dam wall.

According to Cossa, before reaching the Zambezi the four had stayed at a beach in Inhambane province, and spent two nights in the Gorongosa National Park. This looks like an itinerary, not of saboteurs, but of tourists.

Elementary physics shows that, if this was indeed an attempt to sabotage Cahora Bassa, it was a singularly inept one. Any substance tipped into a large body of flowing water will be rapidly diluted. And the Cahora Bassa Lake is a very large body of water indeed - on average it contains 55.8 cubic kilometres of water. 500 kilos of anything dropped into such a lake can only have a small impact, though it might kill some fish at the point of dispersal.

Yet such considerations did not occur to journalists attending Pedro Cossa's press conference who obediently swallowed the police line. Wednesday's issues of the daily papers "Noticias" and "O Pais", and of the newssheets "Mediafax" and "Diario Independente" all carried essentially the same story of the dastardly foreign conspiracy.

Indeed, "Noticias" and "O Pais" carried the same lazy headline "Four foreigners try to sabotage HCB". There is no excuse for this sensationalism, since both papers had spoken to Muxanga and knew that HCB had not been contacted by the police. Yet both papers chose to relegate Muxanga's remarks, undermining the police case, to the bottom of their stories.