A British army major saved 20,000 people from mass murder by the Serbs during the war in Croatia, it was revealed yesterday.
Paul Back, visiting professor of engineering at Oxford, told for the first time how an unsung British officer "brilliantly" foiled plans by the Serbs to destroy the Peruca dam.
The officer, later revealed yesterday by the MoD to be Captain Mark Gray, 29, acting as a UN military observer, risked being disciplined for acting beyond his authority by lowering the water level behind the dam before it was blown up. The dam held 540 million cubic metres of water.
"Some 20,000 people would have been drowned or rendered homeless had the dam failed as intended," said Professor Back.
Capt Gray saved their lives by recognising on a UN monitoring visit to the dam months earlier that the Serbs were raising the water level to help bring it down with explosives. Realising the danger, he forced open a sluice gate, Professor Back told the British Association meeting at Newcastle University. When the Serbs then set off their explosives, the dam was able to hold.
Capt Gray, then a lieutenant, told last night how he used bolt-cutters to force open an upper sluice gate. Water poured out of the dam and the level fell six metres. "I had no option but to take the initiative... because of the extreme danger to the population below," he said.
Although the structure was ruined in the blast two years ago, the officer's actions "saved it from catastrophe", Professor Back said. The officer should be commended, he went on, especially since his action could have led to a reprimand.
The attempt to blast the dam came on 28 January, 1993, when the Serb militia in control of the 65 metre high dam expelled the UN observers and set off three explosions within the structure's foundations. "The whole dam lifted and the crest slumped by two metres," Professor Back said. But the dam, which held back more than twice the volume of water in Britain's biggest reservoir, Kielder, in Northumberland, did not collapse.
At the time, this was attributed to the inherent strength of the structure. But now, said Professor Back, who visited the site two days after the explosion, it was evident that the actions of the British officer had prevented catastrophe. "Had he not been able to reduce the level, there is no doubt the dam would have failed as water would have poured over the slumped crest," Professor Back said. Water breaking over the top is the classic mode of dam failure, he pointed out. But the dam had still been undermined and "was bleeding to death" when he saw it.
Professor Back, flown in after the Croatians regained control of the dam, was then a director of a civil engineering firm. He was unable to carry out a full examination because the area was booby-trapped but said that, thanks to the courage of a Croatian operator who had opened a sluice gate, he was able to ascertain that the threat of the dam collapsing had receded.
Professor Back challenged the practice of building dams with galleries across the whole level of their foundations. "In the society we're living in today, where there is a rising tide of evil, we have to question whether this is the right thing to do," he said.