AS THE sun rose slowly over a picturesque Andean valley in south Ecuador last month, fear-stricken people sheltered on high ground watched helplessly while a deluge of storm water swept through the valley, washing their homes and crops away.

"It's a lifetime's work, senor, the bread for our mouths every day that's under the water. It's so sad, so sad," wept a middle-aged woman. On March 29, a rain-triggered landslide formed a 70-metre-high natural dam across the Paute river and soon it was holding back millions of cubic metres of water in a 11-km-long lake formed by the landslide.

Suddenly, the "dam" burst and storm water engulfed a third of the valley's largest town -- Paute -- and endangered a hydroelectric station supplying about 90 per cent of the country's electricity.

However, as the Paute area's 14,000 residents had been evacuated to tent cities built by the army on high ground, no casualties were reported -- a far cry from the landslide on March 29, which agencies said took a toll of 300 people dead or missing.

Engineers also had the time to cut a channel to drain away some of the storm water and thereby ease the pressure on the "dam", which also reduced the impact of the flood.