Sixteen years after one of Ecuador’s greatest natural disasters -- the landslide that blocked Rio Paute, northeast of Cuenca -- geologists warn that it could happen again.

Commonly called the Josefina landslide, named for a nearby village, the collapse of a mountainside on March 29, 1993, temporarily created the largest lake in Ecuador, destroying more than 1,000 homes and killing a 100 people. The lake backed up to the Cuenca suburbs of La Paz and Challuabamba, causing hundreds of millions of dollars in property damage. Before the 300 foot high landslide dam collapsed 33 days later, on May 2, many thought the flood waters would inundate Cuenca itself.

The landslide, probably caused by heavy rains, dumped more than 20 million cubic meters of earth into Rio Paute in the canyon that connects Cuenca to Paute and Gualaceo, instantly killing as many of 40 people. In the weeks following the landslide, the natural reservoir behind the dam grew to 15 miles in length and contained almost 300 million cubic meters of water.

Sight-seers from across Ecuador flocked to the area to witness colonial-era haciendas, along with modern subdivisions, disappear beneath rising waters. The mayor of Azogues caused a minor scandal when he went boating on the new lake and suggested to a newspaper reporter that it would make a good tourist attraction.

Owners of farms and holiday homes, many of them from Cuenca, agonized as they watched their property destroyed. Cuenca’s El Mercurio newspaper reported that some homeowners hired professional divers to recover valuables from submerged houses. According to the article, little was recovered and some accused the divers of theft.

Geologists and engineers from around the world, including a team from the U.S. Army Corps of Engineers, came to Cuenca to work with local authorities to find a solution as waters rose. Because the blockage was one of the largest in modern history, answers were not easy to come by but measures were taken that proved to reduce damage and loss of life when the blockage finally collapsed.

Authorities agree that things would have much worse had a channel not been cut into the dam to release some of the water as the lake grew. Evacuations of residents for almost 40 kilometers below the landslide were responsible for saving countless lives.

When the dam broke on May 2, only a few dozen lives were lost although hundreds of houses, many of them dating back hundreds of years, were destroyed in the flood. The Paute hydro- electric project, 30 kilometers downstream, sustained serious damage to its turbines but, because the water level in the reservoir had been drawn down, most of the project survived. The Paute plant produced 65% of Ecuador’s electricity in 1993.

Several downstream villages were destroyed and river rose almost a 100 feet near the town of Paute, standing three feet deep in the central square. The volume of water released was so great that measuring stations on the Amazon River, a thousand miles to the east, recorded a rise in water levels after the dam collapsed.

The scouring force of the flood is still evident in the Paute Valley and work continues in many areas to remove rock and gravel from the river bed. A monument stands near the point where the landslide occurred, at the junctions of Rios Paute and Jadan.

Although experts do not predict an imminent reoccurrence of the Josefina slide, they urge that mountain stabilization work continue. The 10-year project that removed millions of meters of rock and gravel near the site of the disaster, concluded in 2008.

The Ecuador Ministry of Transport and Public Works and the Azuay Provincial Council agree that more should be done and they are in talks with the experts who planned the original remedial work. According to geological engineer Raúl Sarra Pistone, author of the master stabilization plan, “We have accomplished a great deal in terms of strengthening the mountain slope. On the other hand we need to do more to make sure we never have another disaster like this one.”

Photo caption: The riverside park in Paute was almost 100 feet under water at the height of the 1993 Josefina flood.