Colombia dam flood
© Joaquin Sarmiento/AFP/Getty Images
Displaced families from the banks of the Cauca river camp on a road near Ituango municipality on 13 May 2018.

600 people already left homeless after heavy floods at hydroelectric dam project, with another wave of flooding feared

Tens of thousands of people have been ordered to evacuate their homes in western Colombia after heavy floods at Colombia's largest hydroelectric dam project, which had already displaced hundreds over the weekend.

The Hidroituango dam on the river Cauca was in the final stages of construction when a blocked tunnel was cleared on Saturday night, causing flooding downstream that swept through a riverside hamlet. Six hundred people were left homeless and two bridges, two schools and a health centre were destroyed.

On Wednesday, authorities issued evacuation orders for eight municipalities downstream from the dam amid fears of another wave of flooding as heavy rains continue to batter the megaproject.

The total number of inhabitants in the eight municipalities is believed to number up to 120,000. So far no deaths or missing people have been reported.

Videos circulating on local media show the harrowing scenes at the dam. One clip shows workers running from massive waves, while another shows flood water engulfing digging machinery.

"In the next few minutes, the flow of water from the Cauca river will be increased, downstream of the dam," a text alert sent by EPM, the company building the dam, shortly after midday read. "People should go immediately to the meeting points."

The latest emergency was triggered after an engine room at the dam reportedly collapsed. Colombia's army, police and disaster management agency were dispatched to the site in the north-western Antioquia province. Red Cross personnel have been on the scene since Saturday.

"We are talking about people being displaced every hour," Isabel Cristina Zuleta, an activist with Ríos Vivos, a local environmental organisation long opposed to the megaproject, told the Guardian from a Sabanalarga, a town upstream affected by floods over the weekend. "The high water pressure is causing landslides and floods upstream right now."

"Communities are losing their way of life," she said. "There's no humanitarian assistance here, it's total abandonment - there's no shelters, no food, no anything."

With water levels rising by the hour, Antioquia's state governor, Luis Pérez Gutiérrez, who had previously brushed off the crisis as a "minor impasse" declared the situation a "public calamity" on Monday. Juan Manuel Santos called an emergency meeting with cabinet members and environmental agencies on Tuesday night.

The precise cause of the disaster is contentious. EPM's manager, Jorge Londoño, told local media that "unpredictable geological conditions" had caused the tunnel to fill and then collapse over the weekend, while activists argue that it was caused by an accumulation of plant material left uncollected by the company. Swaths of surrounding dry tropical rainforest was deforested to clear space for the dam's reservoir.

The crisis had been brewing since late April, when a blockage in the diversion tunnel was breached, causing water levels to rise both up- and downstream.

Several landslides, caused in part by heavy rain, led to further blockages throughout early May.

Authorities told residents that the emergency was under control, but many are now homeless.

"My house is still there but everything in it is destroyed," said Richard Pasta, who lived 35 miles upstream from the dam and fled when water started to reach his doorstep last week. He is now in Sabanalarga, a nearby village further from the river, awaiting aid. "This was foreseeable, this is what happens when you mess with nature."

Many locals in the region have long opposed the project, which has disrupted agriculture and fishing since the licence was granted to EPM in 2009.

Armed groups also operate in the region owing to its wealth of illegal gold mines and cocaine trafficking routes.

Three community leaders from the area were shot dead by unknown assailants this month in two separate incidents. Two of the victims were members of the Ríos Vivos movement and had been campaigning for compensation for communities affected by the project.

Despite the controversies, the Hidroituango dam is being touted as a landmark project by the government and EPM - which is owned by the city of Medellín, 106 miles away. At full capacity the dam should be capable of generating an annual average of 13,930 gigawatt hours through its eight massive turbines. The project has received funding from IDB Invest, the private-sector branch of the Inter-American Development Bank.

The project is due to be fully operational by the end of the year. Around 11,000 people are working round the clock to drain the water and finish construction, the company said.