Colombian crews have closed two-thirds of a large levee canal breach that opened Nov. 30 and spilled millions of gallons of Magdalena River water across vast sections of the country's coastal plain. The disastrous flooding, worsened by persistent rainfall, has killed several hundred people, left millions homeless and resulted in billions of dollars in property damage to the South American nation.
Relief crews on Dec. 27 reported success in closing 178 meters of the the 258-m-wide breach in the Dique Canal, although they warn that the remaining 80 m is the most technically difficult part of the closure operation.
Water is flowing through the 12-m-deep gap at a rate of 1,400 cu m per second, estimates Germain Cardona Gutierrez, transportation minister for the Atlantico department. Since the levee blowout, 15 billion cu m of water has inundated six districts, including eight municipalities, he says.
“I’m an old FEMA guy, and I’ve never seen anything like this,” says Dave Brauner, formerly the U.S. Federal Emergency Management Agency’s deputy director of response and recovery and now a private sector consultant. He joined a group of American engineers sent to Colombia in mid-December to provide emergency support to government officials and water authorities.
“The fact that it’s still raining and continuing to exacerbate problems in Atlantico and Barranquilla [departments] tells me there will be problems with all infrastructure—roads and bridges, buildings, drainage, water and wastewater treatment systems and parks and recreation,” Brauner says.
Those categories align with five of FEMA’s categories for disaster response. The other two, which FEMA considers emergency work, include the removal of debris, animal carcasses and human remains and emergency protective measures to minimize structural damage.
Brauner, who claims experience in 133 disasters, is now program manager of the federal services group at CDM, consulting engineers from Cambridge, Mass. Eliu Perez, CDM senior vice president and Latin American regional manager, says CDM, which dispatched the advisory team, is under contract for the Bogata Water and Sewer Authority, which sponsored the December trip. “I mentioned that we had folks in our firm who had worked with the Army Corps or FEMA in New Orleans on recovery from Katrina and Gustav and they said they welcomed any kind of support doing triage,” Perez says.
The Dique Canal breach is only part of the flooding that affects about 5,000 sq miles, including half of the 1,300-square-mile Atlantico department.
According to the Colombia Red Cross, 281 people have died, 271 have been injured and more than 2.2 million people have been affected by floods, landslides and other incidents caused by the heavy rainfall.
Officials blame an unusually strong El Ni�o weather pattern that has lashed Colombia’s Caribbean coast now for more than a month, and which is expected to continue into March. Damage estimates—put at $5.2 billion on Dec. 22—continue to climb.
Perez referred to current conditions in South America as a “wake-up call” and “a call to action,” much the same as engineers have referred to previous disasters like Hurricane Katrina in New Orleans in 2005 and Hurricane Mitch in Honduras in 1998.
“We need to gain a greater understanding of climate change and El Nino and La Nina effects and apply some engineering and scientific methods to model potential of these seasons and take preventive action,” says Perez. “The engineering community needs to push for greater understanding of these phenomena so we can be more prepared. When levees are built and cities are built under them, the world needs to be more alert, understand that climate change is bringing greater threats to these manmade structures and assess vulnerabilities.”
After observing the effort to close the breach, Perez noted the huge difficulties the contractors face. “They are trying to drive piles in and build some system to seal it with the caissons,” he says. Disaster crews are trying to plug the gap with giant bags of sand dropped from helicopters—the same tactic deployed in New Orleans along the 17th Street Canal after Hurricane Katrina—but the racing waters are washing them away. “I don’t believe [engineers have devised] a design�to fix it,” Perez says.
He says the contractor is doing the best he can to drive piles and close the gap, but “it’s been a heck of a task. While they are advancing a little, they are increasing the velocity of the water going through, so [they are also] increasing the scouring,” he says.
The American advisory team includes Jeff Bedey, former commander of the U.S. Army Corps of Engineers’ Hurricane Protection Office, charged with rebuilding storm surge defenses around New Orleans after Hurricane Katrina. Bedey is chief executive officer of Vali Cooper International, LLC, New Orleans, a service-disabled veteran-owned construction management firm, has a strategic relationship with CDM, Bedey says.
After returning from Colombia, Bedey says, “we offered a transfer of knowledge when we heard the Corps was going there to do an assessment,” Bedey says. The Corps sent a hydraulic engineer and a geotechnical engineer to make assessments, at the request of the U.S. Agency for International Development.
Bedey says he observed work at two levee breaches while in Colombia, one on the Bogata River breach, where he says the response was “very organized.” It was closed in six days. “I thought that was good,” he says. “One in Plaquemines [Parish, Louisiana] took about the same amount of time.”
But the Dique Canal breach is completely different, Bedey says. He compared the Magdalena River to the Mississippi River, and called the situation “much more complex.” There are concerns now that if they are able to close the breach, it could cause unintended consequences, like another breach elsewhere, he says.
The river is flowing north to Port City on Magdalena and a manmade cut-off canal to the coastal resort of Cartagena. He says the breach is about 1.5 km from where the canal branches off from the Magdalena River. “The breach is humongous,” he says. “That isn’t going to be an easy animal to close. It’s riverine flooding, not a hurricane where the storm comes and goes and you can deal with it.”