(CNSNews.com) - Defeating ISIS isn't the only concern of U.S. military commanders in Iraq. The failure of a large dam in the city of Mosul looms as a potential catastrophe, the head of U.S. Central Command told Congress on Tuesday.
"If the dam fails, it will be catastrophic," Gen. Lloyd Austin III told the Senate Armed Services Committee. "There will be thousands of people donwstream that will either be injured or killed, certainly displaced. And the damage could extend all the way down to -- close to Baghdad, or into Baghdad," which is more than 200 miles downstream.
The U.S. Embassy in Baghdad said as many as 500,000 to 1.47 million Iraqis living along the Tigris River "probably would not survive" the impact of floodwaters that could reach depths greater than 45 feet in some parts of Mosul.
Gen. Austin told Congress, "We have worked with the Iraqis to be sure that they are doing the right things to warn people about this, and in the event that it does fail, what actions they should take to get to safety. And we certainly have measures in place to ensure that U.S. citizens are -- or U.S. personnel -- are accounted for and able to be evacuated in case of the dam's failure."
Austin said when Islamic State terrorists captured the dam for a few months in 2014, the maintenance workers fled, and the work to shore up the dam stopped.
"We have encouraged the Iraqi government, since the dam's been back in the hands of the Iraqis, to make sure that they're doing the right things to go about repairing the dam. They have most recently hired an Italian company to perform maintenance on the dam, but it may be several weeks or months before that company is up and running, so there is a time period that we are concerned about (when) there will be limited to no maintenance performed on the dam," he said.
As the Associated Press reported, the dam on the Tigris River was built in the early 1980s on unstable ground where the earth underneath it is constantly eroded by water. Maintenance crews have continuously poured cement under its foundation in a process known as "grouting."
The situation worsened when ISIS terrorists overran the dam and held it for several weeks in 2014. Since then, efforts to reinforce the dam's foundations have not been adequate, partly because ISIS still controls the factory that produces concrete for the dam.
In 2006, a report from the U.S. Army Corps of Engineers called the Mosul dam "the most dangerous dam in the world," and the situation has only deteriorated since then.
The Iraqi government and the U.S. Embassy in Baghdad are now warning people living along the Tigris River to move at least 3 to 4 miles away from its banks.
The U.S. Embassy, in a warning issued on Feb. 29, called the dam's risk of collapse "serious and unprecedented."
"Prompt evacuation offers the most effective tool to save lives of the hundreds of thousands of Iraqis," the embassy said.
According to the warning, "A dam failure would cause significant flooding and interruption of essential services in low-lying areas along the Tigris River Valley from Mosul to Baghdad. Some models estimate that Mosul could be inundated by as much as 70 feet (21 meters) of water within hours of the breach. Downriver cities such as Tikrit, Samarra, and Baghdad could be inundated with smaller, but still significant levels of flooding within 24-72 hours of the breach."