The surge of U.S. troops in Baghdad is succeeding but deeper structural problems continue to plague the American presence in Iraq. The country's largest dam, 40 kilometers northwest of Mosul, near the Turkish border, spectacularly symbolizes this predicament.
Just after occupying Iraq in April 2003, a report found that Mosul Dam's foundation was "leaking like a sieve and ready to collapse." A more recent, still-classified report from the U.S. Army Corps of Engineers concludes that "The dam is judged to have an unacceptable annual failure probability." More explicitly, the corps finds the current probability of failure to be "exceptionally high." A senior aid worker calls the dam "a time bomb waiting to go off."
Mosul Dam, formerly known as Saddam Dam (Arabic: "Sadd Saddam") is in danger of collapse.
That's because the dam was built on unstable bedrock of gypsum that requires a constant infusion of grout to prevent the foundation from eroding and the giant earthen wall from collapsing. Over the years, engineers have pumped into the foundation more than 50,000 tons of a bentonite, cement, water, and air mixture. As the Washington Post explains, "Twenty-four clanging machines churn 24 hours a day to pump grout deep into the dam's base. And sinkholes form periodically as the gypsum dissolves beneath the structure."
Despite these efforts, the dam's condition continues to deteriorate, raising the prospect of its complete collapse. Were this to happen with a reservoir full of water, predicts Engineering News-Record, "as much as 12.5 billion cubic meters of water pooled behind the 3.2-km-long earth-filled impoundment [would go] thundering down the Tigris River Valley toward Mosul, the second largest city in Iraq. The wave behind the 110-meter-high crest would take about two hours to reach the city of 1.7 million." In addition, parts of Baghdad (population 7 million) would come under 5 meters of water.