“….in terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world… If a small problem [at] Mosul Dam occurs, failure is likely.”

 U.S. Army Corps of Engineers, September 2006

Key Facts

  • The Mosul Dam provides critical irrigation, flood control, and hydropower to NW Iraq
  • Leaks were discovered within months of operation
  • U.S. Army study concludes that the dam is at a “high risk” of failure 
  • Projected loss of life from dam failure 500,000 (U.S. Embassy est. 1.47 million)
  • Only permanent solution is to construct second dam at estimated cost of $2 billion


Mosul Dam

  • Located on Tigris River in Northwest Iraq 60 km (37 miles) north of Mosul
  • Fourth largest dam in the Middle East with over 11.11 billion cubic meters of storage; equivalent to twice the size of Lake Pontchartrain – the lake that broke the levies in New Orleans
  • Operated by Iraqi Ministry of Water Resources


Structural problems

  • Built on soft, dissoluble Gypsum, Anhydrite and karstified limestone bedrock
  • Foundation has been severely eroded by water (karstified)
  • Short-term solution has been constant mass-scale grouting (cement filling)


Safety concerns

  • Dam’s safety problems concealed by Ministry until a post-2003 US Army Corps of Engineers investigation
  • The study reports that grouting is not a viable long-term solution
  • Study reports that the soft Gypsum and Anhydrite foundation will collapse from dam weight and water erosion
  • Only permanent solution is to build a second dam at cost of $2 billion


Consequences of the Dam failure

  • Projected loss of life from total dam failure is 500,000 (the U.S. Embassy in Baghdad have even estimated that this could grow to 1.47 million without adequate evacuation)
  • The initial wave will peak at 55m (180 ft) and reach Mosul city within 4 hours of dam failure
  • Floodwater will reach the capital city within 38 hours and will inundate a 261km (138 miles) area of Baghdad 10 hours after that
  • Flooding will eventually stop 700km South of dam (15 miles south of Baghdad) after 48 hours, having caused an “enormous” loss of life and property
  • PM Al-Abadi’s government has downplayed safety risk and rejected new dam construction



  • Originally called Saddam Dam, construction began in 1981 and made operation by 1986
  • A Ba’athist Party deputy under Saddam chose the sit to bring jobs to Mosul
  • Daesh (IS) captured the dam for several weeks in July 2014, generating concerns of a planned demolition
  • Currently, Daesh is in control of Mosul city 50km (30 miles) SE of the Dam



Taken From a Report on “Geological and Engineering Investigations of the World’s Most Dangerous Dam” Report by Dr. Al-Ansari