US Army Corps of Engineers
Louisville District

Corps geologist plays vital role in Mosul Dam completion

Published Oct. 8, 2019

David Robison, Louisville District geologist, recently returned home from Mosul, Iraq, after serving on the Mosul Dam Task Force for the past nine months, where he was able to see the completion of the Corps’ involvement with the project.


Robison, who has been with USACE for 12 years, is a geologist and facilitator in the Geotechnical and Risk Cadre Section of Engineering Division, but held many roles during his deployment.


“My titles have varied during my time at MDTF in the engineering and construction office, but have included geologist, instrumentation lead and acting drill-and-grout lead,” Robison said.


Mosul Dam is Iraq’s largest dam and the fourth largest dam in the Middle East. The main embankment is 371 feet tall and 2.1 miles long and provides water supply, irrigation, flood control and hydropower for the people of Iraq. According to the U.S. Army Corps of Engineers Transatlantic Division, the dam is unique in the fact that it was built on a water-soluble foundation. This means it needs constant maintenance grouting so the dam doesn’t collapse as the foundation erodes. 


As a geologist with the MDTF, Robison analyzed rock core samples and data collected from boreholes to determine the effectiveness of the grout curtain. A grout curtain is a mixture of cement, clay and water used to fill in the foundation’s voids to make it more stable, lengthen flowpaths and minimize embankment erosion. 


Robison also guided the instrumentation and/or exploration program to ensure proper monitoring of potential geologic hazards and increased understanding of the foundation conditions under, and near, Mosul Dam.  


“It was rewarding to have played a part in a construction project that had such immediate benefits,” Robison said. 


Robison first heard about Mosul Dam early in his career. However, concerns about being deployed and away from his family caused him not to pursue the opportunity at that time. That changed a few years later when Robison was encouraged and reminded about how it was a once-in-a-lifetime opportunity. 


“I guess I like a challenge, and there seemed no greater challenge than working on what was then considered the ‘highest risk’ dam in the world,” Robison said.


During his time in Iraq, Robison worked and trained Iraqi engineers and geologists as part of the Integration Program, so the Iraqis were able to continue the dam safety work once USACE left the site. The training sessions involved several site visits, discussions in the office to solve problems, formal classroom instruction and hands-on exercises with data and software from the field. 


“It was great to see their increased understanding and learning why we accomplish the work we do,” Robison said. “For example, the Iraqis found it odd that we search for potential dam safety issues and geologic hazards, instead of only dealing with the issues that are evident. Those with whom we have worked closely now understand the importance of understanding all the potential dam safety risks and how to monitor for them.”


Although there were many successes while working on the MDTF, there were also many challenges.


 “Language barriers and communication issues are nearly daily issues with over seven languages being spoken onsite,” Robison said. “Equipment and materials can also be difficult to obtain, as it often has to travel in from Europe across several borders with various custom laws.” 


Robison enjoyed his time working at Mosul Dam and solving the problems that came with working at a massive construction site where every day is different. 


“The other enjoyable thing is the people,” Robison said. “Onsite we had people from various countries, cultures and backgrounds, but everyone is friendly, eager to help and genuinely wants to do a great job to ensure the integrity of Mosul Dam.” 


The three year project was done in collaboration between USACE, the government of Iraq and Italian contractor Trevi S.p.A and was completed in June 2019.


“What I like most about working for the Corps of Engineers is the variety of projects I have been able to be a part of,” Robison said. “I have analyzed geologic hazards from Alaska to Iraq. I have learned from great geologists and engineers from all over the world. Whether the problems are big or small, I like watching my teams work together to come up with solutions.”


Although he is home, and the maintaining of Mosul Dam has been handed back over to the government of Iraq, Robison will always be able to say he played a part in that project’s success.