This mission report from the Joint Research Centre of the European Commission describes the findings of dam failure scenario mappings for Mosul Dam in Iraq. Upon request of the OCHA Country Office in Iraq, a UN Environment/OCHA Joint Unit Senior Humanitarian Affairs Officer deployed to Iraq for four weeks in March and April 2016 to support preparedness for a potential failure of the Mosul Dam. The mission identified priority preparedness actions focusing on a first tier of activities. As a follow-up to the mission, an UNDAC mission was mobilized. The UNDAC team worked with national and international actors to facilitate the development of protocols for the reception of international humanitarian assistance in the case of a potential dam failure. The UNDAC team, in collaboration with UNDP, also supported the Government to ensure the establishment of an emergency alert system in areas deemed at high risk of flooding. Concurrently, the WHO Emergency Medical Teams’ manager deployed with the UNDAC team to develop joint response protocols. The JEU contributed to this analysis by providing an overview of industrial installations of concern, as identified through the FEAT, in the flood zones.