Irrigation projects realized in Turkey are completely financed by the state through internal funds or foreign credits. Private construction companies deliver these projects under the management of State Hydraulic Works, which is a state foundation responsible for managing the country's water resources. Decisions related to irrigation projects in Turkey are important because of their effect on the agricultural development and high amounts allocated from national budget for their implementation. Exploring the best design among various alternatives at the design development stage is a serious and challenging process that determines the course and success level of irrigation projects. In this regard, this case study introduces a risk assessment procedure experienced in State Hydraulic Works during the design development stage to determine the best design alternative in an irrigation project. Furthermore, the case study includes crucial remarks about another project under construction on which neither State Hydraulic Works nor the contractor company has so far executed risk assessment. While useful decisions were taken associated with design alternatives in the former project, various problems occurred in the latter one during construction because of not applying risk assessment during design development stage.