Design alternatives in construction projects are compared with concurrently taking various criteria into consideration, such as costs, functionality, and constructability. This case study introduces a comparison process based on lifecycle costing (LCC) between two design alternatives in an irrigation project, the Seyhan River Yedigoze Imamoglu Irrigation Project, being implemented in the southern region of Turkey. Decisions related to irrigation projects in Turkey are important because of their effect on the agricultural development and because of the high amounts allocated from the national budget for their implementation. In this regard, comparing the design alternatives properly during the design development stage is critical to exploring the superior design. The aim of this case study is to show how considering only the facility initial construction costs, while ignoring LCC, may lead to wrong decisions, through the example case of an irrigation project undertaken in Turkey. Comparison of two different design alternatives has revealed that Design Alternative 2 (pipe network and concrete covered open main channel of 15.812 km) is superior to Design Alternative 1 (pipe network and concrete covered open main channel of 57.562 km) from the perspective of LCC and such technical criteria as constructability, operation easiness, and water saving. (C) 2014 American Society of Civil Engineers.