It is vital for water utilities to select the most appropriate project delivery method for the design and construction of their infrastructure projects. Alternative project delivery methods (APDM), such as construction management at-risk (CMAR) and design-build (DB), are now being added to design-bid-build (DBB) as part of a more comprehensive project delivery method toolbox for these utilities. The objective of this study is to identify key project delivery method selection factors for the water industry to support utilities in selecting the most suitable delivery method for their treatment plant projects. The authors reviewed about 40 relevant academic research papers and 15 decision-models that highlighted key project delivery method selection factors. As a result, 44 selection factors were identified and ranked in terms of frequency. An industry workshop was conducted with 20 industry experts and resulted in the identification of 13 key selection factors, seven primary factors, and six secondary factors, that inform project delivery method selection for the water industry. The identified factors in this paper will support the development of a decision-support tool that will assist water utilities with their project delivery method selection decisions.