Rigorous evaluations can be a critical element of resource conservation programs, since they provide documented results and feedback important for designing and improving effective programs. Evaluations are uncommon in the world of water conservation programs. This paper discusses the methodology and findings of a comprehensive impact and process evaluation of Seattle Public Utility's 2001 Water Smart Technology program (WST). WST provides financial incentives for commercial and industrial customers to install a variety of water-saving measures. The impact portion of the evaluation estimated actual gross savings from a sample of 25 WST projects using pre- and post-installation measurements of system performance. The impact evaluation also estimated net savings for these projects based on decision-maker interviews. The evaluation then systematically extrapolated gross and net results from evaluated measures to the entire program. The process portion of the evaluation relied upon data gathered in interviews with both participants and non-participants. It yielded insights into organizational structures and decision-making processes among commercial customers, WST program knowledge and satisfaction, barriers to implementing conservation projects, and program tracking and delivery needs. The information gleaned from both the process and impact portions of the evaluation are expected to guide future improvements to the WST program. Includes tables, figures.