A compilation of over 70 project examples, this committee report details various problems that may occur at the design, construction, or operation stages of hydroelectric facilities. Easy-to-read, straightforward case sheets identify the specific intake/diversion, water conduit, power plant, or open channel problem pertaining to that facility, its cause and effect, any investigations into the problem, and the analysis or action taken to correct it. Keywords, owner, location, and other pertinent circumstances surrounding the lesson learned are supplied.