The results of extensive experimental studies on jet-induced mixing in water storage tanks are reported. The experiments were conducted using a newly developed three-dimensional laser-induced fluorescence (3DLIF) system that can measure the whole field of tracer concentrations in the tanks and its temporal evolution through the mixing process. A total of about 140 experiments were done, forming a huge database that should aid in rational tank design and in the development of computational fluid dynamics (CFD) codes. Include CD.