Model tests of three commonly used energy dissipators for storm-drain outlets were conducted to determine the limiting discharges for various sizes of stilling wells, U.S. Bureau of Reclamation type VI basins, and St. Anthony Falls stilling basins. Charts were prepared for each type of energy dissipator, showing the maximum recommended discharge that will result in good performance for given outlet diameters and structure widths in terms of the outlet diameter. With these charts and other known parameters, the designer can select the type of dissipator best suited to protect the outlet. (Author).