Many stream basins in maritime Alaska have significant glacier-covered areas. A methodology is required for determining design floods for facilities in flood plains by glaciated streams. Published techniques for estimating the magnitude of design floods for ungaged streams in maritime Alaska were not applicable if glaciers were present. Available meteorologic and hydrologic data were reviewed to select rain-flood events for analysis. The largest floods occurred in glaciated basins in late summer or fall after glacial snowpacks became melted at lower elevations and saturated at higher elevations. Stream basins studied were located in south coastal Alaska near Seward and Southeast Alaska near Juneau. Meteorologic data, when not available in the basins, were estimated by correlation of surface weather observations to upper air data. Unit hydrograph and hydraulic modeling parameters were selected which were appropriate for forest, rock slopes, snowpacks, firn, glacier ice, englacial tunnels, and stream channels. Attenuation of rain-floods was related to glacier hydrologic controls. Snythetic unit hydrograph and routing parameters were suggested for determining design floods from glaciated basins. Adjustment factors to adapt regional non-glacial peak flow regression models to glaciated terrain were derived.1-10 usually be determined from late ablation season aerial photographs while the equilibrium line must be determined from comprehensive field studies.Firn lines for the study glaciers were given by Marcus (1963), Heusser and Marcus (1964), and Field (1975. Equilibrium lines for glaciers in Alaska were g1ven by Tangborn et al (1977) and these lines are shown in Figures la and lb.Delay times, attenuation, and recession rates for glaciers were found 10