A method for determining flood hydrographs for small, ungaged streams is presented. The intensity-duration-frequency rainfall data are combined with a series of unit hydrographs to determine a series of possible flood hydrographs. The largest flood hydrograph is selected as the critical one. The upper limit on the possible range of unit hydrographs appears to be critical. It is determined that the selection of the unit hydrograph peak is more critical for short duration storms than for long duration storms. It is also shown that for small basins, the short intense storms are the most important and as the size of the basin increases, the larger, less intense storms become more important. (Author)