Abstract: Estimates of the travel time of waterborne particles in streams is important for pollution studies and in the event of spills of contaminants. This report provides data for the 16 Indiana streams on which time-of-travel information has been obtained and a means for estimating the velocity of any naturally flowing stream in Indiana with a drainage area of 80 square miles (210 square kilometers) or more. Measured velocity rates compiled from the time-of-travel data collected in Indiana are related to 25, 50, 100, and 200 percent of the average discharge of streams shown in this report. Velocities at these discharges are significantly related to their respective watershed characteristics (average discharge and slope).Generalized relations of the velocities as functions of the streams' watershed characteristics are developed as multivariate regression equations using the data from each of the measured streams.