This report presents relations for estimating peak flows and mean annual flow characteristics are: (1) The Channel-geometry method, whereby flow characteristics are related to channel dimensions; and (2) the basin-characteristics method, whereby flow characteristics are related to physiographic and climatic features of the drainage basin. Development of the channel-geometry method showed channel width to be the most significant channel dimension for estimating flow characteristics. Use of this method requires a field measurement of channel width. Development of the basin-characteristics method showed drainage-area size to be the most significant basin feature for estimating streamflow. In the mountainous areas, basin elevation also affect streamflow. Because these basin features can be determined from maps, this method does not require a visit to the site. (Woodard-USGS)