Low-flow characteristics of streams in the St. Croix River basin , Wisconsin, are presented. Included are estimates of low-flow frequency and flow duration at 7 gaging stations, low-flow frequency characteristics at 23 low-flow partial-record stations and 78 miscellaneous sites, and a list of base-flow discharge measurements at 29 miscellaneous sites. Equations are provided to estimate low-flow characteristics at ungaged sites and at sites where one base-flow discharge measurement is available. The equations were determined from multiple-regression analyses that related low-flow characteristics at gaging stations and low-flow partial-record stations to basin characteristics. The standard error of estimate is provided for each method of estimating the annual minimum 7-day mean flow below which the flow will fall on the average of once in 2 years and once in 10 years. Standard error provides the user with the expected degree of accuracy for each method. (USGS)