Abstract: A method which relates basin characteristics with peak flow characteristics is presented for determining magnitude and frequency of floods on streams with drainage areas between 0.5 and 200 square miles. Regression equations for each of eight regions are presented for determination of the 10-year flood. Peak flows for the 25- and 50-year floods can then be estimated from ratios developed for each region. Regression equations are not developed because of poor definitions for several areas that total about 20,000 square miles. The equations were based on multiple-regression techniques using annual peaks and basin characteristics for 303 gaged sites.

From introduction: This study is limited to four U.S. Geological Survey stream-flow stations located in Idaho (figure 1). The 6 to 22 years of stations were assembled and evaluated through use of computer techniques for data plotting and regression analysis developed by Steele (1972). Objectives of this evaluation were were (1) to show which parameters were highly correlative with the levels of specific conductance and(or) discharge and (2) to see if any changes in overall chemical character of the stream had occurred over the long term.