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 purpose and scope: Purposes of this report are: (1) To define the areal distribution and occurrence of all thermal springs in the Boise River basin, (2) to evaluate their chemical and isotopic compositions, and (3) to quantify the amount of heat and water presently discharging from the springs.

From purposes of approach of study: The purposes of this study were to: (1) Define, on a reconnaissance level, current (1979) water-quality conditions in major aquifers (water-yielding rock formations) in the eastern Snake River basin; (2) present available geologic and hydrologic data to assist in understanding the natural and man-caused factors that affect water-quality conditions; and (3) establish a hydrologic base upon which future comparisons can be made to evaluate changes.

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.

Purpose and scope: The purpose of the study was to determine whether a thin layer of volcanic ash measurably affects aquatic environments. Study objectives were to: (1) Determine the amount of ash initially deposited in Big Creek basin and the amount remaining 1 year after the eruption, and (2) describe the impact of ash on water quality and benthic invertebrate communities.

From purpose of study: In January 1980, the u.s. Environmental Protection Agency (EPA) recommended that a ground-water monitoring program for organic constituents be started at the INEL. In response to this recommendation, DOE requested the U.S. Geological Survey to undertake such a program. The purpose of the study was to determine the distribution and extent of organic constituents in the ground water beneath the INEL.

From purposes and approach of study: The primary purposes of this study were to: (1) Define, on a reconnaissance level, current (1980) water-quality conditions in major aquifers (water-yielding rock formations) in the western Snake River basin, Swan Falls to Glenns Ferry; (2) summarize and interpret available geologic and hydrologic data to assist in understanding the natural and man-cause factors that affect present and future understanding the natural and man-caused factors that affect present and future water-quality conditions; and (3) establish a hydrologic data base on which future data can be compared to evaluate changes. A secondary purpose was to evaluate the possible effects percolation of thermal water applied for irrigation may have on the quality of local, less mineralized, nonthermal ground water.

From introduction: This study was designed to: (1) Determine present ground-water use, (2) document changes in water levels caused by pumping, and (3) refine estimate of recharge to the artesian aquifer in Camas Prairie, Idaho. It is written in the "STOP" format.