Red Cedar River basin, Wisconsin: Low-flow characteristics

Abstract

The purposes of the report are to determine the low-flow characteristics in the Red Cedar River basin, vhere surplus water may be diverted, and to present methods to determine low-flow characteristics at additional sites. The low-flow characteristics were determined various methods at 71 sites in the basin. For the three gaging stations in the basin frequency analysis was used to determine the low-flow characteristics. At IT partial-record sites correlation analyses were used to estimate the low-flow characteristics Where only a single measurement was available the following equations were developed to estimate lowflow characteristics at hi. sites : where: Q-y 2 and Qy IQ are ^e 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 , A is drainage area, in square miles, and Bf is index. The relationships were determined from multiple-regression analyses that related lowflow characteristics at gaging stations , lowflow partialrecord stations, and sewage-treatment-plant sites to the drainage area and index values. The standard errors of estimate were determined to be 25 percent for the Q equation and 3h percent for the Q equation. f 9 *For the main stem of the Red Cedar River where only one discharge measurement was available the low-flow characteristics were determined from a drainage area-discharge relationship. Low-flow characteristics were determined at an additional 30 sites in the Red Cedar River basin various methods. The method used for these sites depended upon the type and amount of data available at each site. INTRODUCTION The Red Cedar River basin (fig. l) is an area where surplus water h£.s been used extensively for irrigation. Since the drought of 1976, the use of this water has increased dramatically. A method is needed to provide uniform and accurate evaluation of the low-flow resource in this basin. The purposes of this report are to determine the low-flow characteristics in the Red Cedar River basin where surplus water may be diverted and to present a method to determine low-flow characteristics at additional sites. The study was part of the low-flow project in cooperation with tire Wisconsin Department of Natural Resources (DNR). The report includes: estimates of the annual minimum 7-day mean flew below which the flow will fall on the average of once in 2 years (Qy 2) and once in 10 years (Qy 10 ) at 71 sites; two equations that can be used to estimate low-flow characteristics where only one discharge measurement is available; and relationships for estimating low-flow characteristics on the main stem of the Red Cedar River between Mikana and Coifax. For the convenience of readers who may want to use metric units, the data may be converted using the following factors: (mi 2 ) Multiply mile (mi) foot (ft) square mile cubic foot per second (ft3/s) foot per mile (ft/mi) inch (in.) cubic foot per second per square mile {(ft3/s )/mi2 } 609 301*8 59 02832 0109^ To obtain kilometer (km) meter (m) _ square kilometer (km ) cubic meter per second (m3/s) meter per kilometer (m/km) centimeter (cm) cubic meter per second per square kilometer {(m3/s)/km2} LOW-FLOW CHARACTERISTICS Table 1 presents low-flow characteristics for 71 sites in the Red Cedar River basin. Information included for most sites is: station number, station name, measured discharge, drainage area, estimated Qf 2 10» an basis of estimate. The location of each site is shown on plate 1. The low-flow characteristics in table 1 are determined by four methods of analysis, depending upon the type of data available. The four basic types of data available are: (l) continuous record of daily streamflow (gaging stations), (2) 10 to lU base-flow discharge measurements (low-flow partial-record stations), (3) U to 7 base-flow discharge measurements (sewage-treatment-plant sites), and (U) a single discharge measurement made during August 23-26, 1977, or March 21, 1978, for this study (miscellaneous sites).