Hydrologic and water-quality data for the East River Basin in northeastern Wisconsin

Abstract

Hydrologic and precipitation data and water-quality samples were collected by the U.S. Geological Survey from rivers in the East River basin in northeastern Wisconsin during 1985-86. The Fox Valley Water Quality Planning Agency suspected that agricultural and urban nonpoint-source discharges were contributing significantly to the degradation of water quality in the basin. Two continuous record streamflow and waterquality gaging stations were established: one on the East River at Monroe Street in Green Bay and the other on Bower Creek at Sunnyview Road near De Pere. Streamflow for the 1986 water year was greater than twice the long-term (1967-86) average and precipitation was 33 percent greater than the long-term (1951-80) average. Average daily streamflow at the East River during the 1986 water year was 185 cubic feet per second. Average daily streamflow at Bower Creek was 6 cubic feet per second. Suspended-sediment yields were greatest in Bower Creek 264 tons per square mile per year; yields were 125 tons per square mile per year at the East River site. Total-phosphorus yields at the Bower Creek gage were 2,680 pounds per square mile per year yields were 1,130 pounds per square mile per year at the East River site. The measured yields of suspended sediment and total phosphorus from the East River site, during the 1986 water year, were significantly larger than the estimated average yields for the Fox River at Wrightstown. During a year of normal streamflow, the East River would probably contribute a maximum of 10 percent of the total suspended sediment and 9 percent of the total-phosphorus load transported to the mouth of the Fox River. Dissolved-oxygen concentrations tended to decrease upstream from the mouth of the East River. The daily mean dissolved-oxygen concentration was often less than 5 milligrams per liter at all three of the East River monitoring locations. Minimum dissolved-oxygen concentrations of 1 to 2 milligrams per liter were recorded at all sites. The acceptable fecal coliform level for recreational water quality of 200 counts per 100 milliliters was exceeded at the three East River sites and Bower Creek in more than half of the samples. More samples collected at the downstream sites on the East River at Monroe Street in Green Bay and at the Allouez Avenue bridge at Allouez contained fecal-coliform/fecal-streptococcus ratios that exceeded 4.0, indicating that the bacteria was of human origin rather than of animal. Mean concentrations for 5-day biochemical oxygen demand, total-phosphorus concentration, fecal-coliform counts, and fecal-streptococcus counts were higher at Bower Creek than any of the other sites monitored during 1985-86. Mean chlorophyll a concentrations were highest at the East River sites at Monroe Street in Green Bay and at Allouez Avenue bridge at Allouez.