Water-resources investigations in Wisconsin

The statewide average precipitation of 31.79 inches for the 1997 water year was the same as the normal annual precipitation of 31.79 inches for water years 1961-90. Average precipitation values ranged from 78 percent of normal at Mauston 1 SE WWTP weather station in central Wisconsin to 139 percent of normal at Menomonie WWTP weather station in west central Wisconsin (Matt Menne, Acting State Climatologist, UW-Extension, Geological and Natural History Survey, written commun., 1998).

Runoff differed for rivers throughout the State and ranged from 70 percent in southeast Wisconsin to 169 percent in west central and northwest Wisconsin. Runoff was lowest (70 percent of the average annual runoff from 1964-97) for the Root River Canal near Franklin and highest (169 percent of the average annual runoff from 1902-70, 1987-97) for the Apple River near Somerset. Departures of runoff in the 1997 water year as a percent of long-term average runoff in the State are shown in Figure 4.