. The changing Illinois environment : critical trends : technical report of the Critical Trends Assessment Project. Man; Pollution; Environmental protection; Ecology; Environmental impact analysis. GROUND-WATER MINING. Impact of DuPage & Lake County deliveries in 1992 I Projected demand with no 1992 delivery Other expected changes in year 2000 1955 1960 1965 1970 1975 1980 1985 YEAR 1990 1995 2000 2005 2010 Figure 1. Northeastern Illinois pumpage and impact of Lake Michigan water deliveries (actual and forecast) Chicago region. It clearly indicates that major pumpage from this area increas
. The changing Illinois environment : critical trends : technical report of the Critical Trends Assessment Project. Man; Pollution; Environmental protection; Ecology; Environmental impact analysis. GROUND-WATER MINING. Impact of DuPage & Lake County deliveries in 1992 I Projected demand with no 1992 delivery Other expected changes in year 2000 1955 1960 1965 1970 1975 1980 1985 YEAR 1990 1995 2000 2005 2010 Figure 1. Northeastern Illinois pumpage and impact of Lake Michigan water deliveries (actual and forecast) Chicago region. It clearly indicates that major pumpage from this area increased for several decades until the 1980s and 1990s. Water-Level Trends: Lesson in Responsiveness to Lake Michigan Substitutions Each year since 1959, the heavy demand on the most significant aquifer in northeastern Illinois has exceeded the resource's ability to recharge. Consequently, pump- age has had an ever-increasing effect on ground-water levels. By 1960, the drawdowns at the pumping centers associated with each community had overlapped enough to produce a regional cone of depression. Ground-water levels declined by more than 1,000 feet at some locations. In many parts of the Chicago region, the ground-water level had fallen to elevations below sea level. With the deliveries of Lake Michigan water to commu- nities in Cook County in the 1980s, however, the trend began to reverse. Sasman et al. (1986) reported that water levels were rising in some areas that previously had relied on the deep Cambrian-Ordovician aquifer system. Figure 1 shows the impact of this trend on pumpage. More conversions to Lake Michigan water in the late 1980s at Des Plaines, Arlington Heights, and Mt. Prospect resulted in even more areas of rising water levels according to Visocky's 1991 observations (Visocky, 1993). This trend is expected to continue as more Lake Michigan water is delivered to DuPage County and parts of Lake County. The computer simulation by Burch (1991) predicts that this trend ma
Size: 1835px × 1362px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjecte, booksubjectecology, booksubjectman
