Ground-water development in East St. Louis area, Illinois. Urbana, IL ...

Figure 62. Areas of diversion in November 1961 Figure 63. Areas of diversion in December 1956
Areas of diversion of pumping centers in November
1961 are shown in figure 62. The boundaries of areas of
diversion delimit areas within which the general movement
of ground water is toward production wells. The
area (59 sq mi) north and east of Granite City and south
of Wood River and a larger area south of Prairie Du
Pont Creek through Dupo and south along the Mississippi
River were outside areas of diversion. As shown in
figure 63, the area north of Granite City outside areas
of diversion was much smaller, covering about 30 sq
mi, in December 1956. Pumpage in the Granite City area
was 30.1 mgd in 1956 and 8.8 mgd in 1961.
Most of the coefficient of transmissibility of the valley
fill deposits can be attributed to the coarse alluvial
and valley-train sand and gravel encountered in the
lower part of the valley fill. The thickness of the medium
sand and coarser alluvial and valley-train deposits was
determined from logs of wells and is shown in figure 64.
The thickness of the coarse alluvial and valley-train
sand and gravel exceeds 60 feet in an area south of Alton
along the Mississippi River, in an area near Wood
River, in places along the Chain of Rocks Canal, in a
strip 1/2 mile wide and about 3 miles long through National
City, in the Monsanto and Dupo areas, and in a
strip about 1 mile wide and 4 miles long near Fairmont
City. Thicknesses average 40 feet over a large part of the
East St. Louis area. The coarser deposits diminish in
thickness near the bluff, west of the Chain of Rocks
Canal, and in places along the Mississippi River.
The available drawdown to the top of the medium
sand and coarser deposits was estimated by comparing
elevations of the top of the medium sand and coarser deposits
with elevations of the piezometric surface map for
June 1962 (figure 54). As shown in figure 64, available
drawdown is greatest in undeveloped areas, exceeding
80 feet in the vicinity of Long Lake and in an area south
of Horseshoe Lake. In a large part of the area available
drawdown exceeds 60 feet. Average available drawdown
within pumping centers was estimated to be 40 feet
in the Alton area, 20 feet in the Wood River area, 35 feet
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