Champaign County Water Supply
The splendid water supply of Champaign County is accounted for by the
presence of the glacial drift, which forms the striking feature of the surface
geology of Champaign County. Miss DeEtte Rolfe, who has written much and well on
this subject, explains the matter thus: "Irregularly interspersed in this drift
are long strips and beds of gravel which have their outcrops on the flanks of
the moraines. These, being surrounded by the dense clay, form pockets which
become reservoirs for the storage of water. It is on these reservoirs that the
county must rely for its water supply. The water obtained from them is of good
quality, except in the somewhat rare instances where the outcrop of the gravel
bed is so situated as to be exposed to contaminating influences, or in those
cases, which should never occur, where the wells themselves are contaminated. As
these gravel beds are distributed through the drift at different depths, the
well, even on adjoining lots, may vary in depth. The quantity of water furnished
by a well is governed by the size of the gravel bed from which it draws its
supply. The deep wells of the county generally draw from the beds deposited
between the two sheets of drift; their difference in depth depends on the
irregularities of the first drift surface."
What is termed the "Artesian Water Region of Illinois" extends a short distance
into the northeastern portion of Champaign County. It is simply a stratum of
water-bearing sandstone, overlaid by a thick stratum of tough clay, which
confines the water to the sandstone level. Wherever holes are drilled through
this overlying clay, the confined waters of the sandstone rise to the surface
through the outlets, furnishing an economical and valuable supply of water for
agricultural purposes. This stratum of sandstone is called the St. Peter's, and
is supposed to be the same stratum that supplies artesian water to the counties
of LaSalle, Grundy, Will and Cook.
Source: A Standard History of Champaign County, Illinois, by J. R. Stewart, published by The Lewis Publishing Company, Chicago And New York, 1918.