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

Figure 2.
Drainage system and locations of
stream-gaging stations
streams between Prairie Du Pont Floodway and the
southern edge of Centreville and discharges the flow into
the floodway.
The valley bottom is drained through Indian Creek,
several small ditches north of the Cahokia Diversion
Channel, Long Lake, Cahokia Canal, Lansdowne Ditch,
Harding Ditch, the Blue Waters-Goose Lake Ditch system,
and the Dead Creek-Cahokia drainage system. In addition,
closed storm sewer systems drain much of the urban
areas within the valley bottom.
Long Lake drains much of the area to the north of
Horseshoe Lake. During periods of overflow it drains into
Horseshoe Lake through Elm Slough.
The Cahokia Canal consists of an improved and leveed
channel along the old course of Cahokia Creek. The canal
begins in sec 14, T4N, R9W, flows southeasterly to sec 31,
T4N, R8W, and then southwesterly around the southern
end of Horseshoe Lake, through National City and the
northwestern corner of East St. Louis to the Mississippi
River. Discharge to the Mississippi River is by gravity
flow during periods when the stage of the Mississippi
River is low; when the river is at flood stage, water is
pumped from Cahokia Canal to the river at the North
Pumping Station. Runoff in excess of the storage capacity
of Cahokia Canal or of the pumping station is stored
temporarily in Indian and Horseshoe Lakes until it can
be discharged into the river. The principal tributaries to
the canal are Long Lake (by way of Horseshoe Lake),
Lansdowne Ditch, Canteen Creek, and several small
streams to the east.
Harding Ditch begins at Caseyville and flows southwesterly
to Park Lake in Grand Marais State Park, which
acts as a regulating reservoir, thence to Prairie Du Pont
Floodway. Discharge to the Mississippi River is either
by gravity flow or pumps at the South Pumping Station.
The Dead Creek-Cahokia drainage system drains most
of the Monsanto and Cahokia areas. The outlet of the system
is to the Prairie Du Pont Floodway at the Cahokia
Pumping Station.
The Blue Waters-Goose Lake Ditch system drains the
area east of Cahokia, southwest of Centreville, and northwest
of Harding Ditch and Prairie Du Pont Floodway.
Goose Lake Ditch discharges into Blue Waters Ditch near
Harding Ditch. Blue Waters Ditch can discharge into
Prairie Du Pont Floodway or Harding Ditch when the
floodway is at low stage; when the stage of the floodway
is high, runoff is stored temporarily in Blue Waters Ditch
and adjacent low areas.
Numerous lakes were formed in the flood plain by
the meandering of the Mississippi River. Many of the
lakes have been drained and the original lake bottoms are
now being cultivated. Table 1 gives data on the more
important lakes now in existence.
Table I.
Lake
McDonough
Long
Horseshoe
Canteen
Park
Spring
Areas and Water-Surface Elevations of Lakes*
Approximate
surface area
when full
(acres)
75
85
2500
105
990
10
*From Illinois Division of Waterways (1950)
Approximate water
surface elevation
when full
(ft above msl)
404
415
402
403
405.5
410
The average gradient of the Mississippi River from
Alton to Dupo is about 6 inches per mile. The average
gradients of Wood River, Cahokia Diversion Channel,
Cahokia Canal, and Prairie Du Pont Floodway are given
in table 2. The gradients of streams draining the uplands
east of the bluff are much greater, ranging from about
6 feet per mile for Cahokia Creek to about 30 feet per
mile for Schoenberger Creek.
The Chain of Rocks Canal was constructed to bypass
the reach of the Mississippi River known as Chain of
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