the actual damage to the historic wetland resource is greater than
these figures reflect. Only 917,765 acres (approximately three-fourths)
of the currently existing wetlands can be considered natural wetlands.
The other 336,126 acres (one-fourth) of the wetlands have been modified
or created by dikes, impoundments, or excavation activities. These
additional figures reveal Illinois has actually lost over 90 percent
of its original presettlement wetlands. Figure
3-1 illustrates how natural and artificial wetlands are geographically
distributed throughout the state (Suloway and Hubbell 1994).
Southern Illinois currently contains 49 percent (approximately 612,300
acres) of the state's total wetland resources. Twenty-nine percent
(approximately 357,900 acres) are located in central Illinois. Northern
Illinois, once home to a vast amount of the state's wetland acreage,
now only contains the remaining 22 percent (approximately 283,500
acres) (Suloway and Hubbell 1994).
Currently, over half (53) of the counties in Illinois have less than
2 percent of their land area occupied by natural wetlands. Over 57
percent (approximately 519,300 acres) of the State's remaining natural
wetlands are located in southern Illinois. Most of these are located
in the basins of the Big Muddy River, the lower and middle portions
of the Kaskaskia River, the Little Wabash River, and along the Mississippi
River between Reily Lake and Cairo. Northern Illinois contains about
22 percent (approximately 201,400 acres) of the State's natural wetlands.
The remaining 21 percent (approximately 196,900 acres) are located
in central Illinois (Suloway and Hubbell 1994).
Over 48 percent (approximately 161,000 acres) of the State's artificial
wetlands are located in central Illinois. These are mainly concentrated
within the Illinois River valley. Southern Illinois contains 27 percent
(approximately 92,500 acres) of the State's artificially created wetland
acres. Northern Illinois contains the remaining 25 percent (approximately
82,000 acres) (Suloway and Hubbell 1994).
Of the three wetland systems which occur in Illinois, Palustrine wetlands
are the most abundant, occupying approximately 1.17 million acres
(just under 93.7 percent of the total wetland acres). Figure
3-4 illustrates the relative abundance of all three wetland systems
in Illinois. About 50 percent of these acres are found in southern
Illinois where large cypress swamps can still be found along the Cache
River. Only 27 percent of the Palustrine wetlands are located in central
Illinois. The remaining 23 percent are located in northern Illinois.
Figure 3-3 depicts the geographical distribution
of each of the wetland systems in Illinois (Suloway and Hubbell
Lacustrine wetlands are the next most abundant in the state, occupying
just over 50,000 acres (around 4 percent of the overall wetland acreage).
Due in part to the large number of impoundments along the Illinois
River, most of these wetlands (59 percent) are located in central
Illinois. Southern Illinois contains 31 percent of the Lacustrine
wetlands. Northern Illinois is home to the remaining 17 percent (Suloway
and Hubbell 1994).
Riverine wetlands are the rarest systems in Illinois. This is due
in part to the level at which the rivers and streams of the state
have been altered for other human uses. Riverine wetlands occupy just
over 29,000 acres (approximately 2.3 percent) of the total wetland
acres. Most of these, around 43 percent (approximately 12,700 acres),
are located in central Illinois. Thirty-four percent (approximately
9,800 acres) of the Riverine wetlands are located in southern Illinois.
Only 23 percent (approximately 6,800 acres) are found in northern
Illinois (Suloway and Hubbell 1994).
History | Nationwide
Status | Trends | Conclusion