Summary (continued)

Many of these problems result in increased sedimentation. Each year approximately 14 million tons of soil is washed from the Illinois River basin. Of these, 8 million tons are deposited into the Illinois River and its backwater lakes. The remainder passes on to the Mississippi River and the Gulf of Mexico (Cruikshank 1998). As a result of this sedimentation, most backwater lakes have lost more than 70% of their storage capacity and in some cases 100%.

The significant events that occur in the Illinois River basin also lead to major changes to fish populations. In Illinois, 7% of the fish species disappear after 1900 and many more are in decline (USGS). Introduced species, such as the common carp and goldfish become the dominant species until around 1993 when native species begin to recover in numbers; however, other invasive species have been introduced and now compete with native species. Two examples are the Asian carp and bighead carp.

Urban problems exist as well. Land conversion for urban development grows by almost 50% in a recent 20-year period, while the population increases by only 5%. This land conversion results in serious problems for the Illinois and other rivers, including increased runoff and loss of habitat.

The status of the Illinois River appears to be very bleak, but is there good news? Yes there is:

• As a result of the “T” by 2000 program over 75% of Illinois farmland is meeting the “T” or tolerable rate of soil loss;
• The rate of soil loss within the Illinois River basin is below the state average (Beal);
• More than 4.2 million acres of cropland are in conservation tillage systems;
• Forest acreage is also increasing as the state and federal governments and private sporting clubs work to protect the Illinois River floodplain; and
• Communities are required to have a form of sewage treatment

Other good news comes from several state agency programs that are attempting to address the various problems in the Illinois River basin. Three examples follow.