Integrated management of the Illinois River with an emphasis on the ecosystem

The Illinois River is the largest river basin in Illinois (USA) and it is almost fully contained within the borders of the state. The river drains an area of about 46 538 km², most of which is in agriculture. Locks and dams have been constructed to facilitate the commercial navigation on the river. Starting in early 1900, Lake Michigan water was also diverted into the Illinois River. For the last several years, state, federal, and non-governmental agencies have worked together to implement integrated management alternatives for this river. Among the many activities being implemented, two specific actions form the basis of this paper. The first relates to the largest bottomland lake along the Illinois River at Peoria, Illinois, where sedimentation has been identified as the major problem. For this area, various alternatives for the removal of sediment and beneficial use of the dredged sediment are being considered. The second activity relates to ecosystem restoration of the entire river valley. For this component, four areas are now under active consideration. These are: Watershed stabilization, main channel and backwater modifications, water level management, and flood plain restoration and protection. All these activities will be considered as components of an integrated management system for this great river of the State of Illinois.