Rock River Area Assessment

As-part of Phase II of the Critical Trends Assessment Project (CTAP), a regional assessment of the status of natural resources is planned for each model Resource Rich Area (RRA) and for RRAs where a local partnership forms and becomes recognized by the Illinois Department of Natural Resources. These assessments will also serve as a basis for implementing a standardized long-term ecological monitoring program by compiling baseline data and identifying information gaps. This Rock River Area Assessment is the first in this series. The Rock River Assessment Watersheds (RRAW) is an aggregation of 18 (EPA) 305b reporting watersheds 1 and covers approximately 999 mi2 (639,478.75 acres) or 1.8% of the land area of the state. Land cover data suggest the area is approximately 60% agriculture, 23% grassland, 8% upland forest, 6% urban, 1.5% water, 1.0% bottomland forest, and 0.5% wetland. Public land in the area totals over 9,162 acres, while the majority of land (over 98%) is held in private ownership. A summary of features follows: The Rock River originates in Horicon Marsh in Dodge County, Wisconsin, and flows in a southerly direction until the river enters Illinois south of Beloit. It flows south for approximately 45 miles, turns to the southwest at Camp Grant, then curves across the northwestern part of the state, and joins the Mississippi River at Rock Island. The river flows approximately 163 miles (262 kilometers) in Illinois and drains 5,343 mi 2 (8,602 km2). The watershed in Illinois comprises approximately 9.5% of the total area of the state and includes portions of 13 counties???Stephenson, Winnebago, Boone, McHenry, Kane, DeKalb, Ogle, Carroll, Whiteside, Lee, Bureau, Henry, and Rock Island. Five natural divisions are encompassed???Rock River Hill Country, Northeastern Morainal, Grand Prairie, Upper Mississippi River and Illinois River Bottomlands, and Middle Mississippi Border. Soil types in the basin range from thick to thin loess deposits on limestone and thin silty or loamy materials on gravelly Wisconsinan outwash, to sandy or clayey deposits on the bottomlands. The two largest urban centers in the basin are Rockford and Rock Island/Moline.unpublishednot peer reviewe