The IDEM Office of Water Management believes that the most consistent way to evaluate overall use support is best represented by the stream miles supporting aquatic life use. Representative samples for fish community assessment were used to determine overall aquatic life use support as part of the rotating basin approach. Sample results from the White River, East Fork and Whitewater River basins in 1997; and from the Upper Wabash River basin in 1998 were used to obtain an unbiased estimate of aquatic life use support. A stratified random sampling design was used to computer generate sampling sites, which provided a representative sample set for each basin. Fish community index of biotic integrity (IBI) was determined for each sampling location, and the results of each year's sample data set were analyzed to estimate the percentage of stream miles supporting aquatic life use for each basin. In this way, a small number of representative samples were used to estimate aquatic life use support for a large geographic area.