The Indian Lake Watershed, which is about 57,000 acres, is located in west-central Ohio and covers portions of Logan, Hardin and Auglaize Counties.  Its 5000 acre Indian Lake is now used as a recreational lake, but started as a canal feeder lake.  The Indian Lake Watershed is very important to the Miami Valley as it is the headwaters of the Great Miami River and the Miami Valley buried valley aquifer, a sole source aquifer for 97% of the Miami Valley or about 1 million people.  Sediment loading from the surrounding watershed had decreased the lakes capacity by 35%.  Several initiatives were taken by the Ohio EPA, ODNR, and USDA-NRCS to reduce the effects of sediment loading.  These initiatives included No-Till farming and a water quality improvement program.  With all of these programs there is still a nutrient loading problem within Indian Lake.  The aim of this study is determine how different land uses affect the water quality within a given watershed.  A formula can then be developed to determine an approximate concentration of a chemical constituent based on the watershed of the point where the sample was collected.  ArcHydro is used to delineate the watershed of a given point and then the land use of that watershed is found from LANDSAT imageries or existing ODNR data.  The first part of this study will only consider major ion chemistry, nutrients, as well as silica.  This data and the formulas generated can also be applied to predict how a change in land use will affect the water quality.