The Soil and Water Assessment Tool (SWAT) model has been found to be useful in predicting monthly and yearly flow and water quality information for a watershed. Integrated with ArcView Geographic Information Systems (GIS), this model allows for spatial visualization of the water budget in a way that spreadsheet models do not offer. This can prove a vital tool for watershed managers and regulators when determining the allocation of water and pollutants a basin can handle and be the most environmentally productive. This purpose of this research was to use the SWAT model to see the effects of varying the input soil data layer and testing how it affects the model's ability to predict streamflow. This was accomplished by comparing the output of the model with the farthest downstream USGS gauge. Landuse data photo-interpreted from 2004 1-meter color infrared digital aerial photographs were obtained from the Southwest Florida Water Management District (SWFWMD). Soil data was obtained at 30m resolution from Soil Survey Geographic Database (SSURGO) and at 250m resolution from the State Soil Survey Database (STATSGO). Actual local USGS/SWFWMD rainfall was used for meteorological input in the comparison. The study area was the Charlie Creek drainage basin located in central Florida in the Peace River basin. This drainage basin is roughly 855 km2 in size and predominantly rural and agricultural landuse dominate.