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The United States Department of Agriculture Conservation Effects Assessment Project (CEAP) was initiated to quantify the benefits of conservation practices on a national scale. This paper will address water quality benefits from conservation practices implemented at the field level using measured water quality data from the Goodwater Creek watershed in the claypan area of north central Missouri. Eleven years of hydrologic and climatic data from 1993-2003 were analyzed to identify trends and possible effects of best management practices (BMPs), including grassed waterways and terraces, on atrazine stream loadings and concentrations. During this period, area implemented with BMPs increased by 12%. Trends were identified using regression models. Over the time period, atrazine levels have been affected by drier, warmer springs, and increased no-till practices causing earlier application of atrazine, increased levels of atrazine in April, and decreased levels as the season progressed. Atrazine loading was reduced significantly over the entire eleven year time period (P<0.10). Over the months of April, May, and June significant decreases were detected for atrazine concentrations (P<0.05). Data at this time does not attribute the reduction of atrazine to BMPs. SWAT modeling is planned to determine if the SWAT model is sensitive enough to produce data that follow the statistical trends found in this study and to determine what level of BMP implementation would be required to see greater decreases in atrazine.