In June 2008, a 500-year flood occurred in the Mississippi River. A levee along the Iowa River just upstream of Oakville breached. A large inundation area, ~120 square kilometers, was formed and the high water level in this flooded zone remained for several weeks. It was observed that some oily pollutants were leached at multiple locations such as A, B1, B2, C, D, E and F, and transported on the water surface by wind driven flow. CCHE3D was applied to simulate the flow field and CCHE3D_Chem was applied to simulate the oily pollutant transport. The simulated main trend of pollution stripes are generally in good agreement with the satellite imaginary.