While assessing Ike's impact on the lake, Whitman noted that "The velocity and height of a tributary emptying into Lake Michigan at Portage, Indiana went off the chart. We measured a tremendous amount of sediment accumulation Near Ogden Dunes." USGS scientists use high tech, state-of-the-art equipment in the lake to measure runoff, the lake's currents, and sediment input during storms. These data are used to forecast whether a beach is unsafe for swimmers. Beaches are subject to high bacteria levels following storms….
E. coli, image from US Food and Drug Administration