Storm Lake is a recreationally important site in northwestern Iowa. The population of the surrounding area that constitutes the Storm Lake watershed has increased only slightly since the early 1900s. Nearly 60 percent of the watershed area is currently in agriculture, primarily corn and soybean production. The naturally shallow lake has been dredged several times to maintain its recreational qualities. Local citizens are nevertheless concerned about how inputs of sediment, chemical nutrients, and other pollutants may be affecting the lake