A state project to “restore” Clear Lake could cost millions. Don Bonneau of the Iowa Department of Natural Resources says it’s an investment in one of the state’s assets.In late September, a preliminary report will be issued on what could be done to improve the water quality in Clear Lake. There are some preliminary conclusions, like “get rid of some of the fish.” Carp and bullhead in a shallow area known as “Little Clear Lake” are stirring up the bottom — sending sediment into the larger lake.Bonneau says Iowa’s lakes are rare and valuable because about 95 percent of Iowa is tilled for farming.The state has “restored” 10 Iowa lakes in the past two decades by improving wetlands, conserving area soils and dredging the lakes.