The Flood Warning continues for the following rivers in Missouri. Illinois. Mississippi River at Chester. Mississippi River at Grafton. Mississippi River at Mel Price LD. Mississippi River near Herculaneum. Mississippi River at St. Louis. Mississippi River at Alton. River forecasts are based on observed precipitation and forecast precipitation for the next 24 hours. * WHAT. Minor flooding is forecast. * WHERE. Mississippi River near Herculaneum. * WHEN. From late tonight to late Sunday morning. * IMPACTS. At 29.4 feet, Near this height, the Flux Building of the Doe Run Company begins flooding. * ADDITIONAL DETAILS. - At 9:00 PM CDT Tuesday the stage was 24.7 feet and rising. - Forecast. The river is expected to rise above flood stage just after midnight tonight to a crest of 29.3 feet early Thursday afternoon. It will then fall below flood stage early Saturday morning. - Flood stage is 26.0 feet.