(HAWARDEN & AKRON, IA) Cities along the Big Sioux River are preparing for flooding as water levels continue to rise. The National Weather Service has said there is a "significant threat" of flooding along the Big Sioux River basin due to the winter precipitation and above average water levels. As of Friday morning, the levels were at 16.8 feet in both Hawarden and Akron. The river is expected to crest Sunday near 19.9 feet in Hawarden and 20.2 feet in Akron. With rain in the forecast, officials are concerned how high the water may rise. "Probably an inch of rain maybe wouldn’t affect it too much, but it would affect it some. If you get any more than an inch, then you're going to add to what water is still yet to come down. Therefore forecasting 20 feet for us by Monday, that's five feet over flood stage," says Duane Aldrich, Co-op Observer with the NOAA. Officials at the National Weather Service predict Hawarden has a 95% chance of major flooding, while Akron has a 100% chance of major flooding. Any residents who may be affected are encouraged to monitor the forecast and take appropriate action.