The swollen waters of the Mississippi River poured over a levee near St. Louis inundating vast areas of farmland and leaving authorities with no other options but issue evacuation notices.

The waters breached a levee at Winfield, Mo., and then reached a secondary levee. Residents dwelling east of Winfield were ordered to leave their homes, CNN reported.

In Burlington, Iowa, the law enforcement shot hogs that were trying to escape the high waters by seeking safety on top of a levee meant to protect farmland acreage and homes north of the city according to The Des Moines Register. The hogs were breaking plastic and sandbags threatening to destroy the levee.

Des Moines County Sheriff Mike Johnstone said there was no other option but to shoot the hogs. The law enforcement personnel couldn’t contain or round up the farm animals and getting them out of the water would have been nearly impossible.

So far, 20 levees have been overflowed by the rising water and a 280-mile stretch of the Mississippi River remained closed between Fulton, Ill., and Winfield, Mo. The levee system was in a "precarious" situation, said Iowa National Guard Lt. Col. David May.

The massive flood, the worst that the Midwest has experienced in 15 years, has inundated vast sections of the country’s farm belt and forced tens of thousands of people from their homes. This month’s floods have caused a few deaths and the damage has yet to be fully assessed by authorities.