With the Mississippi River forecast to crest at 21.7 feet, John Hark, Hannibal's emergency management director, has announced all five of the city's flood gates will be installed Thursday afternoon beginning at 1 p.m.

The unpredictability of the Mississippi River is a point of emphasis again this week. Less then 72 hours after it appeared the river was in full retreat in Hannibal, Street Department personnel were busy installing all five of the community’s flood gates Thursday afternoon.

The setting of gates was prompted by a revised flood crest forecast of over 21 feet.

“I talked to NOAA national weather this morning and they gave me a revised crest of the best they could without all the figures of 21.7 on June 29,” said John Hark, Hannibal’s emergency management director, on Thursday morning.

By Thursday afternoon the projected crest had been bumped up by almost a foot to 22.6 feet by the National Weather Service’s Advanced Hydrologic Prediction Service. Moderate flooding in Hannibal begins at 22 feet. Major flooding starts at 24 feet.

After falling to 18.3 feet on Wednesday morning, the river had rebounded to 19.71 feet by Thursday afternoon. It is expected to continue its rapid rise until cresting early Saturday afternoon, June 27.

“We’re going to see some rapid rise in the river because I heard through some of my sources that up around Monticello, Mo., some of those areas in Lewis County got 5 to 7 inches of rain last night and this morning,” said Hark. “If in fact that is true some of my tributaries out in the county are going to jump even more and that’s a rapid runoff into the Mississippi north of us, which could bring us up a little more and a little faster.”

Flooding rains fell across Northeast Missouri Wednesday night. Edina led the way with 5.08 inches. Following that Lewis County community came Steffenville, 4.02; Hannibal, 3.28; Saverton, 2.60; Canton, 2.36; Shelbina, 1.50; and Clarence Cannon Dam, 1.40. Through 6 a.m., Quincy, Ill., had received 2.36 inches of rain.

The projected crest of more than 22 feet requires the city set all its flood gates. When a crest prediction of 20.5 feet or more is forecast the gates on Hill and Center streets must be set. The remaining three gates - two on Broadway and one on South Main - are placed when the crest is forecast at 21.5 or more.

If the flood gates are still in on July 4, it would mark the third consecutive National Tom Sawyer Days that the riverfront has been cut off.

“I regret it (setting gates) here at the Fourth of July,” said Hark. “If it crests on the 29th, and somebody down south pulls the plug and lets it drain out rapidly, I’ll take them out as quick as I can. We’re going to protect the city so the events can go on.”

The river’s ups and downs are of particular interest to the Hannibal Cavemen since Clemens Field is not protected by the downtown flood wall.

“The latest river forecast I’ve heard is 21.7, which would bring water right to the edges of the plaza. We have a game Tuesday and if the river crests at 21.7 Monday, we should be able to play, but we’ll have to change the way we get people in the park,” said Deron Johnson, director of marketing and sales for the Cavemen. “Tuesday is a long way away, so we will obviously monitor the weather. From what I understand we’re supposed to get a lot more rain tonight (Thursday). We’ll take it one hour at a time.”