The Hannibal Street Department installed the city’s five flood gates in approximately two hours Monday afternoon.

The city of Hannibal installed all five of its flood gates Monday as the National Weather Service called for a major flood.

John Hark, Hannibal's emergency management director, said over the weekend all the gates would be installed. On Monday, the NWS revised its projected crest for Hannibal to 24.7 feet. Major flooding begins in Hannibal at 24 feet. The river was expected to crest Saturday morning.

Prior to its late-morning update, the NWS had been forecasting a crest of 21.9 feet.

If 24.7 feet is seen, it would rank as Hannibal's ninth highest flooding in recorded history.

The last time the river approached this level was on June 28, 2015, when it crested at 23.67 feet.

Hannibal's all-time record flood crest was 31.8 feet on July 15, 1993.

As of Monday afternoon the river was approaching 20.5 feet. Moderate flooding begins in Hannibal at 22 feet.

Last month, Hannibal saw a flood crest of just over 20.5 feet, which prompted the setting of flood gates at Hill and Center streets. Those two gates were removed after 12 days on Sept. 20.

All five of the city's gates must be set when the river is forecast to reach 21.5 feet or more.

danny.henley@courierpost.com .