It's the surest sign yet that spring is knocking on the door. The flood gates are going in along Hannibal's riverfront.

Emergency Management Director John Hark announced that the city will install all five flood gates starting at 8 a.m. Friday, March 15. The standard protocol is to put in the gates when the projected crest is 20.5 feet or higher. The Mississippi River is predicted to top that height by the middle of next week.

As of 7:15 Wednesday morning, the river level at Hannibal stood at 14.77 feet. By the first full day of spring, March 21, the Mississippi is expected to reach its peak at 21.9 feet.

The levee construction was finished 26 years ago, just in time to save Hannibal's historic downtown from the devastating flood of 1993. At that time, crews even had to add a couple feet to the top of the new wall to keep the river from lapping over top as it surged to 22 feet over flood stage. Since then, the flood wall gates have gone in scores of times to protect downtown. It really proved a life-saver again in 2008 when a monster flood of 29.5 feet hit Hannibal.

The flood gates close off the Hannibal riverfront to traffic when they're installed. It's a minor inconvenience compared to rowing a boat down Main Street when Mother Nature throws us her worst.