What’s the difference between “flood stage” of a river and “cresting”

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Dear Tom,

What’s the difference between “flood stage” of a river and “cresting” ?

Bob Gibby

Dear Bob,

Bill Morris, recently retired National Weather Service hydrologist for the Chicago area, tells us that flood stage is the point or elevation at which the overflow of the natural banks of a stream begins to present a potential flood-damage hazard to the area. Flood stage does not solely depend upon the level where water begins to overflow the banks. In some instances, flood stage can be several feet above bank full because no significant property damage occurs until the water reaches a higher level. Input from local officials and emergency managers is used to set the flood stage thresholds. Cresting is when the river level reaches its highest point as a wave of water passes a particular point.