A number of reports have been received indicating that people who live along the Rock River in Moline are observing greater impacts than they have seen before, relative to what the river gage on the Rock River in Moline is reporting.
The river gage itself is operating correctly, and it has been checked in the past couple days. This has been verified with the Corps of Engineers in Rock Island who owns and operates the gage. The USGS, who owns and operates other gages in the area also checked and verified the accuracy of the gage.
Every flood and it's impacts are unique. For this particular flood, the ground was completely saturated in some places, and frozen in others. Both conditions caused the rainfall to go directly to local runoff. This would cause larger differences in water levels closer to the river gage as water flows overland into the river.
The greater impacts may also be caused by changes in the riverbed in the past few years. Siltation and scouring differences can cause these differences in impact, causing more flooding in one area, and less flooding in another. There has been some significant flooding in the last year, including ice jams just this past winter, and record ice jam flooding last winter. Also, construction in the area will have made other changes to the riverbed. The flooding and construction are just two of many possible causes for the changes to the riverbed.
We will be revisiting our flood impact information along the Rock River in Moline.
Here are links to more information about the river gage on the Rock River at Moline.