Every year, the National Weather Service examines conditions such as the snow pack and how much water it contains, soil moisture and much of the ground is frozen and determines the chances of major flooding.
What did it find?
“It’s pretty much a sure bet we’ll get flooding in the next three months," said Jessica Brooks, hydrologist with the National Weather Service, Davenport. “In the Quad-Cities on the Mississippi River, in a normal year we have about a 57 percent chance to reach flood stage. This year, we have greater than 95 percent chance of the Mississippi reaching flood stage in the Quad-Cities."
Brooks, who focuses on rivers, tributaries, flash floods “and pretty much anything that deals with water," said NWS comes up with statistical probabilities of the river reaching certain levels in the next three months. Across the whole Quad-City area, there is an above-average chance of flooding.
Saturated conditions in the soil means there isn’t much space for the ground to absorb rain. Basins are saturated, so “Any rain that falls Is going to all be into the rivers. That gives a much higher probability for the rivers to be able to rise," she said.
“We’re looking at a pretty cold pattern here for the next months,” she said.
Eventual levels will be highly dependent on how the snow melts.
“A slow melt might mean a peak at low and moderate flood stages,” she said. “A fast melt could be accompanied by heavy springtime rains.”
A flood watch for the Quad-Cities is already in effect through early next week.
The Wapsipinicon River is expected to reach flood stage Monday in DeWitt, and the Rock River at Joslin will reach flood level Tuesday, Brooks said.
• For the Mississippi, flood stage is 15 feet at the Rock Island gauge, which was 7.3 feet on Friday.
• The Rock River flood stage is 12 feet at both Moline and Joslin. The Rock measured 11.7 feet at Joslin and 10.8 feet in Moline on Friday.
• The flood stage on the Wapsi, which measured 7.8 feet Friday, is 11 feet at DeWitt.
“This weekend, with the rain coming, it’s possible we could get to flood stage at the lower end of the Rock,” Brooks said.
Public works crews are ready
In the meantime, Quad-City public-works crews are prepared to deal with whatever water comes their way.
“There’s not a lot of prep stuff that we need to do,” said Rodd Schick, municipal services general manager, Moline.
Moline is fortunate when it comes to flooding, he said. “There are gate valves in the storm sewers that get closed” during floods, he said, in the downtown area were the ground elevation is relatively low.
“As it rains and snow and ice melt, it’s going into the storm system instead of flowing into the river via gravity.”
“We used to have to do sandbagging,” said Schick, who has been with the city 18 years. “That’s no longer necessary because of the construction and work done there at the Interstate 74 area.
“it’s been elevated. That has taken care of that issue.”
Now when there’s a flood, “We pretty much need to do a little bit of sandbagging near Western Illinois University campus on 34th Street,” he said. “We’re talking near-record type flooding events when we have to do that.”
The city now has permanent pumps in some spots, along with portable pumps that are used as needed.
“When it gets over flood stage, we get some things on old River Drive, near 55th Street, old River Drive on Ben Butterworth, and low spots in front of the Western Illinois University campus in Moline,” he said. “That’s low there – there’s actually a little drainage way there.”
Nicole Gleason, public works director, Davenport, said flooding in Davenport usually starts in the Wapello-Concord and Credit Island areas. Crews that respond to floods are primarily about 60 street and sewer workers, she said.
“We don’t get super-excited when (the Mississippi) is below 16 feet,” she said. When the river rises to 17 or 18 feet, crews begin to set up temporary flood barriers, she said.
Fortunately, the forecast usually provides three days of advance warning. “We can usually have temporary flood barriers set up in two days or even a day and a half,” she said.
“It really is about being prepared,” Schick said.