By MIKE NESTER
While the National Weather Service has decreased the flood risk over the past two weeks, the Mississippi River is still expected to come out of its banks in Savanna.
The latest forecast released March 23 calls for a 50 to 75 percent chance that the river will rise to over 19 feet between May 1 and May 8, and a 90 percent chance that it will reach 16 feet during the same time period in Pool 13. The new forecast dropped the river level about six inches.
The updated report has a 90 percent chance of the Mississippi reaching 16 feet in Pool 13 on April 24 and a 75 to 95 percent chance of reaching 16 feet on April 17. The new report has the river dropping fast after the crest, a 90 percent chance of a level of 10 feet from May 15-22.
Savanna Fire Chief Scott Wolfe said the news is good, but the city still remains on call for a possible flood.
"The latest flood numbers are slightly better than the last update on March 6," Wolfe told the Times-Journal. "The update also moved the potential crest out to the end of April which will give us a few more weeks to keep an eye on the forecast before making any major decisions."
Floodwater starts entering basements in Savanna between 16 and 17 feet, and at 18 feet floods the alley west of Main Street. The lower section of Marquette Park and Broderick Drive also experience flooding at 17 feet.
According to the National Weather Service, in 2019 the Mississippi crested about 20 feet twice — 21.77 on April 30 and 20.91 on April 8. The river has crested above 20 feet 11 times since 1951, with a record crest of 24.75 in 1965 and 23.31 feet in 2001.
An above normal snow pack for Minnesota and northern Wisconsin, along with saturated solid conditions in the Upper Mississippi River basin, are the main concerns for a possible flood this spring.
Additional precipitation and the rate of snowmelt up north will be the main factors determining the severity of the flooding.
The 10-day forecast for Minneapolis calls for temperatures in the 40s during the day and below freezing at night, which will cause a slow snow melt and help decrease a possible spring flood.
The river level at Lock and Dam 13 on Monday, March 27, was 7.8 feet, with a projected level of 8.4 feet on April 1.