PROJECT ALERT NOTICE (MN) Flooding in Minnesota, day 9

Date: Tue, 18 Apr 2023 16:19:23 EDT

Summary: Flooding continues across Minnesota due to melting of near record snowpack.

Many tributaries have peaked while mainstem rivers continue to rise including the Red River of the North, Rainy, St Croix, Minnesota, Mississippi Rivers. These mainstem rivers are forecast to begin peaking in the next few days and continue into the following days or weeks.

Currently 37 are above NWS flood stage; with 16 above moderate flood stage and 2 above major flood stage. The NWS forecasts 9 gages will peak above major flood stage in the current forecast period.

All gages are currently operating and telemetering. Today 12 streamgaging staff from Minnesota are in the field across the state. Activities include making discharge measurements and repairing gages. Office staff have supported field efforts, communicated with other agencies including the NWS & USACE via NWSChat, responded to emails and phone calls. Since flooding began in earnest April 10, approximately 70 discharge measurements have been made, 2 stage-discharge ratings have been extended, 1 site has been flagged for an indirect, a few sites have lost orifice lines, and many crest-stage pipes have been lost or damaged to ice out. Most peaks to date have estimated Annual Exceedance Probabilities of 0.1 - 0.25. Station 05291000 Whetstone River at Big Stone City, SD peak had an AEP <0.01.

News media have posted USGS time lapse videos ice going out and rivers rising, including
Minneapolis Star Tribune https://video.startribune.com/watch-rivers-rise-rapidly-across-minnesota/600267080/
and Minnesota Public Radio https://www.mprnews.org/story/2023/04/12/river-levels-flooding-forecasts-minnesota-map

Up to an inch of rain is forecast for the parts of eastern Minnesota that are still experiencing high water from snowmelt.

A news release is not planned.