The chance of significant flooding along the St. Croix and Mississippi rivers rose to a near certainty in the latest National Weather Service flood outlook with fresh powder this week falling on an already deep snowpack in one of the state's snowiest winters on record.
The amount of flooding will depend on rain and temperature patterns in the coming weeks, wrote meteorologist Craig Schmidt, but big snow piles this late in March mean it's becoming more likely that the first warmup of spring will let loose a torrent.
"With no strong signal as yet for April, we will be at the mercy of individual weather systems to determine whether all of that snowpack ends up causing flood problems," said Schmidt, who added in the March 9 report that he plans to issue an updated spring flood outlook in two weeks because of this year's threat.
The flood outlook has set off alarms among Stillwater city staff, with Public Works Director Shawn Sanders reporting to the City Council this week that he plans to build a dike in the city's riverside green space known as Lowell Park. Sanders said he's begun ordering sandbags, jersey barriers, poly and fencing in preparation.
The Weather Service said that, for now, the St. Croix River at Stillwater has a 91 percent chance of moderate (88 feet) flooding and a 73 percent chance of major (89 feet) flooding. (The gauge in Stillwater marks the river's depth starting at 600 feet above sea level, so 89 feet would mean the river is at 689 feet above sea level.)
The worst-ever flood in Stillwater took place over Easter in 1965, when the river crested at 94.1 feet.
Families were evacuated from riverside communities like Afton, Bayport and Lakeland while teenagers and college students home on Easter Break did much of the work behind a 4-to-8 foot dike running along railroad tracks through Lowell Park. The "Teenager's Dike," as it was known, held back the river and saved downtown Stillwater.
Since then, the river has topped 90 feet just four times, in 1969, 1997 and twice in 2001.
