ESFBIS
The Missouri River now has ice pans floating downstream through the
Bismarck and Mandan reach of the river. Thus far, the river
continues to flow unimpeded with the ice most likely being carried
down into Lake Oahe. While this often initiates the accumulation of
immobile ice, and eventually higher water through the Bismarck and
Mandan area, warmer weather later this week is likely to delay this
annual ritual until sometime later in December.
Nonetheless, residents and others interested in water levels through
the metro area should remain vigilant for the eventuality of an ice
covered Missouri River and higher water.
Since 2010, once the river ice collects in the Bismarck and Mandan
area, the rise in the Missouri River ranges between 4.9 and 6.9
feet, with an average rise of just over 6.0 feet. The Bismarck gage
for the Missouri River is currently right around 4.7 feet. This
suggests if the river were to become ice filled or covered, the
Bismarck gage would rise to a maximum stage between 9.6 and 11.6
feet. Minor Flood Stage, where problematic high water begins, is
defined as a stage of 14.5 feet as measured at the Bismarck gage.
Once the river starts to collect ice, the river can rise very fast
and reach its winter maximum in less than 24 hours.
Again, warmer weather towards the end of the week is likely to
minimize the chances of higher water this week, but with the winter
season in full swing, the icing in of the river is likely to occur
within the next few weeks.
As a reminder, people should avoid walking on the Missouri River as
ice accumulates. The first ice on the Missouri River tends to be a
collection of small, unstable ice pans that can give way with no
notice. Also, anyone who notices damaging high water should report
their observations to local emergency management.