Flooding: Then And Now

FORT WAYNE, Ind. (WANE)  This winter has been anything but easy.

One of the snowiest and coldest winters on record will soon come to an end, and the first signs of spring are imminent.

Temperatures in the third week of February are forecast to be the warmest they’ve been in more than eight weeks. While many welcome the warmer air, the drastic change also brings some risk.

“We’re concerned about flooding,” National Weather Service Meteorologist Evan Bentley said.

“Some people look at the snow and think, ‘boy this is really pretty,'” Director of the Maumee River Basin Commission Rodney Renkenberger said. “But others may look at it and say, ‘this may end up in my basement or end up in my house.'”

Breaking down the variables

1. To have flooding conditions, there must be excess water. Record rainfall of more than an inch fell on February 1 in Fort Wayne, most of which is still frozen under a deep snowpack. But just how much water equivalent is sitting on our surface?

The national weather service measures it by melting a core of the ice and snow.

“We take our rain gauge, slowly push it down on top of the snow, and get a good core of ice and snow,” Bentley said.

The ice and snow sample is then melted allowing meteorologists to measure how much water it is equivalent to. The results turned up some pretty impressive numbers.

“Anywhere between 1.7 and 3.5 inches of water equivalent,” Bentley said.

2. With up to 3.5 inches of water equivalent already on the surface in some areas, the forecast for appreciable rain means adding even more water to the situation, and it has to go somewhere.

Normally, some water would soak into the ground. However, the soil is currently frozen solid at an impressive depth which means most of the water will runoff into rivers, streams, and other low lying areas.

“We’ve seen frost depths from 6 to 12 inches of actual frozen soil,” Bentley said. “We’ve seen 32 degree soils three to four feet across the area, and some may even be deeper than that. This water is just going to run off the surface, because the surface is like concrete.”

“The few inches of water that’s laying here in the form of snow right now is not just here in the immediate metro area,” Renkenberger said. “When that starts to melt, that is all headed towards Fort Wayne.”

3. Another concern this year is ice jamming.

The incredibly cold winter has created thick river ice that will eventually breakup and bring the potential for it to jam near bridges and narrow passes.

“We’ve had multiple days where we’ve been subzero, so the rivers are frozen a lot deeper than what they’ve been in the past,” Renkenberger said.

“This year almost all of our rivers are completely iced over,” Bentley said. “That’s going to cause a lot of ice to go downstream and if we do get that quick warm up with all the ice going downstream and all the added water, ice jam flooding could be a significant issue.”

While the variables for flooding may all be there, it’s impossible to predict just how severe it will be or if it even happens.

But anyone living in a flood-prone area should monitor rivers and streams carefully, and have a plan of action in case flooding does come to fruition.

 

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