A rapid increase in temperatures is the culprit behind standing water and flood watches in Washington County as the ground still is too frozen to absorb snow that is rapidly melting.
As temperatures steadily climbed this week, reaching as high as 58 on Wednesday, snow and ice quickly melted but had nowhere to go. Washington County Emergency Management Director Marissa Reisen said that as of March 7, the English River at Kalona was at a greater than 50 percent chance of minor flooding and that percentage has only gone up as the snow continues to melt. She said minor flooding will mainly affect agricultural land, stating the frost depth, how deep the ground is frozen, is between 6 and 12 inches.
“Minor flooding is pretty limited to agricultural flooding, so your fields, more country, rural roads as opposed to major highways,” she said. “We have a higher risk of minor flooding but we still have a low risk of moderate flooding.”
The amount of rainfall will determine the type of flooding Washington County may experience.
“If we have a nice slow rise in temperatures, the snow will slowly melt and the ground will slowly thaw and it will all slowly move down as it should, whereas if we get a pretty rapid rise in temperature, all the snow is going to melt,” she explained, saying that because the ground still is frozen the water will not absorb.
According to the National Weather Service, a flood warning is in effect until the morning of Sunday, March 17, for The English River at Kalona. The flood stage is 14 feet and the river is expected to rise to 19 feet by Friday morning, then fall back below the flood stage Sunday morning.
Reisen said the unusual amount of snow is the reason precipitation levels are unusually high, stating in the fall of 2018, Washington County saw 200-300 percent of the rainfall normally seen in a year while from December 2018 to February 2019 the area saw 175 percent of normal precipitation.
Reisen said the biggest risk for most citizens will be in travel. She said because the water has nowhere to go, there are large bodies of standing water on the roadways and warns people to use caution when driving.
“Six inches of water with a current can knock a person down and less than 2 feet of moving water can move a vehicle,” she said. “We definitely don’t want people to drive in it.”
She said if anyone sees standing water with no signage, to call the engineer’s office or dispatch to notify them of the situation so proper signage can be placed.