Author: Mary Knapp

We know about general flooding and flash flooding, but what other factors cause flooding? Two forms associated with winter precipitation are rapid snow melt and ice dams, both of which caused problems this spring. Both are products of the accumulation of winter precipitation but their format is quite different. With ice dams, chunks of ice from the breaking ice cap on rivers and lakes clog the drainage path, causing flooding upstream of the dam. With snow melt, the rapid conversion of the winter’s accumulation of snow to liquid form creates rising water levels and flooding downstream of source. Believe it or not, snow melt in the Rockies has produced flooding in western Kansas along the Arkansas River. Due to dry weather and dam building, that hasn’t been a problem since at least the 1940's.

Figure 1. Ice Dam flooding (public domain)

Mary Knapp, Weather Data Library