What is an ice jam?

Pieces of floating ice carried with a stream's current can accumulate at any obstruction to the stream flow. These ice jams can develop near river bends, mouths of tributaries, points where the river slope decreases, downstream of dams and upstream of bridges or obstructions. The water held back can cause flooding upstream, and if the obstruction suddenly breaks, flash flooding can then occur downstream as well.

Show All Answers

1. What is an ice jam?
2. When is an ice jam likely to occur?
3. What effect does snow have on flooding potential?
4. How fast do the snow and ice melt?
5. What happens when rain falls on top of snow?
6. What is the Spring Snowmelt Flood Potential Outlook?