What is a River Levy?

Identification

• Earthen levees -- also known as flood banks, stop banks, artificial embankments or dikes -- follow riverways. Dirt is piled on cleared riverbanks to create broad-based levees that taper to a flattened top. Sandbags can be stacked atop the levees as temporary embankments during heavy rain and river cresting.

Function

• Manmade levees avert flooding of nearby cities and farming communities. They also restrict rivers within their banks, creating higher rivers that drain water toward the sea much more quickly.

Considerations

• Silt deposits raise riverbeds, making rivers shallower; restricting rivers with levees increases the flowing waters' speed, increasing the likelihood of levee breaks during heavy rains or when rivers crest. These effects indicate the need for ongoing flood prevention planning and continued levee maintenance. Planning and maintenance may include wider river channels, a system of multiple levees and plans for rescues, road closures and cleanup following levee breaks.