Which is a traditional flood control method used to keep a stream's flow in its channel?

A traditional flood control method used to keep a stream's flow in its channel is the construction of levees or flood dikes. These earthen embankments are built alongside rivers and streams to prevent overflow during high water events, directing the flow back into the channel. Additionally, riverbank stabilization techniques, such as planting vegetation or using riprap, can help maintain the integrity of the banks and reduce erosion.