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60 Ways Farmers Can Protect  Surface Water
50 ways 57 ways 60 ways

25. Avoid Channelization of Streams and Creeks

Channelized stream

From the 1920s through the 60s, it wasn't unusual for landowners to channelize, or straighten, the streams meandering through their land.

By straightening the kinks in a stream, landowners increased the speed of water moving downstream and the rate at which water drained away from their land. Straightening the channel also made their fields more farmable because now they could farm along a straight waterway. But as many discovered, channelization often makes things worse in the long run.

a deepend streambed By increasing the velocity of water moving in the channel, the flowing water scours the stream bed and deepens the channel. This means the banks are higher and often more unstable. Huge chunks of the bank can suddenly crumble into the stream. As channelization increases streambank erosion, more sediment enters and clogs the stream, while the accelerated velocity of water increases flooding downstream.
channelized streambed In addition, channelization reduces the amount of vegetation along the streambank, which means less food and cover for wildlife. Increased sedimentation makes it difficult for some fish to feed and spawn, and the increased velocity of the stream drives out fish that cannot tolerate fast-moving water.
normal streambed The best course of action is to let the stream follow its normal path. Streambank erosion is an inevitable process, but by letting the stream meander naturally, at least the process will be a slow one. With channelization, it can take only 10 years for streambank erosion to do the amount of damage it might have taken 100 years to do naturally.

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