They basically did that.

What people call „Rhine“ is a heavily straightened and channelized artificial water road.

Especially in the 19th century they cut off many loops and bends to make it more accessible for ships, to make the land useable and to get rid of flooding (narrator: „it didn’t work“):

https://de.wikipedia.org/wiki/Rheinbegradigung

(don’t have an english article, just look at the pictures)