@tsarstepan,
Stream "repair" has been an example of overengineering for many years. The US Army Corps has much time and money invested in keeping rivers in their engineered banks , and the dynamics of the ultimate shape of a meandering wtream (one that is called "mature") often results in the Corps just rip rapping a straight channel to go up to a point just past a city or rural area, and then the stream, using all this pent up energy, will start carving meanders that cut into adjacent propereties.
By not ******* with mother natures ability , or better yet, learning to understand and design projects (Like bridges and riparian features) that exist naturally within the streams cross section is desirable.
The Corps of Engineers has pretty much screwed with the Mississippi, and the Missouri Rivers so t5hat they are overengineered with these god awful levees that really dont work past the project areas they were designed to protect.
Major Universities have geomorphology and geotechnical labs where these stream dynamics are studied and many graduate geotech engineers and geomorphologists are cranked out.
The lastest flavor of stream stabilization and bank repairs are a series of books by a fellow name of Rosgen. I thimk his work is crp, but he seems to have a decent audience who buy into his stuff.
Stream "repair" is job security for areas where its often not warranted