Got me interested enough to Google, maybe you should too
Research and planning work on the project started in the 1930s and was carried out on a large scale in the 1960s through the early 1980s. The controversial project was abandoned in 1986, primarily for environmental reasons, without much actual construction work ever done.
Got me interested enough to Google, maybe you should too
If you mean the rivers part, then yes.
If you mean the steppe part, then no, they’ve caused a few ecological catastrophes first before stopping.